Rapid Aluminum Crack Arresting Kit Navy SBIR FY2016.1 Sol No.: Navy SBIR FY2016.1 Topic No.: N161-069 Topic Title: Rapid Aluminum Crack Arresting Kit Proposal No.: N161-069-0144 Firm: Physical Optics Corporation 1845 West 205th Street Torrance, California 90501 Contact: Kang-Bin Chua Phone: (310) 320-3088 Web Site: http://www.poc.com Abstract: To meet the Navy's need for a crack arresting method for welded aluminum structures, Physical Optics Corporation (POC) proposes to develop a new Rapid Aluminum Crack Arresting Kit (RACAK) that uses a proprietary material that rapidly welds a metal patch over the crack area without adding residual stress and to arrest crack growth, a database to help user's select the application method, and a sensor to monitor the repaired structure. RACAK uses fumeless, safe, nontoxic welding compound that is made of readily available materials. In Phase I, POC will demonstrate RACAK at lab scale under low-cycle tension-tension fatigue loading conditions. In Phase II, POC will refine the RACAK methodology, expand the low-cycle fatigue testing and analysis to capture higher stress levels and increased stress state complexity with constant and random amplitude fatigue spectrum loading, and demonstrate crack arresting capabilities for full-scale structural components. Detailed numerical analysis will be performed on the experimental testing to develop the loading scenario, facilitate the estimation of a fatigue lifetime limit, and demonstrate the ability of the technology to arrest crack growth or significantly decrease the crack growth rate and increase the load cycles to failure of the repaired plate. Benefits: RACAK is a novel implementation of materials used in certain welding applications. RACAK consists of welding compounds, metal patches, and clamping hardware that is conformable to the surface of any curvature/contour. The welding compound can be modified to work on different metals to provide a versatile and long-lasting weld repair. Consequently, RACAK can be used to repair a broad range of metalwork including pipe joints on both commercial and Navy ships, hydraulic pipes, sewer pipes, steam pipes, and water pipes, and the repair work can be easily performed while a ship is underway. In addition to shipboard use, RACAK can be used in a number of commercial applications, including noncritical aircraft structures, building structures, industrial and residential plumbing, crude oil pipelines, water mains, pipes for chemical and industrial processing, industrial hydraulic pipes, and utility pipes for gas and steam. Return