Research of reliability of engineering structures has experienced a developing history for more than 90 years. However, the problem of how to resolve the global reliability of structural systems still remains open, especially the problem of the combinatorial explosion and the challenge of correlation between failure modes. Benefiting from the research of probability density evolution theory in recent years, the physics-based system reliability researches open a new way for bypassing this dilemma. The present paper introduces the theoretical foundation of probability density evolution method in view of a broad background, whereby a probability density evolution equation for probability dissipative system is deduced. In conjunction of physical equations and structural failure criteria, a general engineering reliability analysis frame is then presented. For illustrative purposes, several cases are studied which prove the value of the proposed engineering reliability analysis method.

工程结构可靠性研究经历了90多年的发展历史。然而，如何解决结构系统整体可靠性的问题仍然悬而未决，特别是组合爆炸问题和失效模式之间的相关性挑战。得益于近年来概率密度演化理论的研究，基于物理的系统可靠性研究为绕开这一难题开辟了一条新途径。本文从广阔的背景出发，介绍了概率密度演化方法的理论基础，推导了概率耗散系统的概率密度演化方程。结合物理方程式和结构破坏准则，然后提出了通用的工程可靠性分析框架。为了说明的目的，研究了几种情况，这些情况证明了所提出的工程可靠性分析方法的价值。