移动荷载列过桥共振状态分析

发布时间：2018-09-19 11:25

【摘要】：列车以不同速度通过桥梁时,其加载频率生变化,当此加载频率与桥梁的自振频率相同时,将引起强烈的振动,发生共振现象。随着我国铁路事业的快速发展,以及列车行驶速度的不断提升,车桥共振问题比以往更受人们的关注。本文采用简支梁在单个移动力,等间距移动荷载以及列车荷载作用下的竖向振动分析模型,推导出桥梁的振动响应解析解,通过振动响应分析,对桥梁以及车辆的共振问题进行了深入探讨,并对车桥系统竖向共振的影响因素做了进一步分析。主要的研究工作以及结论如下:1.推导了考虑阻尼条件下的移动荷载列过桥动力位移及加速度响应的解析解。分析了简支梁在移动荷载列作用下的两种共振反应以及引起桥梁共振的列车临界速度。2.以MATLAB为平台,编制了移动荷载过桥过程的动力仿真计算程序,对共振情况下桥梁竖向振动响应进行了分析,探讨了车桥共振过程中的放大机理。3.以典型高速铁路车辆和桥梁为研究基础,对车桥系统竖向共振影响因素进行了分析,分析结果表明:(1)当列车以桥梁跨径、车辆定距、转向架固定轴距为荷载间距时所计算的临界车速匀速行驶时,没有发生共振现象,却在以车辆长度为荷载间距时计算所得的临界车速下发生了共振反应,证明了列车长度是车桥共振的主要影响因素;(2)桥梁的阻尼可以有效的减小列车-桥梁系统的共振响应;(3)验证了长距离的等跨桥梁中加布少量不同跨度的梁的布置方案对车辆共振几乎没有影响。(4)桥梁的刚度直接影响桥梁的自振频率,随着桥梁刚度的提高,桥梁跨中的振动响应是逐渐减少的,且车桥的共振临界速度是逐渐提高的。因此在经济合理的范围内提高桥梁刚度,可以避免前几次主要的共振临界车速出现在正常营运速度内,且减少桥梁的竖向振动响应。
[Abstract]:When the train passes through the bridge at different speeds, the loading frequency changes. When the loading frequency is the same as the natural vibration frequency of the bridge, it will cause strong vibration and resonance phenomenon. With the rapid development of China's railway industry and the continuous improvement of train speed, the bridge resonance problem has attracted more attention than ever before. In this paper, the analytical solution of bridge vibration response is derived by using the vertical vibration analysis model of simply supported beam under single moving force, equal distance moving load and train load. The problem of bridge and vehicle resonance is discussed, and the factors influencing the vertical resonance of vehicle-bridge system are further analyzed. The main research work and conclusions are as follows: 1. The analytical solution of the dynamic displacement and acceleration response of a moving load train bridge with damping is derived. Two kinds of resonance responses of simply supported beam under moving load series and the critical speed of train caused by bridge resonance are analyzed. Based on MATLAB, a dynamic simulation program for bridge crossing with moving load is developed. The vertical vibration response of bridge under resonance is analyzed, and the amplification mechanism of vehicle-bridge resonance is discussed. Based on the research of typical high-speed railway vehicles and bridges, the factors affecting vertical resonance of vehicle-bridge system are analyzed. The results show that: (1) when the train spans the bridge, the vehicle is fixed. When the calculated critical speed of bogie with fixed wheelbase is load spacing, there is no resonance phenomenon, but the resonance reaction occurs at the critical speed calculated when the vehicle length is the load spacing. It is proved that the train length is the main factor affecting the bridge resonance, (2) the damping of the bridge can effectively reduce the resonance response of the train-bridge system, and (3) the arrangement of a small number of beams with different spans is verified in the long distance equal-span bridges. The scheme has little effect on the vehicle resonance. (4) the stiffness of the bridge directly affects the natural vibration frequency of the bridge. With the increase of bridge stiffness, the vibration response of bridge is gradually reduced, and the critical velocity of bridge resonance is gradually increased. Therefore, increasing the stiffness of the bridge within a reasonable economic range can avoid the occurrence of the main resonant critical speed in the normal operating speed and reduce the vertical vibration response of the bridge.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441.3;U211.3

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