基于混合近似模型的镁合金差温成形压边圈结构形状优化  

Shape optimization of blank holder structure in nonisothermal stamping of magnesium alloy based on ensemble surrogate

作　　者：谢延敏[1] 唐维 黄仁勇 张飞 潘贝贝 XIE Yan-min;TANG Wei;HUANG Ren-yong;ZHANG Fei;PAN Bei-bei(Institute of Advanced Design and Manufacturing, Southwest Jiaotong University, Chengdu 610031, China)

机构地区：[1]西南交通大学先进设计与制造技术研究所

出　　处：《塑性工程学报》2018年第2期22-29,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51005193);国家大学生创新创业训练计划项目(201710613033)

摘　　要：为提高差温成形冲压件的成形质量，提出一种自适应SVR-ELM混合近似模型，并应用于压边圈结构优化。基于NUMISHE-ET2011中的镁合金十字杯形件差温成形有限元模型，对影响成形质量的压边圈关键区域进行分区并作为输入变量，建立分区与成形件侧壁厚度均匀性之间的SVR-ELM混合近似模型，采用启发式算法求解混合近似模型权系数。基于自适应方法更新混合近似模型，通过粒子群算法对近似模型寻优以获得最佳压边圈子区域组合，通过对板料法兰部位温度场的控制，实现法兰各区域塑性差异化，更好的控制材料流动。基于形状优化理论对压边圈应力集中区域进行形状优化，改善其应力分布。利用优化后的压边圈对十字杯形件进行数值模拟，结果表明，与原压边圈成形试验值相比，优化后的压边圈能有效提高板料成形厚度均匀性。To improve the forming quality of nonisothermal stamping parts, an adaptive SYR-ELM ensemble surrogate model was presented, and applied to optimize blank holder structure. Based on cross-shaped cup part finite element model of magnesium in NUMISHEET2011, the key area of blank holder affecting forming quality was divided into subareas and used as input parameters. The SVR-ELM ensemble surrogate model was estabilished between subareas and side wall thickness uniformity, and the weight coefficient of ensemble surrogate was calculated by heuristic algorithms. The surrogate model could be updated based on an adaptive method, and the optimum subareas could be obtained by optimizing the surrogate model with particle swarm optimization （PSO）. So the plasticity difference of the blank flange was realized by con- trolling temperature field on the blank flange, and material flow was controlled better. Shape optimization was carried out in stress concentra- tion areas of blank holder based on shape optimization theory to improve the stress distribution. The simulation of cross-shaped cup part was carried out based on the optimized blank holder. Compared with the experiment data based on the initial blank holder, the optimization re- sults show that the optimized blank holder can improve thickness uniformity effectively in sheet metal forming.

关 键 词：差温成形 自适应SVR-ELM混合近似模型 粒子群算法 压边圈 形状优化 

分 类 号：TG386[金属学及工艺—金属压力加工]