基于损伤等效的多轴疲劳试验谱编制研究

针对多轴载荷下多危险点单轴应力破坏模式,以损伤等效为基础,提出了一种多轴载荷下的疲劳试验载荷谱编制方法.该方法首先对最危险点处的应力应变历程进行雨流计数,对得到的应力应变循环按幅值进行分组统计,再根据损伤等效原则对各组进行循环载荷搜索,最后将各组搜索到的包含一定次数的循环载荷按顺序连接起来,即为疲劳试验谱.试验结果分析表明,该方法定量地保证了试验载荷谱与原载荷谱的疲劳损伤一致,操作简单可行. 

Research on multi-axial fatigue test loading spectrum formation based on damage equivalent principle

A new method based on damage equivalent principle was developed for multi-axial fatigue test loading spectrum formation.It could be applied to uniaxial stress destroying mode with several dangerous positions under multi-axial loading.Firstly,the stain histories of the initial crack position were decomposed into a series of simple individual cycles by the rain-flow counting algorithm.And these cycles were divided into several groups by the stain amplitude,then all the combinations of multi-axial loading cycles were searched according to the damage equivalent principle,and several constant multi-axial loading cycles were found.After these constant cycles were linked,the fatigue test loading spectrum was presented,with the damage equivalent to the origin loading spectrum.According to the test of simple structure,the method can assure the equivalent damage of the test spectrum and the origin spectrum,and the operation is simple and feasible.