摘要
断裂是镍钛合金(NiTi合金)材料和构件失效的重要原因之一。为了研究退火工艺对NiTi合金断裂力学行为的影响,采用二维数字图像相关(Digital Image Correlation,简称DIC)加载系统分别在室温(19℃)和高温(150℃)环境下对经不同退火温度处理的带张开型(I型)缺口的NiTi合金试件进行单轴拉伸实验。利用DIC测量了加载过程中裂纹尖端位移场数据,并将其带入裂尖位移方程,通过最小二乘法计算裂尖应力强度因子。结果表明:温度对NiTi形状记忆合金的应力强度因子和断裂行为有显著的影响,它能够改变裂缝尖端的相变行为和由此产生的应力应变分布情况,在室温和高温下NiTi合金断裂时的临界应力强度因子随退火温度的升高而增大,且高温下退火试件的临界应力强度因子高于室温下同组试件的相应值。
Fracture is one of the most important factors for the failure of NiTi alloy materials and components.In order to analyze the influence of annealing process on the fracture behavior of NiTi alloy,two-dimensional digital image correlation(DIC)loading system was used to carry out uniaxial tensile tests on NiTi alloy specimens with opening notch(Type I)under different annealing temperature treatment at room temperature(19℃)and higher temperature(150℃),respectively.The displacement field of crack tip during loading was measured by DIC.The data of displacement field was brought into the displacement equation of crack tip,and the stress intensity factor of crack tip was calculated by the least square method.The results demonstrate that temperature has a significant effect on the stress intensity factor and fracture behavior of NiTi shape memory alloy,which can change the transformation behavior of the crack tip and the resulting stress-strain distribution.Both of the critical stress intensity factor of the NiTi alloy at room temperature and at higer temperature increase with the rise of the annealing temperature,and the critical stress intensity factor of the annealed specimens at higher temperature is larger than that of the annealed specimens at room temperature.
作者
郝元灏
李艳杰
张昊
张晓川
杨佳
HAO Yuanhao;LI Yanjie;ZHANG Hao;ZHANG Xiaochuan;YANG Jia(School of Civil Engineering and Architecture,University of Jinan,Jinan 250022,Shangdong,China;Qilu Research Institute of Aerospace Information Research Institute,Chinese Academy of Sciences,Jinan 250132,Shangdong,China;School of Mechanical Engineering,Tianjin University of Commerce,Tianjin 300134,China)
出处
《实验力学》
CSCD
北大核心
2022年第2期243-252,共10页
Journal of Experimental Mechanics
基金
山东省高等学校科技计划项目(J16LJ12)资助。
关键词
NITI合金
数字图像相关法
断裂力学
应力强度因子
应力诱发马氏体相变
NiTi alloy
digital image correlation method
fracture mechanics
stress intensity factor
stress induced martensitic transformation
