摘要
以某双主跨悬索桥为背景,进行了动力特性有限元分析和全桥气弹模型颤振风洞试验。分析了主要模态的自振频率、振型、等效质量和模态之间的相似关系;在风洞试验中测试了不同风攻角和风偏角下的颤振临界风速,并观测了颤振形态的演化规律;从结构模态出发,对颤振形态进行了分析和讨论。结果表明:在颤振临界风速下,桥梁结构由反对称扭转振动经两跨交替扭转振动,过渡到对称扭转振动发散;由于双主跨悬索桥不存在单跨半正弦波双跨对称的竖弯模态,传统的利用零风速时的多模态来描述和解释非分离流扭转颤振的方法无法应用于双主跨悬索桥;传统的需事先挑选模态的多模态颤振分析方法不能应用于双主跨悬索桥颤振数值分析。
Based on a suspension bridge with double main span,dynamic characteristics were calculated by finite element method（FEM）,and flutter stability of a full aeroelastic model was tested in wind tunnel.Similar relations of natural frequencies,mode shapes,equivalent masses and some main modes were analyzed.Flutter critical wind speeds under different wind attack angles and yawed angles were obtained in wind tunnel test.Evolution rule of flutter mode was also observed.Flutter modes were analyzed and discussed based on structural mode.The results show that under the flutter critical wind speed,model oscillation with first anti-symmetrical torsional mode transfers to alternative torsional oscillation between double spans,then transfers to oscillation with first symmetrical torsional mode,and violent oscillation happens at last.The symmetrical bending mode with semi-sine wave in single span dose not exist in suspension bridges with double main-span,so the flutter mode can＇t be described and explained with the modes at zero wind speed,and traditional multimode flutter analysis method which needs to choose modes in advance is invalid in suspension bridges with double main span.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2010年第4期58-62,共5页
China Journal of Highway and Transport
基金
国家自然科学基金重大研究计划重点支持项目(90715039)
国家西部交通建设科技项目(200631849426)
关键词
桥梁工程
双主跨悬索桥
风洞试验
动力特性
相似性
颤振
模态耦合
bridge engineering
suspension bridge with double main span
wind tunnel test
dynamic characteristic
similarity
flutter
modal coupling
