改进TCD算法的疲劳寿命预测研究

Research on Prediction of Fatigue Life Based on Improved TCD Algorithm

在实际工程领域中,零件的疲劳破坏给工程界带来了难以计量的损失。所谓疲劳,是指零件在承受远低于其屈服极限的循环载荷时突然失效的情况。疲劳问题一直受到广泛关注,关键距离法(TCD算法)最初由Taylor等人提出,该理论将试件缺口附近区域某点,线上的应力特征值作为疲劳失效判断准则。拟选用疲劳试验机对45#钢缺口试样在四种应力级下进行疲劳试验,对45#钢缺口试样的疲劳性能进行了试验研究。同时运用了传统TCD算法以及改进TCD算法对45#钢缺口试样的疲劳寿命进行了预测,与实验结果进行比较,改进的TCD算法相对于传统TCD算法获得的预测结果更令人满意。从而为工程上缺口构件的疲劳寿命预测提供了理论计算方法。

In the field of practical engineering,the fatigue damage of the part has brought an immeasurable loss to the user,which means that the part suddenly fails when it receives a cyclic load well below its yield limit. Fatigue problems have always been the attention of mechanical design engineers.The critical distance method(TCD algorithm)was first proposed by Taylor et al. This theory uses the stress eigenvalues at a point or line in the vicinity of the notch as the criterion for fatigue failure.In this paper,the fatigue test was carried out on the 45# steel specimen under the four stress levels,and the fatigue performance of the 45# steel specimen was studied. At the same time,the traditional TCD algorithm and the improved TCD algorithm are used to predict the fatigue life of the 45# steel notch specimen. Compared with the experimental results,the improved TCD algorithm is more satisfactory than the traditional TCD algorithm.So as to provide a theoretical calculation method for fatigue life prediction of engineering components.