The Research Of Structural Safety Simulation On Rear-end Collision Of Coaches And Back Wall Penetration Of Truck Cab

With the development of national economy and improvement of road conditions, thequantity of motor vehicles in china is growing rapidly and the road transport is playing anincreasingly important role in the national economy and integrated transport system. But atthe same time, China’s road safety situation is not optimistic, for the number of casualties isconsistently high due to road traffic safety issues each year. Commercial vehicle for passengertransportation and operating trucks belong to commercial vehicles, while compared with thepassive safety performance and evaluation of passenger cars, those of commercial vehicleswere not paid enough attention to in quite a long period. Therefore, It’s of great significance toconduct a research on structural safety simulation of operating passenger car body and truckcab as well as their evaluation methods.Although the proportion of rear-end collision is not very high in traffic accident forms,the losses caused can be considerably great. In this thesis, based on the study of our country’straffic safety in recent years, finite element models of the research objects----the6127-typecoach and one heavy truck cab, are established using HyperMesh. Then with LS-DYNAexplicit finite element program and according to the relevant research materials at home andabroad, rear-end collision simulation of the coach is operated, followed by the analysis of theeffects of different collision angles and collision coincidence rates on the body structure andthe neck injury of the occupant, and the comparative analysis of the related factors whichinfluence the results of rear-end collision simulation. What’s more, with the simulation inback wall penetration of truck cab, this thesis studies the main factors influencing thepenetration test, aiming to provide reference for the improvement of structural safety ofcommercial vehicles.Simulation results show that coincidence rates of rear-end collision have different effectson the deformation of rear body and passengers’ safety. The two forms of collisions arenon-substitutable. Greater than40%coincidence rate of rear collision in intensity, the100%coincidence rate of rear collision is suggested to evaluate the safety of passenger and work asthe verification mode of the seat’s safety and the effectiveness of energy absorption device.And with the large deformation of back wall structure, the40%coincidence rate of rearcollision is recommended to assess the crashworthiness of body structure. Furthermore,compared with rear collisions at a90angle, those at a45or30angle tend to cause moreserious injuries to rear-row passengers. So, besides the simulation of rear collision at a90angle, that at a45or30angle is also recommended so as to guarantee the reliability and theaccuracy of the simulation. In penetration testing simulation of cab back wall, although therear wall of cab does not show obvious penetration phenomena, it doesn’t mean that the cabrear wall possesses sufficient strength. Due to a variety of factors, such as emergency brakingspeed, braking deceleration, the weight of the goods, the contact area and the contact locations,this test requires more comprehensive and thorough future researches.