Experimental measurement and finite element simulation of the interaction between residual stresses and mechanical loading

Residual stresses, which can be produced during the manufacturing process, play an important role in an industrial environment. Residual stresses can and do change in service. In this paper, measurements of the statistical distribution of the initial residual stress in shot blast bars of En15R steel are presented. Also measured was the relaxation of the residual stresses after simple tensile and cyclic tension–compression loading. Results from an elastic–plastic finite element (FE) analysis of the interaction between residual stresses and mechanical loading are given. Two material hardening models were used in an FE analyses: simple linear kinematic hardening and multilinear hardening. It is shown that residual stress relaxation occurs when the applied strains are below the elastic limit. Furthermore, the results from the simulations were found to depend on the type of material model. Using the complex multilinear model led to greater residual stress relaxation compared to the simple linear model. Agreement between measurements and predictions was poor for cyclic loading, and good for simple tensile loading.