Hybrid TPA method applying measurement and simulation

For correct detection of noise sources and their path into a vehicle Transfer Path Analysis (TPA) is more or less a state of the art method. The basic idea is to evaluate specific potentials of countermeasures to reduce disturbing noise based on results of a TPA. Unfortunately the complexity of a TPA, needing correct specification for all relevant paths and acting forces make this method costly and time-consuming. For this reason in many cases it is not first choice once acoustical problems occur on a vehicle in testing. It is very common that project management, once faced with costs and duration for a complete TPA, requests to go ahead with simpler, heuristic “try-out”-methods. Based on our experiences in several projects, we implemented a very efficient TPA method to enable a quicker analysis. A key to success was to join the potentials of simulation with efficient measurement methods to get results for the most important noise paths into the vehicle quickly. We called our method of TPA “hybrid”, due to the fact that both, measurement and simulation, is applied. As rolling noise TPA is a very complex topic, and reduction of rolling noise becomes more important in time of electrification and hybridization of vehicles, we focus on rolling noise TPA. This paper describes the method Magna Steyr Engineering developed and shows some examples of successful application.