Study On The Stiffness And Damping Characteristics Of Annular Rubber-Silicone Oil Damper

Tail shaft drive system is an important part of helicopter transmission system,helicopter tail drive shaft consists of multi-stage thin-walled hollow shaft,with the characteristics of long transmission chain,many elastic supports and high rotational speed,and the bending vibration problem is prominent during high-speed operation.Annular rubber-silicone oil damper is installed between the bearing and the base,whicn can reduce the bending vibration of the tail drive shaft at high speed.In this study,the stiffness and damping characteristics of annular rubber-silicone oil damper were studied.The main research as follows:Firstly,the structure and damping mechanism of annular rubber-silicone oil damper were analyzed.The energy dissipation theory of rubber and oil was introduced;the performance of common rubber materials was analyzed,chosen the polyurethane rubber;the effects of temperature and pressure on several silicone oils were analyzed,selected the dimethyl silicone oil as the filling fluid.Secondly,the parameters of hyperelastic constitutive model and viscoelastic constitutive model of rubber material were determined.The uniaxial tensile testing of rubber samples was carried out,the influence of the pre-load times and the tensile speed on the uniaxial tensile test was analyzed;according to the uniaxial tensile test data,a variety of hyperelastic constitutive model parameters were obtained;the dynamic tensile test of rubber material was carried out,the data of shear modulus and loss modulus within 0 Hz to 70 Hz are obtained,the viscoelastic constitutive model parameters of rubber material were obtained by fitting the data of shear modulus and loss modulus.Thirdly,the static analysis of annular rubber-silicone oil damper is carried out.The finite element model of rubber and silicone oil was established respectively,the two-way FSI simulation of annular rubber-silicone oil damper was built;the static stiffness test of annular rubber-silicone oil shock absorber was carried out by the electro-hydraulic servo-controlled fatigue testing machine;comparing the static simulation with the static experiment,the Neo-Hookean hyperelastic constitutive model was selected.;the static characteristics of annular rubber-silicone oil damper and rubber damper were analyzed,the influence of rubber outer diameter,rubber inner diameter and viscosity of silicone oil on static stiffness of annular rubber-silicone oil damper was researched.Finally,the dynamic analysis of annular rubber-silicone oil damper was carried out.The dynamic simulation of annular rubber-silicone oil damper was carried out based on Neo-Hookean hyperelastic constitutive model and viscoelastic constitutive model;the dynamic stiffness and damping test of annular rubber-silicone oil damper was carried out by the electro-hydraulic servo-controlled fatigue testing machine;the dynamic characteristics of annular rubber-silicone oil damper and rubber damper were analyzed,the effects of frequency,amplitude and viscosity of silicone oil on the dynamic characteristics of annular rubber-silicone oil damper were analyzed by using the orthogonal method;...