春回和內時本構模型二次收益分析

Using thermodynamic consistency elastoplastic large deformation material constitutive model established by a simple mechanism, the model meets basic thermodynamics of irreversible constraints, and taking into account the residual energy stored in the micro stress field, with the corresponding algorithm, prepared a user subroutine UMAT, and embedded into commercial software ABAQUS, the resilience and the secondary yield analyzes of cylindrical workpieces elastic tool upsetting and upsetting when closed mold. comparison of simulation and experiment measured load - displacement relationship can be seen in the plastic deformation of upsetting the first stage of lateral deformation of the workpiece in the axial loading process has been due to the elastic deformation of the mold radial constraint caused by the rapid increase in load; second stage axial pressure reducing mold springback so that the radial deformation of the workpiece can be restored, but with the increase of plastic strain occurs strengthen the work; the third phase of mold constraint lifted, increasing the radial dimension of the work with the constitutive model. calculation closed mold upsetting, showing the calculation results and the experimental results are consistent.