Numerical and Theoretical Modal Analysis of Transit Buses

This work aims to study the dynamic behaviour of a passenger bus. The transportation sector demands high important technological improvements, strived for high safety standards and environmental sustainability. In this work, a simplified dynamic model of a single body bus is introduced to determine the natural frequencies spectrum variation, mainly caused by the induction of the flexible behaviour of the suspension and unforeseen external loads, particularly wind gusts. More complex vibrational modes have been studied via Finite Element Method (FEM) modelling. A significantly simplified link arrangement is presented, which models the behaviour between the road and tire contact as well as the suspension features. This deformation model leads to a combined stiffness matrix with the whole model. As a result, an acceptable agreement was obtained amongst the numerical and analytical solutions.