铝基合金支座的减振性能及其应用研究

发布时间：2018-05-23 08:20

本文选题：铝基合金支座 + 力学性能　；参考：《西南交通大学》2017年硕士论文

【摘要】：近年来,现代隔震技术已在全世界飞速发展,橡胶支座普遍应用于建筑结构和桥梁结构当中。橡胶支座能有效的吸收振动带来的能量,橡胶支座的研制和开发已受到全世界广泛的关注,但是由于橡胶材料阻尼较小,变形过大后难以复位,需要配合阻尼器共同使用,而铅芯橡胶支座虽然具有良好的隔震能力,但同时也是由于铅芯的存在使得支座的自恢复能力降低,并且铅芯的大量使用也会对自然环境造成严重的重金属污染。据研究发现,锌铝合金具有低的屈服应力、高的延展性和不易加工硬化的特性,是一种非常有潜力的耗能材料,但是,目前国内对铝基合金的力学性能以及减振性能的研究不多,特别是应用到实际结构中进行抗震的研究更少。本文根据铝基合金减振支座的特点,尝试将其应用于桥梁结构领域。论文首先对支座的力学模型进行了分析,然后通过有限元软件模拟对支座的力学性能和减振性能进行了数值分析和试验研究,最后将支座应用于桥梁结构中并分析其隔振效果,论文的主要研究方向和成果如下:(1)综述了减振与隔振结构体系的研究现状,主要包括减振与隔振结构的工作原理以及支座种类等,总结了国内外关于橡胶、合金支座在结构减振与隔振以及振动控制领域的研究进展和应用情况。根据合金的材性选择支座的力学模型,并给出模型参数的计算方法,其中重点介绍了本文所采用的锌铝合金材料的力学性能研究现状。(2)采用ANSYS有限元分析软件,模拟了几种铝基合金支座在不同载荷工况下的应力—应变关系,研究了支座受到剪切位移以及竖向压力共同作用下的刚度变化,建立了多组不同形状系数的锌铝合金支座,对他们进行低频段范围的定频激振模拟实验。结果表明,第一形状系数的增大能够提高支座的减振性能,同样的,第二形状系数的减小也能提高支座的减振性能。(3)设计激振试验,分析不同厚度的锌铝合金支座在低频段正弦载荷激振作用下的力传递率和加速度振级落差,并分析了支座在自身低阶固有频率正弦载荷激振作用下的减振性能,同时进行了激光扫频试验测试合金材料的阻尼比系数。试验结果表明,锌铝合金支座在1～25Hz激振频段的减振率在30%左右,且随着支座厚度的增加,支座减振率也呈上升趋势,锌铝合金材料的阻尼比系数为0.2左右。(4)将锌铝合金支座应用于桥梁结构进行隔震研究,考虑对比隔震与非隔震结构的地震响应特征,分析了两种工况下桥梁结构不同位置的加速度变化。结果显示将锌铝合金支座安装到桥梁结构中能有效延长结构的自振周期,能显著改变桥梁结构的动力特性,有很好的隔震效果。
[Abstract]:In recent years, modern isolation technology has developed rapidly all over the world. Rubber bearings are widely used in building structures and bridge structures. Rubber bearings can absorb the energy brought by vibration effectively. The research and development of rubber bearings have been paid more and more attention all over the world. However, due to the small damping of rubber materials, it is difficult to reset after the deformation is too large, so it is necessary to cooperate with dampers to use them together. Although lead-rubber bearing has good isolation ability, but also because of the existence of lead core, the self-recovery ability of the bearing is reduced, and the extensive use of lead core will also cause serious heavy metal pollution to the natural environment. It has been found that Zn-Al alloy is a potential energy-consuming material with low yield stress, high ductility and hard to work hardening. At present, there are few researches on the mechanical properties and vibration absorption properties of aluminum-base alloys, especially in the practical structures. According to the characteristics of aluminum base alloy bearing, this paper tries to apply it to the field of bridge structure. Firstly, the mechanical model of the bearing is analyzed, and then the mechanical performance and vibration absorption performance of the bearing are numerically analyzed and tested by the finite element software. Finally, the bearing is applied to the bridge structure and its vibration isolation effect is analyzed. The main research directions and results are as follows: (1) the research status of vibration absorption and vibration isolation structure system is summarized, including the working principle of vibration absorption and vibration isolation structure and the type of bearing, and so on, and the rubber at home and abroad is summarized. Research progress and application of alloy bearing in structure vibration absorption and vibration isolation and vibration control. According to the material properties of the alloy, the mechanical model of the bearing is selected, and the calculation method of the model parameters is given. The research status of the mechanical properties of the zinc-aluminum alloy material used in this paper is emphatically introduced. The ANSYS finite element analysis software is used. The stress-strain relationship of several Al-base alloy supports under different load conditions is simulated. The stiffness changes of the bearing subjected to shear displacement and vertical pressure are studied, and several groups of Zn-Al alloy bearing with different shape coefficients are established. They were simulated with constant frequency excitation in low frequency range. The results show that the increase of the first shape coefficient can improve the vibration absorption performance of the bearing. Similarly, the decrease of the second shape coefficient can also improve the vibration absorption performance of the bearing. This paper analyzes the force transfer rate and the difference of acceleration vibration level of Zn-Al alloy bearing with different thickness under the action of sinusoidal load in low frequency band, and analyzes the vibration absorption performance of the bearing under the action of its own low natural frequency sinusoidal load. At the same time, the damping ratio coefficient of the alloy was tested by laser scanning frequency test. The results show that the damping rate of Zn-Al alloy bearing is about 30% in the 1~25Hz frequency band, and the damping rate of the bearing increases with the increase of the thickness of the bearing. The damping ratio coefficient of Zn-Al alloy material is about 0.2.) the Zn-Al alloy bearing is applied to the isolation study of bridge structure, and the seismic response characteristics of the isolated and non-isolated structures are considered. The acceleration variation of bridge structure at different positions under two working conditions is analyzed. The results show that the Zn-Al alloy bearing can effectively prolong the natural vibration period of the bridge structure, can significantly change the dynamic characteristics of the bridge structure, and has a good isolation effect.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB535

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