抄録
This paper is concerned with an importance sampling method combined with the conditional expectation in simulation-based structural reliability assessment with multi-failure modes of the load and resistance parameters. First, to reduce the number of the basic random variables, let the limit state function redefined by the expected value and variance of the original one and Some limit state functions contributed to the failure probability are choosed. Second, approximated optimal importance sampling marginal densities are expressed to be proportional with the value of the conditional failure probabilities and the original p.d.f.. Next, an importance sampling simulation is executed by using importance sampling densities above determined. The proposed method gives the accurate failure probability with shorter processing time.
