Study on the stability of compressive residual stress induced by high-frequency mechanical impact under cyclic loadings with spike loads

Abstract

In this study, the residual stress simulations of the out-of-plane gusset welded joints examined by Leitner et al. (2016) in As-welded and HFMI-treated conditions which are performed by Ruiz (2018, 2019) are reviewed and verified. Based on the reviewed simulation’s results, the changes of residual stress under constant amplitude and compressive spike loads with various stress amplitudes are simulated. Sensitivity analyses of the simulation parameters in stress response simulation are carried out, and recommendations on residual stress relaxation simulation are proposed. From the residual stress relaxation simulation results, the following are found: (1) for constant amplitude cyclic loading cases, the residual stress induced by HFMI treatment shows considerable relaxation. The longitudinal component of the residual stress shows a slight increase when the maximum stress of the cyclic loading is large, about 44.5%; (2) for spike followed by constant amplitude cyclic loading cases, the residual stress shows considerable relaxation. The degree of the relaxation becomes more significant with the increase of spike load and/or the maximum stress in the constant amplitude loading except the longitudinal stress component on the top face. The longitudinal residual stress near top face shows considerable improvement showing around 21% of increment compared with the as-peened condition.