Development And Vibration Reduction Performance Study Of A New Rotation-magnified Viscoelastic Damper

The vibration control of civil engineering structure is an effective means to improve the seismic performance of the structure.The viscoelastic damper based on passive control is an efficient energy dissipation element,which is widely used in seismic design and reinforcement of buildings.The working principle of viscoelastic damper is to dissipate the energy input by external load into the structure through the shear deformation of viscoelastic materials,to ensure the safety of the structure.Beam-column joints of building structure are the core parts and weak links,which are vulnerable to damage under external loads,thus threatening the overall stability of the structure.However,under external load,the corner deformation at beam-column joints is generally small.The traditional joint damper is difficult to play an ideal energy dissipation effect.Based on this,a new rotation-magnified viscoelastic damper is studied in this paper.The leverage principle is used to magnify the relatively small rotation angle at the beam-column joint of a structure,thereby increasing the shear deformation and hysteretic energy dissipation of viscoelastic materials,and achieving a more ideal energy dissipation effect.In this paper,the test,theoretical model,and damping performance are researched.The main work includes:（1）Rubber materials are widely used in viscoelastic damper,and the mechanical properties of the material directly affect the energy dissipation and damping effect of the damper.The tensile strength and other quality indexes of high damping butyl rubber are explored through uniaxial tensile test and shear test.Plate rubber damper was fabricated using high damping butyl rubber as viscoelastic energy dissipation material.The cyclic loading tests of the damper under different working conditions were carried out.The hysteretic curves and the variation of mechanical properties with loading frequency and shear deformation were analyzed.The fatigue tests under different shear deformation amplitudes were carried out.The hysteresis performance of the damper was fitted by Maxwell model,and the simulation results were in good agreement with the test results,which verified the accuracy of the mechanical model.（2）Aiming at the failure mechanism of frame structure joints,the physical model of a new rotation-magnified viscoelastic damper is manufactured,and its basic structure and working principle are introduced.The frequency correlation,deformation correlation and fatigue tests were carried out.The hysteretic curve of the new damper is smooth,plump,and symmetrically stable.The variation of mechanical properties such as energy consumption per cycle under different working conditions was explored.At the same time,the mechanical properties of the new damper were compared with those of the traditional angle damper without amplification function under the same working condition,which confirmed that the new damper had better energy dissipation capacity.（3）According to the structural characteristic and test results of the new rotation-magnified viscoelastic damper and the traditional angle damper without amplification function,the mechanical models are proposed to numerically simulate two dampers.The hysteresis curves and mechanical performance indexes of numerical simulation and test results are compared.The results show that the hysteresis curves are in good agreement with each other,and the error of each mechanical performance index is small.The reliability of the mechanical model is verified,which lays a foundation for the study of damper damping performance.（4）In order to verify the damping control effect of the new rotation-magnified viscoelastic damper,the dynamic time history analysis of the steel frame structure installed with the new damper at the beam-column joint was carried out based on Open SEES software.The damping performance of the damper and the traditional angle damper without amplification function is quantitatively compared.The results show that the new damper has a better damping capacity.Then,the new damper layout schemes are compared and selected,and the influence of six different layout positions on the structural damping effect is analyzed.