Composite Material Repair Update
Today’s weapons systems are increasingly comprised of advanced composite materials. Inspecting and repairing these materials can be extremely difficult and may involve multiple analysis and/or repair methods depending on the material being repaired, the environmental considerations, the time involved, and the impact on costs and readiness. In order to affordably sustain readiness, DoD maintenance activities require efficient and effective composite inspection and repair capabilities. During this Joint Technology Exchange Group (JTEG) forum, SMEs from across DoD’s maintenance enterprise will discuss current composite repair processes and outline the challenges. This SME panel will also present on-going and future initiatives aimed at improving the composite inspection and repair process and reducing composite sustainment costs.
Tech Forum Access
Enter as a guest on DCS at https://conference.apps.mil/webconf/JTEGMonthlyTechForum
We will be using a separate line for audio:
Call: 888-537-7715,
Conference ID: 16161715#
Note: Several participants had difficulty connecting to DCS receiving “Server error” messages. This may be a “Site certificate” issue. The https://conference.apps.mil site certificate used by DCS was changed on 3/27/2015 and renewed on 3/27/2017. To update your site certificates, click on the “security report” shield in the pink highlighted IE warning tab. Then select “View Certificates”. The “Certificate” window has an “Install Certificate” button. Follow the wizard prompts until the ‘success’ window appears. Unfortunately, most DoD users may not have the authority to execute so the “Install certificate” button may not appear in the “Certificate” window, and you’ll need to ask for IT support.
Agenda
1300-1309: Welcome and Overview – Greg Kilchenstein (OSD-MPP)
1309-1310: Administrative Notes – Debbie Lilu (NCMS)
1310-1330: USCG Aviation Bonded Material Inspection System – Rusty Waldrop (USCG)
1330-1400: Army Composite Repair & Support Activities – Kimberly Cockrell (AMRDEC)
1400-1420: NAVAIR Composite Material Repair Projects – Dave Motley (FRC-E)
1420-1435: Composite Materials Components for Reduced Maintenance and Total Ownership Cost – Scott Bartlett (NSWCCD)
1435-1450: The Use of Composites to Repair and Replace Damaged Metallic Ship Structures and Components: Composite Patch Repair of Cracked Aluminum Plates – Dan Hart (NSWCCD)
1450-1500: Wrap-up and JTEG Principals Comments
Minutes
Event: On 15 December, 2015, the Joint Technology Exchange Group (JTEG), in coordination with the National Center for Manufacturing Sciences (NCMS), hosted a virtual forum on “Composite Material Repair”.
Purpose: The purpose of the forum was to provide information and exchange ideas on composite material repair projects and techniques, the challenges, and the tools and processes being employed by DoD maintenance activities and supporting activities.
Welcome: Greg Kilchenstein (OSD-Maintenance), welcomed everyone to the forum and emphasized the importance of composite material repair. Inspecting and repairing these materials can be extremely difficult and may involve multiple analysis and/or repair methods depending on the material being repaired, the environmental considerations, the time involved, and the impact on costs and readiness.
Administrative: This was an open forum. The presentations, along with questions and answers, were conducted through Defense Collaboration Services (DCS) and an audio line. Approximately 60 participants from across DoD and industry joined in the forum. Questions were sent through DCS and answered by the presenters during the forum.
USCG Aviation Bonded Material Inspection System – Rusty Waldrop (USCG) provided an update of the USCG aviation bonded material inspection system which is the 2015 DoD Maintenance Innovation Challenge winner. Bonded Material Testing (BMT) offers more accurate results and exact measurement of defects compared to tap testing and is easier to interpret than ultrasonic testing. The BMT uses a portable instrument designed to detect un-bonded conditions in laminate plies and in sandwiched constructed materials. DoD aviation has begun implementation, but the knowledge needs to be grown and training increased.
