To evaluate the vibroacoustic behaviour of a brake system, usually during the beginning of development, dynamometer tests are performed due to being faster and cheaper when compared to vehicle tests procedures. However, some inconsistencies on noise occurrences levels are often observed when comparing the results of dynamometer and vehicle tests. This work presents a tool capable of correlate the sound intensity between any dynamometer standard noise tests to any kind of vehicle. At first, the transfer function method used to create this tool is presented. Next, the experiment used to obtain the transfer functions used to correlate the dynamometer and vehicle is shown. Finally, the validation results comparing the dynamometer and vehicle showing the method great advantages are presented. With this tool it is possible to predict the noise level inside a vehicle base on a dynamometer test, however it is not possible to predict noise percentage of occurrences. It is expected that anybody will be able to replicate Fras-le Acoustic Correlation Tool (FACT) in order to predict noise level inside a vehicle based on a dynamometer test.
Fulco, Erico Romera; Matozo, Luciano Tedesco; Tonet, Gustavo; Varante, Paulo Emilio Dias; - FRAS-LE S.A.