Numerical Simulation of Stress in a Rotational Autofrettaged Thick Walled Tube Using the Actual Material Stress-Strain Curve

Autofrettage is a practical method for increasing the elastic carrying capacity and its fatigue life of thick-walled tube such as cannon, high-pressure tubular reactor. Rotational autofrettage is a recently developed technology. The analytical model for the stress analysis of a rotational autofrettage is based on the elastic-perfectly plastic assumption. Because of the effect of Bauschinger and the strain-hardening, most actual materials do not satisfy the elastic-perfectly plastic assumption. In this paper, FEA has been used to simulate the stress distributions in the tube under rotation and the residual stresses in the tube after Rotational Autofrettage. The actual tensile-compressive curve of material, which includes the material strain-hardening and the effect of Bauschinger, was adopted as the material model. Finally, the residual stress distribution caused by Rotational Autofrettage and Hydraulic Autofrettage with the same plastic deformation were compared and analyzed.