Vibroacoustic simulation of an electric motor: Methodology and focus on the structural FEM representativity

The automotive industry is being transformed by the emergence of hybrid and electric vehicles. The design and integration of combustion engines is well known. It is now necessary to build a new expertise and new simulation tools related to electrical machines. This paper presents a complete methodology for simulating the noise radiated by an electric traction motor. This is a 3-step multiphysic calculation. The first step is the estimation of the electromagnetic excitation applied to the structure. The second step is the calculation of the dynamic response thanks to a structural finite element solver. The third is an acoustic radiation calculation. The paper focuses specifically on the representativity of the structural finite element model. Indeed, the laminated magnetic core has a complex dynamic behaviour. A homogenization method leads to an equivalent homogeneous material and the elasto-dynamic characteristics of this material are obtained thanks to a model updating procedure.