一种预测板材成形回弹的新的自适应无网格法

摘要

The shape precision of formed part was seriously affected by springback of Advanced High Strength Steel (AHSS) forming.To optimize the process parameters and obtain the precise shape geometries of formed part,an advanced adaptive meshless method was employed to accurately predict the springback of advanced AHSS forming.Stress and strain gradients were described with multi-scale characteristic of meshless shape function by which stress and strain decomposed into high and low scale components.More nodes were distributed automatically in high gradient zone by using a developed adaptive algorithm.An adaptive meshless numerical model of AHSS forming was constructed based on building constitutive relation of AHSS accurately.Numerical simulations for U-bending process of AHSS were performed,and the numerical simulation results showed that the proposed meshless numerical model could accurately predict the springback of AHSS forming process and improve the forming quality of AHSS.%先进高强钢成形后回弹严重影响成形件形状精度,为准确预测并控制回弹,提出一种新的多尺度无网格自适应分析方法,优化工艺参数,降低回弹提高成形精度.利用无网格形函数多尺度特性将应力、应变分解为高、低尺度分量,采用应力、应变高尺度分量表征应力、应变梯度;采取自适应分析技术在高梯度区加密无网格节点;在准确构建先进高强钢本构关系的基础上建立先进高强钢板材成形自适应无网格数值模型.针对先进高强钢U形弯曲进行无网格数值模拟,数值结果表明,所构建的无网格数值模型可准确预测先进高强钢成形后的回弹,有效提高先进高强钢成形质量.