Below is the text version of the Marine Hydrokinetic Advanced Materials webinar.
Rita:
Ladies and gentlemen, welcome and thank you for joining today's conference, Advanced Materials webinar. Please note, all partisan lines will be muted until the Q&A portion of the call. We'll provide you with instructions on how to ask a verbal question at that time. You are welcome to submit written questions during the presentation. These will be addressed during Q&A. To submit a written question, use the chat panel on the right-hand side of your screen. Choose 'All Panelists' from the 'Send to' drop-down menu. If you require technical assistance, send a note to the event producer or call our help desk at 888-796-6118. With that, I'll turn the call over to Lauren Moraski, technology manager in the Water Power Technology office. Please go ahead.
Lauren:
Thanks, Rita. Good morning everyone or good afternoon for those overseas. Just wanted to thank you again for joining and welcome you to our webinar for Advanced Materials. I'm just going to give a quick, five-minute overview here for those who may not be familiar with either the project or the office just so you're familiar. Over the next three hours, you'll hear about the work to date from three of our national laboratories: Sandia National Lab, National Renewable Energy Lab, and Pacific Northwest National Lab, as well as two universities; Montana State University and Florida Atlantic University for the MHK or Marine Renewable Energy Advanced Materials project. Dr. Bernadette Hernandez Sanchez will provide an overview of the project shortly but the primary objective of the project is to reduce uncertainty in using composites for marine renewable energy designs by investigating materials, performance, the potential for manufacture and providing validated composites resources to industry.
This project was merit-reviewed back in 2016 and was presented during our Water Power Technology's Office peer review in February of 2017. Since the project is now roughly at its halfway point, this webinar will provide an opportunity for the team to present their research findings and recommendations to date, as well as receive input on the scope for the remaining one and a half years of the project.
Next slide. For those who may not be as familiar with our office, this slide provides a high-level overview just for your reference. We're a funding organization, provide funds through funding opportunity announcements, that's mostly funds out to industry but as well as annual operating plan to lab so just to name a few. As you can see on the slide here, our primary interest is in early-stage research and development, performance validation and information dissemination as it relates to the Marine hydro-kinetic or Marine Renewable Energy industry.
We've been growing as a program over the last few years. As you can see in the graph on the bottom right corner and as such we recently reorganized our research into the four categories shown on the bottom left part of the screen. This Advance Materials project fits into that first category, you see highlighted there. Foundational and cross-cutting RND, which also contains some of our controls research modeling, components development and resource characterization work. Next slide. This slide is just intended to show a snapshot of the industry and illustrate the progress that's been made in recent years. You'll notice a combination of wave and current energy converted devices depicted here and during the webinar, you'll hear about some considerations for when composite materials may prove to be an appropriate material choice for various components along with factors influencing effectivity of material coding.
Next slide. This is my last slide. I'll like to sometimes keep it short and sweet. Before I hand it over to Dr. Bernadette Hernandez Sanchez of Sandia, I'd like to thank you again for your participation here today. We'd love to hear your feedback on the topics as shown particularly with the planned work going forward. At the bottom of the screen, you'll see a website. There is a comment template available at that site shown there which would be great for you to email me any of your comments, questions or thoughts based on what you heard today.
Use that template if you find it useful but really, we'll take feedback in any form that's easiest for you to provide. Please send those to me and my email is shown right there, Lauren.moraski@ee.eoe.gov and as well as any outstanding questions. As Rita mentioned, we're going to do some Q&A throughout the webinar as well as near the end. If you have any lingering burning questions that weren't addressed, please include those as well. With that, we'll transition to Bernie's slides and she can take you through an overview of the project and introduce the team members. Thanks again.
Dr. Bernadette:
Thank you Lauren, and thanks everyone for joining this morning and this afternoon for those of you overseas as well. We really appreciate the time that you're taking to come and listen to the information that we're developing and sharing. Before I begin, I would like to first thank all my co-authors who are supporting a lot of this research and there was a number of researchers that helped some of our early research in the previous FY16 and I'll show you some of that information. I also like to take this opportunity to thank the Water Power Technologies Office within the US Department of Energy and this is office of efficient and Renewable Energy program.
Without their support, this wouldn't have been made possible. You're going to hear from a number of our collaborators which are listed here. Next slide, please. I also like to take this opportunity to thank all the different industry members and developers who submitted samples for FY17 and 18 program. We know we couldn't have done a lot of this work without your support. Just for some background, during FY17, we had a webinar to announce a call for coupons of interests for those who wanted to submit some samples to be tested for both composite evaluation and their saltwater effects as well as biofouling. The companies and programs that are listed here include Composites Engineering Research Laboratory, Composites Technology Development Incorporated, Hydro-tech Jana key industries, Ocean Renewable Power Company, Polly lon and Burden Power.
Thanks again. Next slide, please. Love to introduce you right now to our multidisciplinary team. This is a team that was assembled based on their expertise and helping to explore some of the areas where materials are needed for MHK development. From Sandia, I'm the TI. I'm helping with the materials chemistry. I've been with the program since 2008 where we started to learn about the coatings needs and some of the different materials aspects that were required for some of the designs that were being produced. Another teammate of mine from Sandia National Labs is Budi Gunawan, and he's going to tell us about some of the loads and SVG sensors work that he's been involved in.
Moving down the list, we have Pacific Northwest National Laboratory who's been partnered with us since, I say around 2013-14 timeframe, where they were helping us look at biofouling coatings. This is George Bonheyo from Pacific West National Laboratories Marine Science Center and he'll be telling us a little bit more about his biofouling activities and trying to understand how we can potentially mitigate some of these areas. Next is National Renewable Energy Laboratory and representing this laboratory is Scott Hughes. He's from the Wind Testing facility out there in Colorado, and he's helping us to support our understanding of substructure testing, how do we move forward from coupon scale materials to larger scale devices and he's going to be sharing some information with you as well on some of our industry information surveys.
Next on our team is Montana State University, David Miller, he's also been supporting us since 2008 in trying to understand the composite behavior of materials in the marine environment. Finally, is Florida Atlantic University. Representing FAU is Francisco Presuel-Moreno and he's helping us to understand some of the corrosion behavior that can occur when you have a metal interconnect or some bolted joint that's connected to carbon fiber materials. He's also going to be sharing some of the information that he's been gathering for our program. Next slide please. Today, I have the webinar agenda. The times listed are in Eastern Daylight Savings Time.
Just to give you where we're going to be heading, we will have some time for Q&A throughout the session. We will also have a break to give us some time to regroup but throughout, as mentioned earlier, you will be able to send questions by the Chat session or you can also ask by voice when the Moderator allows us to do so. Next slide, please. Just to give you some brief background, as mentioned before, the Marine Hydro Kinetic Advanced Materials program was established really to help support the industry. We're doing this by providing applied research, we're also trying to provide guidance on any materials and coatings issues that are coming up. We are doing this to enable viability to help lower the cost of energy as well as accelerate commercialization and we are focusing on the challenges at hand.
Right now, we feel that having a good understanding of proper structural component materials and coding are needed since they are critical to reducing both energy barriers and the cost as well as some of the commercialization time. Within this challenge, we're looking at structure design and components, especially loads. There's a lot of information about loads that are uncertain in composite materials and designs and we're trying to get into that information. We know that there's environmental exposure issues. We have to have a good understanding of how these materials operate under the environmental conditions that they're placed under, how all this impacts our costs, as well as how a lot of these materials will eventually lead to some of the safety and certification practices to be considered.
Now, our current program objective is really to help reduce the uncertainty in using composites in design. This direction was taken from a 2015 workshop on composite needs for Marine Hydrokinetic Energy in which industrial academic and enabled participants came together and explained what were the short and long-term needs as well as some of the needs for data to help them move forward. In the past, for our program, we've looked at understanding materials for coatings and biofouling. There was some effort in designing a novel coatings as well as examining some marine effects on some wind-based composites where we got initial start in first NDM.
Next slide, please. Why are we investigating fiber reinforced composites? Well, right now, if you look throughout the various designs that are being conducted, you can see, this cartoon illustrates. There are many ways that you can capture energy and they are all varied in their design. We also have noted that there's a number of areas of concern by design, there's a number of materials that are being considered for all of these particular device manufacturing needs. These range from hydraulics to the hydraulic fluid that are going to be used to help move some of these devices, to a number of polymers that are being of interest, cements, magnetic materials for the generators, number of coatings and various composites.
When evaluating the surveys of industry, we noticed that the composites include reinforced rubbers, concrete and different plastics. Now, we started to really study to target in reinforced composites because a number of studies were indicating that we can make a difference in cost based on reference models as well as looking at some reports by Wave Energy Scotland on structural loads and materials landscape study and a 2011 carbon trust report. All indicated that structure cost could be impacted by changing from a metal or steel that's traditionally used to using more lightweight and perhaps non-corroding materials.
This really gave us the direction to focus on reinforce composites at this time, but we do recognize there are a number of materials out there that will affect marine energy design development. Next slide please. In addition to the structural costs as I just mentioned, materials are also very important because they impact other areas that affect the commercialization and those are also listed shown here. What my program is trying to do is we're trying to reduce risk by really testing all the materials that developers and other researchers are trying to explore. We're also trying to validate materials from other marine base industries under the MHK conditions. We recognize that the MHK conditions are unique devices and so maybe not all of those other industrial materials will translate.
Part of this is trying to get ready to set up for future testing materials under deployed conditions so we can have that validation. Along the lines overall, ourselves and others that are working in materials programs throughout the community are really trying to help the industry with materials and protective coating challenges. Some of the images that you see below on the slide include some corrosion that happened on a pump and this is courtesy of Resolute Marine Energy. Not only do the structural components need to be understood and supported but also the supporting components are needed as well. How do we go from composites used in yacht and boats and wind designs that can take the loads of some of the MHK devices and also how do we either work with marine fouling or support some sort of system that prevent some of the marine fouling that occurs along with corrosion that you hear.
These are just some examples shown on the lower right of fouling that's taking place on a turban as well as some studies being performed at EMAC. Next slide, please. As mentioned, we've been working for quite some time. This is just a summary of some of the previous work our program conducted. We've made some progress in trying to understand coatings assessments. We've published papers on developing new methods for High-Throughput protection and analyzation as well as development of Zwitterionic coating that was developed. We've also started to explore how we could use structural health monitoring of the composite behavior under marine conditions. Getting a real fundamental understanding of the effects on composite materials.
In terms of corrosion, we've done some in situ TEM work at the labs here at Sandia to try to understand some of the corrosion mechanisms of pitting and as well as developed various explored some nanomaterials at the time we were interested in seeing how nano could potentially play a role in the coatings area. The team members are all listed below and I also like to acknowledge BYU and North Dakota State, who also helped contribute a number of the novel coatings performance, results that we've obtained. Next slide, please. With the progression of our program as mentioned, we led to our focus on composites.
