Study Onmechanical Properties Of A Novel Three-dimensional Isolation Bearing

Earthquake is a kind of multi-dimensional random vibration.It not only has three orthogonal translational components in horizontal and vertical directions,but also has torsional and swaying rotational components.Therefore,the multi-dimensional nature of ground motion should be taken into consideration in structural design,and different structures are different.Seismic design of different seismic components with different structures.However,only the horizontal base isolation technology is widely used in the actual engineering technology at present,and the seismic isolation technology for vertical and rotational components is not yet mature.Aiming at the problems in the field of vertical seismic isolation,this paper presents a new type of three-dimensional seismic isolation bearing,which has both horizontal and vertical seismic isolation performance and can effectively solve the vertical isolation problem.The main research contents and achievements of the paper are as follows:1.This paper analyzes the characteristics of the traditional disc springs and improves the shortcomings of the traditional disc springs.It proposes a vertical isolation bearing composed of improved disc springs.The horizontal rubber isolation support and the vertical isolation device are combined in series through the support conversion platform to form a three-dimensional seismic isolation device with three-way appropriate stiffness and damping performance.The three-dimensional seismic isolation device can not only reduce the influence of the horizontal direction ground motion on the building structure,but also reduce the influence of vertical ground motion on the building structure,and is easy to install and simple in construction.2.In this paper,the performance of the disc spring model under vertical load is studied by AB AQUS and obtains curves of Kv and F-Disp.The effects ofD?Do?d?h?t?fy and materials on stiffness and limit performance of disc springs are systematically studied.The following conclusions are obtained through analysis:The vertical stiffness of the disc springs decreases with increasing D/d,D/t,and h0/t ratios,respectively.In the analysis of the ultimate bearing capacity of the disc spring finite element,compared with the traditional spring steel and Q345 steel,the titanium alloy has a large vertical ultimate bearing capacity and a small vertical stiffness,which is very large Research value in the vertical isolation bearing.Referring to the approximate calculation method of American Alman and Lazro,the relevant formulas of the modified disc spring were theoretically deduced,and the stress calculation formula,stiffness formula and load calculation formula were obtained.3 The intention of this paper is to research the mechanical properties relationship between the three-dimensional isolation bearing and the two-dimensional isolation bearing.Tests about the horizontal and vertical mechanical properties of the LNR,the disc spring vertical isolation bearing and the 3D isolation bearing were carried out respectively.Analyses were conducted on the relationship of the mechanical properties between the 2D isolation bearings and the 3D isolation bearings under independent conditions.Test results show that the vertical stiffness of the disc spring vertical isolation bearing varies linearly with the increase of compressive stress.And the frequency has little effect on the vertical stiffness of that at low frequencies.The horizontal stiffness of the 3D isolation bearing is slightly lower than that of LNR in the independent state.The effect of LNR on the overall vertical stiffness of 3D isolation bearings is not significant.4.In this paper,the parameters of the 3D isolation device are redesigned based on the seismic isolation structure in the actual project,and the 3D seismic response analysis is performed by etabs to compare the acceleration response and displacement response of different isolation structures under 3D seismic action.The results show that 3D seismic isolation structure has a longer period than horizontal isolation structure and non-isolation period.The displacement angle between the three-dimensional isolation bearings is larger than that under the horizontal isolation structure,but is smaller than that under non-isolation conditions and meets the requirements of the building isolation.Relative to non-isolated structures and horizontally isolated structures,the vertical interlayer acceleration peaks of three-dimensional seismic isolation structures are significantly reduced,indicating that the vertical damping effect is significant and the vertical isolation period is extended.The bearing displacement of the three-dimensional seismic isolation structure is obvious,but it is still in the limit range of finite element simulation and theoretical calculation,indicating that the disc spring meets the design requirements.The horizontal displacement of the horizontally isolated structure is not significantly different from that of the three-dimensional seismic isolation structure,indicating that the vertical isolation device has an effect on the horizontal isolation performance,but this effect is insignificant.