DP780高强双相钢激光拼焊接头GTN损伤模型参数标定

GTN damage model parameters calibration on laser tailor welded joint for DP780 high strength dual-phase steel

为了获得DP780高强双相钢激光拼焊接头的模拟参数,根据混合法则对激光拼焊接头进行区域细化,采用ABAQUS有限元仿真软件对母材、焊缝和纵向接头的拉伸实验以及极限拱顶高度实验进行了有限元建模,依据拉伸实验的工程应力-工程应变、拉伸试样断裂位置及拼焊板断裂失效模式结果并结合有限元反推法,确定了接头各区域的GTN损伤模型参数,从而对横向接头的拉伸实验和极限拱顶高度实验进行了模拟。结果表明:不同热输入下接头的拉伸实验曲线与模拟曲线、模拟断裂位置与实际断裂位置较吻合;拼焊板失效时的极限拱顶高度值与实验值相接近;拼焊板失效模式与实验结果相一致。

In order to obtain the simulation parameters of laser tailor welded joint for DP780 high strength dual-phase steel,the laser tailor welded joint was area-refined according to the mixing law,and the finite element(FE) modeling of base metal,weld and longitudinal joint tensile test and limit dome height(LDH) test was conducted by ABAQUS FE simulation software.Then,according to the results of engineering stress-engineering strain for tensile test,fracture position of tensile sample and fracture failure mode of the laser tailor welded blanks(LTWBs) and the FE inversion method,the parameters of the GTN damage model in each joint partition were determined,and the tensile test and LDH test of the transverse joint were simulated.The results show that the tensile test curves of joints under different heat inputs are consistent with the simulated curves,and the simulated fracture position is consistent with the actual fracture position.The LDH value when the tailor welded blank fails is close to the test value,and the failure mode of tailor welded blank is in good agreement with the test results.