Identification of Small-Sized Cracks on Cross-Stiffened Plate Structures for Ships

In this paper we discuss the results of experimental and numerical studies carried out for monitoring the integrity of a 1∕20th model of the side shell of a ship’s structure, using its vibration responses. The model was tested for different crack development scenarios under random exciting force having a dominant spectral frequency much lower (≈2Hz) than the first natural frequency of the structure (≈580Hz). Sensor locations were justified based on modal responses under intact and damaged conditions. A damage detection procedure using the root mean square response modal amplitudes is also presented.

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