We submitted a proposal entitled material design tools for marine and hydrokinetic composite structures and within this proposal, we decided to focus on a couple of key areas to help the short-term needs of the industry and right now we're focusing on providing an industry approved composites materials and structures database. This is an open resource available to anybody who has interest in need. What do I mean by industry improved? We asked the industry members, what would they need to help them with their modeling, their calculations? A number of the information and data presented was derived from those directions. In addition, we're not collecting information for just to collect information. We are trying to understand the fundamental material science engineering behind the composites that we're working with.
The information that's being presented in the database is being backed by publications, dissertations, and also being represented at a number of conferences and those are shown within the database. With our program too, we're trying to mitigate environmental effects of biofouling and the corrosion issues and also really trying to hone in on the MHK load challenges of these materials. Next slide please. To give you a little bit of background on the database itself, the database is actually born from materials discovery in wind energy. This was started back in the 80s by Montana State and Sandia National Labs and was populated heavily with a number of composite materials from them.
Since then we started to move towards environmental effects on these composite materials, how the salt water and salt fog impact these materials and that information has been stored in the database. This slide represents the types of users that currently have been accessing the database. You could see there's a number of countries that are accessing it as well as different types of users from schools to laboratories to different manufacturers. We're also seeing an increase in water and marine users who are starting to use this database since the development of this.
There's a link below where you can go and connect to our database. Next slide, please. Another way to access the database could be going directly to Sandia's website as well as going to the open EI website. If you look to your right, I circled the Water and Wind icons that will also directly take you to the different areas and applications to connect to the database. Also, I'd like to point out some of the information for those of you who are interested in environmental aspects could visit P&L website which is shown down here. [00:20:47 inaudible].
They have a number of information surrounding the environmental aspects. Next slide, please. Just to start wrapping up on some of the other aspects that you're going to see, we do recognize that there's more to the development of composite materials. So, you're going to see really a snapshot of what we're starting to work on. We would like you to know there's information on understanding the materials behavior with your modeling components, both material dynamic to molecular as well as structural load bearing. There's interest in understanding how these materials affect our cost. Of course, we're doing a lot of composite testing of coupons and so you'll see how we're changing from the coupon to small scale to eventually large-scale devices and applications. Then finally on the bottom row, you can see where some of the validation and some of the future activities which include looking at quality assurance.
How do we use non-destructive inspection repair to help support operation and maintenance as well as the manufacturing certification and the safety of these devices using these materials. Next slide, please. For today's webinar, you're going to hear some summaries of the current activities and as well as some of our future directions and this just highlights some of the key areas that you will be seeing. This includes saltwater effects, the biofouling, the corrosion aspects, as well as results from our industry information as well as our plans to go forward into full subscale testing.
What I like to draw your attention to is the figure on the bottom right. You see a pyramid in which we go from coupons to complete structure, and you can see our program is starting to go beyond the coupon state. We're starting to get into the subscale elements. This is a method used by the wind industry and we're starting to also mirror this method to help support the MHK industry as well. Next slide, please. In summary, you're going to hear about what we've learned and where else we would like to know and go with our future activities. Some of the themes that you're going to be hearing about include water absorption into the composite, how they impact the performance properties and corrosion.
We're going to talk about how not all anti-fouling coatings are created equal and there's also some specific MHK conditions that we need to consider for coatings applications. We are going to tell you about what we've learned for some of the industry needs for subcomponent testing, as well as some of our work on the corrosion. Francisco is going to tell you about some of his work on understanding anodes and characteristic deposits and Budi will lead us into some of the characterization measurement testing being conducted to advance our understanding of MHK condition on composite materials. Finally, all these results are going to be provided in and downloaded to our database, which is public. This is also going to be used to support these decisions. Next slide please.
Again, as mentioned before, feedback and recommendations are more than welcome. You can send them to myself, but in particular for this seminar, Lauren is also available for contact as well. Next slide please. Just to go ahead and get the remaining portion of this webinar kicked off, I'd just like to go back to the agenda which is shown here. Our next speaker will be talking about the biofouling evaluation and this is Dr. George Bonheyo and he'll be speaking next and I will go ahead and like to conclude and go ahead and if there's any questions please let us know. Thank you for your time.
Rita:
Ladies and gentlemen, as we move to Q&A, please feel free to place yourself into the question queue by pressing #2. You'll see a notification when your line is unmuted. At the time, please state your name and questions. Just a reminder to submit a written question, use the chat panel on the right-hand side of your screen. Choose 'All Panelists' from the 'Send to' drop-down menu. At this time, there are no questions and in the queue.
Dr. Bernadette:
Bernadette: Our next presenter is George Bonheyo.
George:
Hello everybody. Just to double check, can you hear me?
Dr. Bernadette:
Yes, we can.
George:
Okay, perfect. All right, so I'm George Bonheyo. I'm from the Pacific Northwest National Laboratory. I also have a joint appointment with Washington State University. I'll be talking about the biofouling testing that we're doing. Next slide please. As Bernadette introduced, again this is part of the Advanced Materials program sponsored by the US Department of Energy Water Power Technology office. The goal of the testing is to address the barriers and uncertainty facing marine renewable energy developers and using composite materials.
I apologize right away, you'll hear me interchange between Marine Renewable Energy or MHK, as we often say in the United States for Marine and Hydro Kinetic. The objective for the task that I'll be talking about today is we want to assess the effects of biofouling on composites. This includes evaluating coatings that are being used on the composites or any sort of anti-fouling material that might be integrated into the composite itself, into the resident for example. We're looking at the rate and extent of biofouling accumulation, any potential impact on the material, self-swelling, weight gain corrosion. I'll also touch briefly on a prior effort that we had with Sandia and other partners on anti-fouling coatings development.
Next slide. Real quick orientation for those of you not familiar with the Pacific Northwest National Laboratory, we're located in the Northwest of the United States in Washington State. P&L itself is in the desert portion of Washington over in Richland, Washington. However, I'm located at Sequim Washington, at our marine sciences facility. That's the picture in the middle on the right-hand side. We're located at the Strait of Juan de Fuca that opens up into the Pacific Ocean. The lab itself is at a very narrow entry into Sequim Bay where we get tidal flexes of about five knots or 2.6 meters per second at peak velocity. Next slide. What you'll hear me talk about today is, again the biofouling program. Quick introduction as to why fouling matters, what are some of the issues facing marine renewable.
The location for the studies, again, a little bit about that prior effort with coatings development. I'll talk about the sort of test methods that we're using, most of which were developed in part by this program. Then we'll talk about the current effort and some of the early results. Next slide. For those of you not familiar with biofouling, it's classically described as a four-step process. It begins immediately when any object enters the water. So, within seconds to minutes, you start to get a conditioning film. This is an accumulation of soluble and non-soluble organic matter that's in the water. It can be fatty acids, fats, lipids, free DNA, proteins and amino acids and sugars.
That alters the surface properties of any coating or any surface that's in the water and it helps prime the surface to allow the next step which is the settling of live cells onto the surface. That happens within hours to days depending on the environment in the coating. It's followed by third step in which those cells grow into a biofilm. Biofilm is a very tightly adhered massive cells. It's encased in a matrix of polysaccharides and other materials that protect the cells. It allows them to survive desiccation should the surface get out of the water. It also helps protect the cells from cleaning agents. So, for example, a biofilm in your sink drain, if you pour bleach down the drain, the biofilm is able to resist the effects of the bleach.
The final stage of biofouling, that biofilm is very sticky and it helps recruit larvae spores and other organisms from the environment to allow them to adhere and then you get the outgrowth of microbiota, things like barnacles, muscles, CN enemies, large bladed kelp, another LG. Next slide. The problem with fouling is several fold. Obviously, if you have large growth on a surface you can get increased drag that can affect the motion of a paddle or a piston on a wave device or buoy. It adds extra strain on your moorings. It could impact the motion of a turbine blade. A considerable problem with fouling is accelerated corrosion.
Fouling can impact just about every type of corrosion that's out there. There's classic it might seem, microbial induced corrosion which is the acid-base corrosion, but cells will also accelerate galvanic pitting, crack and crevice corrosion. The outgrowth of the biomaterial can physically interfere with function. The photo on the upper right shows some inner connects that were at the marked site and the reported that fouling was starting to interfere with some of the connections. You can also get enough growth that can prevent motion of certain objects. Hard fouling can add weight that can impact the inertia of the device. Safeties and major concern, you can get slippery surfaces from the LG but you can also get very sharp surfaces. From the barnacles and cuts in the marine environment are very, very prone to infection.
A few other items are listed there like sensor failures. The photo on the lower right shows and an ADCP, for example, that was completely covered in muscles and rendered useless. Then the final one I want to touch on is as you start to get fouling on objects, it creates an artificial reef. This can attract animals to the site including birds, marine mammals, obviously fish and so that can increase the potential for strike or other problems that can be an environmental concern for a new device going in the water. Next slide please. Bringing us to this slide up before, the fouling program began in 2017. We're conducting studies for about two and a half years after the initial receipt of materials. Spring indicated we're about midway through the program right now. The data that I have is from about six months of exposure. It's a single time point at this point, but we will have data going out to 20 months of exposure during the study. Next slide.
Very briefly, starting around 2015, we had a prior program that was looking at the development of new anti-fouling coatings. The reason for doing this is that most of the commercial anti-fouling coatings that are out were developed for boats and the assumption with those coatings is that a ship is going to be moving at least 5.1 meters per second. The reason that's important is the relative velocity of the water across the surface, if you have a toxic coating, those are typically ablative, meaning the coating is designed to slowly erode. This allows for fresh toxin to be expressed at the surface. That toxin is typically a copper-based material these days and that erosion also causes the release of some of the fouling organisms on the surface. Other coating strategies that we call foul release strategies rely on the velocity of the water to knock the organism off.
These are slippery surfaces, if you will. The problem, however, is marine renewables are typically experiencing velocities of less than 10 knots, you might find those high velocity, say, off the coast of Orkney island in Scotland. Here in the US, typically our velocities are going to be less than five knots or less than 2.6 meters per second well below the threshold that most of the paints are designed to function. Another challenge, as I indicated already, is of course most of the commercial paints, all but about 12 of them frankly, rely on the use of copper or zinc, or some other toxin and in the case of copper, we're finding more and more locations are considering banning the use of copper or banning it above certain concentrations.
Generally, those that are developing renewables are trying to be good stewards of the environment. There is a bit of pressure not to use any sort of toxin in the environment. Under that program, we attempt to develop some new coatings, we explored the ceragenins. These are artificial peptides that have anti-microbial activity, our colleagues at Sandia were putting nanoparticulate silver into materials. These were used to create modified fouling release coatings using a commercial product called Inner sleek 900 from AkzoNobel International Marine of the base paint. We also looked at some soft coatings based on polyethylene glycol.
