金属板料拉延二次成形的有限元法模拟

Finite Element Simulation of Two Stroke Deep Drawing in Sheet Metal Forming

建立了二次拉延成形加工的有限元分析计算模型；采用一次成形-回弹计算-二次成形的连续计算过程模拟了实际加工过程；有限元计算采用动力显式计算程序MSC／DYTRAN；用主从面(master surface-slave surface)模型定义板料和模具的接触，摩擦力用库仑定律计算；利用动力松驰法对成形过程中的回弹进行了计算。模拟结果和实际零件比较，证明模型合理，算法稳定，结果可靠，具有良好的应用价值。

Finite element analysis model has been established to simulate the process of two stroke deep drawing in sheet metal forming. A successive computing method of one stroke-springback-two stoke is presented to accomplish the simulation. Dynamic explicity FEM code-MSC/DYTRAN is employed to solve this forming problem. Master surface-slave surface contact model is used to define the contact between tools and blank. Contact constraints are enforced with a kinematic algorithm and friction stress is computed by Coulomb friction law. Dynamic relaxation method is used to treat springback after forming stroke. The numerical results are in good agreements with those obtained by practical product experiment. The method and algorithm are proved robust and reliable.