针对复杂结构疲劳寿命预测中S-N特性多样性导致疲劳寿命预测偏差较大的问题,提出了基于几何相似性的复杂结构疲劳寿命预测方法。该方法将复杂结构中的常用缺口结构分为标准结构和衍生结构,从缺口结构疲劳强度影响因素出发提出基于疲劳特性的结构几何相似性判断准则及相似度计算方法,结合匹配标准结构疲劳特性与相似度修正衍生结构S-N关系曲线。该方法在永磁同步无齿轮曳引机机座疲劳寿命预测中得到了应用验证,预测结果与实际失效吻合度较高。
Based on the problem that bigger deviation could be caused by the diversity of S-N characteristics in the fatigue life prediction of complex structure,the method for predicting the fatigue life of complex structure wais proposed based on the geometric similarity.This method classifies the commonly used gap structures with the complex structures into standard structures and derived structures.Starting from the influence factors of the gap structure fatigue,the judging criterion for structure geometric similarity and similarity degree calculating method based on the fatigue properties was proposed by combining the fatigue property of the matched standard structure with S-N relationship curve of the similarity correcting derived structure.This method has been applied and proved in the fatigue life prediction of the permanent magnet gearless synchronous traction machine base,and the predicted result highly coincides with the actual failure.