Seismic Design Method Of Viscous Damper Base On Additional Damping Ratio Control And Method Of Regulating Damping Scheme

With the urgent need for improved seismic performance of building structures,energy dissipation technologies have been widely studied by scholars and applied in practical engineering.Viscous dampers provide additional damping without adding stiffness,offering advantages that other devices cannot match.When viscous dampers are applied in practical engineering,it is necessary to determine earthquake-resistant and cost-effective vibration reduction schemes through the use of design methods and control strategies specific to viscous dampers.However,the design methods and control strategies employed for viscous dampers in engineering are primarily based on empirical approaches,with limited theoretical foundations and a high level of subjectivity in the resulting damping schemes.Based on these considerations,this paper presents the following research work:(1)Five different viscous damper vibration reduction schemes are set up using a three-story,three-span reinforced concrete frame model as the test specimen,and shaking table tests are conducted on each scheme.The structural dynamic responses of the models corresponding to each damping scheme are obtained,and the impact of various damping parameters on the structural dynamic responses is analyzed.(2)Due to limitations in the shaking table model and measurement methods,the data obtained from the shaking table tests are relatively limited.Therefore,numerical simulation methods are employed to further investigate the influence of planar layout,mechanical parameters,and the number of dampers on the structural dynamic responses.Based on the research findings,different damping schemes are formulated,and the structures are analyzed using numerical simulation methods.(3)A virtual model for additional damping ratio is defined,theoretical assumptions are proposed,and theoretical derivations are conducted to develop a seismic design method of viscous damper.The impact rules of various damping parameters on the structural dynamic responses are summarized,and a method for adjusting the vibration reduction scheme is proposed.The research results of this paper demonstrate the following:(1)After conducting shaking table tests on the five damping schemes,it is found that increasing the number of viscous dampers enhances their ability to control the displacement and acceleration of the structure.When the number of dampers on the second floor increases from 2 to 6,the reduction rate of lateral displacement on the second floor is 35.62%,and the reduction rate of acceleration is 54.18%.The dampers exhibit better control over acceleration than lateral displacement.When the total damping coefficient of the floors remains the same,increasing the number of dampers on the second floor from 2 to 4 achieves a lateral displacement reduction rate of 5.01%and an acceleration reduction rate of 7.94%.(2)The influence of planar layout on the structural dynamic responses is investigated through numerical simulations.The installation of viscous dampers at different planar positions results in variations in their energy dissipation capacity.The difference between the optimal and worst additional damping ratios is 11.87%.When the column size on which the viscous dampers are installed is larger,the beam span is longer,and the beam size is smaller,the energy dissipation capacity of the viscous dampers installed in that sub-frame is stronger.(3)Investigating the influence of the number and mechanical parameters of viscous dampers on the dynamic response of structures through numerical simulations.Increasing the number of viscous dampers effectively enhances the energy dissipation capacity and control capability of dynamic response.Increasing the number of viscous dampers can improve the additional damping ratio of the model,with an optimum value of up to 7.93%.Increasing the damping coefficient of the viscous dampers effectively controls the displacement response of the structure,but there exists an optimal relationship between the damping coefficient and the additional damping ratio.When the total damping coefficient of the viscous dampers arranged on each floor of the model is 3200 k N/(m/s)~α,the peak value of the additional damping ratio reaches 8.56%.(4)Validating the proposed energy dissipation and seismic control design methods through a practical case.The designed model using the design method exhibits a maximum displacement angle of 1/427 under the design seismic demand,satisfying the code limitations.The additional damping ratio is measured to be 3.47%,which is close to the expected seismic control target.