摘要
阻尼作为桥梁的固有属性,可以显著减小桥梁的动力响应,从而提高行车的安全性和舒适性。然而,为方便求解移动车辆下的空间桥梁动力学方程,通常会忽略桥梁阻尼的影响。因此,以单轴双自由度车辆通过单箱单室空间薄壁箱梁为例,推导了考虑薄壁箱梁阻尼影响下车-桥耦合振动解析解。依据该解析解验证了利用车辆响应或轮胎-桥梁接触点响应识别桥梁扭转-弯曲耦合频率与竖向弯曲频率的可行性。此外,桥梁截面的单对称轴形式使得其质心与剪切中心不重合,导致桥梁横向与扭转运动耦合,而竖向运动相对独立。考虑桥梁双向阻尼特性,即允许为竖向运动和横向-扭转运动分配不同的阻尼比。同时,基于横截面刚性假设推导了车辆的摇摆和竖向接触响应,实现了桥梁扭转-弯曲频率和竖向频率的分离,并通过残余接触点响应技术消除了路面粗糙度的影响。研究结果表明:(1)通过摇摆和竖向接触响应可分别识别桥梁的前几阶扭转-弯曲耦合频率和竖向频率;(2)竖向和扭转-弯曲方向的阻尼比只影响自身方向频率的可见性,尤其是高阶频率;(3)残余接触响应技术表现出一定的鲁棒性,即在较差的路面状态下仍表现出较好的识别效果;(4)实际工程应用时,建议检测车以10 m·s^(-1)(36 km·h^(-1))的速度运行。
As an inherent attribute of bridges,damping can greatly reduce the induced dynamic responses and can further improve the safety and comfort of driving.However,the effect of bridge damping is often ignored when solving the dynamic equations of space bridges under moving vehicle conditions.For this reason,the analytical solution for the vehicle-bridge interaction vibration was derived by considering the effects of the beam's damping using the example of a single-axle vehicle passing over a thin-wall box girder.The feasibility of identifying the torsional-flexural frequencies and vertical frequencies was verified using the analytical solution and the vehicle or vehicle-bridge contact responses.Additionally,the characteristic of the bridge's monosymmetric cross-section caused the center of mass and shear center to be offset,thus implying that its lateral and torsional movements were coupled,while the vertical motion was relatively independent.Additionally,the bidirectional damping characteristics that allow the assignment of various damping ratios for vertical and transverse-torsional motions were considered.Meanwhile,the rocking and vertical contact responses of the vehicle were derived based on the cross-sectional rigidity hypothesis,which realized that the torsional-flexural frequencies and vertical frequencies of the thin-walled beam were separated.The negative influences of road roughness in the effort to retrieve the bridge frequencies were eliminated by using residual contact response technology.The results show that:(1)The first several torsional-flexural and vertical frequencies of the thin-walled beam can be respectively identified by the rocking and vertical contact responses;(2)The damping ratios of vertical and torsional-flexural directions only affect the visibility of their directional frequencies,especially higher-order frequencies;(3)The residual contact response technology yields a good performance in identifying the beam frequencies,even under poor pavement conditions;(4)A running speed of 10 m·s^
作者
莫向前
杨永斌
史康
高丝雨
耿波
袁佩
郑植
MO Xiang-qian;YANG Yong-bin;SHI Kang;GAO Si-yu;GENG Bo;YUAN Pei;ZHENG Zhi(National Engineering and Research Center for Mountainous Highways,Chongqing 400067,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China;China Merchants Chongqing Transportation Research and Design Institute,Chongqing 400067,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2024年第8期1-16,共16页
China Journal of Highway and Transport
基金
国家自然科学基金项目(52378131,52008060)
国家山区公路工程技术研究中心开放基金项目(GSGZJ-2022-03)
重庆市自然科学基金项目(CSTB2022NSCQ-MSX1448,CSTB2022NSCQ-MSX1658)
重庆市留创计划项目(cx2022014)
贵州省科技计划项目(黔科合支撑[2022]一般026)
关键词
桥梁工程
薄壁梁
解析解
车桥耦合
阻尼
bridge engineering
thin-walled beam
analytical solution
vehicle-bridge interaction
damping