Army Composite Repair & Support Activities – Kimberly Cockrell (AMRDEC) provided updates to continuing composite repair activities to include the Composite Maintainers Technical Interchange Meeting (TIM) in June, the AMRDEC Composites Working Group, repair-based training & certification, and the National Composite Consortiums. The also described several repair efforts to include a dry de-paint modernization report and UAS repair.
NAVAIR Composite Material Repair Projects – Dave Motley (FRC-E) described several projects to include cyanate ester high temp repair resin, FTIR heat damage detection, and StressCheck (ESRD) composite repair analysis tools.
Composite Materials Components for Reduced Maintenance and Total Ownership Cost – Scott Bartlett (NSWCCD) described Carderock’s actions to replace corroded components with new composite replacements. Components made out of composite materials offer the potential to be more resistant to environmental effects, lighter weight and in some cases, lower cost than the legacy metallic components. NSWCCD is always looking for components that could be converted to composite materials to reduce the maintenance burden. NSWCCD has some composite electrical enclosures in stock that are available for ships that are looking to try out the technology. Also, NSWCCD is currently soliciting for points of contacts within the surface ship community for future trial demonstrations of composite deck drain inserts as these components transition to the fleet.
The Use of Composites to Repair and Replace Damaged Metallic Ship Structures and Components: Composite Patch Repair of Cracked Aluminum Plates – Dan Hart (NSWCCD) briefed NSWCCD efforts to address cracking of aluminum deckhouses currently experiencing stress corrosion cracking as a result of inter-granular corrosion of sensitized plating. These generally are not repairable by welding, and often require large scale replacement of sensitized plating resulting in high maintenance costs to the fleet and potential impacts to operational availability. Composite patch repairs restore environmental and potentially structural integrity without further degrading adjacent structure thereby avoiding costly and time-consuming structural replacement
Closing Comments: Greg Kilchenstein and the other JTEG Principals thanked the presenters for their briefs and the audience for their active participation in the Q&A, and noted the importance of collaboration amongst the military Services and agencies.
Presentation Slides and Questions & Answers: These meeting minutes, the Q&A, and those briefing slides approved for public release, will be posted on the JTEG website at https://jteg.ncms.org/ .
Next JTEG Meeting: The next JTEG virtual forum is 19 January 2015, 1:00 – 3:00 pm EST. The topic is Integrated Circuit Test, Repair & Re-Manufacturing.
POC this action is Ray Langlais, rlanglais@lmi.org , (571) 633-8019
Questions & Answers
USCG – Rusty Waldrop
Answered Questions 5
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Q1. Has the USCG done any economic analysis depicting the benefits of Bonded Material Testing over traditional methods such as tap testing and UT?
A1. We have not gotten that far into it. As far as efficiency of inspection, there are some efficiencies experienced.
Q2. Is the Bonded Material Testing system the USCG uses commercially available? Who is the tech supplier? What does a BMT inspection system cost?
A2. Yes, it is available on GSA. The qualified vendor is Olympus NDT. Cost is approximately $8,000
Q3. Is the USCG still teaching the tap test or have you moved on to using the BMT exclusively?
A3. There is no course on the tap test, the Composite repair course does not teach the tap test. However, it is part of our ultrasound testing.
Q4. Can your training be made available to members of other Services?
A4. Yes. We are already embedded with the USAF.
Q5. What is the target schedule for BMT equipment and training to be provided to all relevant USCG maintainers?
A5. Everybody has the instrument. In 2 years all inspectors will have them.
Comment 1: The CH-53K is a composite aircraft and we have developed (under an SBIR) Airframe Impact ID and Rotor Impact ID, that detects impacts and will give maintenance workers a location within 6″.
Comment 2: NAVAIR has the Olympus Bondmaster 1000E+ fielded. It is taught….very briefly at the NDI C-school.
Army – Kim Cockrell (AMRDEC)
Answered Questions 5
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Q1. When/Where is the next joint composite TIM?
A1. In VA, David Motley briefed that the TIM is tentatively scheduled for Little Creek, June 14-16.
Q2. Is the AMRDEC training and deploying BMT equipment similar to the Coast Guard?
