Standard deviation as a suitable criterion for localizing damages in Nano- composite structures

Wavelet transform is a proper method for detecting damages in signals such as vibration mode shapes. This study introduces the standard deviation as a suitable criterion for selecting and analyzing wavelet function in damage detection of nano-laminated composite structures. In this way, a Fe۲O۳-carbon epoxy fiber laminated composite structure is studied. Experimental modal analysis is conducted to obtain the natural frequencies and their corresponding mode shapes. Findings show that the standard deviation can effectively find the best analyzing wavelet function for structural damage detection when the damages are led to local and subtle changes in vibration mode shapes.

Keywords:

Damage identification , wavelet transform , optimal wavelet seletion , damage detection , structural health monitoring..