Three possible instability sequences in vehicle combinations were obtained by using graph theory and the link relationship of each unit of the vehicle.A multi-body dynamic model,including nonlinear tire model of the vehicle combination was established by TruckSim.By simulation of the change of the state variables of each vehicle unit under high-speed step response,it was obtained that the main factor to influence the instability of the vehicle is the roll rate.Combining with the energy equation,the maximum ...