对5052铝合金进行单向拉伸试验,使用试验曲线拟合Voce模型参数。观察拉伸试样断口形貌,并使用光学显微镜测量拉伸试样断口的最小厚度。结合单向拉伸仿真和试验结果,求解得到Cockcroft-Latham韧性断裂准则中的材料参数。将Voce模型和Cockcroft-Latham韧性断裂准则引入球头胀形仿真,并进行试验对比。结果表明:采用该拟合的Voce模型和Cockcroft-Latham韧性断裂准则预测所得零件开裂位置和裂口形状与试验结果吻合,采用的基于有限元仿真与简单试验相结合的材料参数反求方法具有求解方便、计算精度高的优点。
The uniaxial tensile tests were conducted on 5052 aluminum alloy and Voce model parameters were determined by fitting with the experimental curves. The fracture surface was observed and the minimum thickness of it was measured with optical microscope. The material parameter of Cockcroft-Latham ductile damage criteria was achieved through uniaxial tensile simulation and test results. Voce model and Cockcroft-Latham ductile damage criterion were introduced into the numerical simulation of spherical bulging and simulation approach was employed to compare with the experimental results. The results show that the position and shape of the fracture surface simulated with Voce model and Cockcroft-Latham ductile damage criteria are in good agreement with the experimental ones. The method of material parameters identification based on finite element simulation and simple tests has high accuracy and can be applied conveniently.