Nonlinear Aerostatic Response of Catwalk of Suspension Bridge

Abstract

In order to make the study of aerostatic response of suspension bridge catwalk more realistic, the FEA (Finite Element Analysis) model of the catwalk of Lishuihe grand suspension bridge was established based on the FEA software ANSYS. Based on the section model wind tunnel test for the aerostatic tri-component force of the catwalk and considering the geometric nonlinearity and aerostatic nonlinearity of the catwalk of the bridge, a program that can accurately calculate the aerostatic instability of the catwalk of the suspension bridge was established by combining the incremental, as well as internal and external iteration. The 3D nonlinear static wind instability analysis for the catwalk of the bridge was then performed. The research result indicates that (1) the lift force can cause the tension of the load-bearing rope in the catwalk to gradually relax and the torsional stiffness of the small span catwalk to decrease; and (2) the aerostatic torsional instability is caused by the decreased torsional stiffness not being sufficient to resist the aerial torque effect.