Study on Multidimensional Structural Reliability Based on the Rotating Copula Model

ABSTRACT Throughout its service life, a bridge structure endures various coupled loads that affect its lifespan. In response to this, the paper proposes a reliability analysis method for bridge structures based on the Copula function. Initially, different types of Vine Copula models are constructed using the sequential relationship of nodes. Subsequently, the rotated copula functions are incorporated into the function candidate set. Furthermore, considering the differences in the correlation of multivariate variables, a multivariate joint probability density function is constructed based on the established model, and a corresponding reliability method is proposed in conjunction with the first‐order second‐moment method. Finally, the accuracy of the established function model and the efficiency and precision of the MCS calculation results were verified through a cantilever beam example. The effectiveness of this method was verified through numerical examples of the Fumin Bridge in Tianjin. The results showed that compared with the MCS method, the computational efficiency of the new model was improved by about 6000 times, and the average error was reduced by 0.4% compared to the commonly used C/D Vine model.