载荷谱型对疲劳损伤分布的影响

疲劳累积损伤分布规律是结构疲劳可靠性分析与设计的关键内容之一。本文考察了疲劳外载荷谱的谱型对疲劳累积损伤分布的影响，定义了任意载荷谱的等效增强和载荷谱的形状因子，给出了一个分析疲劳累积损伤分布的模型，讨论了载荷谱型与疲劳累积损伤分布之间的关系。数值模拟结果表明：谱强度描述了疲劳累积损伤的均值，载荷谱的形状因子描述了疲劳累积损伤的变异系数。

Effect of Cyclic Load Type on Distribution of Fatigue Cumulative Damage

The fatigue damage cumulative rule plays a key role on the structure design against fatigue. The equivalent intensity and the shape fa ctor of a fatigue spectrum are defined, and a model is introduced to simulate the scatter caused by random load based on the local stress-strain approach. A numerical example is presented to demonstrate the simulation. The equivalent intensity mainly describes the mean value of the cumulativ e damage and shape factor mainly characterizes the scatter of the fatigue cumula tive damage. Numerical simulation shows that the intensity of the load spectrum indicates the mean of fatigue damage and the shape of the load spectrum describe s the deviation of the fatigue damage.