ESTIMATION OF CRACK DEPTHS IN ALUMINUM PLATES USING UNIFORM SURFACE EXCITATION AND GMR DETECTION
Ribeiro, A. L.
;
Pasadas, D.
;
Ramos, H.
ESTIMATION OF CRACK DEPTHS IN ALUMINUM PLATES USING UNIFORM SURFACE EXCITATION AND GMR DETECTION, Proc RELACRE - Conferência Nacional em Ensaios Não Destrutivos - CNEND, Évora, Portugal, Vol. Pen Drive, pp. ST1 - ST6, December, 2017.
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Abstract
This work presents a method to determine the depth of cracks in aluminium plates using the eddy current method. Three types of excitation have been compared, namely sinusoidal single frequency excitation with frequencies covering a bandwidth compatible with the standard depths of penetration up to the plate thickness. The second method is a multi-frequency excitation with all the frequencies applied simultaneously and covering the same bandwidth as used in the first method. Finally, in a third method, gaussian white noise is used as excitation, also covering the same bandwidth. The method is used to detect both surface and subsurface cracks.
