Critical assessment of operational path analysis: mathematical problems of transmissibility estimation

Peter Gajdatsy, Karl Janssens, Ludo Gielen, Peter Mas, Herman Van Der Auweraer
2008 Journal of the Acoustical Society of America  
Acoustics 08 Paris 5463 Classical transfer path analysis (TPA) is a widely used and reliable method for tackling noise and vibration problems. But due to its complexity and time-consuming procedure the industry is constantly seeking for simpler and faster methods. Several have been proposed in the last years, and one of them, most often referred to as operational path analysis (OPA), attracted particular attention as it uses only measured operational input and output signals and calculates the
more » ... ransmissibilities between them to characterize the paths. The claim for its accuracy is based on being able to reproduce the original output signal by summing the calculated partial contributions but it has not yet been compared to other TPA methods. This new method is now critically examined and compared to a reference classical TPA measurement. The results of this examination reveal three significant weaknesses. This paper focuses on the problems related to the estimation of transmissibilities which mostly arise from the limited amount of orders present in the signal and the coherence between inputs. It is shown that despite the advantages of the method, it is not applicable in many situations and has to be used with care for it can easily give misleading results.
doi:10.1121/1.2935749 fatcat:c6qjxsbdbnbkpp6ppyz2nhjsmq