On the first-order third-moment reliability method

In this article, the reliability evaluation with inclusion of random variable with unknown probability distribution will be discussed, in which the only information of the first three moments of the random variable will be used instead of probability distribution. The second-order polynomial normal transformation technique using the first three central moments is investigated and a pseudo standard normal space is defined based on the investigation. The first-order third-moment reliability analysis in the reduced space and that in the pseudo standard normal space are compared. Through the numerical examples presented, the proposed methods are found to be sufficiently accurate to include the random variables with unknown cumulative distribution functions in the first-order reliability analysis with little extra computational effort.