多铅芯橡胶支座水平力学性能研究

Study on the horizontal mechanical properties of multi-core lead rubber bearings

当前多铅芯橡胶支座在我国建筑结构中应用正逐渐增多,但是其力学性能研究较少。文章首先利用压剪试验机对多铅芯橡胶支座进行水平单向压剪试验,分析其在单向压剪状态下的力学性能,然后以此试验样本为原型,利用ABAQUS建立多铅芯橡胶支座精细化有限元模型,进行水平双向压剪工况的数值模拟,以弥补试验条件的不足。经过对多铅芯橡胶支座在水平单向与水平双向压剪作用下的力学性能参数的对比,发现多铅芯橡胶支座在双向压剪状态时存在明显的双向耦合效应,单向作用的力学性能有不同程度的下降。最后通过改变一个加载方向的幅值和频率,来探究在双向加载时一个加载方向幅值与频率的改变对另外一个方向力学性能的影响。研究发现随着一个方向幅值和加载频率的增加,另外一个方向的大多数力学性能都有降低的趋势,有些力学性能的变化趋势会因加载函数的不同而呈现出不同的规律。这些特点的发现将有助于多铅芯橡胶支座的合理设计与布置,使其能更好地发挥减隔震的功效。

Nowadays, the application of multi-lead core rubber bearing is increasing gradually in China’s building structures. However, the studies of mechanical properties are less. The horizontal unidirectional compressive shear test of multi-lead core rubber support was carried out by using the compression shear test machine firstly, analyzed its unidirectional compressive mechanical properties under uniaxial compressive shear state. To make up for the lack of experimental conditions, a refined finite element model of multi-lead core rubber bearing was established by ABAQUS based on the test sample, had a numerical simulation in the condition of horizontal bidirectional compressive shear. Through the comparison of the mechanical properties of the multi-lead core rubber bearing under horizontal uniaxial and biaxial compression shear state, it is found that there is an obvious two-way coupling effect on the multi-lead core rubber bearing under bidirectional compressive shear, the mechanical properties of the composites were decreased in different degree compared with the one-way action. Finally, by changing the amplitude and frequency of the one loading direction, the influences of the amplitude and frequency of the loading direction on the mechanical properties of the other direction were investigated. It is found that with the increase of the amplitude and frequency of one direction, most of the mechanical properties in the other direction have a tendency to decrease, and the variation tendency of some mechanical properties will be different because of the different loading function. The discovery of these characteristics will be helpful to the reasonable design and layout of the multi-lead rubber bearings, so that they can play a better role in seismic isolation.