影响板料成形回弹数值模拟精度的因素分析

Analysis on the Effects of Numerical Simulation Precision on Springback Prediction

分析了影响板料回弹精度的数值模拟因素:屈服准则、硬化模式、单元技术及有限元数值计算方法。研究结果表明各向异性屈服准则Barlat89更接近于材料的实际屈服行为;对于具有Bauschinger效应的材料及复杂加载问题,采用非线性混合强化材料模型预测板料回弹量的精度最高;由于实体壳单元具有实体单元和壳单元的优点,预测回弹模拟结果精度高。研究还表明,在时间允许的条件下,采用较小单元尺寸模拟精度高。

Numerical simulation factors, affecting the accuracy of springback prediction in sheet metal forming, such as yield criterion,hardening rules,unit technique and finite element numerical algorithm have been studied. The research result indicated that Barlat＇s 89 anisotropic yield criteria was more close to the actual material yield behavior. For material of Bauschinger effect and complex loading problems, nonlinear combined hardening material model was more accurate in prediction of sheet metal springback.As continuum shell element directly combines the advantages of both solid and shell element,it was more accurate in springback prediction.In addition,on the condition of time cost permission, smaller element size was with more accurate in simulation.