空洞敏感型超塑材料充模胀形的有限元模拟

Finite Element Simulation of Filling-die Bulging for Cavity-sensitive Super-plastic Materials

本文采用大变形刚粘塑性有限元模拟，研究了空洞敏感型超塑材料的充模胀形过程，模具为轴对称任意倾角锥形模。采用轴对称薄膜环单元，由修正的Ｌａｇｒａｎｇｅ法建立包含摩擦项的泛函并在此基础上形成有限元列式。通过对基体厚度耦合迭代和由修正的Ｇｕｒｓｏｎ方程导出的空洞长大模型来计算空洞发展。文中分析了材料参数、模具几何形状参数等对充模过程和胀形件厚度分布不均性的影响。模拟结果与实验值吻合得较好。

The process of filling-die bulging for cavity-sensitive super-plastic materials is investigated by large deformation rigid-viscoplastic finite element simulation. The die is a conical one with arbitrary slant angle.The FEM formula are deduced based on the functional including frictional one formed by updated Lagrangian method and by using symmetric ring membrane element.The growth of cavities is calculated by using the model deduced by coupling iteration of the matrix thickness and the modified Gurson equation. The effects of the material parameters and the geometri shape parameters of die etc,on the bulging process and the ununiformity in the distribution of the thickness of specimen are analysed. the numerical results agree well with the experiment.