Research On Rigid-Flexible Coupling Vehicle System Dynamic For Sub-Frame Bogie

The current tendency of the railway goods transportation is to develop in the direction of high speed and heavy haul. While this tendency bring huge gains to the national economy, it request for the railway department advancing with times at the same time, it also speed up the frequency of upgrades of the railway technical equipment. Bogie is the key part to ensure the quality of vehicle among all this technical equipment. By improving the structure of the truck bogie, make it has higher speed and higher axle load and can keep track force at the previous bogies’level has become the goal to improve truck running performance. Sub-frame bogie can accomplish this task in a satisfactory way. In this thesis, ZK7 bogie is selected for the research subject as the typical sub-frame radial bogie.Vehicle system is considered as rigid system in the vehicle system dynamics performance analysis normally. The U shaped sub-frames and sideframes of the ZK7 bogie is characterized by a longer length in one direction than others. Hence this two parts of the bogie has elasticity to some extent, it may generate vibration and elastic deformation when it bears complex forces. In order to investigating the effect that two parts" elasticity on vehicle’s dynamics performance, this thesis builds the rigid dynamic model of the gondola car C80 with two ZK7 bogies installed using multibody dynamic software SIMPACK based on the multibody system dynamics theory. Then it builds the flexible body of sub-frame and sideframe using finite elements software ANSYS, using interface program importing the flexible body into SIMPACK to form several rigid-flexible coupling dynamic models. At last this thesis compares the several models’dynamics performance by same running condition, and using GB/T5599-1985 as standard, it concludes the degree of the influence flexible body exert on vehicle dynamics.The simulation results indicate that while the two parts’elasticity makes the vibration acceleration amplitude become greater both lateral and vertical, it has more obvious influence on vertical. The vibration is given priority to the low level vibration. The flexibility of the side frame and sub-frame can reduce the vehicle’s critical speed and stability. It will improve the overall vehicle curve negotiation performance, but the impact is limited. The flexibility of the sub-frame has a certain improving effect on the vehicle guidance performance.