一种修正的基于临界平面多轴循环计数法

A Modified Multiaxial Cycle Counting Based on Critical Plane Methods

进行多轴随机载荷下的结构疲劳寿命分析时,需选择合适的循环计数方法提取损伤事件.结合疲劳寿命预测方法中的临界平面法,对Langlais多轴循环计数法进行了讨论,并在此基础上完成了对Langlais多轴循环计数法的修正.修正后的多轴循环计数法可以精确地考虑到1个主通道循环内辅助通道的全部载荷信息;同时发展了修正Langlais法新的实现方法,可以用于封闭曲面法计算有效载荷;对三点雨流计数法的循环计数起始点选择进行了改进,提高了循环计数效率.

A proper cycle counting method should be selected when predicting the fatigue life of engineering components under variable-amplitude and multiaxial random loading.Based on the critical plane method,the Langlais multiaxial rainflow counting algorithm was discussed.Then,a modified Langlais multiaxial rainflow algorithm was proposed and a realization method for modified Langlais multiaxial rainflow algorithm was developed.The modified Langlais multiaxial rainflow algorithm can accurately take into account all load information in the auxiliary channel,corresponding to a complete cycle in the counting channel.And it can be used for the enclosing surface method to calculate the effective stress or strain range.For a new cycle counting process of the 3-point rainflow method,the method of choosing the starting point was modified,which improved the efficiency of cycle counting.