Research On Vibration Characteristic Of Airspring Suspension For Automotive Seat

Researches show that vibration has a great extent influence on the heatlth of the humanbody. As to driver,which commonly work and run in worse environment,bears takingvibration of high strength and low frequency for a long time. To research the vibrationcharacteristics of truck driver seat suspension system, this dissertation analyses the verticalcharacteristics of air spring with non-linear finite element theory, meanwhile, some test andsimulation work were done basic on abaqus.At the same time, based on MATLAB/Simulinkmodule, a mechanical model of single degree of freedom was established to analyze thevibration characteristics in two respects of time domain and frequency domain. Summarizethe full text, the contents of this dissertation are:1.The basic theory of finite element and finite element analyzing software ABAQUS usedin this study was briefly introduced. And then the material nonlinearity, geometry nonlinearity,contact nonlinearity and the air-structure coupling characteristic of air spring were analyzed,the necessary of induction of finite element method is represented. A detailed modelbuildingprocess was introduced from several aspects, such as rubber model and material parameter,the rate of change of the rebar geometry peculiarities in the course of working and hegas-solid coupling between the gas elements and the rubber elements.2.Based on GB/T13061-1991, the static vertical characteristics experiments were finished,what’s more, the results proved that the finite element simulation model is correct by makinga comparison between the experiment results and simulation results. According to thesimulation model, sensitivity analysis of air spring structure parameters(initial inflationpressure, angle of rebar, spacing of rebar in the plain and the hardness of the rubber) wasaccomplished, the results show that the initial inflation pressure and angle of rebar have agreat effect on the vertical characteristics of air spring.3.The mechanical simulation model of single degree of freedom was established byMATLAB/Simulink module and the differential equation were derived. Based on thedifferential equation, the system equivalent stiffness and relative damping coefficient are allclear. The steady response to sinusoidal excitation and random road inputs were analyzed,theresults show that large damping can reduce resonance peak, but it would increase the acceleration root of mean squares in high frequency. So a appropriate damping coefficient isvery important to the vibraiton system, meanwhile, the system stiffness should also be takeninto consideration to make sure that the system resonance frequency is out of the bodysensitive frequency range.