Parametric Experimental Study Of Variable Damping Viscous Dampers

Years of seismic practice shows that the seismic design of buildings is very effective in reducing the seismic damage of buildings.Structural shock absorption by viscous dampers is one of the most effective energy dissipation methods.Viscous damper is a common energy dissipating component.While viscous damper is widely used in energy dissipation projects,it also exposes a structural defect that It can’t achieve good energy dissipation performance in both large and small earthquakes.To solve the defect,Dr.Liang Shahe come up with a new variable damping viscous dampers with variable aperture damping bar structure.However,the wider application of the variable damping viscous dampers in engineering needs further experimental study and the establishment of its simulation unit in the finite element analysis software.The working performance and damping coefficient distribution of variable damping viscous damper is studied from two aspects of theoretical analysis and experimental research with the example of two-stage variable damping viscous damper.Base on the damping coefficient distribution rule obtained in experiment,a new material element,which can be used to simulate variable damping viscous dampers,is added in the OpenSees program.The revised OpenSees finite elemen program is used to analyze an energy dissipation example with variable damping viscous damper,which verifies the feasibility of engineering application of variable damping damper.The main concerns and conclusions are as follows:1.The theoretical formula of damping force of variable damping viscous damper is deduced and supplemented.The formula for calculating the damping coefficient in the case that the range of piston contains the varying aperture is supplemented on the basis of the piecewise formula for damping force proposed by Dr.Liang Shahe.2.The loading test of variable damping viscous damper is carried out to verified that the specimen can achieve the variable damping purpose with a good energy dissipation performance.Study on the influence law of the performance of variable damping viscous damper with taking several key structural parameters of damping bar as control variables.3.A new kind of OpenSees material element,which can be used to simulate variable damping viscous dampers,is established based on C++ language.Standard sinusoidal displacement wave loading is carried out on this new material element by matlab program.The comparison between simulated results and experimental results proves that the new material has a good simulation effect.4.An OpenSees program embedded in a new material element is used to analyze an energy dissipation example with variable damping viscous damper.And the analysis results show that the introduction of variable damping viscous dampers can significantly reduce the structure dynamic response under seismic action.And compared with conventional dampers,variable damping viscous dampers solve the contradiction between the demands of damper nonlinear and the flame shock absorption rate under the action of rare earthquake.