A nonlinear mechanical scheme to analyze suspension bridges under large deformation scenarios

Abstract

This paper proposes an enhanced mechanical model for analyzing the vertical deformation of suspension bridges under large structural deformation scenarios. The model can be superior to the traditional deflection theory by incorporating several factors frequently overlooked, including the horizontal displacement of the main cable, the elongation of the hanger, and the bending of the tower, and a two-step analysis strategy is proposed to integrate these factors into a comprehensive analysis approach. On this basis, a numerical solution based on the weighted residual method and a nonlinear adjustment algorithm is developed to solve the nonlinear model. The case study of a suspension bridge is presented to demonstrate the applicability and accuracy of the proposed method, and the results are compared with those obtained from the finite element method and the deflection theory, which confirm that the proposed method can produce more accurate results than the deflection theory, especially when the bridge deformation is large enough. The subsequent comparative analysis reveals that the horizontal deformation of the cable and the bending of the towers are the key points contributing to this improvement.