Volume 5, Issue 7 (July 2008)
Fatigue Response of Aluminum Aircraft Structure under Engineered Residual Stress Processing
Advanced surface treatment methods for imparting beneficial residual compressive stresses into fatigue-prone metallic components such as laser shock processing (LSP) and low plasticity burnishing (LPB) have proven highly effective in prolonging the life of titanium turbine engine blades. The objective of the current effort was to experimentally evaluate whether similar life enhancement benefits are possible for metallic aircraft structures. Under this initiative, aluminum test specimens were processed using three engineered residual stress techniques, referred to as LSP 1, LSP 2, and LPB, and subsequently fatigue tested under uniaxial, constant amplitude loading conditions. Evaluation of the test results indicated that both the LSP and LPB processes, if carefully designed and applied, have the potential to increase the fatigue life of aircraft structural components.