摘要
为研究大跨度悬索桥在随机车流作用下加劲梁纵向运动及纵向累计位移行程简化计算方法,基于移动荷载作用下加劲梁纵向运动特征,将悬挂加劲梁体系等效为单自度(single-degree-of-freedom,SDOF)振动体系,推导了基于SDOF振动体系的移动荷载作用下悬索桥加劲梁纵向振动方程和随机车流作用下加劲梁纵向振动方程,提出了一种快速计算随机车流作用下加劲梁纵向振动响应的方法。以某单跨悬索桥为实例,基于实测车流数据,采用蒙特卡罗抽样方法生成随机车流样本,将其等效为SDOF体系下随机荷载时程,进行SDOF体系振动方程求解得到纵向响应位移时程,并与基于ANSYS的全桥模型瞬态分析结果进行对比。结果表明:随机车流作用下,加劲梁发生纵向运动并形成巨大累计位移行程,累计位移包括静态位移和动态位移,后者对累计位移贡献更大;与有限元瞬态动力分析相比,基于简化SDOF体系获得的位移响应结果中除累计位移差别稍大(约13%~19%)外,其幅值和均方根值(root mean square,RMS)均差别很小(小于5%),简化振动模型能反映随机车流下加劲梁纵向运动特征规律,所提计算方法可极大地简化随机车流作用下加劲梁纵向运动分析,可用于结构设计阶段随机车流作用下加劲梁纵向运动评估及振动控制参数优化。
A simplified method for calculating the longitudinal movement and cumulative displacement of the stiffening girder in long-span suspension bridges under random traffic flow is proposed.In this method,the suspended stiffening girder system is equivalent to a single-degree-of-freedom(SDOF)vibration system.Based on this SDOF system,the longitudinal vibration equations of the suspension bridge’s stiffening girder under moving loads and random traffic flow are derived.A rapid calculation method for the stiffening girder’s longitudinal vibration response under random traffic flow is proposed.Taking an example of a long-span suspension bridge and using existing traffic measurement data,random traffic flow samples are generated based on the Monte Carlo method.These samples are then treated as random loads on the SDOF system.The SDOF vibration equation is solved,and the results are compared with ANSYS dynamic analysis results.The findings reveal that under random traffic flow,the stiffening girder undergoes longitudinal movement and accumulates a significant displacement.This cumulative displacement consists of both static and dynamic components,with the latter contributing more significantly.Compared to the finite element transient dynamic analysis,the displacement response results obtained from the simplified SDOF system show minimal differences in extreme values and root mean square(RMS)values(less than 5%),although there is a slightly larger difference in cumulative displacement(approximately 13%~19%).This indicates that the simplified vibration model can capture the stiffening girder’s longitudinal movement characteristics under random traffic flow.The proposed simplified method greatly simplifies the analysis of the stiffening girder’s longitudinal movement under random traffic flow,enabling response evaluation and parameter optimization in the preliminary design stage.
作者
黄国平
胡建华
华旭刚
封周权
陈政清
HUANG Guoping;HU Jianhua;HUA Xugang;FENG Zhouquan;CHEN Zhengqing(Key Laboratory of Green Building and Intelligent Construction in Higher Educational Institutions of Hunan Province,Hunan City University,Yiyang 413000,China;Key Laboratory for Wind and Bridge Engineering of Hunan Province,Hunan University,Changsha 410082,China;Hunan Province Communications Planning,Survey and Design Institute,Changsha 410008,China;Hunan Engineering Research Center of Development and Application of Ceramsite Concrete Technology,Hunan City University,Yiyang 413000,China)
出处
《地震工程与工程振动》
北大核心
2025年第4期75-85,共11页
Earthquake Engineering and Engineering Dynamics
基金
国家自然科学基金项目(52178284)
湖南省教育厅科研项目(24A0566,24B0734,22A0558)
湖南省科技人才托举工程项目(2019TJ-Y08)
湖南省普通高等学校科技创新团队支持计划。
关键词
随机车流
悬索桥
加劲梁
纵向运动
简化模型
random traffic flow
suspension bridge
stiffening girder
longitudinal movement
equivalent simplified model
