A Time Variant Reliability Analysis Method Based on Stochastic Process Discretization

Abstract

Timevariant reliability problems caused by deterioration in material properties, dynamic load uncertainty, and other causes are widespread among practical engineering applications. This study proposes a novel timevariant reliability analysis method based on stochastic process discretization (TRPD), which provides an effective analytical tool for assessing design reliability over the whole lifecycle of a complex structure. Using time discretization, a stochastic process can be converted into random variables, thereby transforming a timevariant reliability problem into a conventional timeinvariant system reliability problem. By linearizing the limitstate function with the firstorder reliability method (FORM) and furthermore, introducing a new random variable, the converted system reliability problem can be efficiently solved. The TRPD avoids the calculation of outcrossing rates, which simplifies the process of solving timevariant reliability problems and produces high computational efficiency. Finally, three numerical examples are used to verify the effectiveness of this approach.