论文部分内容阅读
为了对含多裂纹结构的可靠性进行评估，在疲劳多裂纹扩展随机模型的基础上，建立了含多裂纹结构的可靠性分析模型．结构的可靠度是控制裂纹扩展的多维随机变量落在等寿命曲面（线）与坐标面（轴）围起的范围内的概率，即多维随机变量的概率密度函数在等寿命曲面（线）与坐标面（轴）围起的范围内的积分．针对较为简单的情况，建立了完全积分可靠性模型；针对复杂结构但各条裂纹扩展特性相差不大的情况，建立了简化串联可靠性模型；针对复杂结构各条裂纹扩展特性相差较大的情况，建立了修正简化串联可靠性模型．考虑结构可靠性的粗略分析，给出了可靠度的上限值．结合多裂纹扩展随机模型给出了算例
In order to evaluate the reliability of multi-cracked structures, a reliability analysis model with multi-cracked structures was established based on the stochastic multi-crack fatigue propagation model. The structural reliability is the probability that the multidimensional random variable that controls crack propagation falls within the bounds of the isolitic surface (line) and the coordinate surface (axis), that is, the probability density function of the multidimensional random variable between equal life surfaces (lines) and Coordinate surface (axis) enclosed within the range of points. For the simpler case, a complete integral reliability model is established. For the complex structure but with little difference between the crack propagation characteristics, a simplified series reliability model is established. In the case that the crack propagation characteristics vary greatly in complicated structures , Established a modified simplified series reliability model. Considering the rough analysis of structural reliability, the upper limit of reliability is given. Combined with the multi-crack propagation model, an example is given