Next slide. The summary of that study, we conducted the tests under very low flow conditions, nearly static and low title velocity of about one and a half meters per second. Did a comparison with commercial products that Inner Sleek 900, the foul release coating SN1, which is a catalytic coating. It generates peroxide at the surface. This is a favorite coating of the US Coast Guard. It used to be only available to the Coast Guard and the military, but it has now been made available for commercial use.
Then we used Island 77 from Seahawk, which is a good example of an ablative copper-based paint. In total, we had 596 individual coupons which included triplicate samples at three different time points. It was a relatively short study 90 days, it was the longest exposure. In summary, what we found was not surprising all of the paints fouled but those paints that use the foul-release strategy were easily cleaned and typically we only got heavy slime on the foul-release coatings. Unlike the others, we didn't get the development of barnacles or muscles. Coatings development continues, many labs including ours and our partners but we're no longer doing that as part of the deal we program and instead what we realized is based on the needs of the industry we realized there needs to be a focus not on the development of new coatings for our study, but an examination of those commercially available coatings so we could make recommendations about what the marine industry could purchase now and what should be used to protect different surfaces.
Next slide. The other thing, as I mentioned, we had a very large number of coatings we had to analyze over 500, and typical studies only look at less than 50 coupons. The reason for that is the standard methods such as the SDM methods, they are very time-consuming. It entails drawing an imaginary grid over a coupon and counting the number of barnacles, tunicates, sardines, running through a long list of organisms, how much is in each coupon. It's very subjective. It depends on the expertise to the individual to identify the organisms and their assessment as to whether or not there's heavy or light slime.
We want to be able to conduct studies where we have a large number of samples in the water at the same time getting the same exposure so we can make a direct comparison from one coding to another. We also wanted to be able to get hard numbers and very defensible numbers. We wound up to inventing some new methods. Some of these have already been published. Some are coming out in publications the summer based on some presentations recently at the International Congress on marine corrosion and fouling. We've been asked to write up the new methods for SDM standards.
I'll describe these methods in just a few moments but this now allows us to begin to analyze several hundred samples very, very rapidly and what we're now able to provide the composites industry and marine industry is a very good direct comparison of one coating to another to show how well these materials do or don't work in absolute sense or relative to another coating. Next slide please. The first method, just to describe it briefly, is based on standing and image analysis. We use a blend of stains that represent different color channels that bind to different organic compounds, one of those stains is fluorescence. We're able to do this on very dark substrates like black colored coatings. The idea is the amount of organic matter that has accumulated on the surface determines how much of the stain has been taken up onto the surface.
Take a digital photograph, we have a software script that we've written that separates color channels and then looks pixel by pixel to determine the intensity of the color on that pixel, integrates and gives you a measure of how much fouling has accumulated. It turns out that this does really well to direct measures of total organic carbon accumulation and the reference for these papers provided in the lower right corner.
Next slide. We also had the developed the method for doing total organic carbon and nitrogen analysis. The challenge here that we had to overcome was how to extract the material off of the surface of a coupon without damaging the underlying coating, the paper that's coming out this summer. This again, gives us a hard number for determining biomass accumulation. We're adapting the method now so that we can also get the inorganic carbon, that would be the calcium carbonate from the shell of a muscle or from a barnacle. Then we also developed a way of very accurately doing both a wet mass and a dry mass measurement.
This allows us to distinguish between the contributions of hard fouling organisms, the shelled organisms versus soft organisms like anemones. Next slide. For the composite materials program, again, what we ultimately want to do is be able to build up that database that Bernie mentioned and I have the website up there again so that we can input comparisons of composite materials and coatings tested under different conditions. Our purpose is not to recommend a particular coating but to provide the data so that companies can make their own selection based on the type of surface they're protecting, and the type of environment they're working in. Through the process, though, we're identifying ways to mitigate fouling on composites, particulate and mitigate corrosion as well. You'll hear a bit about that from Francisco later today.
Looking at how we can protect in particular things like dissimilar joint materials, like a carbon fiber bonded to an alloy, some sort. Then you also hear from Scott and David Miller later about looking at some of the load challenges and strength testing. Next slide. For the fouling tests, again, we're working this time just with commercial coatings and paints. In some cases, there isn't a coating, if the company provided an anti-fouling material that they directly incorporated into the resin.
These are all commercially available or at least emerging materials. The samples were provided by the composites manufacturers, folks that are designing Emery systems or coatings manufacturers. Again, we have about 500 individual coatings in the water right now. We are conducting our tests under Emery relevant velocities, nearly static, point one meters per second, and then 2.6 meters per second. The exposures are ranging from six months to 20 months. The analyses are those that I already mentioned. TOC, total nitrogen image analysis, wet dry measurements. Briefly, the reason we're doing nitrogen is we have found that some composites continue to allot carbon into the environment.
Even though these are cured composites, there is still some carbon leaching from some of them in the environment, and it throws off the measurements. Doing that organic nitrogen helps us to overcome that. The results of the tests are going to be made public. Proprietary information about the coatings themselves and the composites formulation or the process of manufacture will not be made public. However, we do protect the proprietary information of the companies. Next slide. Briefly without reading through the list, these are the materials that we have already received.
At the bottom in blue, those are in a few cases, the substrates we're using where we're just testing coatings. Again, the samples were kindly provided by various industries. Next slide. After six months exposure, this is a little bit premature to try to present results. We're finding a light to heavy slime on some of the coupon so far, it's not really a good time to make any absolute determinations about performance. The coatings just happened to go in the water just in late fall prior to our winter season when we do get slower rates of fouling. We also had a very unusual die-off of barnacles this fall and winter, something we hadn't seen before. We're not sure if there was a virus or something else that was in the water. We had this even in our non-test tank so it wasn't related to the coatings.
We're now getting barnacle growth once again though, so we'll see how the coupons fair with barnacles at least. Durability, I do want to draw this to your attention. We very frequently find, particularly with the sorts of surfaces that we get on Emery devices where the sharp corners or maybe a tapered edge like on a turbine blade, that the priming and adhesion of some of the coatings is fouling. A lot of the paints developed for anti-fouling were developed for ships and if you think about a freighter, those surfaces are nearly flat. They don't have very many sharp edges. Those coatings are not going on propellers, for example. If you look in the upper right, and I think this is a good example of some coupons, where the coating did not adhere well around the edge of the coupon.
That became the point of failure, water began to intrude and the coating started to delaminate. We're also finding in many cases that companies aren't necessarily preparing their surfaces very well. Roughening up the surface for example, to allow for a good adhesion of the primer or in some cases, not selecting the best primer for the coating that they want to have. Fouling-wise, we are seeing slime developing and all the slot coupons. I'll have some additional photos of that. At the lower right, you see two different carbon composites. The one on the left is rather green looking, a little bluish because it had gone through the stain compared to the carbon fiber on the right which had a much better coating. Next slide.
Just some example photos. In the middle there, those are some FRP samples. It's interesting that in a few of them, the slime seems to be penetrating into the coupon itself working its way into the fibers. Coupon on the left was a very unique copper based coating from a company out of Spokane, Washington. The challenge with that one is, over time, the curing agent they had us did not work. After six months, the coating softened, and it became almost like an uncured paint. They're working with AkzoNobel right now to fix that. Otherwise, the anti-fouling performance was rather good. Then we're also finding on some soft composites on the right is a soft, almost rubbery like material.
Those continue to be very hard to protect, and we're seeing some heavy fouling on those materials and even some distortion of the material itself where that particular material is starting to get very curved shape to it. It appears to be swelling in some of the corners. There just aren't many coatings out there that don't cure to a hard finish that work on soft flexible materials. We also are going to be deploying some additional materials in the August and September timeframe. If there's anyone in the audience would like to get some materials into our test program, please contact Bernie and myself directly. If you want to do some strength testing, that may be possible as well. I don't want to speak for Scott and David but we will be putting more materials into the water here in Sequim for fouling testing.
Next slide. Some general recommendations, if you have an aluminum substrate we strongly recommend, there's more than antifouling community not to use copper-based paints. There are some companies out there that pitch the idea that with the proper primer you can put a copper paint over aluminum however what we're finding again and again in our own research and the research of others like Jeff Slain down at FIT, is eventually you're going to get some cracking through the coating and the primer and once the water penetrates, it's able to penetrate through the coating to be aluminum substrate. If you have a copper-based coating, you're going to get very aggressive corrosion at those points of failure.
Again, I'd also reiterate employ professional ship painters, both for the preparation of the surface and the application of the coating. All too often when we get samples to test, if they're not properly prepared we're testing the quality of the paint job perhaps even more than we're testing the quality of the paint itself. We still see that foul release coatings show great promise.
They are more expensive but they've got good fouling protection and they are very easy to clean. Inner sleek's newer product 1100 ASR is working rather well. PPG industry has sigma combined 1290. We're hoping to get some of the new Hempel and Joe tuned paints into our test matrix as well. The catches, some of those foul release coatings again, don't work very well on sharp edges. As I already mentioned, the soft flexible elastic materials remain difficult to protect. Next slide. We're closing out our second year here. For year three, we're going to finish the exposures and analysis of existing coupons. That'll be the next two-time points including the 20 month.
We'll be looking at fouling and corrosion of joined dissimilar materials. We are hoping to get some device sub-structures and things like a blade off of a title turbine or maybe a scaled paddle or rather component off of a wave energy converter. We have the possibility of putting those into our test tanks or into the water of Sequim Bay. We'll be building up a reference table of anti-fouling products that are currently on the market. The company, the product, mode of action, links to the product data sheets. Where we have test data, we'll put in our own test data but there are many more products currently than we are able to get into the water. Again, we'll be... Point you to that Sandia website again for the data. Next slide.
Looking beyond this project, aims for future project would be a broader testing program to look at commercial coatings. There's several hundred that are out there. We would want to test representatives of the different types of fouling strategies, different substrates, different geometries, to, again, build up a more robust database for the emery industry to use that shows what coatings work on what type of surface substrate geometry under what sort of environmental conditions. We believe that's something that's very hard for the industry to conduct themselves and if companies do their own testing, they tend to hold on to that data. We would like to make a database that's available for everybody to use an apples to apples comparison if you will. Next slide. I believe that was the last one. With that I will take any questions.
Rita:
Just a reminder to our audience, if you like to ask a verbal question please press #2 on the telephone keypad and to submit a written question use the Chat panel on the right-hand side of your screen. Chose "All Panelists" from the "Send to" drop-down menu. We just received a question, caller line unmuted. Please state your name and go ahead.
Zack:
Hi George. This is Zack [0:55:37 inaudible]. Thank you for the excellent presentation. I was wondering about the role of composites and paintings. Most composites whether it's thermostats or thermoplastic-based resin systems, their modulus of elasticity is below 10 GPA, and is there something that you could propose to utilize without having to resort to paintings and coatings? Is there a threshold of hardness that above which you could minimize this activity of biofouling?
