Numerical Simulations of Vibro-acoustic Behaviors related to Drive Train Assemblies

In the current pedelec industry, one of the core problems encountered with in Drive Units are the vibrations. Curtailing these structure borne emissions along with the associated air borne noises is vital to improve the performances of electro-mechanical systems. This paper deals with study and optimization of vibro-acoustic behavior concerning the drive train components using the system modelling and Finite Element calculations. Excitation’s for these systems can majorly arise from the gearbox. The paper initially depicts gear mesh model which considers the non-rigid vibro-dynamics through visco-elastic elements, followed by analysis of structure-borne emissions at the housings with aid of the state space model. The Uncertainty Quantification technique is applied to realize various complexities involved in the systems. Additionally, the system modelling approach includes multi-domain coupling across domains like electrical, mechanical and thermal etc. Heterogeneity principles are used for linking the different physical domains. Later, acoustical characterization of the variants is comprehended by the study of emitted acoustic pressures, which are calculated using the setups of Helmholtz equations. Eventually, the experimental validations are performed with aid of laser vibrometer, microphones and the acoustic camera installed. Finally, it is depicted that the system level simulations allows for the better comprehension of the vibro-acoustics involved in the drive train assemblies.