Practical Diagrammatical Technique for 3-DOF Bridge Flutter Analysis

Abstract

For long bridges with bluff deck sections, the influence of lateral wind loads on flutter performance needs to be carefully investigated. In this paper, an advanced three-degree-of-freedom (3-DOF) analytical framework considering lateral aeroelastic effects is developed to refine bridge flutter analysis. This approach uses high-order nonlinear equations to determine twin critical flutter parameters, i.e., velocity and frequency. An optimization model to determine the critical flutter parameters is developed. A practical diagrammatical technique is proposed to solve this problem, which is an improvement over the traditional optimization techniques. The intuitiveness and effectiveness of the diagrammatical technique is fully verified using a numerical example. The optimization model and diagrammatical technique are applied to the 3-DOF flutter analyses of two bridges with bluff deck sections. It is revealed that the flutter derivatives