考虑材料韧性损伤的中厚板半冲孔成形过程分析

Numerical analysis of medium-thick sheet metal semi-cutting process considering ductile damage

为研究半冲孔成形过程中韧性损伤的演化以及部分工艺参数对成形质量的影响规律,本文在ABAQUS有限元模拟软件中建立了半冲孔轴对称有限元模型,并通过VUMAT用户子程序引入GTN(Gurson-Tvergaard-Needle-man)损伤模型,结合同时考虑空穴形状与体积变化影响的韧性断裂准则,进行弹塑性大变形有限元分析。基于该有限元模型,预测了半冲孔工艺中静水压力、等效应力、等效应变、应力三轴度以及损伤断裂的产生和发展趋势,分析了反顶力、压边力和冲裁间隙对零件的影响规律,并与实验结果进行对比分析,验证了数值模拟的准确性。

In order to study the evolution of the ductile damage and the influence of the process parameters on the forming quality in the process of the semi-cutting,an axisymmetric FE model was created by using ABAQUS software,and the GTN（Gurson-Tvergaard-Needleman） porous material model which was introduced through the VUMAT subroutine,and a ductile fracture model which took into account the influence of stress triaxiality and deviatoric stress tensor on material damage,were used for elastic-plastic large deformation FE analysis.The distributions of hydrostatic stress,equivalent stress,equivalent strain,stress triaxiality and fracture of sheet metal in the process of semi-cutting parts were predicted,and the influencing laws of the process parameters,such as counter force,blank holder force and clearance,on parts were analyzed by the simulation results which were in agreement with the experimental results.