基于三角形膜单元的钣金成形有限元逆算法

以三角形膜单元为基础，推导了精度较高的有限元逆算法．算法中考虑了摩擦、压边力、拉延筋等实际工艺条件，并实现了计算机程序．利用此程序可以计算出与冲压件相对应的毛坯的展开形状，冲压件最终的应力、应变分布和厚度变化率等信息．以锥形盆为例，验证了根据有限元逆算法设计的毛料展开程序在毛料展开中的有效性和精确性．实例分析表明在工程允许精度范围内，有限元逆算法可对板料成形工艺方案进行快速评价，优化冲压工艺参数，是一种有效的钣金展开算法．

The finite element inverse approach for sheet metal forming based on the triangular membrane element

Based on the triangular membrane element model, a high precision inverse approach with fmite element is deduced. The process parameters, such as friction, holding force and draw-bead force are considered. The blank shape, the final distributions of stress and strain, and the thickness change corresponding to the stamping parts can be calculated by this program. The effectiveness and accuracy of the inverse approach method in blank design are validated by a typical example of a cone-shaped basin. The results show that the inverse approach is an effective approach for blank design, which can be used to quickly evaluate the sheet metal forming process and to optimize the stamping technological parameters.