Design And Research Of Shear Thickening Fluid Damper

The liquid whose viscosity increases significantly with the increase of shear rate is called Shear Thickening Fluid(STF).When the external shear rate is large enough,the liquid can show solid-like properties.With the removal of the external force,the STF can quickly return to its initial state.Compared with traditional viscous materials,STF can change its viscosity with changes in the external loading environment,which has good adaptability.In this paper,STF is applied to the structure of the damper,and a new type of STF damper is designed.This paper studies STF damper through theory and experiment,and analyzes the effects of different parameters on its performance.The specific work of this paper includes the following aspects:1.In the aspect of theoretical research of STF damper,based on the theory of fluid mechanics and the viscosity characteristics of STF,the damping force theoretical formulas of the STF dampers of the gap type,the orifice type,and the combined type are derived.2.In the aspect of STF damper simulation analysis,according to the derived damping force theoretical formula,Matlab is used to numerically calculate the damping force of gap type and orifice type STF dampers.The study found that the damping force and energy dissipation capacity of STF damper increase with the increase of input frequency,amplitude and gap length,and the decrease of gap width,number of damping holes and diameter of damping holes.To understand the internal flow of STF damper in detail,the distribution of velocity and pressure,and the influence of parameters in the gap type damper model were analyzed by Fluent flow field calculation.3.In the aspect of STF damper performance test,nine kinds of STF dampers are designed.The periodic tension-compression test is carried out on the STF damper by fatigue testing machine,and the hysteresis curve of the damper is obtained.The effects of gap width,piston partition,piston thread and the number of holes on the performance of STF damper are analyzed.The results show that: with the increase of amplitude and frequency,the shape of the hysteresis curve of STF damper changes from rectangle to ellipse and then to bow,and the hysteresis curve has prominent asymmetric characteristics.The results show that the damping force and energy dissipation capacity of STF damper have good "adaptive" ability with the increase of loading frequency and loading amplitude;even if the vibration amplitude is tiny,STF damper can output larger damping force and has excellent energy dissipation characteristics;In this paper,based on the numerical analysis of damping force,the STF damper which can provide considerable damping force in small amplitude,is designed and manufactured,and the experimental test is carried out to verify its performance.The influencing factors of its performance are analyzed,which provides a valuable reference for the engineering application of the new STF damper.