基于极限应变分析的十字形试件有限元设计

为了通过十字形双向拉伸试验来实现复杂加载,研究复杂应变加载路径下板材的极限应变,采用有限元数值模拟技术,设计出臂上及中心区带槽的十字形双向拉伸试件,建立了有限元计算模型.基于试件在拉伸时中心区受力均匀并能实现大变形的条件下,优化出较佳的试件形式,通过调节速度加载边界条件可实现中心区不同的应变路径,为复杂应变路径下成形极限的研究提供基础. 

FEM Design of Cruciform Biaxial Tensile SpecimenBased on Limit Strain Analysis

A cruciform biaxial tensile specimen with chamfer in arm and center region is designed by the method of finite element numerical simulation in order to realize the complex loading using cruciform biaxial tensile test and study the limit strains of sheet metals under the complex strain loading paths. Finite element calculated model is established. An optimum shape of specimen is obtained on the basis of the following conditions: the stress distribution in the center region is uniform and large deformation is obtained easily during stretching of the specimen. Different strain paths in the center region can be realized by adjusting the velocity boundary conditions. This paper provides the basis for the study of sheet forming limit under the complex strain loading paths.