Finite element analysis of residual stress evolution with multiple impacts on one point in ultrasonic impact treatment process

Abstract

The ultrasonic impact treatment process is widely used to improve the fatigue life of the weldments by inducing compressive residual stresses at the sub-surface. The purpose of the article is to conduct the dynamic elastic-plastic finite element analysis of multiple impacts on 5A06 aluminum alloy with different controlled parameters. The numerical model was validated by pin drop test. The changes in penetration depth, maximum compressive residual stress, and surface residual stress were obtained by analyzing the residual stress field and equivalent plastic strain. The effect of impact times, impact velocities, pin shapes, and impact angles on the residual stress was investigated so that the ultrasonic impact treatment parameters could be controlled to obtain expected residual stress distributions.

Surface layer properties of ultrasonic impact–treated AA7075 aluminum alloy

“…UIT is especially used as a post-welding process of joints made of various steels and alloys for improving fatigue strength by reducing the welding stresses. [13][14][15][16][17][18] UIT is also called as ultrasonic treatment (UT), needle peening, ultrasonic peening (UP), and ultrasonic impact peening (UIP). In the process, ultrasonic waves produced by an ultrasonic transducer are transferred to the material surface as peening impacts by steel pins.…”

A Progress in the Effect and Mechanism of Ultrasonic Impact Treatment on Additive Manufactured Metal Fabrications

“…The maximum residual stress gradually increases with increasing the semi-axis of the impact needle. The effective impact depth and the maximum residual stress depth will decrease, which is mainly related to the concentration of energy transfer after varying the shape of the impact needle, as shown in Figure 4c,d [37]. Impact amplitude and load are closely related to the energy of the impact needle in the UIT process.…”

Progress on the Effect and Mechanism of Ultrasonic Impact Treatment on Additive Manufactured Metal Fabrications

“…Equivalent plastic strain, Indentation profile, residual stress, crack arrest stress and propagation rate [33,35] Impact amplitude Effective depth and residual stress [36] Impact load Plastic deformation, residual stress and crack density [32] Impact form Impact angle Indentation profile and residual stress [37,38] Pin shape (pin length, pin sharpness, pin diameter)…”

“…In addition, the residual tensile stress generated during the additive manufacturing deposition is continuously released. It gradually introduces residual compressive stress on the material surface, as shown in Figure 2 [37]. For a specific material, the surface hardness and residual compressive stress reach the maximum when performing a certain number of impacts.…”