简支转连续连续梁桥车桥振动特性计算研究.docx

哈尔滨工业大学工学硕士学位论文
摘要
桥梁在车辆荷载作用下的振动,实质是桥梁和车辆两个动力系统的耦合振动。诸多的因素对车辆一桥梁系统的相互作用产生什么影响,桥梁不同截面的冲击系数之间的关系如何,用桥梁的基础频率度量冲击系数是否更为合理等等都是值得研究的问题。本文通过对简支转连续的连续梁桥一车辆相互作用问题的研究,试图从理论上探讨上述问题,为今后完善桥梁设计提供理论依据。
本文利用振型叠加法的思想,在利用现有通用有限元软件对桥梁结构模态分析的基础上,建立车桥耦合振动方程。推导了单自由度和七自由度两种车辆模型的振动方程,并且与桥梁振动方程耦合,建立耦合振动方程,最后
通过Matlab数学语言编制程序将计算方法实现。
本文对公路上常见的四种跨径的简支转连续连续箱梁桥进行了车桥耦合振动动力特性的对比分析。同时也详细对比分析了桥面铺装、截面尺寸和行驶车速的变化等对该类桥型的车桥振动动力特性的影响,得到影响该类桥车桥耦合振动性能的关键因素,并且提出设计建议。论文中通过算例与其它资料和试验数据的对比,验证了计算方法和所编程序的可靠性。
在车辆动荷载作用下,桥梁结构容易和行驶车辆产生共振,其产生的应力远远大于同样量值的静力荷载作用下的应力,引起结构局部疲劳损伤,或会形成影响桥面上行车舒适性和安全性的振动变形和加速度,甚至使桥梁结构完全破坏。因此对公路上日益增多的简支转连续连续梁桥的车桥耦合振动特性进行分析是非常必要的,具有重要的现实意义。
关键词车桥振动;模态分析;车辆振动模型;共振;振型叠加法
Abstraet
In essence,vibration of bridge exited by vehicle is coupled vibration of two dynamic systems of vehicle- is worthwhile to study such problems as the interactive effect in vehicle—bridge system due to the changes of some parameters,the relationship of impact factor among different cross—sections of bridges,the reasonableness to measure impact factor by means of the fundermental frequencies,and SO this discussion,the author attempts to discuss theoretically the problems mentioned above,.,to study the interactive effect in vehicle—bridge system for the sake of providing scientific bases for the modification of design for concrete simply supported--continuous bridge in
future.
In this discussion,the coupled equations of the vehicle—bridge system of simply supported--continuous bridge are built by the way of mode superposition method,and are based on the modal analysis of the structure.
In this discussion,the vibration equations of two kinds of vehicle modes are
built:the equations of a vehicle mode with one freedom and the equations of a
vehicle mode with seven the two vehicle modes’vehicle-bridge
coupled vibration equations are also last,this paper provide the analysis piled with Matlab to realize the analysis theory of vehicle。bridge system vibration,which bases on t