Study On 3D Base Isolator For Free-Standing Equipments

In the earthquake disaster, important Free-Standing Equipments, precision instruments, as well as precious cultural relics and so on, are vulnerable to be damaged, their questions on Anti-seismic and seismic- relieving are the important issues in the field of disaster prevention and reduction. Due to important Free-Standing Equipments, precision instruments, as well as precious cultural relics and so on, such as the general quality of light is different from the great quality of engineering structures such as buildings. How to control the vibration isolation devices in three main directions of stiffness, damping, and other mechanical properties parameters is the key of the study. Three- dimensional isolation device for Free-Standing Equipments is expected to make the above-mentioned problems to be resolved, that has important theoretical and engineering significance.This paper creatively put forward design theory that can solve the horizontal and vertical seismic isolation of the new components-- - Three-dimensional disc spring sliding friction bearings, base on the intensive study of structural characteristics of horizontal isolation devices, vertical vibration isolation devices, dampers and so on.Through theoretical research, numerical simulation, as well as with other similar technologies to reduce isolation of comparative analysis ,show that the three- dimensional bearing is not only with easy stable performance and compact system, easy to manufacture as well, but also it can achieve an effective, economic, and security, so it has good prospect .First of all, the paper studies the analyzing process of three- dimensional isolation system, using finite element method. Then, basing on the intensive studying to the characteristics of three-dimensional isolated structure, some of the rationalization of simplification and assumptions is done for the upper part of its structure and isolation layer, establishes a vibration model of computing. And then According to the three-dimensional wooden pagoda isolation system in the National Palace Museum, for example, conduct a comprehensive analysis of the effect of reducing isolation. Numerical analysis results show,after the measures in isolation are proposed, the three-dimensional wooden pagoda isolation system of horizontal acceleration can be controlled ground acceleration of the input level of 25% or less, three-dimensional isolation system of vertical acceleration can be controlled ground acceleration of the input level of 50% or less. This paper also carry out anti-isolated structure overturning stability analysis, it shows that the overall structure of the anti- overturning stability and structural stability of the local anti-overturning are well, the device can be effectively isolated to protect wooden pagoda safety in the rare event of seismic. At the last, select the different horizontal isolation bearings: lead-rubber bearings, Sliding friction bearings, the friction pendulum bearings, summed up their advantages and disadvantages, contrast to the effect of isolation bearings, it showed that sliding friction bearing is the most reasonable for the horizontal isolation bearing.The results show, the free-Standing precious cultural relics or precision instruments and equipment using three-dimensional mechanical isolation system having the right stiffness and damping parameters in this paper, will enable to avoid the shock of the Predominant period effectively after isolated the floating structure of the system, reduced greatly resonance phenomenon occurring in the three-dimensional ground motions, reduce effectively the seismic response, reach to the goal of protecting the seismic safety. The three-dimensional vibration isolation system can be used to all free-Standing Equipments to control by isolation with similar characteristics.