Analysis of Integrity of Chassis Structure Contend Defect 2005-01-3998

The integrity structural analysis of a bus structure is a difficult task, by several aspects involved as combinations of different type of loads acting on, and the complex geometry of the system. An alternative, which allows taking in account all these aspects, is the use of refined finite elements models. So that, the generated model represents all the important details of the real structure and the volume of information manipulated is very great, what also makes difficult the evaluation of the results and conclusions that improve the structural project. One form to avoid such difficulties consists on the rational use of structural models with different levels of complexity. Applying this philosophy, this work carries out the study of a flaw for propagation of crack by fatigue in the structure of an interurban chassis bus. Some types of numerical models are constructed to get information on the structural behavior, focusing the region where the flaw was occurring and identifying alternative solutions for the problem. The models with high level of detailing are presented later with the idea to confirm the cause of the flaw, through a verification of fatigue of the flaw region, mounting possible scenes of stress and geometry and initial size of cracks. Conclusions are presented on the results developed and the adequacy of the methodology is evaluated.