George:
The short answer is hardness alone won't prevent fouling. Fouling aggressively forms on steel, for example, or glass and smoothness of the surface also won't prevent fouling. You need to have a feature be it a toxin or again something like a slippery surface that interferes with adhesion. Then some other folks are looking at some chemical tricks such as Zwitter ionic surfaces, so both positive and negative charges polar and non-polar to try to prevent fouling and what we're finding in general is, fouling is still going to happen. It's a matter of how long you can delay it, slow it or allow for easy cleaning.
Zack:
Okay, thank you.
Rita:
Then we'll move to our next speaker, go ahead.
David:
Good day everyone. I am David Miller from Montana State University. Thanks, everybody coming. We'll start off kind of walk through a little bit of the processes of design and then do move into some results. Next slide. The engineering materials for MHK devices, they're difficult change challenges, but they're not necessarily unique and they're things that we've seen before. They must be lightweight, strong, stiff. We'll cover these multiple times, durability and this resistance environmental degradation plus they must be inexpensive and easy to integrate into a manufacturing system.
Lots of different challenges and nothing here is unique in and of itself, but when you put them all together, let's move to the next slide. Our technical approach here, when you look at the aerospace composites, the left-hand side, really have that durability or damage tolerance need and they have to be the strong, lightweight, stiff all of those types of things you think of in that MHK or that aerospace world. Well, then we have marine composites on another hand and they have the environmental degradation and they have different design characteristics that you have to lead to, but they also have the inexpensive side and integration into manufacturing that is not necessarily coming from that or related to that aerospace.
MHK kind of develops these four systems out of the composites technologies that are out there today. You can also say transportation is a similar circle for the MHK and what you also know is that composites as structural elements in the transportation world is really just finding its stronghold and footing there as well. How we kind of moved to this, right? There's not a whole lot of engineering systems out there that have these types of application, the sophistication, the background of knowledge for the engineers and designers to come in. There's a lot of new challenges that materials engineers or maybe mechanical engineers or ocean engineers have this background. Our technology, our approach is to really help bridge those gaps and fill in the concerns, the knowledge, the data and the science that span across all four of these challenges and we'll do that through coupons to substructures and then to disseminating that data out.
Next slide. Putting on the professor hat, I guess, and walk through a little bit through where composite theories are and what the engineer has to in his toolbox to look at designing the materials to go into their system. Well, you start off with selecting your matrix and your fiber and how do you want to lay those up and what forms do those come into and so we have really pretty reliable generalized theories. The engineer has a pretty good toolbox to go predict what homogenized composite differences are and we're pretty good at that. For the composite strengths, a little different, there are very many different generalized theories for composite strengths and some are really good and some are good for some systems and better for other systems and not so good for others.
They're out there and if you have a lot of experience and know various things, you can choose the right ones for your strength. We also have the moisture and temperature effects that are coming in. There are some simplistic models out there that you learn as engineers to look at the effects of what upgraded moisture would be the validation of those still requires some knowledge and some expertise and some experience in the background and then I would say they're even less successful for predicting fatigue.
There are, again, some good fatigue theories out there. However, with composites and the variability in matrix selections and the variability of fiber reinforcements, and then the ability for every engineer to design that and tune that for the layup and pick the correct fatigue theory that will allow the designer the correct design margins is difficult at best, I would say. For the composite guys, there's you can't go to a handbook and say, well, what's my strength? What's the fatigue life? A lot of these still require experimental validation for each configuration and it's expensive and it's difficult, it requires experience. A lot of people can go out and do some testing and get some pretty good background. Our goal and our opportunity that the deal has provided for us is to be that opportunity to have the time, the experience and use those technical abilities to help out this difficult problem. Next.
MHK design is not any different than designing any other type of widgets system. Right? You have your design constraints of strength and weight and durability. If you choose a fiberglass composites, we have a lot of experience at MSU in providing database materials for the application of this and this is really kind of how MSU was involved with lots of fatigue data, lots of characterization, lots of industry involvement. However, we have different types of constraints here now that the exposure to the seawater and how can we put something that will be exposed without the inspection and maintenance and feel confident that the designers can design for that long lead time.
Some of the questions that we're having, what is the result and strength after saturation? What happens was that partially as that diffusion processes is coming in, or other changes and material. What else is happening material-wise. Next slide please. Some of the things, our research goals and what we've been looking at here is to provide that mechanical characterization of material systems and forms for the MHK industry and advance the scientific understanding. Not just run tests and present data, but to understand that the science is going on there but in the end still as I have said lots of time, an engineer at the end of the day, I'd like to present data that the MHK industry can help worth the design for best practices and use the data and understand that will optimize their design systems.
With that for the probably the next iteration of link to the database., we put our data, we run test, we look at materials and we summarize that into an Excel sheet to give you manufacturing matrix layup, all that type of data with a just a straight up number and strength along with that. However, the science in that is not captured in an Excel sheet. The science is captured in thesis and reports and conference proceedings and papers. This is just to show you the types of places that we've gone to in the past and presented some of that data. There's a couple other papers that aren't listed there and journals that aren't listed there.
You'll reference that some of the data you'll see in today will reference some of these proceedings and you could go out and look for those if you so desire. Next slide please. We'll go to the next run through the slides here is kind of give you some results that we've been developing over the history of this project, as Bernie said, since 2008. We started off with just effects of soaking and test temperature. We've looked at how does the saturation, how is it affected by being under an applied stress? What changes being under that applied stress? We've done some fatigue data, we've looked at the effects of stack and sequence and partial saturation. We've looked at and have papers out for ultra-damage mechanisms after saturation.
Not just a before and after, but what is the damage progression and what is the change in damage mechanism type due to the saturation and then the final one that will spend the most time on is our industry supplied coupon investigation. Next slide. Some of the early data started off with just looking at effects of full saturation or partial saturation on unidirectional composite systems. Did coupon work in testing at 5°C, 20°, 40°C. That's test temperatures, so these were soaked at a higher temperature such a 40°C for these material systems and the higher thickness, 90°C and what do we see is we did see a significant drop and this is where we first started back in 2008, 2009 data was published in 2012 here. First data that's coming out. Next slide. George, this data is in the database.
An example of some of the work that we looked at what happens under an applied stress, the equations here. I had to put in at least one equation, or two equations for you. Looking at the effect of stress on infinity, which is the final mass uptake and these are equations that are out in the literature from Springer's work. You do start to see and whether the results show 18 MPa or 30 MPa, a very modest, very low-level stress that might be applied in a material system but it does affect how much moisture is being absorbed. We didn't test these afterwards. This is just simply static test we applied under stress and looked at the changes, the variation in numbers here are changes in applied layup. The zero ° systems that have where the fiber is carrying most of the load does not see much of an intake from an unstressed control sample. When you go to like the 90 degree, which is the purple, so mostly matrix dominated direction, you start to see an increased moisture uptake and increased diffusion rate. Next slide.
That was a thesis that's available here at MSU. We've also done fatigue work for soaked, these are carbon laminates that were supplied by direct for us and this data is presented that came in 2014 and we also have some E glass systems that we've made here on campus and presented in 2012 but also looking at intentional tension. These are our point one and looking at the effect of moisture on the change and fatigue life. Again, carbon is on the left, glass on the right, systems that are in the database data that is out there and been included starting to develop and put these things out there for engineers to look at. Next slide. Pretty minimal slide compared with the other.
This is a recent thesis by one of our students. We're really looking at the effect of stacking sequence. When we teach young engineers how to develop we typically put our strongest plight of any system in bending which every picture that Lauren had up has a MHK device with bending at some level. Well, when we teach bending, we put the stronger plies on the outside. Well, does that have an effect on MHK where diffusion comes from the outside? And the answer was yes. All right. We kind of intuitively knew this but we now we're able to come back and prove that.
You're looking at the effect of 0-90 coupons, or 90-0 coupons. When you put the higher stiffness materials on the outside of the part where it absorbs the most, you see a drop-in strength faster because of that. Maybe there are guidelines that we can help them start to develop to engineers to have a different type of mentality when they're starting to look at this. Then also the ply on the left is looking at all facts of strength, what are the change from dry saturation and just other data that's out there and looking at the effect of ply layup and damage mechanism with those systems.
Next slide please. This data was a thesis in a new publication in wind energy science. What we're looking at is various systems of dried, controlled, saturated, undried and then dried and looking at the effects of material systems and how the damage mechanism itself is altered by the saturation. Next slide. Which brings us to the current data sets that we have provided. This came from the coupon call. We have static intentional tension test on 33 different laminates from five different suppliers. Condition and unconditional both of those systems.
Then we have thermal set and thermoplastics. Also coming out of this data is we're starting to reproduce some of these and look at the acoustic emission data and looking at the change of the damage mechanisms in these systems as well. Next slide. Here's a set of the thermal sets that we retested and you can see a combination of carbon systems, E glasses and both hybrid systems and with the wide variety of layups. Almost tropic type systems to just biaxial systems. Next slide. The thermoplastics, very similar types of things, so wide variety of E glass and different types of thermal plastic resonates with, I'd say, at least a smaller class of layup systems, but things that were provided and developed.
Next slide. What comes out of this and just here's a set of samples, a set of coupons that we've looked at, the type of things that will go into the database and will come out of this. Types of database numbers will be average thickness of coupons, fiber volume fractions. This is a big key for engineers. What percentage of those fibers? What the layup ends up being? How it was tested? What the configuration is of that also behind this is manufacturing process. If you go to the next slide you have the layup. What fabrics were used? What fabrics went into the system? What resin and how it was manufactured? There's a lot of background so that the user of the database can come back and compare apples to apples of how this data was developed. Next slide. Data that it's going to be presented, for each every one of those material systems, we have a weight gain curve and you can look at, this is an idea of the data that's going to be presented for all 33 of those material systems. We have weight gain versus soaking time.
Next slide. There is microstructural analysis. With coupons, there was sectioning, polishing and looking at microstructure to provide more insight to the test results. Next slide. Then a summary of the experimental results. For material systems, percentage moisture uptakes. Again, the fiber volume fraction and then modulus and ultimate tensile strength both in the zero direction and the transverse direction. Material provided, this is the type of data that is coming out of these results for an engineer to be able to come in and help look at and help design and help them move forward and what material properties they can use into their design. This is the sample of what the data is going to look like when it goes into the database.
Next slide. The other side of that would be fatigue. With the number of coupons that we've had and the number of material systems, we weren't able to do a complete SN curve for every system so what we chose is a single stress level. Plus or minus, I'd say, a small deviation to try to get some longer ten of the fourth, ten of the fifth type strain events, but we have dry and saturated fatigue data. It's just a single data point, a single stress level that was provided and will go into the data to help one more through. Next slide please. One more results slide is well, individual test data. It's not presented in the database but is available and we'll go into final reports in those types of things. Next slide. All of this is repeated for thermoplastics, so the next set. Thermal set, thermoplastic very similar systems. Next slide.
