深切口椭圆柔性铰链疲劳寿命预测方法与模型

摘要

针对深切口椭圆柔性铰链疲劳失效难以准确预测的难题,提出了一种应力-寿命模型的方法.该方法首先采用有限元对柔性铰链进行结构与受力分析,发现缺口薄弱处的应力最大处易发生失效,并给出最大应力计算公式;然后建立应力-寿命模型,利用经验估算法获取柔性铰链材料的疲劳强度估计值;最后通过引入Marin方法来修正疲劳强度精度,进而获取寿命预测值.实例表明该方法可以为柔性铰链疲劳寿命预测提供一种新途径.%It is difficult to accurately predict the fatigue failure of elliptical flexure hinges with deep notch, a method of stress life model is proposed.In this method, the finite element method is used to analyze the structure and stress of the flexible hinge, and found that the maximum stress is easy to failure, and the maximum stress calculation formula is given;then, the stress life model is established, and the fatigue strength of the flexible hinge material is obtained by the method of empirical estimation;finally, the Marin method is introduced to modify the precision of fatigue strength, and then obtain the life prediction value.An example shows that the method can provide a new way to predict the fatigue life of flexure hinges.