Experimental And Simulation Study Of Third Generation Viscous Damper

This paper introduces the principle of energy dissipation of viscous dampers,and summarizes the research progress and development of viscous dampers at home and abroad.The third generation viscous dampers were used as the research object,combined with fluid dynamics calculations and related theories,using ICEM CFD modeling and meshing,and imported into the FLUENT software for numerical simulation.The dimethyl silicone oil was subjected to shear test to obtain the viscosity.The curve of shear stress with shear rate;verify the feasibility and accuracy of numerical simulation,study the influence of frequency and displacement amplitude on the viscous damper,and the pressure distribution and velocity of the flow field inside the damper.Streamline distribution.The results show that the pressure in the left and right chambers of the viscous dampers is basically constant,and the pressure in the gaps and holes is linearly changed.27 sets of viscous dampers with different parameters were designed.The energy dissipation performance of the viscous dampers was studied by using seven parameters of cylinder bore diameter,piston rod diameter,piston thickness,orifice diameter,gap size,number of orifices,and silicone oil viscosity.Influence and law.The results show that the inner diameter of the cylinder and the diameter of the piston rod affect the silicone oil volume of the inner cavity of the damper.When the piston speed is fixed,the larger the silicone oil capacity of the cavity,the greater the output and damping coefficient of the damper;the thickness of the piston affects the length of the orifice and the gap.The greater the piston thickness,the larger the damper output and damping coefficient;the diameter of the orifice,the number of orifices and the size of the gap affect the flow area of the silicone oil on the piston.When the piston speed is constant,the larger the flow area,the damper output and the damping coefficient.The smaller the orifice diameter and the number of orifices,the smaller the diameter of the orifice and the number of orifices.The smaller the damping coefficient,the smaller the influence on the damping coefficient.The larger the viscosity,the larger the damper output and the damping coefficient.The smaller the velocity index is..A cyclic loading test was performed on a comparative specimen of a traditional thirdgeneration viscous damper and an improved viscous damper.The basic mechanical properties of the viscous damper were compared and the effects of frequency and displacement amplitude on the viscous damper were examined.The pressure resistance of the improved viscous damper was compared.The influence of the triangular wave and sine wave on the viscous damper test was compared.The influence of temperature on its basic mechanical properties was studied,and the two dampers were examined for fatigue and earthquake in wind vibration.Based on the basic mechanical properties under fatigue loading,the influence of installation clearance on the performance of the damper was analyzed.The results show that the changes in amplitude and frequency of displacement are not essential factors affecting the output of the damper.The speed of the piston movement is the main factor in determining the output of the damper;the damper output and delay of the improved viscous damper at low speed The return energy consumption is superior to that of the traditional third-generation viscous dampers;the test speed should be as small as possible when testing the low-speed frictional resistance of the viscous dampers,and it is recommended to apply a velocity of ? 0.1 mm/s;the improved viscous dampers Good pressure resistance,good sealing performance;less displacement of the damper,installation gap has a greater impact on the energy consumption of the viscous damper,the lower the temperature of the silicone oil within the damper,the clearance is obvious;the damper in low temperature environment The output is increased compared with the normal temperature.The output of the damper under high temperature environment is lower than that at room temperature,but it is within 15%;the basic performance is unchanged after the wind-induced fatigue test of the improved viscous damper,and the third generation viscous damping After the wind-induced vibration fatigue test,the damper output decreased,the difference was within 7%,and the basic performance of the third generation viscous damper after the earthquake fatigue test decreased by about 30% compared with the initial performance.Into the type of viscous damper seismic fatigue test substantially the same performance.Basic performance tests and fatigue tests were conducted on the viscous dampers of the 144 Beijing New Airport Project.Through statistical analysis,it was found that the low-speed frictional resistance and ultimate displacement of 100% met the specification requirements.Combining HITEC,European Standard EN15129,Building Energy Damper,Building Energy Dissipation and Damping Technical Regulations,Bridge Viscous Fluid Damper,etc.,the viscous damper testing requirements were discussed and given Corresponding suggestions;at the same time,the damping coefficient and velocity index were discussed.The results show that: a viscous damper characteristic parameter determined through testing,as long as the viscous damper output is within ±15% of the theoretical output within a specified speed range,This damper can be said to meet the design requirements;the damping coefficient and velocity index are essentially complementary to the damping output,and there is no need to additionally satisfy the error of ±15% for the damping coefficient and velocity index.In order to prevent the viscous damper from energy accumulation under the long-term wind load,the internal temperature is too high due to lack of heat dissipation,and then the softness of the internal sealing device is damaged,and the power of the viscous damper for super high-rise wind vibration control needs to be checked.The method of calculating the demand power of the viscous dampers with the instantaneous power method and the average power method is compared.The test method based on the demand power equivalent principle of viscous dampers is proposed.The performance of the viscous dampers under different wind loads is given.Claim.Taking a super high-rise building as an example,the effect of herringbone support and toggle support on the wind vibration control effect and the demand power of the viscous damper are compared.The results show that the maximum instantaneous power is used as the demand power.Conservative,the average power considering the safety factor is relatively reasonable;the toggle support method can more effectively improve the wind vibration control effect of the viscous damper,and the required power of the corresponding viscous damper in the structure will also be greatly improved.