变厚板材料模型表征方法的比较研究

Comparison study of description methods for material model of variable-thickness rolled blank

针对变厚板板厚非均一性的特点,为建立相对准确的变厚板材料模型,基于变厚板数字散斑单向拉伸试验和不同厚度应力应变曲线的计算,提出了整体法和分段法的表征方法。在分段法中,对过渡区分别采用了离散、插值和平均法进行表征。并将这些方法分别应用到变厚板单向拉伸仿真模拟中,对比试验和仿真的力-位移曲线差异性,结果显示,采用分段法得到的仿真数据更接近试验数据,因此变厚板的材料模型采用分段法表征更合理。

Since variable-thidcness rolled blank （VRB） owns the characteristic of non-uniform thickness, in order to describe material model of VRB accurately, overall methods and segmentation methods were put forward based on digital image correlation （DIC） tensile test of VRB and stress-strain curve calculation under different thicknesses. There are three ways, which is interpolation, discretization and average among segmentation methods to deal with transition zone of VRB. All these methods were applied to numerical simulation of VRB, and the force-displacement curves acquired from real test and simulation were compared. The results show that simulation data of segmentation method are more closer to experimental data, which is reasonable to describe material model of VRB.