Establishment And Application Of Elastic-plastic Constitutive Model For Cyclic Loading

The finite element commercial simulation software is used to analyze the sheet forming problem,which has become the main auxiliary means in industrial design.How to improve the efficiency and accuracy of simulation calculation is a hot issue that needs to be solved at present.The material constitutive model is the key factor to influence the numerical simulation results.the sheet has reverse loading and cyclic loading characteristics under some complex loading,in addition,stamping sheets typically have material anisotropy,so constitutive model depend on isotropic yield and isotropic hardening can not describe this deformation behavior.In this paper,based on anisotropic yield criterion and anisotropic hardending,a new constitutive model is developed,in order to describe complex loading behavior accurately.Various constitutive model is developed in ABAQUS,including Barlat yield criterion combined with isotropic hardening,Barlat yield criterion combined with A-F hardening,Barlat yield criterion combined with Chaboche kinematic hardening,Hill yield criterion combined with isotropic hardening,Hill yield criterion combined with A-F hardening and Hill yield criterion combined with Chaboche kinematic hardening.The method of obtaining the material parameters in each constitutive model was studied.Using Fortran language program,through the ABAQUS software UMAT interface achieving the interface of the constitutive model of the secondary development.The correctness of the subroutines was demonstrated by example.The process of uniaxial tensile deformation analysis is simulated,and the constitutive model of Hill yield criterion combined with Chaboche kinematic hardening has the highest precision than other constitutive model by comparing with the experimental results.Then this model and the material model of the ABAQUS were used to study the effect of different structure parameters of drawbead on resistance drawbead and the strain of the plate,the calculation of developed material model was more closer to the experimental results.The developed material model was used in the simulation about deep drawing of the rectangular straight wall box,compared with the several kinds of the effects of draw bead structure,the accuracy of the program was verified by comparing the numerical simulation and experiment results.