金属板料渐进成形有限元仿真过程中复杂成形路径的构建方法

METHOD ON GENERATING COMPLEX LOADING PATH FOR FEM SIMULATION OF INCREMENTAL SHEET METAL FORMING PROCESS

提出一种用于获得复杂空间运动轨迹的方法——虚拟靠模导向法。该方法借鉴了数控加工中COPY铣的思想,利用轨迹生成球在由零件派生出的虚拟靠模表面上的持续运动来模拟实际成形工具的运动过程,从而获得最终成形路径。基于该思想和简单的运动学原理,轨迹球与虚拟靠模有限元模型被构建起来。通过对计算过程进行分析,确定运用该法时适合的加载力、成形速度及计算精度的影响因素。因该法完全基于有限元模拟计算,故获得的成形路径可直接导入至后续的金属板料成形过程的模拟分析。该法已在有限元软件PAMSTAMP平台上得以实现,并主要用于金属板料渐进成形过程的有限元仿真。

An acceptable approach to generate a 3D forming path, which is called virtual guiding model method is accomplished. The method has the similar idea with the conventional COPY mill. A track ball is forced to move continuously on a virtual guiding tool which is generated from the part to simulate the real moving process of the forming tool. Based on the idea and the simple principle of kinematics, the FEM model of the track ball and the virtual guiding tool is constructed. Through the analysis of the computing process, the suitable loading force and forming velocity are ascertained, and the influence factors of the computing precision are also discussed. Because the method is based on FEM simulation completely, the generated forming path can be used directly for the subsequent metal blank forming process. This method is realized in the FEM software PAM-STAMP and mainly used in the simulation of the sheet metal incremental forming process.