Research On The Shearing Construction Model Of Electrorheological Fluid And Its Application In Shock Absorber

Suspension,as the only device connecting wheels and car body,is the key to ensure vehicle ride comfort and handling stability.Semi-active suspension has attracted wide attention because of its low cost and superior performance.There are two main research points of semi-active suspension: the development of adjustable shock absorber with high efficiency and wide adjustment range and the research of semi-active control algorithm.Valve-controlled dampers and magnetorheological dampers are the most frequently used in the adjustable dampers currently in the market,which have a long response time.The core of ER damper is Electrorheological fluid,an intelligent material with adjustable physical and mechanical properties.Therefore,based on the study of material characteristics of electrorheological fluids,we complete the development of ER dampers based on material characteristics of electrorheological fluids,and the advantages of Electrorheological dampers are analyzed according to the different response characteristics of ER dampers and MR dampers.The main contents include:Firstly,develop the electrorheological fluid rheometer and tested.According to the material characteristics of electrorheological fluids and referring to existing rheological instruments on the market,an experimental platform for special rheological instruments is built.Complete the shear stress-strain experiments of electrorheological fluids under different electric field modes,and try to build the discrete Fourier constitutive model.Secondly,the frequency sweep experiment of electrorheological fluids and the construction model.Finish the sweep frequency experiment of electrorheological fluids,and then obtain the energy storage modulus and loss modulus matched under different frequencies of electrorheological fluids.modify The four-element model which can express both fluid and solid characteristics.The optimal constitutive model was determined by fitting the parameters of experimental data,and finally complete the viscosity analysis and time domain expression.Thirdly,the development,simulation and experiment of ER damper.Based on the constitutive characteristics of Electrorheological fluid,the design and development of ER damper are completed.The feasibility of the design is verified by the finite element simulation of the uniformity of electric field intensity in the damping channel area.The mathematic model and Amesim simulation model of the structure-based electrorheological damper are established to explore the influence of the applied electric field and the moving speed of the damper on the damping characteristics.Develop the prototype of ER damper and complete the experiment of damping characteristics.The experimental results are compared with the simulation results,which lays a foundation for the modeling of semi-active suspension system.Fourth: Semi-active suspension system simulation.Based on the experimental data,the dynamic model of the electrorheological damper is established based on the empirical formula.Design the Skyhook controller and sliding mode controller and then establish semi-active suspension system According to the different response time characteristics of ER dampers and MR dampers,the effects of the two dampers on vehicle ride comfort and handling stability under different control algorithms are analyzed.The results show that the performance of ER damper is better than that of MR damper.Sliding mode control can alleviate the influence of time delay on ride comfort to a certain extent,but it will deteriorate the handling stability at high frequency.