考虑静水压力和LODE 角的塑性模型 在GH4169 合金上的应用

针对典型盘用镍基高温合金GH4169,采用Bai-Wierzbizki(B-W)塑性理论对其塑性变形行为进行建模和应用评估。B-W塑性理论假设金属材料塑性变形仍服从von Mises屈服准则,但屈服函数考虑了静水压力和LODE角(偏应力第3不变量)对塑性行为的影响。采用Abaqus/Explicit商业有限元软件编制了该塑性模型的用户材料子程序,设计开展了GH4169合金的光滑、缺口圆棒和缺口平板拉伸试验,基于有限元分析和优化方法确定了B-W模型相关材料参数,对GH4169合金光滑和缺口拉伸响应曲线进行有限元预测,并与试验结果进行对比分析。结果表明:B-W模型预测的GH4169合金缺口圆棒和平板拉伸响应曲线与试验结果非常吻合,而基于传统von Mises塑性模型预测的GH4169合金缺口拉伸响应曲线均明显高于试验曲线。

Application of a Plastic Model with Hydrostatic Pressure and Lode Angle in the GH4169 Alloy

The plastic deformation behavior was modeled and evaluated by Bai-Wierzbizki (B-W)plastic theory for typical Ni-based super-alloy GH4169 for disk. The B-W plastic theory assumed that the plastic deformation of metallic materials were still subject to the von Mises yield criterion,but the yield function took into account the effect of hydrostatic pressure and LODE angle (the third invariant of deviant stress)on the plastic behavior. The user material subprogram of the plastic model was compiled by using Abaqus/Explicit commercial finite element software and the smooth,notched rods and notched plates tensile tests of GH4169 alloy were designed and launched. The material parameters of B-W model were determined based on the finite element analysis and optimization method. The smooth and notched tensile response curves of GH4169 alloy were predicted by finite element method,and the results were compared with the test results. The results show that the tensile response curves of GH4169 alloy notched rods and plates predicted by the B-W model are identical with the test results,while the notched tensile response curves of GH4169 alloy predicted by traditional von Mises plastic modelare obviously higher than the test curves.