Dynamic Characteristic Analysis Of Bus Body Structure

At present, although the design of some buses meets requirements of static strength, in practical use there are still problems occurring. The main reason is that the bus body sustains more complicated random excitation loads in practical working conditions. The more accurate dynamic stress course could be attained with the road test or experiment, but the precondition is that sample cars have been manufactured .If in the early stage of design making use of FEM to build up model cars of body framework, it will get dynamic stress courses of body structure under all different kinds of road conditions. Reliability and service life of body framework can be accurately predicted and by re-optimizing the structure, the quality of the whole car will be decreased. Therefore, the study of dynamic stress response of body structure under the road random excitation has a very important practical significance.This paper is combined with new high-grade bus development project of a passenger bus company .The development of new large-scale passenger bus in 2006 is analyzed with FEM. The bus used in the calculation possesses imported chassis with a mature technology; Its body is the style of entire loading .Body framework is welded with multi-section rectangular steel tubes.The main purpose of this paper is :to establish finite element model for the analysis of the dynamic response ;to understand low-order vibration mode and frequency of the free modal and constrained modal for bus body; to establish the finite element model of glass; to preliminarily know about the glass effect on the body dynamic characteristics; to inspect the bar section parameters effect on the low-order free modal ;to research dynamic response of the body and know about dynamic stress level of bus body.According to the above-mentioned objectives, this paper carries out the following work:(1)Based on the 2-D drawings and real vehicle photographs provided by the company, simplify and establish the 3-D CAD model by CATIA; According to the...