摘要
为了研究中央稳定板的气动作用机理,首先采用三自由度耦合振动时域识别的强迫振动法,一次识别出桁架断面在有无中央稳定板时的18个气动导数,然后以识别的气动导数作为输入参数,利用自主研发的NACS软件对矮寨大桥进行了颤振分析;最后通过能量原理对中央稳定板的作用机理进行了证明。结果表明:中央稳定板对气动性能的影响主要体现在气动导数A2*降低了气动负阻尼;中央稳定板的作用机理是提高了颤振发生时竖弯自由度的参与程度和扭弯耦合程度,使得颤振形态由单自由度扭转振动向弯扭耦合振动转移,从而降低了颤振频率,提高了颤振临界风速。
In order to analyze the aerodynamic mechanism of central stabilizers,firstly,a data processing method for identification of the bridge aerodynamic derivatives in time domain was presented based on three degrees of freedom coupling forced vibration method and 18 aerodynamic derivatives were identified at truss-girder section with and without central stabilizer.Regarded identified aerodynamic derivatives as input parameters,a multimode-based flutter analysis for predicting the lowest critical flutter velocity of Aizhai Bridge was then carried out by using the software NACS.Aerodynamic mechanism of central stabilizer was verified by energy principle.The results show that influences of central stabilizer on aerodynamic property mainly incarnate that aerodynamic derivatives A＊2 decreases negative aerodynamic damping.The extent of mode coupling between vertical-bending mode and torsional mode increases when using the central stabilizers.It makes flutter mode shift from single degree of freedom torsional vibration to coupling vibration between vertical-bending mode and torsional mode so that flutter frequency is decreased and flutter critical wind velocity is increased.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2009年第6期53-59,共7页
China Journal of Highway and Transport
基金
国家自然科学基金重点项目(50738002)
关键词
桥梁工程
中央稳定板
强迫振动法
颤振稳定性
能量原理
bridge engineering central stabilizer forced vibration method flutter stability energy principle
