Beyond Design Performance of Viscoelastic Dampers
Viscoelastic(VE)dampers have been widely applied in civil engineering for mitigating wind-induced vibration and seismic responses of building structures.However,their actual performance and damage under maximum considered shaking or greater earthquakes as well as their residual performance under aftershocks was rarely discussed before.In this study,firstly,for characterizing the fundamental mechanical behaviors of VE dampers,sinusoidal reversal tests with different combinations of excitation frequencies,ambient temperatures,and shear strain levels less than 300%were conducted.Accordingly,four coefficients of the fraction differential model considering ambient temperature,temperature rising,cyclic soften,and strain hardening effects can be determined.Secondly,VE dampers were tested with larger shear strain levels,i.e.480%,600%,720%,840%,and 960%in order,to realize their ultimate performance.Besides,in between each shear strain level,the performance test under 300%shear strain at an ambient temperature of 20oC was performed to further understand their residual performance after damage.The fraction differential model was also adopted for characterizing their post-damage behavior.Thirdly,VE dampers were tested subjected to seismic response histories,which can be numerically analyzed in an off-line manner.Similarly,the test results were also compared with the predictions by the fraction differential model.The visible damage of VE material occurred at about 600%shear strain.The stiffness and damping coefficient of VE dampers decrease proportionally with varying shear strain levels from 600%to 840%,and can remain at the constant value of half of the original values after 840%shear strain.Further,the force amplification at the first cycle turns more significant when subjected to a larger shear strain level.This effect should be considered very seriously for practical design of connections and structures.Either before or after damage,the predictions by the fraction differential model have a very good agreement with the test results.
Viscoelastic Damper Beyond Design Performance Dynamic Test Fraction Differential Model
S.J.Wang C.H.Yu I.C.Chiu K.C.Changc Y.W.Chang
Department of Civil and Construction Engineering,National Taiwan University of Science and Technolog Structural Control Division,National Center for Research on Earthquake Engineering,Taipei,Taiwan Department of Civil Engineering,National Taiwan University,Taipei,Taiwan 4Strong Motion Division,Nat Strong Motion Division,National Center for Research on Earthquake Engineering,Taipei,Taiwan
国际会议
The 7th World Conference on Structural Control and Monitoring(7WCSCM)(第七届结构控制与监测世界大会)
青岛
英文
3362-3371
2018-07-22（万方平台首次上网日期，不代表论文的发表时间）