Investigation On Mechanical Properties Of Viscous Dampers Based On Numerical Simulation

With the economic development,a variety of high-rise buildings,cross-sea bridge appear.In order to improve the seismic performance of these structures,there is a growing demand for isolation and energy dissipation of these structures in the industry.Viscous dampers,as a shock absorber(vibration)device,appeared in 1970 s.With the development of the past few decades,the mechanical properties of viscous dampers have become more and more perfect,and more and more structures have been applied.Viscous damper is a speed-dependent damper.It works through its piston rod movement which driven by the external structure vibration.It achieves the purpose of energy dissipation through the friction between the damping hole and internal viscous fluid.Its control of the structural vibration is a passive control,that is,no additional energy-driven.In this paper,finite element software FLUENT was used to simulate the viscous fluid dampers with different piston pore structures and different dynamic viscosities.The mechanical properties and their parameters were studied.The work carried out and the results achieved are as presented:(1)The numerical simulation of the prototype viscous dampers with mechanical performance test is carried out and compared with the experimental results.The feasibility and model of the viscous dampers are analyzed by FLUENT software.At the same time,the internal flow field characteristics are obtained through the flow field diagram.(2)Based on the finite element model of the damper,the influence of the structural parameters and the viscous fluid dynamic viscosity coefficient on the mechanical properties of the viscous dampers were studied by numerical simulation.The influence of the hole form on the mechanical properties of the damper is studied by numerical simulation of the viscous dampers in the form of various holes,holegap hybrid piston holes and thin-walled holes.The kinematic viscosity of silicone oil is the main influencing factor of viscous damper velocity index,and increasing the cross section area of piston can effectively reduce the velocity index.(3)The numerical simulation of the jet hole dampers is carried out to study the effect of the structural parameters of the jet or the viscous fluid dynamic viscosity coefficient on the mechanical properties.Increasing the size of the energy exchange chamber can effectively reduce the velocity index of the nozzle hole viscous damper.