系统可靠性预计的上（下）限法

An Upper (Lower) Bound Method for System Reliability Prediction

用文献［１］提出的上限计算法预计的系统可靠度的上限会单调收敛至一个小于精确值的错误数值，并使系统可靠度的单一预计值过于保守。本文提出一种计算系统可靠度上限的新方法，并给出了完全对偶的、实用的上下限计算公式。实例表明，对于任何非单纯串联的复杂系统，应用本文的公式均能保证使计算结果单调收敛至真值，并使系统可靠度的单一预计值具有较高的精度。

he upper bound of system reliability predicted by the upper bound method pres-ented in ref.[1]will monotonically converge to a wrong value which is less than the precise one,and the predicted single value of the system reliability will be too conservative.A new method for calcula-ting upper bounds of system reliability arid fully coupled practical calculation formulas for upper and lower bounds are presented in this paper.Examples show that for any complex system with non-sin-gle series,the application of the formulas given in this paper can make the calculated results monotonically converged to the true value,and the predicted single value of the system reliability of higher aecuracy.