Simulation Analysis And Performance Study On Viscous Dampers

The development of China’s economy and its architectural engineering technology has stimulated the prosperity of large buildings and bridges.In order to protect buildings from damages caused by earthquake and gale,a number of shock absorbers and seismic isolation devices,including metal damper,lock-up device,friction damper,viscous damper etc.,have been invented to improve buildings’ seismic resistance property.Viscous damper mentioned in this paper refers to the buffering and damping device installed between bridge span and pier.When viscous damper receives strong external disturbance,its piston moves along,and the energy generated by damping medium through contraction and friction in damping pore or gap to buffer.Viscous dampers are extensively applied in bridge construction and other architecture engineering industries.However,the changing rule and control method of its damping coefficient and velocity index remain to be studied further.This paper makes preliminary study on the performance of viscous damper on basis of experiments,and then focuses on further study with methods of simulation and optimized simulation.The contents are summarized as below:(1)In accordance to the structure and energy-consumption principle of viscous damper,the paper derives to the damping force formula for double-bar pore and gap damper,so as to lay out foundation for further analysis.(2)The paper use energy dissipation test machine under the condition of different silicon oil viscosity;on the gap damper and combined damper with different structure parameters by using vibration table under the condition of different silicon oil viscosity.After the experiment data is collected and the result is analyzed,the factors that affects velocity index and damping coefficient are discussed.(3)The paper describes modeling and simulation analysis by using hydrodynamics simulation software called Fluent and with viscous damper as reference.Adjustment and optimization for the simulation have been conducted by making comparison between simulation results and experiment results and taking consideration of the difference between the actual condition and ideal simulation status on experiment.In the end,a high level of accuracy has been attained with the error between simulation results and experiment results within 5%.(4)On the basis of simulation,the paper studies on the effect of the piston head length and the gap size on the performance of gap viscous damper,especially the effect on velocity index and damping index.Meanwhile,the effect of combination of the pore length and circulation area on the performance of pore viscous damper is also discussed in the paper.