车辆对桥梁气动导数及风致振动的影响研究

发布时间：2018-04-25 20:12

本文选题：风-车-桥耦合振动 + 气动导数　；参考：《长沙理工大学》2014年硕士论文

【摘要】：随着我国经济的发展及社会对交通便利的更高要求,桥梁的设计和建造越来越多的朝着大跨度、轻柔化方向发展,更多的跨峡谷、跨江河及跨海大桥已经建成或正在建设当中。但是,跨度的增大和轻柔化就必须降低结构阻尼和刚度,这就造成桥梁对风的和车振效应更加敏感,因此研究车辆对桥梁风致振动的影响具有实用价值和理论意义。本课题以国家自然科学基金资助项目“风-车-桥风洞试验研究”为背景,在湖南大学风洞试验室进行车辆对桥梁风致振动影响的风洞试验研究,主要内容如下：1.为了考虑实际运营车辆对桥梁气动导数的影响,基于强迫振动装置,分别对不同交通流状态下的桥梁气动导数进行风洞试验研究,讨论了不同攻角下不同车流的车辆对桥梁气动导数的影响,探究了车辆对气动导数影响的百分比以及气动导数变化量的变化规律。研究结果表明：车辆对桥梁气动导数的影响不容忽略,不同攻角下不同车流的车辆对气动导数的影响程度及影响规律也不同。2.结构的涡激振动是风致振动中最常见的一种现象,通常在较低的风速下发生,且对结构气动外形的变化很敏感,车辆行驶在桥梁上势必会改变桥梁断面的外形。为了考虑实际运营中车辆对桥梁涡振的影响,基于自由悬挂节段模型试验系统,分别对不同交通流状态下车辆对桥梁涡振振动的影响进行风洞试验研究,分析讨论了其对桥梁涡振的影响及影响原因。研究结果表明,不同交通流下车辆对桥梁涡振振动有抑制作用,偏于安全考虑,实际桥梁的涡激振动试验可以不用考虑车辆的影响。3.采用测压法测试了不同车流下桥梁断面三分力系数随攻角的变化情况,研究了不同车流下车辆对三分力系数以及局部风压的影响。结果表明：在堵车情况下车辆对桥梁断面三分力影响最大,车辆引起桥梁阻力系数和升力矩系数显著减小,使升力系数增大.在车桥耦合风场作用下,桥梁顶面迎风侧压力值产生由正到负的剧烈幅值变化。
[Abstract]:With the development of China's economy and the higher requirements for the convenience of the traffic, the design and construction of bridges are becoming more and more long span, softening and softening, more cross canyons, cross river and sea crossing bridges have been built or are being built. However, the structural damping and stiffness must be reduced by the enlargement and softening of the span. The bridge is more sensitive to wind and vibration effect, so it is of practical value and theoretical significance to study the effect of vehicle on the wind induced vibration of bridge. This subject takes the wind car bridge wind tunnel test of the National Natural Science Foundation of National Natural Science Fund as the background, and carries out the wind effect on the wind induced vibration of the bridge in the wind tunnel test room of Hunan University. The main contents of the experiment are as follows: 1. in order to consider the effect of the actual operating vehicle on the aerodynamic derivative of the bridge, based on the forced vibration device, the wind tunnel test on the aerodynamic derivatives of the bridge under different traffic flow states is carried out, and the influence of the vehicle with different vehicle flow on the aerodynamic derivative of the bridge is discussed at different angle of attack, and the vehicle is explored. The results show that the influence of vehicles on the aerodynamic derivatives of bridges can not be ignored. The influence degree and the influence law of vehicles with different vehicle flow on the aerodynamic derivatives at different angle of attack are also different from the vortex excited vibration of.2. structure, which is the most common phenomenon in wind vibration. In order to consider the effect of vehicles on bridge vortex vibration in actual operation, the free suspension segment model test system is based on the free suspension segment model test system, which can be divided into the vibration vibration vibration of the bridge under different traffic flow conditions. The effect of dynamic wind tunnel test on the vortex vibration of bridge and its influence reasons are analyzed and discussed. The results show that the vibration of bridge vortex vibration is inhibited by different traffic flow, and it is partial to safety consideration. The actual bridge vortex vibration test can not take into account the effect of vehicle.3. pressure measurement method to test different traffic flow. The influence of the three force coefficient of the bridge section with the angle of attack on the three force coefficient and the local wind pressure under different traffic flow is studied. The results show that the vehicle has the greatest influence on the three force of the bridge section under the traffic jam, the drag coefficient and the lift torque coefficient of the bridge decrease significantly, and the lift coefficient is increased. In the bridge, the vehicle bridge is increased. Under the coupled wind field, the wind pressure on the top side of the bridge produces a dramatic amplitude change from positive to negative.

【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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