A2. Different equipment. We are looking at many different types of NDT technologies. They complement each other.
Q3. Do you share your Blackhawk repair efforts across the DoD via Team Hawk?
A3. I am not involved with Team Hawk.
Q4. What format is AMRDEC specifying for the 3-D models?
A4. We are not right now. That is one of the challenges.
Q5. Have you seen something called TransMagic made by a small business in Colorado? (Beardon)
A5. I have not.
Beardon: I recently received a brief on TransMagic (Now loaded on the JTEG website). It provides 3D CAD translation and data usability. They have worked with aerospace, automotive and defense customers.
Comment: It is especially useful on core materials where traditional pulse-echo ultrasonics does not work well. Laser-shearography is being considered for F-35 for similar NDI applications. Thermography is another candidate technology to consider.
Comment: NAVAIR NDI Engineering is hesitant to use Bondmaster procedures without a part-specific reference standard because the instrument tends to be sensitive to changes in construction and geometry. It is preferred over tap test because tap test is so subjective.
NAVAIR – Dave Motley (FRC-E)
Answered Questions 5
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Q1. Is the TIM meeting open to all DoD/Commercial/Academic interested parties?
A1. Yes
Q2. Will the TIM focus on the contracting language issue?
A2: That is up to what issues people want to bring up.
Q3. Are you assessing any technologies to accelerate the resin curing time?
A2. We have looked into some, through microwave and other things. Nothing has been promising.
Q4. Are the FRC’s using BMT equipment similar to what Rusty briefed for the coast guard?
A4. We already have the Olympus Bondmaster 1000E+ fielded as an I level piece of eqpt. Also, laser shearography is being used on radoms & flight control surfaces. Flash spectroscopy and ultrasound are also being used.
Q5. Can you announce when/where/ contact info for TIM ?
A5. Information will be posted on the JTEG website and included in the CTMA bulletin.
NAVSEA – Bartlett (NCWCCD)
Answered Questions 5
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Q1. How do you assess the lifecycle implications when changing from traditional materials to composite materials?
A1. Typically, we have limited data for doing replacements. If the maintenance is conducted at the depot level, it is easy to track the cost data. However, if sailors do the work, it is more difficult to track.
Q2. What is the general cost difference between the metallic components and their composite replacements?
A2. Fairly similar. For example, the electrical boxes are very similar. The composite replacements cost a little more, but the payoff is on the maintenance side as there is no blasting, painting, or replacement needed with the composite replacement.
Q3. Are they 3D printing the deck drains out of ULTEM
A3. No. We are not there yet.
Q4. Are these composite replacement parts repairable or are they consumable?
A4. The majority are consumable. We found that the lifecycle is increased over the metallic equivalent.
Q5. Is there a DoD approach to develop the cost-benefit analysis … for life-cycle-cost savings as generally the replacement cost/acquisition cost is pretty simple?
A5. Not that we are aware of. The only good lifecycle cost data is different.
Comment: Many of these composite replacements were developed and qualified by leveraging DOD’s corrosion program $$. This is a great source of partnering funds!!
NAVSEA – Dan Hart (NSWCCD)
Answered Questions 4
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Q1. What are the reparability concerns with the composite patches? Is a detailed reparability analysis done prior to making the change?
A1. We are hoping to go there. Currently, projects are brought to us very quickly. They are high profile, but limited to non-structural.
Q2. How did you prep/treat the aluminum deck prior to bonding the patch repair?
A2. This is semi-frustrating, as it depends on where you are. Some of the different techniques being used include needle-gunning, grit blasting (San Diego was the best), grinders, wire brush and sandpaper.
Q3. Do you have to worry about galvanic corrosion…are all patches made with e-glass?
A3. No. All patches to date have been made with e-glass. Europe and Australia have experience using carbon fiber.
Q4. Are there recurring inspections of the patches and/or underlying aluminum?
A4. Yes, there is. Based on inspector availability. If they know there are patches they will use an ultrasonic or eddy scan.