Experimental Study and Fatigue Life Prediction of Laser Shock‐Peened Aluminum Alloy With Hole Structures

ABSTRACT This study examines laser shock peening (LSP) effects on fatigue performance of 7050 aluminum alloy specimens with circular holes. Experimental measurements and finite element analysis (FEA) characterize residual stress distributions under varying LSP parameters. High‐cycle fatigue tests are conducted to evaluate the fatigue performance. Fatigue life predictions employ a novel method integrating stress weighting factors with the theory of critical distances (TCD). Results show that FEA using the Johnson–Cook model accurately replicates measured residual stresses. LSP‐induced gradient residual stress fields shift crack initiation from the hole edge to the interior of the hole, resulting in up to a sevenfold improvement in fatigue life. The proposed weighting factor effectively characterizes gradient stress and identifies crack initiation locations. Fatigue life predictions based on the modified TCD method with weighting factors demonstrated high accuracy, with all results falling within a threefold scatter band.