Reliability Analysis by Combining Higher-Order Unscented Transformation and Fourth-Moment Method

In this work, the fourth-moment method and the higher-order unscented transformation is combined to calculate the failure probability. The higher-order unscented transformation is used to efficiently estimate the first four moments of the limit-state function, and then the fourth-moment method is used to estimate the failure probability. Compared with the traditional first-order and second-order reliability methods, the proposed method is not required to find the design point, and it is also not required to calculate the derivatives. Compared with the three-point estimation method, the proposed method has a good accuracy and lower computational cost. The numerical and engineering examples show the accuracy and efficiency of the proposed method.