铅芯橡胶支座动力学特性及其在钢结构中减震应用研究

发布时间：2018-07-24 12:12

【摘要】：据资料显示,我国是地球上大陆地震最多的国家。在占全球7%的国土上发生了全球33%的地震。同时,进入21世纪后,我国经济发展迅速(尤其是高科技产业)。出于对精密仪器的考虑,对所处建筑结构抗震性能的要求越来越高。本文拟采用铅芯橡胶隔震支座,以速度、加速度为主要控制指标对结构的隔震效果进行探究。并将结果与国家的振动设备评定标准进行对比。结果发现,设置隔震支座后,能有效降低地震对仪器的破坏。在与支座厂家沟通过程中发现厂家所测定的支座等效刚度并没有严格遵循国家标准。另外发现,在叠层橡胶支座隔震技术规程中测定支座刚度所需位移加载的频率与国家标准是不同的。同时了解到不同厂家测定支座刚度,位移加载的频率也是不尽相同。本文在分析基础隔震结构减震效果和减震规律的同时探究了铅芯橡胶支座水平等效刚度试验中的水平位移加载频率对支座性能的影响。主要包括以下几方面的内容:(1)考虑结构地震响应下的最不利角度。对结构输入水平单向地震动,角度分别与Z轴(本文定义Y轴为竖向,X、Z轴为水平方向)成0°、15°、30°、45°、60°、75°和90°。在以结构顶点位移、层间位移和层间位移角为控制指标下寻找出文中所述七层钢框架在单向地震动输入下的最不利角度是90°。(2)控制铅芯橡胶支座的水平位移加载频率分别为0.1Hz、0.2Hz、0.3Hz、0.4Hz和0.5Hz。目的是探究水平位移加载频率对支座力学参数(等效水平刚度、支座耗能和等效阻尼比等)的影响。结果发现,在一定误差允许范围内,位移加载频率的改变对支座的等效水平刚度、支座耗能和支座的等效阻尼比影响极小。(3)探究文中所述钢框架结构设置隔震支座后的减震效果。结果发现,通过设置铅芯橡胶支座,可以有效降低结构各个楼层间的加速度和速度大小,进而可以降低对精密仪器的损害程度,达到了隔震的目的。(4)本文探究了在改变铅芯橡胶支座等效水平刚度的情况下对结构隔震效果的影响。结果发现,支座水平等效刚度的改变对结构的减震效果有较大的影响。随着支座水平等效刚度的增加,会导致结构楼层加速度和速度增大,不利于结构抗震。
[Abstract]:According to the data, China is the most earthquake country on the earth. There were 33 per cent of the world's earthquakes on 7 per cent of the world's territory. At the same time, after entering 21 st century, our country economy develops rapidly (especially high-tech industry). Due to the consideration of precision instruments, the seismic performance of the building structure is becoming more and more demanding. In this paper, the vibration isolation effect of the structure is studied by using lead rubber isolation bearing and velocity and acceleration as the main control index. The results are compared with the national vibration equipment evaluation standard. The results show that the seismic damage to the instrument can be effectively reduced by setting the isolation support. In the process of communicating with the pedestal manufacturer, it is found that the equivalent stiffness of the pedestal measured by the manufacturer is not strictly in accordance with the national standard. It is also found that the frequency of displacement loading required for determining the stiffness of the bearing in the technical specification for isolation of laminated rubber bearings is different from that of the national standard. At the same time, it is found that the frequency of displacement loading is different when measuring support stiffness by different manufacturers. In this paper, the effect of horizontal displacement loading frequency on the performance of lead-rubber bearing is studied in the experiment of horizontal equivalent stiffness of lead-rubber bearing. The main contents are as follows: (1) considering the most unfavorable angle of structural seismic response. For the horizontal unidirectional ground motion of the structure, the angle of the input horizontal ground motion is 0 掳15 掳15 掳30 掳30 掳45 掳60 掳60 掳75 掳and 90 掳respectively with the Z axis (which is defined in this paper as the horizontal direction of the Y axis). Under the control index of structural vertex displacement, interstory displacement and interstory displacement angle, it is found that the most disadvantageous angle of the seven-story steel frame under unidirectional ground motion input is 90 掳. (2) the horizontal displacement loading frequency of the control lead rubber bearing is 0.1 Hz 0.2HzN 0.3Hz and 0.5Hz respectively. The aim of this paper is to investigate the effect of the loading frequency of horizontal displacement on the mechanical parameters (equivalent horizontal stiffness, support energy consumption and equivalent damping ratio). The results show that the equivalent horizontal stiffness of the bearing is affected by the change of the displacement loading frequency within a certain range of errors. The effect of energy dissipation and the equivalent damping ratio of the bearing is minimal. (3) the effect of the isolation bearing on the steel frame structure is discussed in this paper. The results show that the acceleration and velocity between each floor of the structure can be reduced effectively by setting the lead rubber bearing, and the damage degree to the precision instrument can be reduced. The aim of isolation is achieved. (4) the effect of changing the equivalent horizontal stiffness of lead-rubber bearing on the isolation effect of the structure is studied in this paper. It is found that the change of the horizontal equivalent stiffness of the bearing has a great influence on the seismic absorption effect of the structure. With the increase of the horizontal equivalent stiffness of the support, the acceleration and velocity of the structure floor will increase, which is not conducive to the seismic resistance of the structure.
【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】：TU391;TU352.1

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