The micrographs, slide 24. The results here are not what we're really trying to present. The data that will that will be presented for you that you can go find. I'm sorry. Yeah, go ahead to the next one, 24 please. The static results for the thermoplastics micrograph data. You can start to see that there are some voids and there may be some effects on the manufacturing process that led into the issues or concerns or some of the things that I've seen. All of this data has been generated and has been put into reports and published out to systems and to manufacturers and as the next iteration of the database comes out, then that all of these material systems will be in there. Next slide please. Other systems and other projects that are going on out all of this, another big question that has come to us is diffusion rates, diffusion times. We're doing the diffusion studies and so we have four different resin systems at four different temperatures and looking at the diffusion rates of those.
Another big one is not just looking at before and after and what you know... Yes, it dropped but now it's the why, the science behind these issues. Using acoustic emission, which we can go into later if you have some questions, but looking at what is the damage propagation? What is the damage mechanisms that are changing or and do they change from a dry material to a saturated material? We're also looking at the structure toughness testings. We have some saturated DCB coupons, and those tests are in works. The DCB coupons are big, which means it takes longer for them to come to full saturation. Lots of other things coming in. Then the big one is go to the next slide. The long-range data needs and where we're looking at. The three circles here. Mechanical loading, damage propagation, or environmental exposure, diffusion, mass uptake, and then to the upper left, material selection and architecture and performance. We kind of live in the intersection of the three of these individually. We can look at our architecture, we can look and understand what our strength is, we can do the mass uptake, and live in that world. We can do the mechanical loading before and after degradation.
The real question for the long-term need is, is this intersection of all of them. As we now look at exposure and mechanical testing together, right? Look at that coupled problem between the systems. Those are the systems that we really... That's the long-term goal that we need to get to. That hopefully as we as we move forward in this program, and we can start to provide this data and really hone in on the science and the materials engineering side of the future and help the designers and the program move faster. The last slide, the next slide is really just a 'who we are' type of slide and that you can use that if you look at the slides later and look at what we can do and what we have so it's just kind of an equipment list of the things that we have. Really not much to talk about there and be free to open up for questions.
Rita:
Just a reminder to our audience, if you'd like to ask a verbal question please press #2 on the telephone keypad and to submit a written question, use the Chat panel on the right-hand side of your screen. Chose 'All Panelists' from the 'Send to' drop-down menu. At this time, there are no questions in the queue. I'd like to move to our next speaker.
Francisco:
All right, good morning everyone. My name is Francisco Presuel-Moreno and I'm from Florida Atlantic University, Department of ocean and mechanical engineering and our main campus is located in Boca Raton but as you can see in the picture we are right on the shore of the ocean in Dania beach. As Davis and George and Bernie have mentioned, we are looking at material design tools for Marine Hydro Kinetic deposit structures and part of the research that we are looking at are metal carbon fiber composite in [1:23:29 inaudible]. In sea water
The picture that you see in the center and the bottom is a mass that is used for some of the vessels that are available in the market and they actually use carbon fiber composites with some alloy hardware attachment to keep the structure together. I'll stress out that when these [01:23:56 inaudible] in seawater they can with time corrode. We'll be talking about this. Just very briefly, I think that all the speakers have mentioned this, but we also would like to acknowledge the funding provided through the Water Power Technology office of the UAE. Next slide please.
All right. I'm going to do the inverse of what David just did and I will mention some of the facilities that we have here at FAU city campus. We have a system that allows us to bring fresh sea water being pumped into the lab. From there we can have experiments that are either in constant flow or more regularly, we have permanent immersion samples that can be exposed either in low temperature. We have a chiller that allow us to close down and simulate lower bottom of the ocean conditions.
We have also room temperature conditions as well as we have several tanks that we have heaters that we can set up to age the samples at elevated temperature. We also have a badge. You see in the picture on the top left, we are right next to a mariner, part of the intercostal, so we can deploy the smaller samples directly in the intercostal water. We only have one empty aesthetic machine, 100 cubes and also, we have environmental SEM so we can do some observations without having to dry completely the sample and as part of these research we also use old XRD Philips model that has had the source replaced recently with a cobalt source type to have the X rays being applied. Next slide please.
Okay, why investigate this carbon fiber alloy interconnects in seawater? Well, first out I'm assuming that some of you might be familiar but for those of you that are not familiar carbon is a very novel material and when you immerse this, for example in seawater, it will develop an electrochemical potential when you measure versus something called a reference electrode that is quite novel or very positive value. It turns out that corrosion resistant alloys might have also novel values or potential values but typically are more negative than those of the carbon fiber composite. When you do the galvanic coupling that is going to tend to shift the potential of the alloy to a more positive value.
In the event that this value reaches the threshold where localized corrosion initiate, then that can become an issue. Let's first talk about a situation where this doesn't take place. If that is the case, then there would be no major interactions, at least from the corrosion point of view. However, if localized corrosion initiates in the alloy, then the potential instead of being the positive value that I mentioned, it becomes more negative and then that can activate the carbon fiber composite that is a very potent source as a catalyst, which then can accelerate the corrosion of the alloy that is interconnected to it. Those are the main motivation for trying to understand what happens when you interconnect these alloys to carbon fiber composite. Fortunately, glass fibers don't have that issue.
They are not as conductive and oxidation-reduction reaction cannot take place but in carbon fibers this is something that is a concern. In addition, as George mentioned, fouling could cause microbial induced corrosion and that was beyond the scope of the study that we're conducting right now but that's something that one needs. Also mentioned by George is that there are other types of corrosion for example crevice corrosion that could take place if you're using fasteners and knots made of metallic alloy and you have, not regardless of the type of composite you have, eventually corrosion can initiate in the form of crevice corrosion. Again, several of the participants in the survey mentioned that this is a concern. Again, we would like to look into it, but at the moment we are not looking to crevice corrosion per se. Next slide please.
I will be talking about the system that we investigated. We have two different type of carbon fiber composites and both use the 700 carbon fiber and with a [1:29:26 inaudible] type of sizing. At the bottom you can read what is the meaning of that. That means that it's especially designed for vinyl ester. There were two different types of vinyl ester that we investigate. One is [01:29:38 inaudible] and the other one is something [1:29:40 inaudible]. They are the two composite systems and then we expose these samples to either room temperature with sea water or to tank with seawater that has temperature elevated to 100°F. On the right you can see a diagram as to how we did electrical connection. Sorry, let me go back to the panel first. We prepared this panel actually almost nine years ago in 2009 and these were room temperature. What does that mean?
They were not elevated temperature as David was mentioning a moment ago, depending on the matrix you might want to cure them at different temperature and the reason for that is that when we prepared these panels we were thinking of simulating ship hall and if you have a ship hall you are not going to place that into a knot. Regarding the technique that was used, we used the vacuum assisted resin transfer or platinum and the fibers were in the unidirectional direction and we have between five and seven layers.
Okay, so we have these large panels that were about four feet by four feet and recently during the summer of 2017, we cut a couple of these panels into 10 by 10 pieces. One that we have these smaller samples, what we did is that the edges where the fibers were transferred, we apply filbert epoxy and copper wire and then we covered that with a marine grade epoxy. Then this copper wire that is covered with an insulating material can then be interconnected with alloys that are relevant to the study. In this case, we use sacrificial anode material titanium alloy mesh and nickel foil representative for a nickel base alloy.
Next slide please. In this image, you can see a couple of four pictures and the top two are the room temperature tanks. You can see in here only the composite, ones that they were with electrical connection, and I forgot to mention that we actually coated all of the edges to try to ensure that the water was penetrating only from the larger area cross-section. At the bottom is a picture of the tank that had a heater that has a controller so we can keep it at 100 ° Fahrenheit. We have six per tank. We have six samples per matrix. Two of each connected to the different alloys of interest. Then the same for the older system and practically of that for the elevated temperature tank. The sea water was replaced every other week.
In some cases, due to, for example, when we had staff coming through or because of the holiday break, the water was replaced once a month. Next slide please. This picture here shows the coupons of the recent alloys on the left. We have the titanium mesh alloys on the center. The sacrificial anode material is likely that is either aluminum coupons or zinc coupons. They have very similar electrochemical characteristics. On the right is the nickel foil and what we try to do is to have similar surface area exposed for the different alloys then interconnected to the composite. The composites were immersed first in September, but the last year we have several storms and that caused FAU to shut down so we were not able to do the initial testing that we were hoping to do.
Then next slide please. This place is that we found that some of the electrical connection needs to be good so we found that by mid-October and we improve the electrical connections we deploy them again by late October early November and then we did the interconnection with the different alloys. The way that we characterize these tests was where whereby theoretically measuring the copper potential. So, the composite was interconnected to each one of the different alloys and this was measured by something called separated calomel electrode. About once a week initially we ran something called electrochemical impedance spectroscopy. I will talk a little bit more about that in just a moment.
Initially, it was once a week and later about once a month. It was best that we carry out during April of 2018 where something called cathodic polarization on the carbon fiber composites and anodic polarization scans on the alloys that were investigated. About the same time maybe May or June, we observed that there were, in some sample, some calcareous deposits. The strip was about 2.5 centimeters wide and then additional cuts were made so that they could be placed either on the x ray holder or they place in through the scanning electron microscope. Now going back to the electrochemical impedance, what we did is that we momentarily disconnected the sample that was going to be tested and this was done for at least two hours for the samples in the room temperature and up to at least three hours for the elevated temperature.
In some cases, we waited 24 hours to allow for the polarization to take place. This technique, what it does is that it applies very small sinusoidal AC signals about 10 mV around the press potential by using something called accounted electrode. In our case this was made of titanium mixed metal both sides and this curve is from multiple frequencies anywhere between, in our case we started at 100 kHz as low as 3mHz and we run the test in seawater at temperature. Electrochemical impedance is a test which is done at room temperature. Next slide please. Regarding the couple potential, in this is slide where we are presenting, there was measurements in room temperature.
In each plot, we have four feeds and on the left on top we have the corporate potential that was measured between the carbon fiber composite connected to the different titanium samples. You can see that the potential it starts at a value from -0.3 volts versus Calomel and then by 60 or so day, values range between zero to +0.3 volts versus Calomel. Again, this is the couple potential. On the right, we see similar type of transient or potential versus time for before samples that were connected to Nickel and in that case, you can see that the potentials and particularly at the end of the test range between 0 to -0.2 volts versus Calomel.
These are relatively potential of positive values and indicative that likely corrosion has not initiated on either titanium or the nickel alloy. With respect to the sacrificial anode, the picture on the bottom in the left shows that they value from the beginning was a little bit more negative than -0.9 and remain that around -0.9 for the duration of the tests. We have an excursion around day 100 and we think that that probably was because the solution was not replenished as frequently as every two weeks, but that was one of the instances that it was replaced only once a month and it was measured towards the end of that particular cycle before replacing the...
