Influence Analysis On The Structure Of Truck Body With Longitudinal Force

With the rapid development of modern economy, in order to improve the railway transport capacity, freight trains have been developed to the heavy direction. However, with the increase of body length and traction weight, the longitudinal force among the vehicles will be increased, and the damage of vehicle structure is even more prominent. The C80B private gondola car has emerged many problems, such as the weld crack of the root weld side column, the sleeper beam web, center plate, side wall connecting plate and so on. Currently scholars study its causes only from the perspective of technology, and the fatigue damage of body structure by the longitudinal excitation is rarely. Previous research on the method of dynamic stress is combining the multi-body dynamics and finite element analysis, establishing the vehicle system dynamics model, obtaining the dynamic response of key parts of the body under the random excitation, using dynamic stress analysis method to calculate the body structure dynamic stress. However, the present research is only the vertical and horizontal random excitation, impact on the body of the longitudinal excitation had little research. Therefore, studying the influence of longitudinal force on the body structure and analyzing the fatigue damage on the body by the longitudinal force is a significant issue.This paper has established C80B finite element simulation model, using finite element analysis software I-DEAS, analyzing body stress under working conditions, separately discussed affect parts and large stress parts of the empty truck-body and heavy truck-body under static longitudinal force. Secondly, the paper analyzed dynamic stress of the empty truck-body and heavy truck-body, obtained affect parts and larger stress parts under start and emergency brake longitudinal force, and contrasted with static longitudinal force; analyzed the stress, acceleration and displacement impact with start and emergency brake longitudinal force. Analyzed the different impact with body which under static and dynamic longitudinal force. Finally calculating the dynamic stress amplitude of the key points, reached the great injury structure. Calculate results shows that the side wall of gondola does not meet the strength requirements, pillow cover arcs under the beam is the most sensitive position under the static longitudinal tensile force. In the role of longitudinal dynamic excitation of starting and emergency braking, the influence structure of body is half of the chassis part of excitation side, larger dynamic stress position is the first chassis beam connecting plate, occipital flange of the beam, root of lateral column and the column cover of large beams, which is different from analysis of static strength; the part of largest dynamic stress amplitude is sleeper beam web, root of lateral column and large beams under dynamic longitudinal excitation, same to the crack condition of C80B gondola car. Therefore transient dynamic stress analysis method of this paper is feasible.