Static and dynamic analyses of a suspension bridge with three-dimensionally curved main cables using a continuum model

In this paper, a continuum model is proposed for static and dynamic analyses of a three-span suspension bridge with three-dimensionally curved main cables. To obtain equations of motion for this model, coupled differential equations are derived for vertical displacements of a main cable and a girder as well as lateral displacements of a main cable subjected to external loads. A compatibility equation of a three-dimensionally curved cable is also derived. Utilizing the Galerkin method, the equations of motion are obtained in matrix form. A case study bridge is used to verify the continuum model against a finite element model. Verification results show that, for distributed static loads on the girder and temperature changes in the main cable and the hangers and for dynamic moving loads on the girder, the continuum model can accurately determine static and dynamic responses, namely displacements, velocities, accelerations, bending moments, and shear forces of the girder and additional horizontal forces in the main cable.