OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Sustainment
OBJECTIVE: Evaluate the implementation of a novel repair technique for AM-2 aluminum matting repair in-situ. The idea is to analyze the repair effectiveness by comparing virgin AM-2 specimens to specimens artificially damaged and repaired, in terms of mechanical performance.
DESCRIPTION: Rapid deployment of Expeditionary Airfields (EAF) is critical to expedited military transportation and sustained presence across multiple military theaters around the world. At the core of EAF, utilization of aluminum matting, referred to as EAF AM-2 matting, is essential to lay down for air vehicles to successfully land in a variety of soil environments. Maintenance of such a system ensures prevention of premature structural failure, thereby preventing in-service landing failures and loss of life. However, AM-2 matting is often shipped back to a refurbishment facility for various reasons, one of which includes significant structural damage.
The decision to repair is influenced by the type of damage and the defect size encountered when the matting is damaged. Guidance will be provided to awardees. Damage due to forklift tines are also taken into account, where the maximum allowable hole dimensions for repair are 1.5 in. (3.81 cm) wide by 10 in. (25.4 cm) long. If the matting is damaged, the EAF Marines have to pull up and remove all of the surrounding mat to be able to remove and replace the affected piece. Depending on where the damaged mat is in the airfield the current process of removal and replacement can take a substantial amount of time and labor to complete both while downing that portion of the airfield. With the ability to rapidly repair in situ, the mean time to repair (MTTR) will be greatly decreased, thus improving the Operational Availability.
The EAF Marines are an expeditionary force, therefore a premium is placed on weight, size, and maneuverability of materials, which imposes constraints on any solution. The EAF Marines must be prepared to operate in any feasible climate, a requirement that extends to their equipment as well. AM-2 matting is manufactured in either 6 ft (1.83 m) or 12 ft (3.66 m) by 1.5 in. (3.81 cm) by 2 ft (.61 m) pieces of aluminum and weigh 75 lbs (34.02 kg) or 150 lbs (68.04 kg) respectively. AM2 mats are additionally treated with nonskid coating.
The aim of this STTR topic is to enhance the repair and refurbishment capability of EAF AM-2 aluminum matting. Ultimately, an ideal application would involve on-site repair of holes and cracks that form on AM-2 matting while installed on an airfield. Areas of consideration for a potential solution should include fuel/power consumption (if needed), time to repair, and comparable mechanical properties to undamaged AM-2. The threshold for this effort is to repair the damaged aluminum AM-2 matting utilizing a preferred repair technique or method. The objective is to repair the damaged matting and provide some semblance of a friction surface for the repaired surface area.
PHASE I: Provide a conceptual design for a process for the repair and refurbishment of EAF AM-2 aluminum matting. Prove the engineering and economic feasibility of meeting the stated requirements through analysis and lab demonstrations. Identify specific strategies for meeting performance and reliability goals. Optimize the processing parameters for application to various hole and crack sizes on AM-2 matting specimens. Assess representative macrostructural matting specimens under flexure loading is recommended in this phase. Sustainment or improvement of mechanical properties is to be evaluated with use of the chosen repair method/technique. The Phase I effort will include prototype plans to be developed under Phase II.
PHASE II: Demonstrate prototype performance with AM-2 matting. Provide an estimate of costs including manufacturing. Provide a failure analysis, service life estimate, and assessment of meeting requirements. Using optimized parameters evaluated in Phase I, repairs would ideally be conducted on full-scale AM-2 matting structures (6 ft–12 ft) (1.83 m–3.66 m), and full-scale mechanical testing is to be conducted. Data sets are to be obtained and compared to existing data on AM-2 mechanical analyses.
PHASE III DUAL USE APPLICATIONS: In partnership with the PMA and the Arresting Gear IPT, new repair/refurbishment cost and logistics estimates are to be assessed given the optimal materials and parameters established in the previous phases. This will ultimately prepare the repair method for fielding.
Any aluminum paneling or matting that is utilized in commercial systems (e.g., stiffener walls for a train, aircraft fuselage paneling and floorboard repair, building materials and building structures) can be repaired with relative ease without having to replace or even remove the part from the rest of the structure or system.
- Widener, C. A.; Ozdemir, O. C. and Carter, M. “Structural repair using cold spray technology for enhanced sustainability of high value assets.” Procedia Manufacturing, 21, 2018, pp. 361-368. https://doi.org/10.1016/j.promfg.2018.02.132
- Chaudhary, B.;, Jain, N. K. and Murugesan, J. “Development of friction stir powder deposition process for repairing of aerospace-grade aluminum alloys.” CIRP Journal of Manufacturing Science and Technology, 38, 2022, pp. 252-267. https://doi.org/10.1016/j.cirpj.2022.04.016
KEYWORDS: aluminum; matting; in-situ; repair; expeditionary; airfield