一种新的体系可靠度的近似计算方法

提出了一种新的体系可靠度的近似计算方法.首先将一个线性失效模式在另一线性失效模式失效前提下的条件失效模式近似为一个等价的线性失效模式,然后利用条件概率的基本原理并结合所推导的等价失效模式的理论表达式,提出了一种并联体系可靠度的近似计算方法,从而将求解一组失效模式交集失效概率的复杂问题转化为求解一组线性等价失效模式失效概率乘积的简单问题.由于串联体系以及串并联混合体系均可表示为一系列失效模式交集的线性组合,因此方法可以很方便地应用于串联体系以及串并联混合体系的体系可靠度计算.此算法计算过程简单、计算量小、计算精度高,适合于大型结构体系的体系可靠度计算.

A NEW APPROXIMATE ALGORITHM FOR CALCULATION OF THE FAILURE PROBABILITY OF A SYSTEM

A new approximate algorithm for calculation of the failure probability of a system is presented. Firstly, an equivalent linear failure mode is introduced to approximate the conditional failure mode; Secondly, a new approximate algorithm for calculating the system reliability of parallel structures is obtained based on the principle of conditional probability and the theoretical expression of conditional failure mode. Thus, a complicated calculation of failure probability of a group of failure modes'intersection is simplified to the calculation of probability product of a group of equivalent linear failure modes. Because the serial system and the mixed system can be expressed as a linear superposition of a series of failure modes?intersection, the algorithm is suitable to the calculation of failure probability of the series and mixed systems. This algorithm is simple, effective and accurate. It is also adaptable to the reliability analysis of large structure systems.