The Study On Carbody Lightening Problems For Railway Speed Up Passenger Cars

With the speed up of railway transportation, the lightening design of vehicle seems to be more and more important. Reducing the weight of vehicle can not only reduce the consumption of the raw materials and the power of traction, and increase the operation speed and improve the starting and braking performance of trains, but also has the advantageous to reduce the wheel/rail interaction forces, vibration and noise, increase the service life of the vehicle and the track, and economize the cost of transportation. In the dead weight of the passenger car, the car body occupies the most part of the weight. So in the course of lightening of the vehicle, the lightening of car-body structure is very important.The lightening design of vehicle should guarantee the strength, stiffness, mode and crashworthiness of the car body in the condition of raising train speed. This thesis utilizes ANSYS software to set up two finite element models of type 25K hard berth passenger car body before and after lightening. The strength, stiffness and mode of car body have been calculated and compared for the two models. Then the dynamic model of the passenger car system using NUCARS dynamic software has been set up. The effect of car body elastic vibration on the ride comfort is analyzed. The ride comfort and acceleration responses of the car system with rigid car body model or elastic car body model are studied and compared. Finally by using ANSYS/LS-DYNA software, the finite element impact models of car body with a rigid wall have been set up, then the displacement, velocity, acceleration and energy variation of the car body are analyzed and compared for before and after lightening cases under the condition of impact speed 5.8m/s and 11.8m/s.The work of this thesis provides the theoretical foundation for the car body lightening of speed up passenger cars.