板材成形回弹数值分析的静力隐式方法

给出了板材成形加载过程，卸载过程数值模拟的静力隐式有限元方法，通过平衡迭代求解有限元方程，并采用隐式算法进行应力积分及接触压力计算，这种方法应力计算准确，因而回弹计算结果具有较高的精度，数值计算表明，纯弹性板大变形卸载后能够完全恢复到原始形状，说明该方法对几何非线性问题的分析是非常准确的，最后对板材柱面、球面成形的回弹进行了分析。

Static Implicit Approach of Springback Simulation for Sheet Metal Forming

Static implicit finite element scheme for the numerical simulation of loading and unloading processes in sheet metal forming is described in this paper. The finite element equation is solved by equilibrium iteration procedure, and the stress integration and contact pressures are calculated by the implicit algorithm. The stresses calculated by static implicit method are accurate, so the results of springback simulation with high precision can be achieved. The pure elastic sheet metal with large deformation recovered its initial state completely after unloading. Such results demonstrate that the method proposed in the paper is very effective for the analysis of geometrical nonlinear problem. The springbacks of a cylindrical part and a multi-point forming part of sheet metal are simulated by the presented method.