Effect of Bauschinger Effect and Yield Criterion on Residual Stress Distribution of Autofrettaged Tube

Many analytical and numerical solutions for determining the residual stress distribution in autofrettaged tube have been reported. The significance of the choice of yield criterion, the Bauschinger effect, strain hardening, and the end conditions on the predicted residual stress distribution has been discussed by many authors. There are some different autofrettage models based on different simplified material strain-hardening behaviors, such as a linear strain-hardening model, power strain-hardening model, etc. Those models give more accurate predictions than that of elastic–perfectly plastic model, and each of them suits different strain-hardening materials. In this paper, an autofrettage model considering the material strain-hardening relationship and the Bauschinger effect, based on the actual tensile-compressive stress-strain curve of material, plane-strain, and modified yield criterion, has been proposed. The predicted residual stress distributions of autofrettaged tubes from the present model are compared to the numerical results and the experimental data. The predicted residual stresses are in good agreement with the experimental data and numerical predictions. The effect of Bauschinger effect and yield criterion on residual stress is discussed based on the present model. To predict residual stress distribution accurately, it is necessary to properly model yield criterion, Bauschinger effect, and appropriate end conditions.