Research On Damping Performance And Application Of Aluminum Base Alloy Bearing

In recent years,modern isolation technology has been developing rapidly all over the world,rubber bearings are widely used in building structures and bridge structures.Rubber bearings can effectively absorb vibration energy,but the rubber bearings have a small damping,and it needs to cooperate with damper because it is difficult to reset after large deformation.The lead rubber bearing(LBR)has good isolation ability,however,the recovery ability of the bearing is reduce due to the lead core,in addition,the extensive use of the lead cores can also damage the environment.According to the research findings,Zn-Al alloy has the characteristics of low yield stress,high ductility and not easy to cold hardening,it is a potential dissipative material,however,at present,there are few researches on the mechanical properties and damping properties of aluminum alloy,the research on the seismic behavior of the actual structure is still less.This paper based on the characteristics of Aluminum Alloy Damping bearings,trying to apply it to bridge structure.Firstly,the mechanical model of bearing is analyzed,then,through finite element analysis and test,the mechanical property and the damping performance of the bearing are analyzed,finally,the bearing is applied to the bridge structure and the isolation effect is analyzed.The main research contents and results are as follows:(1)This paper introduces the research status of isolated structure system,it mainly includes the working principle of the isolation system and the types of bearings,the research progress in the field of vibration attenuation and vibration control is summarized,the mechanical model is selected by the physical properties of the alloy,then,the calculation method of model parameters is given.(2)The stress-strain relationship of several aluminum alloy bearings is simulated under different load conditions by using ANSYS finite element analysis software,the rigidity variation of the bearing subjected to shear displacement and vertical pressure is studied,several sets of Zn-Al alloy bearing with different shape coefficient are established and carry on the low-frequency vibration test.Results show that the increase of the first shape coefficient can improve the damping performance of the bearing,similarly,the reduction of the second shape coefficient can also improve the damping performance of the bearing.(3)Excitation test is designed to analyze the force transfer rate and the acceleration vibration level about the Zn-Al alloy bearing under the low frequency sinusoidal excitation with different thickness,and the damping performance of the bearing under the sine excitation of natural frequency is analyzed,at the same time,the damping coefficient of the material is measured by laser scanning test.Experimental results show that the damping rate of Zn-Al alloy bearing in 1?25Hz excitation frequency range is about 30%,with the increase of the thickness of the bearing,the bearing damping rate also showed an upward trend,and the damping coefficient of Zn-Al alloy is about 0.2.(4)Study on the application of Zn-Al alloy bearing in bridge structure,contrasting the seismic response characteristics of isolated and non isolated structures,the acceleration changes of different positions of bridge structures under two conditions are analyzed.Results show that the installation of Zn-Al alloy bearing in the bridge structure can effectively prolong the natural vibration period of the structure,it can significantly change the dynamic characteristics of bridge structure,Zn-Al alloy bearing has good isolation effect.