Residual Stress Behavior of Rolled Aluminum Alloy A2024T3 in a Thin Plate During Cyclic-Tension Fatigue Studied Using Ultrasonic Horizontally Polarized Shear Waves

Abstract

The cyclic-tension fatigue in a rolled thin-plate of aluminum alloy Al-4Cu-1Mg was evaluated nondestructively using a horizontally polarized shear wave (SH) transmission method under optimized measuring and analyzing conditions. The propagation time of the SH waves, which contained elements of reflected waves, had three distinct stages, the first, middle and final ones, during the fatigue process. The variation of the propagation time was dominated by the residual-stress field during the fatigue progress, as an acoustoelastic effect. The change in the stage of the variation can be elucidated by balance points for the redistribution of the residual stress, which clearly told us the degree of progression of the fatigue in the thin plate.