Abstract:

In order to consider the mean stress effects on the structural vibration fatigue life under cyclic loads,the paper proposed a method to revise the Tovo-Benasciutti  fatigue damage model. An approximate model between the mean stress correcting coefficient and the random stress band coefficient was built with radial basis function, and the Tovo-Benasciutti fatigue damage model was built under considering the mean stress effects. The fatigue life for a simple beam was estimated with Tovo-Benasciutti fatigue damage model under considering the mean stress effects, the results show that the Tovo-Benasciutti fatigue damage model under considering the mean stress effects can get a closer result to the test.

Key words: mean stress, radial basis function, approximate model, vibration fatigue, fatigue life prediction

摘要：

为了考虑平均应力对循环载荷作用下结构振动疲劳寿命的影响，对Tovo-Benasciutti疲劳损伤模型进行了平均应力修正。采用径向基函数法构造平均应力修正系数与随机应力带宽系数之间的近似模型,建立了考虑平均应力的Tovo-Benasciutti疲劳损伤模型。利用所建立的模型对某简单梁进行了疲劳寿命估计。结果表明：考虑平均应力效应的Tovo-Benasciutti模型能得到与试验更一致的结果。

关键词: 平均应力, 径向基函数, 近似模型, 振动疲劳, 疲劳寿命预测