Lu Yongjie

Dynamic analysis of semi-active vehicle suspensions using a co-simulation approach

A multi-body virtual prototype of heavy truck is presented in ADMAS/CAR software. Two kinds of adjustable damper control system are established within MATLAB/Simulik virtual environment, including semiactive dasiaon-offpsila control and semi-active magneto-rheological (MR) control based on revised Bingham model. In addition, co-simulation to the whole truck system is finished through building interface successfully. After simulating on stochastic road, the results show that the semi-active dasiaon-offpsila and MR control all can minimize the root mean square (r.m.s) seat vertical acceleration, r.m.s suspension deflection and r.m.s dynamic tire force compared with passive control. They can improve vehicle dynamical performance, weaken vehicle body vibration and increase ride comfort. But semiactive MR control effects are better than dasiaon-offpsila control. The co-simulation technology offers a new way to model and control complex dynamic system.

Multi-Objective Optimization Study for the Turnout Sub-Rail Parameters Based on Orthogonal Experiment

The stiffness and damping characteristics under the turnout rail are important factors affecting vehicle safety and stable running. According to the variable cross-section structure of a single 60 kg/m turnout No.18, a multi-body dynamic model of the vehicle-turnout coupled system is established. Based on the orthogonal test method, 25 group working conditions have been designed with the combination of the sub-rail stiffness and damping parameters. It has been found that the stiffness parameters under the rail have a greater impact on the vehicles performance through the range analysis of the simulation results. The vertical sub-rail stiffness mainly influences the vehicles vertical response and Sperling indicator. The lateral stiffness effects the derailment coefficient and the riding comfort. The matching scheme of the sub-rail stiffness and damping parameters is deduced by aiming towards the optimal vehicle security, stability and comfort, which provides a reference for the sub-rail structure design.