缺口根部残余应变与疲劳循环次数相关性

为了探索疲劳寿命与材料损伤之间的相关性,研究疲劳寿命的预测方法,对缺口根部的残余应变与疲劳循环次数的相关性进行了实验研究.对带缺口GH4169材料拉伸试件进行了疲劳试验,实验中按一定的疲劳循环周次在零载荷状态下停机,并采集试件表面上的白光散斑图;应用数字散斑相关技术测量缺口附近的残余位移场,求出缺口根部的残余应变,得到缺口根部残余应变与疲劳循环次数的相关性曲线,获得了一些对于研究GH4169材料的疲劳寿命很有意义的重要结果.

Correlation of residual strain at notch root and fatigue life cycle

To search for the correlation of the fatigue life and the material damage and study forecasting of fatigue life,experimental studies on correlation of residual strain at notch root and fatigue life cycle were carried out.The fatigue tests were carried out on the notched tensile specimen made of GH4169.During the experiment,fatigue-loading was paused after a given fatigue cycle and white-light speckle patterns were acquired without loading.The residual displacement fields near the notch were measured by digital speckle correlation technique,the residual train at notch root was calculated and the correlation curves of the residual strain at notch root vs fatigue life cycles were obtained.Some important results were obtained which are significance for researching the fatigue life of GH4169.