Modeling And Optimization Of Hydraulic Shock Absorber Based On Vehicle Ride Comfort

Shock absorber is one of the important parts in the automobile suspensionsystem, its complex nonlinear dynamic characteristics not only affect vehiclehandling stability, but also determine the vehicle ride comfort performance.The traditional design method of shock absorber is to determine the designparameters according to the experience, and find a better dampingcharacteristics scheme according to the test performance of the sample vehicle.What’s more, the internal valve system structure need to be repeatedlyadjusted by shock absorber factory, and finally, shock absorbers that can bematched better with the certain vehicle can be designed successfully afterseveral repeated cycles processes. Its disadvantage mainly focuses on theseparate of shock absorber internal structure design and vehicle dynamicperformance study. Therefore, in order to shorten the development cycle,reduce development costs, improve the efficiency, reduce the number of tests,a shock absorber model that be able to the vehicle performance demand as theoverall goal, which can predict the damping characteristics of shock absorber,and research the effects of structural parameters of damper on vehicleperformance is urgently needed.Firstly, in order to establish the function relationship between thestructural parameters of damper and damping characteristics, a new method tocalculate of the deformation of the shock absorber throttle slice with differentradial positions under uniform load bearing. The throttle slice deformationanalytic formula was established considering the actual structure of shockabsorber valve. The oil flow rule of the valve system structure was analyzedaccording to the principle of fluid mechanics, and the structural parametersmathematical model of the shock absorber was established combined with thedamper working principle. The power characteristics and velocitycharacteristics were calculated used the software called Matlab. And thesimulation results were compared to bench tests results, the correctness of themodel was verified.Secondly, for realizing quick coupling simulation analysis of structuralparameters model and vehicle model, optimizing the shock absorber structureas the overall goal of the vehicle performance. A single wheel road model in time domain was established using filter white noise method, and thesimulation calculation was realized using Simulink. And more, the unilateralfront and rear wheels of road excitation model in time domain and the multiaxis wheel space of road model in time domain were established. A halfvehicle vibration model was established and the coupling simulationcalculation of the shock absorber parameters model and vehicle vibrationmodel was completed by four order Runge Kutta algorithm. The constrainedproblem was converted into the unconstrained problem by using the exteriorpenalty function method, based on vehicle ride comfort evaluation methods,according to the ride comfort evaluation indexes and constraint conditions.Finally, the structure optimization design of the absorber was completed byusing the genetic algorithm, and the optimization results indicated that thismethod not only realized that performance guides design of the shock absorber,but also greatly improved the dynamic performance of the vehicle.