Fatigue Life Prediction of Prefatigued Welded Q235 Steel Butt-Joints Treated by High Frequency Mechanical Impact

Fatigue tests were performed to investigate the effect of fatigue preloads on the fatigue life of welded Q235B steel butt-joints treated with high-frequency mechanical impact (HFMI). Then, the effect of two consecutive HFMI treatments on the fatigue life enhancement of prefatigued welded butt joints was investigated. The total fatigue life of prefatigued specimens decreases as the fatigue preload cycles increase and two repeated HFMI treatments have an insignificant effect further to enhance the fatigue life of the prefatigued specimens. Finally, based on the experimental results, a two-parameter approach is proposed to estimate the total fatigue life of the impacted prefatigued butt joints.