The Anisotropy Of Metal Sheet And Influence On The Sheet Foming

In this thesis,a theoretical analysis of the elastic-plastic ear of orthotropic sheet metal during the process of forming is systematically presented. Conclusions given herein not only contribute to the enrichment and development of plasticity theory, but also provide necessary theoretical basis for the engineering practices. The paper proposes several kinds of orthogonal anisotropic yield criterion and places emphasis on the anisotropic theory of Hill. The effect of plane anisotropic in sheet metal forming and some features of plane stress state with transversely anisotropic are summarized. On the basis of experiments, three common anisotropic metals are analyzed and the parameters in anisotropic yield criterion are derived. In addition, the theoretical prediction of ear is given. Two FEM programs, ANSYS and DYNAFORM, are applied to simulate the deep drawing process of cylinder in order to examine the ear prediction. In detail, a static implicit analysis with R.Hill anisotropic yield criterion is done by using ANSYS, while a explicit dynamic analysis with Barlat-Lian 3-parameter yield criterion is done by DYNAFORM. Then comparison between the two simulation results and are presented based on experimental results. A tensile test is done so as to get the mechanical property required by simulation. Then the cylinder deep drawing test with three different materials is carried out. The tests adopt LabVIEW, 6062E collecting card and its relevant module for data collecting whose manufacturer is NI Company.