Research On Network Synthesis Design Method Of Nonlinear Mem-inerter Suspension System

The inerter instead of the mass element forms a new suspension structure system of Inerter-Spring-Damper,which can open up a new way for the development of passive suspension.The replacement of linear elements with nonlinear passive elements with variable parameters has opened up a new way for the development of traditional passive suspensions.At present,nonlinear damper and spring elements have already been widely studied,but nonlinear inerters and their applications in suspensions are rarely reported.The structure and parameter design of nonlinear inerter suspension is still a difficult problem.Relying on the advantages of self-adaptability,nonlinear passive suspension has gradually become the main development direction of passive suspension system.However,the design of network synthesis method for nonlinear passive suspension system is still a difficult problem.In this context,the equivalent initial coefficient theorem of mem-ineter is proposed based on the energy method,and a network synthesis design method of nonlinear suspension system of mem-inerter is proposed based on the equivalent initial coefficient theorem,then first order and high order mem-inerter suspension structure are designed.Firstly,based on the constitutive relation of the memory element of the linear element,the initial characteristics and the memory characteristics of the hydraulic mem-inerter are analyzed.Equivalent initial coefficient theorem of mem-inerter is established based on energy method,and the self-adaptability of mem-inerter to initial displacement is analyzed.Secondly,based on the equivalent initial coefficient theorem of mem-inerter,a network synthesis method for nonlinear suspension system of mem-inerter is proposed.The suspension structure of mem-inerter is obtained by impedance synthesis method.Through working point synthesis of the suspension system,the suspension parameters are obtained.The load adaptability of the mem-ineretr is verified by simulation.Thirdly,the model of the mem-inerter device with parasitic damper and the 1/4vehicle model of the mem-inerter suspension are established.Taking linear inerter suspension as the comparison object,the response characteristics of mem-inerter suspension under sine excitation,pulse excitation and random excitation are analyzed.The simulation results show that compared with the linear inerter suspension,the mem-inerter suspension can improve the ride comfort and tire grounding performance of the vehicle under different loads,and it is the most obvious under no load,which indicates that the mem-inerter suspension has good vibration isolation performance and load adaptability.Finally,the prototype of the three-component mem-inerter suspension system and linear inerter suspension system are developed.The 1/4 vehicle bench test is carried out on the Instron 8800 single-channel vibration platform.The results show that compared with the linear inerter suspension,the mem-inerter suspension can not only ensure the stability and safety of the vehicle,but also improve the ride comfort of the vehicle under different loads.It is proved that the suspension of mem-inerter designed by the network synthesis method has good load adaptability and comprehensive performance.