Stochastic Process-Based Structural Reliability Considering Correlation between Upcrossings

Structural reliability is a widely used tool to estimate the safety level and remaining service life of civil structures and infrastructure systems. Using a stochastic process to model the resistance or structural response, the structural failure can be treated as the probability of the structural response exceeding the resistance (upcrossing). It has been widely assumed that the occurrence of upcrossings is independent, and thus a Poisson process can be used to describe the sequence of upcrossings. This may lead to significant error in the estimate of structural reliability. This paper presents a new method for structural reliability assessment, where the correlation between upcrossings is taken into account. A closed-form solution is derived for structural reliability, which is beneficial for its application in practical engineering. An illustrative example is presented to demonstrate the applicability of the proposed approach. (c) 2020 American Society of Civil Engineers.