StressWave revolutionizes the science of fatigue enhancement. Fatigue enhancement can now be accomplished simply in a low cost, high speed automated environment, almost anywhere within the production sequence, with better results than legacy methods. StressWave opens a universe of new solutions for difficult to solve fatigue and manufacturing problems. Cold working is a proven method for increased damage tolerance, lower weight and enhanced durability, imparting beneficial residual stresses into the material surrounding a hole or other feature. Legacy methods require a significant amount of costly recurring (per hole) and durable tooling, many manual pre- and post-cold working production steps, and usage must be done in higher cost, late stages of assembly. Automation is not feasible. StressWave cold working is a simple, repeatable process that provides better fatigue enhancement. It is accomplished before a hole or feature is machined, significantly reducing the number of processing steps. It is inherently automatable StressWave works by dimpling the surfaces of a part to a prescribed depth using an indenter. The indenter displaces (compresses) material axially producing a radial flow of material away from the indenter. The diameter of the dimple is normally less than the final hole diameter and is completely removed during machining. The upstream nature of the process lead to treatment of unusual geometries such as blind holes, pocketed holes, rotating component features, etc. StressWave test results proving the effectiveness of StressWave cold working have been confirmed by aerospace manufacturers (Boeing, Airbus, Bombardier, Embraer), material suppliers (Alcoa, Pechiney, Nippon Steel, Arcelor-Mittal), and many universities (Purdue University, University of Washington and others). Phase I and II SBIR programs have demonstrated conclusively that StressWave can provide better fatigue performance than current methods. Cost analyses from a major OEM for a low volume application show that StressWave will about 50% less expensive over the life of a major aircraft acquisition program, and provide manufacturing schedule improvement, as compared to current methods. Other analyses, for high volume applications, indicate that StressWave could be one to two orders of magnitude less expensive than current methods. StressWave enables low cost cold working, at any stage in production, with automation, and with low environmental impact.
