基于广义成形理论,在有限元环境下,以增量算法仿真结果为数据源,提出一种针对汽车覆盖件成形中出现皱曲缺陷的仿真分析方法。该方法对皱曲严重程度进行量化评估,通过分析应变路径和观测参考线应变分布情况,获悉到皱曲关注区在冲压成形过程中的应力情况、成形特点以及皱曲特征,并可提供金属流动调节参考方向以及调节参考量,考虑破裂缺陷区对皱曲缺陷区的调节干涉影响,经干涉分析,对皱曲缺陷调节参考量进行修正,提高其鲁棒性,参照金属流动调节量修改仿真工艺参数,从而消除皱曲缺陷。以某车前翼子板为例,应用该方法分析仿真成形中出现的皱曲缺陷以及受破裂缺陷影响的调节干涉问题,其分析结果验证了该方法的有效性和可行性。
A numerical analysis method for wrinkling in auto-body panel forming based on “universal formability theory (UFT)” is proposed, and simulation results obtained with incremental algorithm is used as data source for wrinkling analysis in the environment for finite element simulations. By using the method, wrinkles can be evaluated quantitatively, stress, characteristic of forming and wrinkling in forming process can be got by analyzing strain path and strain distribution on reference curve, and metal flow adjustment directions and reference quantity are provided, to enhance the robust, the reference quantity will be revised by analyzing the interference caused by rupture, then, refer to adjustment directions and the revised reference quantity, wrinkling defects can be eliminated by adjusting simulation process parameters. A fender part as an example is presented, and the wrinkling, interference caused by split of the part is analyzed, the results validate the effectiveness and efficiency of the method.