大跨桥梁风洞试验模型模态耦合分析  

Modal Coupling Analysis of Long-span Bridge Model in Wind Tunnel Test

作　　者：许福友[1] 陈艾荣[2] 黄才良[1] 张哲[1] 

机构地区：[1]大连理工大学土木水利学院,辽宁大连116024 [2]同济大学桥梁工程系,上海200092

出　　处：《中国公路学报》2009年第3期58-63,共6页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(50708012);教育部高等学校博士学科点新教师基金项目(20070141073);辽宁省博士启动基金项目(20081086)

摘　　要：根据苏通大桥、杭州湾大桥和苏拉马都大桥风洞试验节段模型和气弹模型的脉冲激励信号,首先采用随机子空间方法识别了各模型零风速时系统状态矩阵,分析了各自的固有模态耦合特点,然后识别了苏通大桥节段模型在不同风速时系统状态矩阵,在此基础上分析了模态耦合随风速的变化规律,最后详细研究了结构模态耦合发生的条件及耦合特点。结果表明:桥梁风洞试验模型模态刚度耦合强度低于阻尼耦合强度;对称系统模态耦合强度低于非对称系统强度;节段模型刚性系统模态耦合强度低于气弹模型柔性系统强度;两模态若为同相位,则模态刚度和阻尼耦合元素为正值;实桥也具有类似特点。According to the impulse excitation signals of sectional and aeroelastic models of wind tunnel test for Sutong Bridge, Hangzhou Gulf Bridge and Suramadu Bridge, using stochastic subspace algorithm, the intrinsic state matrices of all systems for windless conditions were identified. The different modal coupling characteristics of different models were analyzed. Moreover, the state matrices of Sutong Bridge sectional model for different wind velocities were identified. Based on it, the variation regularities of modal coupling versus wind velocity were comprehensively investigated. The condition and characteristic of structural modal coupling were elaborately studied. The analytical results reveal that the damping coupling intensities are comparatively higher than stiffness coupling intensities. The modal coupling intensities of symmetric systems are lower than those of asymmetric systems. The modal coupling intensities of sectional models are lower than those of aeroelastic models. If the phase is the same orientation, the coupling damping and stiffness elements are positive. The similar characteristics are applicable to real bridges.

关 键 词：桥梁工程 模态耦合 风洞试验 节段模型 气弹模型 非对称系统 

分 类 号：U446.1[建筑科学—桥梁与隧道工程] U448.27[交通运输工程—道路与铁道工程]