Abstract
Quantitative tools to predict the stability of residual stresses and their impact on fatigue crack propagation life are required to give appropriate credit to the beneficial effects of residual stresses in deciding the service life or inspection intervals of automobile components. The purpose of this paper is to present analytical approaches for characterizing the relaxation rate of residual stresses and the propagation behavior of small fatigue cracks growing through residual stresses induced by shot peening. To quantify the relaxation of residual stresses, a strip model is proposed in winch the evolution of residual stresses under cyclic loading is determined by using a non-linear cinematic hardening constitutive law. Comparisons are made between model predictions and experimental results wider two different loading spectra, showing a good correlation.
Keywords: Rainflow, fatigue, residual stress