ACOUSTIC EMISSION TESTS ON THE ANALYSIS OF CRACKED ROTORS OF DIFFERENT CRACK DEPTHS
Gilberto Luiz dos Santos Pimentel Júnior1; Frederico Bolsoni Oliveira1; Marco Túlio Corrêa de Faria1
1 UFMG
doi:10.20906/CPS/COB-2015-1434
Resumo
This work deals with an experimental study about the influence of transverse crack sizes on the acoustic emission (AE) signals rendered in vibration tests performed on cracked rotors. The experimental apparatus is composed of shafts of different crack sizes and an AE data acquisition system. Basically, the acoustic emission signals from a wideband AE transducer are monitored in bumped tests performed on cracked rotors. Experimental data treatment techniques based on statistical moments, wavelet transforms, and frequency- and time-domain patterns are employed to evaluate the AE signals rendered from the bump tests. Six steel AISI 1020 shafts are specially manufactured for this study. A Transverse crack of a predetermined depth is etched into each shaft. The experimental results indicate that the values of kurtosis and skewness estimated for the AE signals can be used to identify the crack size.
Palavras-chave: acoustic emission; cracked rotors; shaft crack; Bump tests