Investigations of Finite Element Model for a Self-Anchored Suspension Bridge

Three finite element (FE) models were compared for a self-anchored suspension bridge in order to obtain the appropriate analysis model that provides the basis of long term monitoring and safety evaluation for the bridge. The shell element and two types of beam elements based on grillage method are used to simulate the steel box stiffening girder of the bridge. One of the beam elements is the element of Timoshenko beam that can consider not only the bending deflection but also shear deformation. The other is the element of Euler-Bernoulli beam that considers the bending deflection but neglects the shear deformation. Four measurement data of the equivalent stress on the bottom plate of the steel box are used to test the three finite element models. The calculating results of equivalent stresses on the bottom plates are compared among the three different finite element models under the dead load. The equivalent stresses obtained by using the shell element model at the four measurement points closes to the actual measurement data. The tensile stresses of suspenders are studied for the three different finite element models. The numerical results demonstrated that the shell element model is the appropriate model for simulating steel box stiffening girder of the self-anchored suspension bridge. The beam element model is not ideal for simulating the steel box girder.