预应力厚层橡胶三维隔震装置的力学性能分析

Analysis on mechanical properties of prestressed three-dimensional thick rubber seismic isolation device

基于厚层橡胶支座,通过增设预应力螺杆,设计了一种用于工程结构的新型三维隔震装置,构建力学模型,分析其在竖向荷载作用下的受力特点与刚度变化规律.采用ANSYS软件建立其有限元模型,对竖向压缩时装置的竖向刚度和螺杆内部应力分布进行定量研究,并观察装置在压剪时的变形形态.结果表明,该装置在竖直方向上具有两阶段刚度,第1阶段刚度大小可调,可达到第2阶段刚度的4倍以上.在发挥厚层橡胶支座自身三维隔震性能的同时,能够有效控制支座竖向变形.同时,该装置的特殊构造不会影响支座的水平隔震性能,可完全发挥出预期效果.

Based on a thick rubber bearing, a novel three-dimensional(3D) seismic isolation device for engineering structures was proposed by adding prestressed screws. The mechanical model was built. The mechanical characteristics and the stiffness variation law of the device under vertical loads were analyzed. Based on the software ANSYS, the finite element model was established to quantitatively study the vertical stiffness of the device and the internal stress distribution of the prestressed screws under compression, and the deformation of the device under combined compression and shear was observed. The results show that the device has a two-stage stiffness in the vertical direction. The stiffness at the first stage is adjustable and can reach more than 4 times that at the second stage. The device has the capacity of 3D seismic isolation of the thick rubber bearing and limits the vertical deformation of the bearing effectively. Besides, the special construction of the device does not affect the horizontal seismic isolation performance of thick rubber bearing, and the desired effects of the device are totally achieved as expected.