超弹性NiTi形状记忆合金断裂韧性的影响因素分析  

Analysis of Influence Factors on Fracture Toughness of Superelastic NiTi Shape Memory Alloy

作　　者：蒋钦贤 李建[1] 邱博[1] 阚前华[1] 康国政[1] JIANG Qinxian;LI Jian;QIU Bo;KAN Qianhua;KANG Guozheng(School of Mechanics and Engineering, Southwest Jiaotong University, Chengdu 610031, China)

机构地区：[1]西南交通大学力学与工程学院,成都610031

出　　处：《四川理工学院学报（自然科学版）》2019年第2期36-42,共7页Journal of Sichuan University of Science & Engineering(Natural Science Edition)

基　　金：国家自然科学基金(11572265);四川省杰出青年基金(2017JQ0019)

摘　　要：通过有限元软件ABAQUS的用户子程序UMAT开发了超弹性-塑性叠加的材料模型,合理预测了超弹性NiTi形状记忆合金的单调拉伸应力-应变曲线。进而对紧凑拉伸试样的断裂韧性进行了有限元分析,调查平面应变状态下不同材料参数对超弹性NiTi形状记忆合金断裂韧性的影响。分析结果表明,裂纹尖端马氏体相变区呈蝴蝶状且发生小范围马氏体塑性屈服;断裂韧性参数J积分随着马氏体相变开始应力的增加而增加;随着马氏体相变开始应力的提高,马氏体弹性模量、相变应变、马氏体塑性屈服应力对断裂韧性的影响不断弱化,且马氏体弹性模量的变化对断裂韧性影响最小;同时还发现,相变应变和马氏体塑性屈服应力对J积分的影响存在竞争机制。The superelastic-plastic superimposed material model is developed by using the user material subroutine UMAT of finite element software ABAQUS,and the monotonic tensile stress-strain curve is reasonably predicted. Further,the fracture toughness of the compact tensile specimen is analyzed by the finite element method. The effects of different material parameters on the fracture toughness of NiTi shape memory alloy under plane strain are investigated. The analysis results show that the stress-induced martensitic transformation zone at the crack tip is butterfly-like and a small range martensitic plastic yield occurs. The fracture toughness parameter J-integral increases with the increasing of martensitic transformation start stress. The effects of martensitic elastic modulus,transformation strain and martensitic plastic yield stress on the fracture toughness are weakened with the increasing martensitic transformation start stress,and the change of martensitic elastic modulus has a minimum influence on the fracture toughness. It is also found that the influence of transformation strain and martensitic plastic yield stress on the J-integral exhibits a competitive mechanism.

关 键 词：NITI形状记忆合金 超弹性 J积分 材料参数 有限元分析 

分 类 号：TB115[理学—数学]