The Initial Velocity Value of Coach in Frontal Impact Research

Abstract

This paper belongs to the technical field of coach passive safety. The frequent occurrence of frontal collision causes the serious destroyed coaches and heavy casualties for this vehicle have great load and various occupants. So far, not any laws or regulations about coach frontal collision have been formulated yet. Therefore, it is difficult to complete anything whether the theory and test research in frontal collision of coach or safety evaluation of coach structure. The initial impact velocity value will be put forward based on a lot of research. Taking a large-sized coach as the object of study, we built the finite element model accurately and used large deformation finite element analysis method and explicit dynamic analysis software LS-DYNA to simulate impact between the coach and a rigid barrier in a series speeds as 10, 20, 30, 40 and 50 km/h so as to analyse the influences of different speed on coach collision and discuss the initial velocity value in frontal impact of coach. In contrast to deformation of vehicle which at different impact speed, we get the deformation mechanism of the front bus and then further analyse the curve of changed driver space and the energy absorption characteristics of the main assembly in different impact velocities. The results consistently show, 30 km/h could be considered as the of initial impact velocity value in frontal impact. There are few studies in this field domestically and abroad so that some experimental data are needed. This paper preliminarily put forward the initial velocity value that apply to frontal impact test and structural safety evaluation of large bus in the point of the vehicle deformation, driving space change and energy absorption difference of coach assembly and parts. The result can provide reference for simulation analysis, real vehicle test and standard setting in frontal impact of coach speed selection.