气动力矩阵和气动导数对桥梁颤振稳定性的影响

Influence of Aerodynamic Force Matrix and Aerodynamic Derivatives on Flutter Stability for Bridge

采用集中气动力矩阵和一致气动力矩阵2种不同形式的气动力矩阵,并利用4种不同截面的气动导数研究了气动力矩阵对颤振临界状态的影响;采用理想平板的气动导数研究了各气动导数对颤振临界状态的影响。结果表明:采用集中气动力矩阵可降低颤振临界风速,使结果偏于保守;各气动导数对量纲一的风速和颤振临界风速均有一定影响,而对颤振频率影响较小,从而进一步证实了采用流线型断面形式的桥梁,其颤振形态是弯扭耦合的经典颤振。

Two forms of aerodynamic force matrix, ie the lumped aerodynamic force matrix and the consistent aerodynamic force matrix were presented. The influence of aerodynamic force matrix on critical flutter state with aerodynamic derivatives of four different sections was studied. The influence of each aerodynamic derivative on critical flutter state using aerodynamic derivative of idealized zero-height plate was also studied. Results show that lumped aerodynamic force matrix can be used to decrease critical flutter speed and make it conservative; aerodynamic derivatives have influence on dimensionless wind speed and critical flutter speed to a certain extent, but have a little influence on flutter frequency. It approves that the streamline-deck bridge is prone to classical or binary flutter forming from the coalescence of bending and torsional modes.