“…To solve the first passage problem in time-variant reliability analysis involving stationary random processes, Singh et al [49] developed an importance sampling approach to calculate the cumulative probability of failure. Recently, some researchers have utilized metamodeling techniques [50][51][52] to alleviate the computational burden of time-variant reliability analysis. With the consideration of parametric uncertainty, Hu et al [53] construct surrogate models for evaluating the timeinstantaneous reliability index, and then identify the time-instantaneous most probable points using the fast integration method.…”