Design Of Membrane Amplitude Selective Damping Shock Absorber And Its Application In Vehicle Dynamics

For suspension system, the vehicle ride comfort and handling stability is contradictory.To have a good ride comfort, vehicle suspension must be asked to provide the small dampingforce, so the vehicle needs the soft suspension to ensure that the passengers feel comfort.The vehicle handling stability require the suspension to provide a larger damping force, sothe vehicles need to match the hard suspension system. Suspension system is to design forintegrated consideration of the ride comfort and handling stability, on the premise of fullyensuring the vehicle steering stability, it is good to improve the ride comfort of vehicles aspossible.With the continuous development of science and technology, people put forward varioustypes of adjustable damping shock absorber, the damping force can be changed with thecondition, to ensure that the vehicle has good ride comfort and handling stability. This paperputs forward a kind of Membrane Amplitude Selective Damping Shock Absorber, thedamping characteristics can change over the suspension movement amplitude. When thevehicle is riding on good road, the shock absorber damping force is small to ensure good ridecomfort; When the vehicle is steering or driving on the bumpy road, the shock absorberprovides the bigger damping force to ensure the vehicles have good driving safety andhandling stability. According to different driving modes, providing different dampingcharacteristics to meet the demand of different vehicle suspension damping.Compared with the passive shock absorber, Membrane Amplitude Selective DampingShock Absorber is to pass on the piston rod attached rubber membrane and hollow cavity,requireing no additional sensors, control system, etc. Its structure is simple and low cost.Major work of the paper is as follow:Firstly, establish model of Membrane Amplitude Selective Damping Shock Absorber.According to principles of designing shock absorber and knowledge of fluid mechanicstheory to set up the original car shock absorber model, and verify with the test. Analysis theworking principle of Membrane amplitude related and structure characteristics, establish itsmathematical model and finite element model of rubber membrane. On the basis of thosework, establish the model of Membrane Amplitude Selective Damping Shock Absorber in Simulink.Secondly, optimize the parameters of Membrane Amplitude Selective Damping ShockAbsorber. A quarter vehicle model and road surface model are established. On the basis ofthose work establish the optimization model of Membrane-Amplitude-Selective-DampingShock Absorber, at the same time determine the optimization objectives, optimizationvariables and constraints, using the Matlab optimization toolbox, optimize the mainstructural parameters of the model with multi island comprehensively optimization ofgenetic algorithm, finally obtain the main structural parameters of Membrane AmplitudeSelective Damping Shock Absorber.Thirdly, Membrane Amplitude Selective Damping Shock Absorber test. According tothe optimization of structural parameters, make Membrane-Amplitude-Selective-DampingShock Absorber samples, and carry out a shock absorber bench test. Compare test resultswith simulation results to verify the damping characteristics of Membrane AmplitudeSelective Damping Shock Absorber and the accuracy of the establishing theoretical model.Finally, The vehicle performance simulation. At first, Bringing the MembraneAmplitude Selective Damping Shock Absorber model into A-quarter vehicle model, throughthe class A, B, C three road body simulation, contrast the three acceleration amplitudefrequency characteristics, verify Membrane Amplitude Selective Damping Shock Absorbercomparing with the original car shock absorber, improving the vehicle ride comfort.Secondly, establish the vehicle model based on CarSim, Bringing the Membrane AmplitudeSelective Damping Shock Absorber model into the vehicle model, through the jointsimulation by Matlab and CarSim, verify the Membrane Amplitude Selective DampingShock Absorber in a turning, acceleration and deceleration, improving of the stability ofbody posture.