Three-Dimensional Seismic Isolation Bearing And Application In Lattice Shell Structure

ABSTRACT:In this thesis, the research about a new type of three dimensional seismic isolation bearing(3DGZ) is done on the basis of the design, the determination method of the key parameters and basic performance research of the3DGZ. The effect of friction on the bearing is investigated and numerical simulation method of disc spring that is used to be vertical isolation in3DGZ is studied. As the same time, A long span structure with3DGZ is analyzed by ANSYS FEM in order to explore the isolation property of the bearing. The research results are as follows:(1) The three dimensional seismic isolation bearing has a certain capacity of energy dissipation that is dependent on the friction between Teflon plan and corrosion resistant plate, and the friction within parts of the bearing. What is the impact of friction on the bearing and how much is the influence? the bearing is simulated by ANSYS finite element simulation technology, then parametric analysis about friction is done in order to quantify the friction influence. At last, the impact of two friction types on the bearing is clear:the friction between Teflon plan and corrosion resistant plate is greater influence on horizontal hysteretic characteristic and local stress, and the effect of the friction within some bearing parts is very small and could be ignored.(2) The disc spring components are used to be vertical isolation in the three dimensional seismic isolation bearing, it mainly relies on test when the performance of the disc spring is studied, numerical simulation method should be explored and applied to get rid of dependence on test. Static loading test and dynamic loading test for disc spring components are simulated by ANSYS, then the data of numerical simulation is compared with test data. The result show that finite element calculation agree well with test result. It explains that finite element method of studying the performance of disc spring is effective in certain extent and could reduce dependence on test in some cases.(3) The seismic isolation property of3DGZ is studied. A large lattice shell structure is taken as an example in which finite element model is created by ANSYS FEM, and static and dynamic characteristics are analyzed before seismic isolation. Then the isolation bearing for latticed shell structure is applied to create the appropriate isolated structure. Time history analysis for the original non-isolated structure and seismic isolated structure is done and compare node acceleration and axis force of bars and so on. The result shows that:node acceleration and axis force can be reduced by20%～50%under7degree rare earthquake and also be reduced by40%～70%under8degree rare earthquake, the reaction force of the bearings decreases much too, Therefore the3DGZ with good seismic isolation performance in the lattice shell structure, which could protect the structure from damage.