煤矿机械

为解决挖掘机工作装置开裂问题，基于疲劳损伤演化机理对目标构件焊缝疲劳特性进行研究。通过静强度试验与疲劳试验获取构件疲劳性能参数；将构件有限元结果加权实测应变谱反求挖掘机等效载荷谱，确定挖掘机工作装置的疲劳应力谱；结合单位载荷作用下构件应力响应结果，与等效外载谱相乘，对挖掘机工作装置进行疲劳寿命分析。结果表明：动臂与斗杆疲劳计算寿命与台架真实寿命相对误差分别为16.5%、18%，验证了分析方法的准确性。

In order to solve the crack problem of excavator working device, the weld fatigue characteristics of target components were studied based on fatigue damage evolution mechanism. The fatigue performance parameters of components were obtained through static strength test and material fatigue test. The equivalent load spectrum of excavator was inversely calculated by weighting measured strain spectrum of the component finite element results, and the fatigue stress spectrum of the excavator working device was determined. Combined with the stress response results of components under unit load and multiplied by the equivalent external load spectrum, the fatigue life of the excavator working device was analyzed.The results show that relative errors between the calculated fatigue life of boom and arm are 16.5% and 18% respectively, which verifies the accuracy of the analysis method.