混合自激力模型在桥梁风致抖振时域分析中的应用

Application of Hybrid Self-excited Force Model to Time-domain Analysis of Wind-caused Buffeting of Long-span Bridges

提出一种可应用于大跨度桥梁抖振时域分析的混合自激力模型 .其中直接自激力采用Y .K .Lin自激力模型 ,仅采用一个线性滤波器来模拟非定常自激气动力 ,耦合自激力由准定常气动力模型经完全泰勒展开获得 .当风洞试验不能给出完整气动导数试验数据特别是耦合气动导数时 ,采用本文中所提出的混合自激力模型是一个很好的选择 .最后以崖门大桥为例 ,采用本文方法进行计算 。

To deal with the problem that the all 18 aerodyna mi c derivatives, especially part of cross and lateral aerodynamic derivatives, can not be obtained from the wind tunnel experiment at present, a hybrid model of s elf-excited forces for the buffeting analysis of long-span bridges was present ed. In this model, the direct self-excited forces are obtained by Y.K.Lin's mo del and only a linear filter is used to simulate unsteady self-excited forces, while the cross self-excited forces are extracted from the quasi-steady aerody namic force model via Taylor expansion. It is a good choice to adopt the hybrid model proposed here when not all the aerodynamic derivatives, especially the cro ss aerodynamic derivatives, can be obtained from the wind tunnel experiment. At last, an illustrative example was given about the Yamen Bridge, which shows exce llent agreement between the calculated and experimental results of wind tunnel a dopting the aerodynamic elastic turbulence-field model for the whole bridge.