汽车后翼子板冲压成形的有限元逆方法模拟

采用有限元逆方法模拟了汽车后翼子板的冲压成形过程，得到了最终构形的应力、应变和厚度分布以及初始毛坯形状．结果表明：后翼子板冲压件的应力应变分布并不均匀，凹模圆角附近、凸模圆角以及法兰的部分区域等效应力和等效应变较大；其厚度分布也不均匀，法兰大部分区域由于受双向拉应力作用，厚度明显变薄，而内部局部区域由于受双向压应力作用，厚度则明显增大，中心区域同时受拉、压两种应力作用，厚度变化相对较小．这些结果对后翼子板初始毛坯的选择、冲压加工过程控制等具有指导意义。

Numerical simulation of rear fender forming by the finite element inverse approach

The forming process of rear fender is numerically simulated by the finite element inverse approach. The initial blank shape and the distributions of stress, strain and thickness in the final work-piece were obtained. It is obvious that the distributions of equivalent stress and strain are uneven, and the stress and strain are larger near the moulds and flanges. It can also be seen that the depth becomes thinner near flange subjected to tensile stresses in both the directions but thicker in some local regions subjected to compressive stresses in both the directions. These results are important both for the choice of initial blank and forming process control.