Network Synthesis Design Method of Nonlinear Mem-inerter Suspension System

Mem-inerter, corresponding to the memcapacitor in electricity, is a nonlinear passive element with memory characteristics and adaptability. At present, nonlinear damper and spring have been widely studied, but there are few reports on nonlinear mem-inerter and its application in suspension. The structure and parameter design of mem-inerter suspension is still a difficult problem. Under this background, this study proved the equivalent inertance theorem of the mem-inerter according to the energy method. Based on this theorem, it proposed a network synthesis design method for the nonlinear suspension system of the mem-inerter, including structure synthesis and parameter synthesis. The structure synthesis regards the suspension network as a robust controller and obtains the mem-inerter suspension structure by solving the controller. The multi-objective parameter optimization method was used to determine the system parameters of the suspension, and the assembly parameters of the suspension were calculated based on the actual engineering situation. On this basis, the first-order and high-order mem-inerter suspension network system were designed, and the dynamic equations of 1/4 vehicle model was given. The simulation analysis of the suspension model was carried out. The transmission characteristics under sinusoidal excitation input show that each order of mem-inerter suspension has good load adaptability. The response characteristics under random road input show that compared with the corresponding linear suspension, the body acceleration of each order of nonlinear mem-inerter suspension designed by the network synthesis method is significantly reduced, and the dynamic tire load is improved, showing better driving comfort and handling stability and indicating the feasiblity of the suspension network synthesis design method.