基于材料全程本构关系对延性断裂韧性的数值模拟方法与应用

NUMERICAL SIMULATION AND APPLICATION OF DUCTILE FRACTURE TOUGHNESS BASED ON FULL-RANGE CONSTITUTIVE RELATIONSHIP

利用ANSYS APDL编程语言,采用FAT(Finite-element-analysis Aided Testing)方法获取26NiCrMoV11-5汽轮机转子材料、A508-Ⅲ压力容器钢和304不锈钢材料全程单轴拉伸本构关系曲线。借助ABAQUS软件中GTN(Gurson-Tvergaard-Needleman)损伤模型,采用有限元逆向法对3种材料漏斗试样单轴拉伸试验过程进行数值仿真,标定相应的GTN模型参数,获得了较好的结果。在此基础上将3种材料GTN模型参数用以模拟紧凑拉伸(Compact Tension,CT)试样的准静态裂纹扩展,基于载荷分离法实现了对26NiCrMoV11-5、A508-Ⅲ和304不锈钢3种材料J阻力曲线的良好预测。

Full-range constitutive relationship curves of 26 NiCrMoV11-5 steel for steam turbine rotors, stainless steel A508-Ⅲ and stainless steel 304 were obtained by the FAT（Finite-element-analysis Aided Testing） method using the ANSYS APDL technique. Based on the GTN（Gurson-Tvergaard-Needleman） damage model, reverse finite element method was adopted to simulate the uniaxial tension tests of funnel-shaped specimens by ABAQUS. By calibrating GTN model parameters for the three kinds of material, the simulated results were found consistent with experimental results. Subsequently, the calibrated GTN model parameters were used to simulate the ductile crack propagation behavior of compact tension（CT） specimens made of the said materials. Based on the normalization method, the J resistance curves of the three materials were successfully predicted, and were in good agreement with testing results.