金属结构疲劳整体可靠性分析方法

New Method of Analyzing Fatigue Integrated Reliability of Metal Structure

实际工程中的大型金属结构往往是一个由多个构件组成的结构系统,对其构件进行疲劳可靠性分析应从整个系统角度考虑。用基本随机变量表达来自系统中各个构件的不确定因素,如材料、几何、载荷等;针对随机结构构件的疲劳可靠性问题,提出建立在改进的一次二阶矩法和有限元法基础上的估算方法;由于改进的一次二阶矩法求解构件疲劳可靠度时,功能函数不能表达为基本随机变量的显式函数,故采用数值方法和对有限元求偏导的方法,进而获得功能函数的偏导。

The large metal structure in practical engineering is always a structural system consisting of many structural components. So the fatigue reliability analysis of the structural component should be made in view of the whole system. The uncertainties of the components, such as material, geometry and load are expressed with basic random variables. An estimation method of the fatigue reliability analysis of the component of a structural system is proposed based on the improved firstorder secondmoment method (IFOSMM) and FEM (Finite Element Method). The performance function of the component′s fatigue reliability analysis is an implicit one of the basic random variables when using the IFOSMM. So the numerical method and the partial derivatives of FEM are applied to obtaining the partial derivatives of the performance function. 