索承式人行悬索桥自振特性及弯扭耦合特征分析  

Analysis of Natural Vibration Characteristics and Bending-Torsional Coupling Characteristics of Cable-Supported Suspension Footbridges

作　　者：朱连任 李运生 曹杨[1,2] 侯忠明 Zhu Lianren;Li Yunsheng;Cao Yang;Hou Zhongming(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Key Laboratory for Health Monitoring and Control of Large Structures Hebei Province,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Central Research Institute of Building and Construction Co.Ltd.,MCC Group,Beijing 100088,China)

机构地区：[1]石家庄铁道大学土木工程学院,河北石家庄050043 [2]石家庄铁道大学、河北省大型结构健康诊断与控制重点实验室,河北石家庄050043 [3]中冶建筑研究总院有限公司,北京100088

出　　处：《石家庄铁道大学学报（自然科学版）》2023年第3期14-22,共9页Journal of Shijiazhuang Tiedao University(Natural Science Edition)

基　　金：国家自然科学基金(51778377);河北省大型结构健康诊断与控制重点实验室开放基金(KLLSHMC2112)。

摘　　要：为了研究索承式人行桥的自振特性及其弯扭耦合特征,以某实际工程为例,采用Midas软件建立了有限元模型,将各振型中横弯分量和扭转分量贡献度的比值定义为弯扭耦合系数β,分析了索承式人行桥振型模态的弯扭耦合特征,以及主缆矢跨比λc、抗风缆矢跨比λw和抗风缆倾角α对自振特性及弯扭耦合特征的影响。研究发现,竖弯振动不存在与其他振型分量的耦合,而横弯和扭转振型存在耦合,且随振动阶数增加,弯扭耦合系数β减小,振型由横弯为主逐渐过渡到以扭转为主;随主缆矢跨比λc减小,弯扭耦合振型频率增大,β减小;随抗风缆矢跨比λw的减小,以横弯为主的弯扭振型(β≥1)频率下降,以扭转为主的则略有增大;增大抗风缆倾角α会使桥梁整体横向刚度下降,但抗扭刚度增加。In order to study the natural vibration characteristics and bending-torsional coupling characteristics of cable-supported suspension footbridge,the FE model of a real bridge was built using Midas software.By defining the ratio of the contribution of lateral bending component to torsional component in each vibration mode as the bending-torsional coupling coefficientβ,the bending-torsional coupling vibration characteristics of cable-supported suspension footbridge were analyzed,and the influence of the ratio of rise to span of main cable,the ratio of rise to span of wind-resistant cable and the angle of wind-resistant cable on the natural vibration characteristics and bending-torsional coupling characteristics were investigated.The results show that there is no coupling between the vertical bending vibration and other vibration mode components,but the coupling exists between the lateral bending and torsional vibration modes.With the increase of vibration order,the bending-torsional coupling coefficientβdecreases,resulting in a model transition from lateral bending to torsion.As the rise span ratio of the main cable decreases,the bending-torsional coupling frequency increases whileβreduces.With the reduction of the rise/span ratio of the wind-resistant cable,the frequency drops for the bending-torsional mode dominated by lateral bending(β≥1),while increased slightly for that dominated by torsion.And increasing the angle of wind-resistant cable will reduce the overall lateral stiffness but increase the torsional rigidity of the bridge.

关 键 词：桥梁工程 人行悬索桥 索承式桥梁 自振特性 弯扭耦合 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]