ABSTRACT
Diaphragm-to-rib welds are easily subjected to fatigue cracking under cyclic traffic loads. To evaluate the effect of hammer peening technique, the simplified finite element model (FEM) of hammer-peened specimen was developed to investigate the local stress variation after hammer peening. The effective stress was also analysed by another simplified FEM. Besides, three local specimens were peened and the subsequent fatigue test was conducted for comparison. The results show that the crack initiation life of hammer-peened specimen is enhanced significantly, while the crack propagation pattern still remains unchanged. Significant compressive stress is induced by hammer peening, and the effective tensile stress under bending load could be decreased effectively, which is beneficial to the fatigue performance of diaphragm-to-rib welds.
