随机荷载作用下钢构件的疲劳可靠度研究

Fatinue Reliability of Steel Member under Random Loading

本文利用裂纹扩展速率的Ｐａｒｉｓ公式，将应力变程Ｓ＿ｒ和材料参数Ｃ作为随机变量，应用概率的中心极限定理推导出在随机荷载作用下构件的裂纹长度和疲劳寿命的概率密度函数。并且将构件中含有的缺陷个数及长度作为随机变量考虑，导出了构件的疲劳可靠度函数。

Thepan’s formula for the rates of crack growth is used in this dissertation,and the stress range S_r and material parameter C are taken as the random variables.Based on such,the central limit theorem of probability is used to deduce the probability density function of crack length of he member and fatigue life under random loading.Considering the number of cracks in the member and the length of the initial cracks as random variables,then the fatigue reliability function of the member is deduced.