That was the effect if you leave the water is stagnant, maybe buildup of some dissociation into the solution with a little bit of pH change probably. All right, we can move to the next slide, please. Very briefly, I want to review what type of results you get from these electrochemical impedance. We'll start with a we're doing the work by Brown and the 1990, we are look into carbon fiber vinyl ester composites immersed directly into sodium chloride solution in this case. His samples were also cured.
Also he had something analogous to what I show you regarding the anode thing which he held by using a potential start, the carbon fiber at -0.9 volts versus Calomel and in that case he was using 2.5 sodium chloride by weight and he had a small scale as you can see on the right side. There is a built up of salts and what he found is that there was very different trends in the picture on the left top you can see frequency versus models of the impedance that will give you a sense if this were just recorded, the lowest frequency, the higher the amount of impedance, the better the coating. You can see by polarizing on the picture on the right on the top in the center, that by polarizing the sample even after one day, the magnitude of the impedance decreases to somewhere between 10 to the five and 10 to the six whereas it was greater than 10 the seven for the not polarized sample. Next slide, please.
Here is a couple of results for one of the carbon fiber composite exposed at room temperature to interconnected to the nickel and you can see that in the plot on the left is similar to the ones that I described where we have frequency on the x-axis and the impedance magnitude on the Y-axis and in this particular case, the purple-red crosses are the first set of measurements although these were very much samples that might be why at the low frequency we have lower magnitude but then you can see that as time passes there is a slight change on the pattern of the magnitude of the impedance as the frequency changes. For brevity of the time limitations, I won't be talking about the face angle but there's something that is also measure that can give a sense as to how many layers might be present in the system. Next slide please. In here we have, again, for nickel lots of the frequency versus the magnitude of the impedance and on the plot on the left you can see that initially the magnitude for the red and blue series they had significantly higher magnitude at the low frequency.
For more than two weeks they pattern change and remain pretty much the same for the duration of the test. Similar results are observed for 510 sample that in this case was exposed to elevated temperature. Next slide please. In the case of the samples that were interconnected to the titanium alloys, we have a couple of those diagrams presently here. In this case, there was pretty much very little change from the beginning to the duration of the test for both the samples that were exposed at room temperature and elevated temperature.
If you will, there might be two different components and that can be offset by the change in a slope that might be present as the frequency changes. Next slide please. Turns out that the samples that were exposed to the sacrificial anode on the left, I'm showing you 245 and the one on the top was for the sample exposed at room temperature and the one on the bottom for elevated temperature, whereas the one on the right corresponds to area for samples interconnected to the sacrificial anode. In here we can see that there's significant change on how the magnitude of impedance changes as a function of frequency as time passes. Let's for example, take a look at the plot on the left bottom.
The first two measurements were done after about two days and one week after immersion and interconnection and those half about either one or two components similar to what I show you for the titanium in the previous slide, but turns out that even after three to four weeks, then the slope of the line is changes and we can see maybe three different regions that are there. That probably is a little bit easier to observe on one of the ADAD4 diagrams. The other thing is that the magnitude of the impedance and the shape changes from the very initial one to the later ones and is somewhat different depending on the matrix for the 510 versus the 510. If you will, the impedance moved up on the 510 whereas on the one for ADAD4, they shifted towards downward values at intermediate frequencies. What we believe that is taking place is that there is something that is building up.
Next slide please. Well, I'm getting a little bit ahead of myself. In here I'm showing you what is called the anodic and cathodic polarization on the samples and on the figure on the left we have in green the one that was drawn on the titanium sample, the one in blue for nickel sample, and the one in red is the one for the sacrificial anode. The one in green and one in red based on the values as a function as you move the potential to more positive values are suggesting that there is no corrosion taking place whereas, in the case of the sacrificial anode, the current is significantly larger as you move it away from the press potential.
On the right, you see two plots. One with the crosses corresponds to the nickel anodic polarization and the one in light blue corresponds to a 510 cathodic polarization is scanned. The intersection of the two corresponds to what will be likely the couple potential. You can see that there is a little bit of increase on the current but is a model increase from the press potential to the intersection potential. It's likely that the nickel and also the titanium are not corroding because of that. Next slide, please.
What we did observe on the samples that were besides the impedance that I described a moment ago, is that at the surface of the samples interconnected through the sacrificial anode, they develop these whitish products that are known also as calcareous deposit products. Next slide please. What we did then cathodic polarization both on the composite that were connected to the titanium and nickel and then those that were connected to the sacrificial anode, and you can see that the magnitude of the corrosion let's say below -0.6 are significant to the smaller for those composites of where they're interconnected to a sacrificial anode than those that were interconnected to the titanium. Seems that the calcareous deposits are reducing the cathodic capacity on the composite. Next slide, please. This is something similar for ADAD4. For time constraints, we are going to move to the... Up there's something very similar to what I just mentioned, let's just move to the next slide.
All right. I mentioned that we cut a strip of on selected samples both with calcareous deposits as well as those connected to the nickel, titanium and on those that we also had some new material. On the figure on the left, what you are observing is the x-ray patterns that were obtained on the samples that were connected to either nickel or the titanium and the ADAD4 was connected to the titanium whereas the 510 was connected nickel. It turns out that it seems that the vinyl ester signals, this pic that you see on this diagram, corresponds to the vinyl ester and not to any deposits that are on top of it. Whereas in the figure on the right, you can see pictures taken of some of the samples that were placed in the x-ray.
You can see now that they have dried, they are more clearly the buildup calcareous deposits but then on the X-ray you can see very distinctively the peaks that indicate that there is a crystal stricture in the deposit. We believe based on the literature that this is aconite and the light gray suggests that the thickness of the calcareous deposit is so thick that you cannot have as a background noise the vinyl ester is very little whereas for the order three samples you can see similar peaks that are present for the crystalline material but you still observe the vinyl ester background can offer no smoldering posts on it. With time, it might be that enough calcareous deposits form that will prevent the vinyl ester from being observed. Next slide please.
We also did the observations in the scanning environmental microscope, and the pictures on the left correspond top views for the 510 on this particular slide and the one on the top corresponds to samples that were interconnected through the sacrificial anode at elevated temperature whereas the ones at the bottom are the ones that were interconnected to sacrificial anode at room temperature. Indeed, the figures on the left are 160 X, whereas the one in the to the right of it corresponds to images at Alpha X you can see more clearly on the sample that was exposed at elevated temperature that significantly more calcareous deposits.
Finally, what we did is that we did a cross section, we mounted a sample in epoxy, and the pictures on the right are showing how thick this calcareous layer is and we believe that anywhere between 15 to 25 microns for the elevated temperature sample, and the one on the bottom right, shows you that on the room temperature maybe was five to 10 microns. On this particular picture, the layer of the vinyl ester was significantly thinner. You can see that the carbon fibers are visible right next to where the calcareous deposits are located. Next slide please. This is something similar for ADAD4. For the benefit of the time constraint, I'm going to just skip the slide. It's going to be available for you to look at it. Next slide. Finally, the conclusions corrosion did not appear to initiate on the titanium mesh alloy samples nor the nickel samples nor calcareous deposits were identified on the composite connected to this alloys.
The sacrificial anode samples are corroding and produce calcareous deposits on the composites that were interconnected to them and the analysis done via x rays and TS it's got electron microscope collaborate that presence of these calcareous deposits on both types of composites connected to the alloys. For future for work, we would like to consider composite to metallic domains for bolts and nuts for samples that are immersed in seawater and then applied in different torque. This creates different size of gaps that potentially can initiate crevice corrosion and then maybe monitoring the potential and corrosion initiation on the metals or fasteners after a certain amount of time, maybe three or six months of exposure. Next slide please. Thank you for your time and I will be happy to answer any questions you might have.
Moderator:
And as a reminder, you can press #2 on your telephone keypad. If you do have a verbal question or you can go ahead and send your message to all panelists using the 'Send to' drop-down menu on the chat panel located on the lower right-hand side of your screen. We don't seem to be receiving any questions at this time.
Lauren:
This is Lauren Moraski. If there aren't any questions at this point on either Francisco's presentation or any of the presentation material that we've covered this morning, we'll go ahead and take a short break here. We're a little bit behind schedule so I would ask that we come back in about, what do we have, about eight minutes and then we'll get started with Scott Hughes presentation on Industry survey on subcomponent needs. That will be 12.10 Eastern Time. About eight-minute break here and we'll come back and Scott will give his presentation.
Moderator:
Your call will resume in eight minutes. Please standby.
Scott:
Hi, this is Scott Hughes at the National Renewable Energy Lab. Hopefully everyone's back from the break. Today I'm going to be talking about subcomponent validation for MHK devices. Next slide, please. Little background on NRL, our main office and laboratories are in Golden Colorado and we have about 2200 employees and researchers and we work across many different fields in renewable energy from photovoltaic to biomass, water and wind and vehicles of you many different things here at the lab. Where I sit at his at the National Wind Technology Center (NWTC). This facility is located closer to Boulder Colorado and we focus on water and wind technologies.
At the site, we have field demonstration sites. We are increasing our activities around grid simulation and we also have drive train and structural test laboratories. Next slide, please. Little background on the test facilities that we have at NRL. The campus is set up where we have three structural testing labs and three drive train test labs and a new capability for composites manufacturing. These figures show some of the typical configurations of the laboratory space. We work with small items up to things that way a couple of pounds to the things that way 50 or 100 tons. Laboratories are configured to be modular, to be able to enable testing at different scale with components and different types of tests from materials and structural to power electronics and grid simulation.
Next slide, please. A little background, Bernie has talked about this a little bit, the overarching program goal. The objectives of the subcomponents validation efforts are really twofold. One is get a better deeper understanding on subcomponent test methods that improve our understanding of design allowable when we start looking at full-scale components, and these efforts are intended to reduce the time and costs for validating complete systems. In alignment with that, our program is going to be resulting in data from subcomponent tests on composite structures.
Next slide please. A little background about the necessity and the benefits for subcomponent validation maybe looking at the figures on the right-hand side to begin with. David Miller, had a slide that looked at the different areas and some of the challenges with bridging the gaps between mechanical loading and the materials and the environmental effects of these things. Subcomponents can take information from loads, from material properties and provide some level of environmental exposure that helps enable engineers and designers to have a comprehensive knowledge of their structure. The figure on the bottom right, this describes on the very low level.
This shows a couple of different coupon types that range from material characterization of need materials and perhaps it eases and different types of failure and fracture modes of relatively small-scale composites. Moving up, our intent is to evaluate the performance of composites, either at a larger scale near the scale where composites would be used in structures and to look at different types of joint. I'll talk a little bit about the industry survey here in a minute. Essentially, we're trying to build information about composites and structures that are near to the complete structural design of the system.
The very top of the pyramid is how you would go about testing a component. It just shows that the culmination of testing is a demonstration of a complete system. This is a challenge across many industries and for MHK this could be a particularly challenging endeavor to perform a full-scale test of a complete system. Given the environmental conditioning and the scale of these devices, it could be very time and cost intensive to perform a test of a complete component or systems. We feel that by informing the development of subcomponent test methods early, we're able to look at testing elements and components of systems that may alleviate the needs to provide the very long fatigue test or very expensive proof for static loading of a complete device.
