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一、前言最近,材料使用条件越来越恶劣,因而在结构设计上也都采用疲劳设计。材料的疲劳强度(时间寿命和疲劳极限)是离散的,设计时最重要的问题是确定包括可靠性概念在内的安全系数。过去,对疲劳强度的统计的离散度及其分布函数进行过研究,时间寿命按照对数正态分布,其离散度是应力越高越小,当接近疲劳极限时,则非常大。疲劳极限分布接近
First, the foreword Recently, the material conditions of use is getting worse, so in the structural design are also used fatigue design. The material’s fatigue strength (time-of-life and fatigue limit) is discrete and the most important design issue is to determine the safety factor including the concept of reliability. In the past, the statistical dispersion of fatigue strength and its distribution function have been studied. The time and life are logarithmically normal distribution. The dispersion is the higher the stress is, the smaller is it. When it approaches the fatigue limit, it is very large. The fatigue limit is close to the distribution