Field Deployable Welding Technologies for In-Situ Repair of Thermoplastic Composites Components on Naval Aviation Platforms

PROJECTED CMMC LEVEL REQUIREMENT
Level 2 (Self)
TECHNOLOGY AREAS
None
MODERNIZATION PRIORITIES
Advanced Materials
|
Sustainment & Logistics
KEYWORDS
induction welding; field deployable system; automated process control; forward deployed repair; shipboard repair; structural repair
OBJECTIVE
Develop and transition a portable induction welding system capable of in-situ repair of thermoplastic composite components on naval aviation platforms enabling rapid, field-ready maintenance capabilities for next-generation naval aircraft.
DESCRIPTION
Modern aviation platforms are increasingly using high-performance thermoplastic composites such as PAEK, PEEK, PPS, or PEI reinforced with Carbon Fiber for structural and semi-structural components. Their attractiveness is due to their superior damage tolerance, impact, and ability to be reworked for repair. Unlike traditional thermoset composites, which can only be repaired by bonded patches or bolted panels, thermoplastic composites can also be repaired by welding, which restores strength without the need to remove additional material. However, currently available welding systems have a large footprint and are available mostly with OEM and only suited for deployment at the Depots. Thus, without field deployable technofixes, repairs will result in long downtime for repair and likely higher scrap rates.
This STTR topic seeks to leverage the research expertise of academic or government labs in thermoplastic processing and electromagnetic heating to partner with a small business in designing a rugged, portable induction welding system that can be deployed shipboard and/or in Aircraft Intermediate Maintenance Detachments.
The proposed system should: (1) be capable of welding aerospace-grade thermoplastics (at temperatures up to 400 C); (2) be lightweight and field operable, including on aircraft carriers; (3) be electromechanically ruggedized and safe to operate near avionics and flight-critical systems; (4) have a closed-loop thermal control for temperature; (5) be able to repair skins, fairings, panels, and access doors; and (6) have a weld strength of at least 70% of the parent material.
PHASE I
Identify key thermoplastic components and repair scenarios relevant to Navy and Marine Corp Aircraft; develop preliminary induction welding system architecture; build and integrate a TRL 3-4 configuration in collaboration with the research institution; and conduct an initial weld strength test. The weld strength should be at least 70% of parent material. Additionally, the awardee should assess the electromagnetic compatibility and ergonomics of the system.
While this is not an allowable developments program, the awardee may propose a limited amount of testing for calibration and validation of the prototype. The awardee should note that the Phase II down select is based on the performance and final deliverables of the Phase I Base period so plan accordingly.
The Phase I deliverables should include at a minimum: (a) a Weld Feasibility report which should include results of weld trials meeting the key parameters stated above. It should also include assessment of the thermal profile, fusion quality, and repeatability; and (b) a preliminary system concept and architecture that will meet the topic's goals.
PHASE II
Build and validate a ruggedized TRL 6-7 prototype system. Integrate smart controls and thermal feedback into the prototype. Adapt tools and fixtures for real world geometry and repair location. Validate the tool on a sub-element level aircraft part. Demonstrate mechanical integrity of repairs by mechanical testing and nondestructive inspection (NDI). Demonstrate that it meets full EMC qualification per appropriate MIL STD [Ref 3].
Ensure that the prototype meets the Phase II goal (stated in the Description).
Provide a test report summarizing all tests done in Phase II, and an electronic user instruction manual for the prototype and a maintainability and support plan for the delivered prototype.
PHASE III DUAL USE APPLICATIONS
Support the transition to Navy use. Expected transition within government is to fleet resource centers servicing MQ25 and next gen platforms including Maritime Strike.
Additionally, the awardee will be encouraged to transition to commercial maintenance depots.
REFERENCES
"NAVAIR Composite Repair Manual (01-1A-1)." https://www.tinker.af.mil/Portals/106/Documents/Technical%20Orders/AFD-082416-1-1A-1.pdf?ver=2016-08-24-114541-837
"Lap Shear Adhesion Test for Fiber Reinforced Plastics (FRP) ASTM D5868)." January 10, 2023, https://store.astm.org/d5868-01r14.html
"MIL STD-461G: EMC Control Requirement for Aircraft." Department of Defense Interface Standard. https://www.intertek.com/emc/military-aerospace/
"Welding thermoplastic composites." Composites World, Updated February 2023. https://www.compositesworld.com/articles/welding-thermoplastic-composites