This also, subcomponent testing has some benefits. In that, if we look at manufacturing and transportation, if we're able to develop methods that can characterize and validate components that may be built inland for a modular system, then that can further reduce the needs for full-scale testing. Next slide, please. Over the last few months, we have been working with our industry partners and peers to evaluate what are the significant gaps when designing structures with composites. Earlier this year, we sent out a survey which is on the right-hand side of this slide that had a few questions. We followed this up with surveys with our industry partners to get into a little more of the details about what they consider to be limitations or barriers to either using any composites in their designs or using composites, what is additional information that is needed to provide robust designs? We're using this information to inform the development of subcomponents that will be validated.
All right, the next slide please. What did we find out? In current use, there are several different types of laminates. The fiber material as you might expect, glass and carbon are common. Pyramid is being used and then to some extent, there is a hybrid materials which would either consist of fiberglass-carbon, fiberglass-pyramid, or other combinations and different types of fiber architectures, unidirectional for high strength or stiffness areas or unidirectional materials for panels. On the matrix material side, epoxy was the most notable with vinyl ester being used to a reasonable extend and some use of urethane actually. Next slide please. Gaps, the figures on the upper right, the identification of gaps either in performance data or knowledge around composites are identified there.
Through these surveys we continue to hear about the challenges of coatings and protection for some of the things that Francisco described. Some of the gaps that are noted here are more structural in nature, but definitely spring environmental effects. The fatigue resistance of the material were the most frequently cited gaps during the survey. Subcomponent testing, we can take the results build upon the results of what we're learning in coupon testing, build upon while we're learning through Sandia and Budi's engagement with developments of better understanding of the load conditions in the field. George and Francisco's work can be leveraged and brought in to demonstrating the performance of subcomponents.
We're trying to build upon all of the areas that we're working in and leverage that to develop and establish subcomponents that will result in tangible good information that designers, engineers can use when designing a device. Let's see the subcomponents, for most structures, there were will be inevitably bonds between composites and metals or composites to composites and the industry survey results, let's do the conclusion that metal to composite is the type of joint that is currently being most procedure used. We would like to evaluate both composite to composite joints and metal to composite joints. Next slide please. Based on the industry surveys, we are in the process of designing several different types of subcomponents. The figures on the rights are cartoons, concepts of the types of components that we will be building.
Upper right hand corner shows a composites blank that is fitted with the easily bonded metal inserts into each end and the figure at the bottom right shows a metal to composites mechanical joints where we're using IKEA or cable connections to clamp a composite blank against a metal surface so when built up these specimens would be put into a load frame and that's the photo at central bottom and these would be subjected to strength test and a static strength testing and developments of basic fatigue cycle or essence low curves. These types of components will be subjected to... Some components will be saturated. I'll talk a little bit more about that in a minute but we plan to do both dry and saturated testing to get a better understanding of the differences between those two states.
For instrumentation, we're still developing the normative types of sensing equipment that we will use in the most basic configuration loads displacement, strain will be measured. The saturation time may be measured with independent coupons that are soaking for a long period of time. In addition to that we may use more full field instrumentation including digital image correlation potentially UT and acoustic emission as well. Next slide please. These components are additionally considered for this program.
There is going to be prioritization based on time and budget considerations, but we would like to pursue developments of what we call beam components and compression-relaxation components. The figure on the upper right shows a composite beam with a couple of adhesive bond lines. These would be multiple composite components that have chemical bonds at several locations. These might be things that you would see in foils, or even some of the configurations could be panel to stiffener types of configuration. The intent with the beam type components would be not only to characterize the performance of the composite under static and fatigue conditions but also evaluate performance of the adhesives, things that will bond different components together. Here we're talking about composite components, but it's not out of the question. This could include metal to composite bond lines.
The figure on the bottom right is what we refer to the compression-relaxation component. The intent with this type of setup is to compress a composite coupon, a very large-scale composite, with a fairly severe preload. David talked a little bit about some of the studies that MSU has done with applying a creep load to coupons and taking a look at the uptake or the saturation of those. We'll continue that work and be looking at the effects of saturation on the preload at the composite stand and potentially the bulk size change of the composite as it's saturated over time. This would be more of a static type of setup where we clamp the specimen and let it sit while evaluating the geometry in the preload, in the clamping bolts. There are a couple of other possibilities when we talk about component testing. We are working closer to an actual design.
Our intent is to get results that can inform many different types of design configurations. That is, they're general enough where either the compression-relaxation or the uptake or the stress and strain curves from saturated large components can be used to feed designs for many types of systems. A couple of other types of components that were mentioned were molded connections where the geometry has relatively abrupt changes and potentially you're using different types of manufacturing methods to bind dissimilar shapes into one composite piece and also looking at flexible connections between composites and other composites or metallic structures. Next slide please.
This is an example test matrix. It has not been fully defined. I'll speak to you the schedule here in a minute, but our intention is to use commercially available materials. Materials that are coming from studies from the MSU coupon work. We'll be doing static fatigue and relaxation testing. We'll be leveraging the experience of P&L and conditioning these test articles either using natural or synthetic seawater and the duration time, the immersion time is going to be something we are looking at it and will require a little more thought. For the coupons, 60-90 days may be adequate for immersion time to test those, these being larger scale components that immersion time requirements may go up. Inevitably, we will be limited to some extent with the overall program schedule.
We will be working towards establishing suitable immersion times for each of these specimens. All of the results that we get will be made public. Looking at the table, this is just an example of different types of composites and metal components that will be combining for subcomponents. Right, next slide please. The timeline, we are rapidly approaching the time we need to fix the design of components. Next month, we anticipate finalizing the type of components that will be tested and by September we will be completing the design for those. December of this year we'll be fabricating, completing fabrication of the components and provide a little time for reporting into next year.
We will need to be complete with testing by July of next year. Next slide please. We are on a relatively short timeline here but there's still time to inform the developments of the subcomponents tests portion. If you have thoughts and ideas or materials that are of interest to you, we would love to hear your feedback and try to work these into the test matrix. In addition to the devices that are the components that were listed, it might be possible to include additional types of subcomponents, the results, again, will be publicly disseminated. If have components that may be useful for this program, we would consider testing those. However, again the results with the public. To provide feedback, please contact Bernie or myself, and we would certainly enjoy speaking with you on what best meets your needs in subcomponents. I think with that, I think that's the last slide, question please.
Moderator:
Again, as a reminder, you can press #2 on your telephone keypad. If you do have a verbal question at this time, or of course submit a question through the chat by submitting your question to all panelists. it looks as though we have one question coming in through the chat here. Why are you only testing stainless steel and titanium metal? Why not any other materials?
Scott:
The test matrix is still in development. Stainless steel and titanium through the industry surveys were identified as materials that were being used in several devices. We still have a little work to do in the definition of the test matrix but right now those two materials are perceived to be the most commonly used in the types of stainless steel and titanium are not noted on there but those will be reviewed and identified within the next couple months. Again, if there are other materials that you have interest in, please, please let us know.
Moderator:
And it looks like we have a comment here. Thanks for including the plant comp in relaxation.
Scott:
Absolutely. You're welcome.
Moderator:
A few more moments, of course for any further questions to come in. All right, and we don't seem to be receiving any further questions at this time. We did have one last question coming here. How likely and at what timeline will be industrial adoption?
Scott:
I would, and please correct me if I'm wrong here, industrial adoption I would take to mean the methods that we are developing for subcomponent validation. When would these methods be implemented? Maybe backing up a step, I think the results from the testing that we do can be used in the very near term to inform designs. The adoption would be more a function of when standards are developed either international standards or you can use to inform protocols of internal validation work. You have a near-term components of results being useful to inform designs and longer term as standards are developed around validation needs. Hopefully, they should be available at that time.
Moderator:
Alright, and there's a follow-up. Is ABS included in the project?
Scott:
No, we have not worked with certification bodies per se, or we have not worked with certification bodies. There has been limited developments in standards that are specific to validation. I think that that is forthcoming in the next few years. We have worked closely with groups like DNV GL and others in development of say wind standards and they are engaged on water power standards and their engagements formally would be in the development of standards. However, if there is a contact, someone that has some interest or knowledge in this area that we can be talking to, I would certainly appreciate a point of contact. I'm happy to reach out to them.
Moderator:
Alright and with that I'm not seeing any additional questions. I would like we can go ahead and move to our next speaker.
Budi:
Thank you. Good morning and good afternoon everyone. This is Budi Gunawan from Sandia National Lab. I'm going to talk about the marine energy converter or MHK load characterization and measurement works that's part of this advanced materials research program. Next slide please. Just a background of Sandia National Lab. Sandia was established in 1948 and was made one of the different energies national Lab in 1979. We have around 12,000 branches located in different places in the [02:21:26 inaudible], around $3 billion of annual budgets.
Most our work is in defense and nuclear weapons, but we also have an energy program that includes various types of renewable types energy like solar, wind, water, geothermal, and biomass. Next slide, please. The motivations of doing this load task for this program are two. The first one, the MHK design loads. The first motivation is to provide characteristic design loads for material performance studies that was described earlier by Dave and other colleagues. The second motivation is because of the industry needs for structural and mechanical load measurements. This was identified as one of the [2:22:30 inaudible], also the recent ICPC11 for strategic business plan.
It can define load measurement and verification after the highest priority or standards departments and do that and we actually already have the comment these working specifically with mechanical load measurements that was started late last year and to do from the objective for this task and to first provide defined elastic load for our material performance testing and our work for this FYI to find guidelines and also try to work on based on the guideline and how to calculate the defined load for representatives [2:23:38 inaudible] and of course the ice best to technical specification as well as everything for report by me. [2:23:48 inaudible] energy has called on are amongst the first who were providing guidance for us to design. Second objective is to [2:23:57 inaudible] our scientific understanding of load measurements and [2:24:02 inaudible] on composite materials for specifically MHK applications. As being, MHK and next devices are deployed in harsh environment and dynamic compared to say oil industry.
We need to better understand how the centers and measurements going to respond to be able to be a reliable load data. So, as I said before as one of the first objective they're looking at the IC technical specifications and the Wave energy Scotland are a big part and as you can see on the picture on the right-hand side, there are pretty complex load exchanges between the structural and the chemical components of Max with [2:25:03 inaudible] as well environmental conditions as well and the weather.
We plan to follow in the recommendations to combine these two these two bodies for especially the subcomponent testing outlined before by Scott, FY19 and all of these load exchanges have to be taken into account when defining a Mac in order for structural integrity of the Mac during its life period and the IC technical specification gives a recommendation on how to calculate the design load and material strength as shown on the equations on the green box which includes the use of the safety factor. The main tool for doing this calculation is to ensure that the strength of collective material should always be greater than the design load.
