Analysis On Earing, Thicking And Buckling From Crystal Orientation In Deep Drawing Of Sheet

Sheet metal has good elasticity, plasticity and plastic processing performance, so it has wide application in real life. Deep drawing is a major means of sheet forming process, but often produces ear, and the size of the ears can measure the degree of anisotropy of metal materials. In turn, the degree of anisotropy of sheet metal has affected the system size and the number of ears. In the process of deep drawing, product tend to generate fracture and wrinkling, led useless product, or need post-processing, and increase the manufacturing procedure, which increases the cost of production.This paper introduces the texture of polycrystalline material representation-orientation distribution function, and derives elastic constitutive relation and the plastic constitutive relation that contain texture coefficient of orthogonal sheet with Voigt model and Reuss model; We decompose the plastic constitutive relation into isotropic, transverse anisotropy and orthogonal anisotropy three parts, and determine containing the number of parameters of the part and get the relations between parameters of the part and six parameters of the Hill yield function. Using balance differential equation, geometric equation and deep coefficient, we derive the theoretical relationship of sheet with transverse isotropic and orthogonal anisotropic among earing, thickness, wrinkling, texture coefficient and plastic coefficient in deep drawing; Take different texture coefficient, different deep drawing coefficient and different parameters of the plastic as an example, and then get the texture coefficient, thickness change and plastic parameters of the sheet with transverse isotropic and orthotropic when the sheet have the minimum ear and the minimum increase of thickness; Using the energy principle derives stage instability wrinkling in the flange of the cubic sheet.Due to the texture coefficient of the sheet can be controlled and measured in the manufacturing process, so the results of this paper can be a basis that used as a control materials microstructure in the actual production.