Dynamic Loading Test And Seismic Reduction Performance Analysis Of New Viscous Damping Outrigger Truss System

Among many damping technologies for super high-rise frame-core tube structures,viscous damping outrigger truss has been widely used in recent years because it can better meet the needs of buildings.The viscous damping outrigger truss is usually installed on the equipment layer or refuge layer of the structure,and the location and number of damping layers will be limited,which will affect the damping effect of the viscous damping outrigger truss on the structure.In addition,as the height of the structure increases is located in a high seismic intensity region,the use of viscous damping outriggers often needs to increase the damping coefficient or set up multiple damping outriggers to meet the design requirements of seismic reduction.In order to improve the energy consumption efficiency of the viscous damper,Based on the research of the viscous damping outrigger and building space,a viscous damping outrigger truss displacement amplification system based on the principle of lever is proposed(new viscous damping outrigger truss for short).The article taked a super high-rise frame-core tube structure as an example,designed and manufactured traditional viscous damping outrigger truss frame structure and new viscous damping outrigger truss frame structure specimens,and carried out dynamic cyclic loading test.The numerical simulation analysis method was used to study the shock absorption performance of the new viscous damped outrigger truss in super high-rise structure,and the parameters(damper parameters and leverage ratio)that affect its energy consumption efficiency were analyzed.The main research contents:(1)The structure and displacement magnification factor of the new viscous damping outrigger system were described,and the formula for calculating the displacement amplification coefficient and energy dissipation capacity of the viscous damper was derived.Taking a super high-rise prototype structure as the research object,the feasibility of a new type of viscous damping outrigger truss super high-rise structure was initially discussed;selecting the shock-absorbing layer in the model and using a 1:4 reduction ratio to design and fabricate a traditional viscous damping outrigger truss frame structure and a new viscous damping outrigger truss frame structure specimen;according to the characteristics of the velocity type viscous damper,a dynamic cyclic loading system of the test piece was developed to test its dynamic hysteretic performance.(2)The traditional viscous damping outrigger truss and new viscous damping outrigger truss specimens were subjected to dynamic cyclic loading tests under different displacement amplitudes and load frequencies.The load-displacement curve and hysteresis curve of two viscous damping outrigger truss specimens under different displacements and frequencies were analyzed;by analyzing the variation law of the energy dissipation ratio of the two viscous damping outrigger truss specimens and viscous dampers under different displacements and frequencies,it was verified that the T-shaped lever device can increase the energy consumption of the damper;compared with the traditional viscous damping outrigger truss,the change of the damper amplification effect of the lever device under different working conditions was analyzed,including positive and negative displacement amplification and damper positive and negative output amplification.The results showed: the new viscous damping outrigger truss could amplify the relative displacement of the two ends of the damper and enhance the damping force generated by it,the amplification factor changed with displacement and frequency.(3)Through the ETABS and PERFORM-3D finite element software,the super high-rise structural models of traditional viscous damping outrigger truss and new viscous damping outrigger truss were established,the seismic performance of the new viscous damping outrigger truss structure under different earthquakes was studied.The results showed that the super high-rise structure with the new viscous damping outrigger truss had better damping effect,the new viscous damping outrigger truss can achieve higher energy consumption efficiency by increasing the working displacement of the viscous damper,the ratio of the energy consumption and displacement amplification factor of the damper of the traditional viscous damping outrigger truss was approximately equal to the leverage ratio.(4)Researched on the main parameters(damping coefficient and damping index)that affect the energy consumption efficiency of the new viscous damping outriggers,analyzed the structure’s overturning moment reduction,inter-layer shear reduction,inter-layer displacement angle reduction,additional damping ratio reduction and the working law of viscous dampers to determine the optimal damping coefficient and damping index interval.The results showed that with the increase of the leverage ratio,the new viscous damping outrigger truss structure could reduce the damping coefficient to a large extent to meet the design requirements of shock absorption,the optimal damping coefficient could be converted by the optimal damping coefficient of the viscous damping outrigger structure;the smaller the damping index,the better the damping effect achieved by the structure,it was recommended that the damping index be 0.2 to 0.4.