Next slide please. Though this is just showing from our breathing on these reports and how we plan to do calculation from the collective subcomponents or our next FY testing. To use this on the flow chart on the right is showing the process of determining the design load and the first step is to get a lot of detail load table and they're like five different items that comes into account.
First one is the environment condition is mainly on the research as itself, typically the standards like just the IC either energy resources assessment becoming that thing as long-term probably a few months measurements in reverse or either channel to obtain the velocity data. This is going to be slideshows of some of our [2:27:33 inaudible] 2011, where we put like measure velocity on [2:27:45 inaudible] and long-term measurement will give us data such as in figures. it is the variations of current speed and water level throughout the measurement period as well as the relationship between [2:28:03 inaudible] intensity and velocity in magnitude which is kind of part of important component to estimate the fatigue load to the design.
Once we obtain those measurement we will be able to calculate the environmental process before we dive in because he will be able to calculate the defined it in period [02:28:36 inaudible] period where we can be on for like some of the extreme cases to be built a stable. Other factors included from [02:28:51 inaudible] design conditions and also limited space, next slide please. Once we have the DLC payables or just the one shown in the top right.
We have one dynamic simulation CSD for example model and the which will be able to determine the characteristic load. These takes CSE models can show a distribution of stress load on structural component of another mechanical components of the sample you'll be like a few critical location and where we have the highest loads on the map itself. Based on that direct versus load including a safety factor. Be able to calculate next slide. Once we have a chance for a field deployment will be able to do some measurement in deployment and use the data for validating that define load as well as the CFT mode running and this showing an example of previous work where we put like—for instances for measuring load on turbine [02:30:38 inaudible] for deployment a vertical axis turbine in an irrigation, we also measure the inflow and weight flow philosophy, [02:30:50 inaudible] thus under current data, as low the load data.
Let's go after most data worth use for the That before but to optimize and improve the process design and next slide. So, on the second part on the objective to investigate loads done first, we just completed the very first testing of bolted joint samples. I believed was done about two weeks ago bolted joint was selected for testing based on the industry months ago that Scott already presented earlier next slide please.
We received samples of on carbon fiber components from developers and as you see on those figures on the left-hand side and we are trying our pressed to use the AFN standards to comply with them doing the both the joined testing or shouldn't be billing response of the sample so on the figure unless we cut the large sample in to small one. As shown on the right. Which has a length of 155 millimeters and we drill a hole in the middle and then we check part of possibly six millimeters, help them and them and we are doing testing on [02:32:40 inaudible] and during testing, we are also investing how nondestructive inspection techniques.
Which has been used in various applications as wind energy, or airplane industry might be used for inspecting flaws or defects on the materials specifically use for NHK. Of course, we also will attempt to correct price sensor response and performance the fiber strain centers and this will be an ideal after we follow that, because we know precisely and of course, that will be applied to the specimen. [02:33:29 inaudible] a fellow in chemistry on the next slide.
So, on the nondestructive inspection or NDI side, we did [02:33:45 inaudible] CT scanning for the samples and in general, we find out that specimens to be very clean with occasion. To get high accuracy. CT scan can be used as a reference method for quantifying the effectiveness of other NDI techniques which eventually could be less expensive and it's relatively expensive and not be the best option to use on an ongoing basis. Yeah, maybe perhaps some of the manufacturers already have CT scans in Panama. We can be [02:34:37 inaudible] to use it while—company Next slide, please.
Another NDI inspection we did ultrasonic immersion testing. [02:34:56 inaudible] immersed in water and within ultrasonic [02:35:00 inaudible] measuring the basically rest detecting [02:35:10 inaudible] mismatch between different materials or medium for example you brought up that's the new thing this by outsourcing signal Wi-Fi find me and what we see here on the left-hand side the scan of the samples from different angles.
The bottom candor, this Ascension showing up along the thickness of the samples, they are like different layers of material rather the stamping out one thing we all search on business because we have many layers of material, we found multiple pics that of the materials layers and we will be wanting to do some optimization of this happening and the [02:36:18 inaudible] to be able to track like especially flaw and other things on the material. During response testing we mounted the sample and you've seen on the second figures the left, test specimen with the black colors and bolted fixtures. Both the picture and specimen mounted on the grip, that picture from the last and each testing for each of these examples takes a few minutes to complete, show the data, that displacement as well as the actual forest on 20 hertz next slide. Our test are trying to also use fiber optic sensors, train sensors, fiber optic sensors such as the fiber Brett grading our aphegy sensor. Has been rapidly becoming an instrument of choice for string especially, because they're working principle that use lasers inside instead of electric signal. They are relatively small in size as you can see on the figure on the left there showing the size of the sensor we use compared pencil and it's waterproof which is kind of very suitable, [02:38:21 inaudible] application.
Basically, we've done a bit of testing previously at waste by practical axis scale turbine, at city New Hampshire to demonstration testing the aphegy sensors. The key figure focus on the bottom right where we have friends from number one three and six in green, red and purple. They are located more in similar locations at different. [02:39:05 inaudible] could be encouraging. They're able to detect alarm at very low in the range of a few micro stream and their measurement pretty consistent with each other for different task cases between the X-axis showing the different task cases.
It's different this year for more than 20-- showing real reliable charts that are preliminary quite Elman model. Next slide, please. This is the response of the bearing sensor testing. Unfortunately, the SPG sensor mounted, as you can see, on the first two figures there are broken and we were not able to-- at this point. We plan to do more testing in the future where we better to find the mounting location of the sensors so that we will be able to get—can see figure on the right, there are like six samples and different-- well, more or less they have a similar sailor mode on six of the-- was identified as the lateral net based on the SPM standards and preliminary data. The next slide, please.
Showing the bearing strain versus the bearing stress response from all the six examples. Much of them lining up with each other pretty well and we can estimate the new strength and also the ultimate strength of the samples and their lining. Next slide. The next five future steps are load sensor we have like a few options here but one of them is to continue testing for different conditions for some of our web samples and actually also doing fatigue testing for design loads on the large subcomponent to be tested in FY19 and also potentially appearing at the...
Also instrument of subcomponent with load sensors. We probably can select all or a few of these depending on the... on the MDI side, there are a few steps that we intend to do forward versus to better understanding on inspection needs, online inspections and also the only to optimize inspection which might include changing the different settings of the program and other instruments. Also, to accelerate potential additional inspection methods such as the... next slide, please… That's enough of my presentation and really welcome back and recommendations on any of the... Thank you.
Moderator:
As an additional reminder, you can press #2 on your telephone keypad. If you do have a verbal question or of course, submit your question in writing by using the 'Send to' drop-down menu in addressing your question to all panelist. We're currently awaiting any incoming questions. We don't seem to be receiving any questions at the moment. It looks like we did receive one question here. Would fiber optic strain sensor be suitable for open ocean TV?
Budi:
Thank you for the question. Actually, we are planning to do that for a few projects in the future and one of them will be the law projects, some national labs are still working together with car wave power technologies and Aqua harmonics. They're planning to deploy their scales model for notion probably in two years from now and our past will be to instrument them the defiance heat load sensors including the fiber optic strains sensors. Yeah, that's something that we plan to investigate in more details in the future.
Moderator:
What are the risks of additional soaking on composite structure by including sensors?
Budi:
So actually, in the past, we've done… it's probably more Dave and Bernie have done tests… composite components for like four years ago or so and some are showing the [02:45:31 inaudible] of the sensor response. Either Dave or Bernie, do you want to… on that question?
David:
Well, certainly. This is Dave Miller, Montana State. Certainly, some of the concerns are the additional risk with that would be new diffusion pathways. The opportunity for crack initiation sites for any different nonhomogenous material inside the composite? it's a question whether or not it's on top, on the structure or within the structure. So, I mean, there would be risks and if you put them in the structure and as Budi's alluding to, we had done some work previous, several years back, where they were on the structure and being on the structure, it didn't affect the composite structure itself. I was going to say, I hope that hope that answered.
Budi:
Yeah, I just want to add a bit on the about the sensors testing and is showing a test on a scale turbine and we're been doing it for about 10 days, and facing no big degradations on readings [inaudible 02:47:00] under crosschecking of turbines but yeah, we need to investigate more how the sensors can perform in longer deployment.
Moderator:
Those are all the questions I see at this time.
Dr. Bernadette:
Hello everyone. This is Bernadette Hernandez again, and I would like to go ahead and take this time to wrap up this session. We thank you for your time and attention and participation in today's webinar. We're very excited and I'm very proud of all my team's efforts in getting all the work that they've done out and in such a short period of time and making the vision of the composites program happen for us. Just to recap, if you have any additional comments or questions, please send to Lauren Moraski and also, we're going to be in putting a lot of the different results into the database at the end of this fiscal year.
A lot of those results will be uploaded and there's a link to the database again. It does look like there's another general question. I think this is for George. It says how it's a general question, how do pollutants affect the anti-fouling materials explained in the first presentation? How does the environment of the sea floor, for example, its application in hydropower explained in the first presentation affect the materials versus the environment of the surface level water?
George:
A very good question, addressed a few different ways. Pollutants in terms of turbidity will affect how much sunlight gets on to the surface and depth, of course, affects that. Sunlight's critical, a lot of the primary fouling organisms are photosynthetic, things like diatoms and cyanobacteria and then in the later stages, we do see large algae that can develop. If you're in deeper waters, turbid waters, there's less sunlight, you may see less of those organisms. The water line is where we typically see the worst fouling.
That's because of some natural features such as the surface microlayer, which is a high concentration of organic matter. Also, in that microlayer, you have three to five orders of magnitude of more living cells present. If you get down to the sea floor where you transect sediment you get into some other issues anaerobicity where you can get microbiologist corrosion, you can get galvanic potential as you go through the sediment as well and then also with pollution if you have a lot of organic matter, we often see this in estuaries anywhere that you have a river, an outflow from the coastal zone, the increased organic matter can lead to greater fouling by some organisms but it might also inhibit others.
Human pollutants other than fertilizer from agriculture, oils, it's unclear what the effect is. Let see, is there another aspect of the question. I think that covers it. Yes, water depth, water quality definitely impacts the rate of fouling. It may or may not impact the selection of the coating.
Typically, the, the coating selection is more dependent on again, things like the velocity, the amount of abrasion that might be there, if you have sand in the water, salinity, and I think I already mentioned temperature. There are differences in the coatings between the coatings recommended for the tropics versus more temperate regions.
Rita:
Thank you, George. Just as also a reminder. I'll ask this to the Moderator just really quickly, just to remind the audience this session is being recorded. Is that correct?
Moderator:
That's correct.
Rita:
Yes, this will be available for later reviewing if any of the panelists would like to see it again. And I don't see any more additional questions, so I'll go ahead and once again, say thank you again for your time and we're happy you spent the time with us today. I hope everyone has a great rest of your day. Thank you.
Moderator:
Thank you for joining today's conference. The session has now concluded and you may disconnect.