板料成形极限曲线测试及NADDRG模型预测

Forming Limit Curve for Sheet Plate Obtained by Measurement and Prediction of NADDRG Model

利用ARAMIS动态应变测量系统测试了不同钢板的成形极限曲线(FLC),分析了钢板厚度、应变硬化指数和强度对成形极限的影响,并与NADDRG模型预测的FLC进行了对比。结果表明:钢板的成形极限应变与钢板厚度和硬化指数正相关,与强度负相关;NADDRG模型对DC系列冷轧低碳钢的FLC预测结果基本准确,但平面应变点并非试验所测FLC的最低点,试验所测FLC的最低点较平面应变点向右偏移,其主应变值与NADDRG模型预测结果一致,次应变值与各向异性塑性应变比显著负相关。

The forming limit curves（FLC）for various steel plates were tested by ARAMIS dynamic strain measurement system,and the effects of the thickness,strain hardening exponent and strength on the forming limit were analyzed.The FLCs predicted by NADDRG model was verified and compared with experimental FLCs.The results show that forming limits of steel plates had positive correlation with the thickness and strain hardening exponent,and negative correlation with the strength.The FLCs for DC series cold-rolled steel predicted by NADDRG model were generally accurate.However,the plane strain point was not the lowest point of the experimental FLC,which shifted to the right of the plane strain point.The major strain of the experimental FLC was in accordance with the results of NADDRG model,and minor strain has significant negative correlation with anisotropic plastic strain ratio.