A finite-element analysis of the residual stress distribution in the vicinity of a fatigue fractured surface

Abstract

An analytical study by the elastic–plastic finite element method was made of the residual stress and equivalent plastic strain distributions near the fatigue crack surface. Emphasis was on finding the correlation between the residual stress on the fracture surface and the applied stress intensity factor range ΔK. Special attention was given to the effects of applied stress ratio and the work-hardening rate. A characteristic behavior was found: the residual stress on the fracture surface increases with the increase of ΔK, reaches a maximum at a certain value of ΔK, and then decreases. The decrease of the residual stress on the crack surface was correlated with the growth of an instability into the distributions of residual stresses and equivalent plastic strain under the fracture surface. It was also found that both the residual stress and equivalent plastic strain distributions under the fracture surface were useful for the estimation of the monotonic plastic zone size or Kmax and the cyclic plastic zone size or ΔK.