用模糊推理及分级优化确定板料冲压的工艺条件

Fuzzy Reasoning and Hierarchical Optimizing Strategy Applied to Determine Process Conditions in Sheet Metal Forming

提出在动力显式非线性有限元计算的各增量步中,用模糊推理技术来判断被加工零件的应力、应变状态并处理相关的工艺专家知识,在此基础上建立了以凹模入口圆角半径、压边力、拉延筋约束力为设计变量,以零件无破裂情况下起皱趋势最轻为目标的二级优化模型,从而用分级优化搜索策略实现了上述主要工艺条件的自动确定.用此方法确定的典型Dashpot零件的冲压仿真工艺条件在DYNAFORM中所得的仿真结果与现有结论及实际加工经验相一致.

It is suggested that in sheet metal forming simulation, within each increment step of dynamic explicit non-linear finite element method, the fuzzy reasoning is adopted to estimate the states of stress and strain of the stamped part and to deal with the corresponding process expert knowledge. Moreover, a second order optimization model, taking the die opening radius, the blank holder force, and the drawbead constraint force as the design variables and the slightest wrinkling tendency without any fracture as the objective function, is established to determine automatically the above mentioned process conditions with the hierarchical optimization searching strategy. The numerical simulation of forming process of a typical Dashpot part is performed with the process conditions obtained by the proposed determination method in DYNAFORM and the results reveal a good agreement with the available conclusions and practical experience.