A Simple Third-Moment Reliability Index

Abstract

The third-moment (3M) method has been considered to be one of the most reliable methods for calculating structural reliability with high computing efficiency. This paper proposes a new 3M reliability index that has a wider applicable range and less limitation. Numerical experiments show that the accuracy of the proposed method is higher than that of existing methods. In particular, when existing 3M methods are out of their respective applicable ranges, the proposed method can still be used to evaluate the failure probability. Therefore, the proposed method is deemed more applicable for practical engineering.