Jixie qiangdu (Jan 2015)
EFFECT OF MATERIAL WORK HARDENING MODEL ON THE SIMULATION PRECISION FOR SPRINGBACK
Abstract
Springback is an inevitable phenomenon in the stamping process,which not only affects the dimension precision,but also affects the structure reliability. Therefore,an accurate prediction of springback is the first important to decrease and control the springback. The material in the stamping process will undergo reversed loading,and shows different mechanical properties from monotonic loading. Therefore,the material work hardening model is one of the most important factors affect the simulation precision. This paper uses finite element method to study the springback in the punching of a flanging,and the effects of isotropic,kinematic and mixed hardening models have been discussed,which is verified by the experimental. The results show that the isotropic hardening model does not consider the Bauschinger effect,which leads to an overestimation of springback. The kinematic hardening model does not consider the effect induced by the quick stress-strain,which leads to underestimation of springback. The mixed hardening model considers both the Bauschinger effect and transient characteristics,showing a true stress and strain,which leads to an accurate calculation of bending residual stress and springback. The result of mixed hardening model is well consistent with the experimental.
