Structural reliability assessment based on fourth moment standardization of performance function

In order to avoid the difficulties involved in searching the design point by iteration using the derivatives of the performance function, a principle shortcoming of reliability methods based on the first-order reliability method (FORM), an explicit fourth-moment reliability index, which is derived from the fourth-moment standardization of performance function, is presented and investigated in the present paper. The proposed formula is simple, and does not require integration or solve nonlinear equations, which are necessary in current used formulas. Through the investigations of the present paper, it is found that the third-moment method can be significantly improved by the proposed simple fourth moment reliability index and the fourth-moment reliability index has sufficient accuracy as a reliability index based on the fourth-moment standardization of performance function.