Predicting The Effect Of Shot Peening On Weld Fatigue Life

Author:  Chang, S. and Lawrence Jr., F.V.
Source:  Conf Proc: ICSP-1, (p.461-478)
Doc ID:  1981053
Year of Publication:  1981
Abstract:  
An analytical model was developed to predict the effect of shot peening on the fatigue life of a weld. The total fatigue life of a weld was considered to be composed of a crack initiation and crack propagation period. Residual stresses and the material properties of the peened surface were considered in the estimation of the crack initiation life but not in the crack propagation life. The shot-peened weld toe was considered to be a strain hardened and heavily plastic-deformed surface layer with altered material properties and high compressive residual stresses. Fatigue notch factors (K sub f) were estimated using Peterson's equation and the K sub f max. concept. The max. compressive residual stresses at weld toe introduced by shot peening were estimated from experimental data. Neuber's rule was used to determine the local stress--strain behavior and the mean stress established during the set-up cycle at weld toe. Fatigue tests of A514 grade F/E110 steel butt welds in the spot peened and as-welded conditions were conducted to verify the analytically predicted total fatigue lives. Descriptors: High strength low alloy steels-- Welding; Butt welds-- Mechanical properties; Fatigue life; Shot peening; Mathematical models