A MODIFIED HYDROSTATIC STRESS CALCULATION METHOD FOR LARGE DEFORMATION ELASTOPLASTIC FINITE ELEMENT

To solve the problem of poor accuracy in calculation of the hydrostatic stress in large deformation elastoplastic finite element, the paper presented a study on the super-accuracy locations of deviatoric stress derivatives for 3-D 8-node iso-parametric elemeflt, and established a modified indirect integral method for hydrostatic stress. Application of the method in the finite element simulation of metal forming process obtains a good accuracy in stress calculation with large strain increments.