Analysis of an automotive vibration issue through bond-graphs

Modal coupling phenomena are one of the most sensitive issues to the vehicle occupant perception. Commonly understood as a vibrational transfer function (VTF) problem only, those events not rarely are the root cause of noise transfer function (NTF) issues too, increasing exponentially its potential to degrade the vehicle comfort performance. As result, when not solved through computer aided engineering (CAE) tools along initial project phases, the vehicle must use expensive masses and dampers to fix, with delay, a design issue that could have be solved earlier. The use of bond graph modeling technique makes possible to segregate and evaluate only a specific part of the vehicle structure, calibrating its mass and stiffness separately. The results of this analysis allows to design a modal decoupled system faster and accurately than using a complete finite element model (FEM), in order to feedback the design conception parameters with the optimized modal responses, improving its development time and cost besides the final product quality.