Abstract: The mathematical model and dynamic simulation model of the center axle train are established in view of the instability phenomenon in the running process of the center axle train. At the speed of 70 km/h and 50 km/h, the lateral acceleration, roll angle and yaw rate under step condition, serpentine condition and double line shifting condition are simulated and analysed, and the driving stability tests under step condition and double lane change condition are carried out. The results of simulation and experiment show that:At the same speed, the maximum roll angle of tractor is greater than that of trailer;The maximum lateral acceleration and yaw rate of the trailer are greater than that of the tractor, and there is obvious tail amplification effect of the trailer. The faster the driving speed is, the more obvious the amplification effect of dynamic parameters is;The response time of the rear trailer is obviously delayed than that of the tractor, The faster the train speed, the shorter the response delay time of the trailer, the lower the stability and the greater the rollover risk. At the same time, it is found that the maximum lateral acceleration, the maximum roll angle and the maximum yaw rate of the tractor and trailer occur under the condition of double lane change, and the stability of the train is lower and the risk of rollover is higher under the condition of double lane shifting.

Key words: center axle train, lateral acceleration, yaw rate, driving stability, double line shifting condition