DIAGNOSTIC OF COMPOSITE MATERIALS BY LASER TECHNIQUES: APPLICATION ON PANELS WITH DIFFERENT STRUCTURES AND SHAPES

摘要

Damage detection is one of the fields where major efforts have been spent in last years by vibration engineers and researchers. In fact, the importance of structural diagnostic is well recognised in many industrial sectors, as the aerospace or the civil construction ones. The technique based on the vibration analysis by scanning laser Doppler vibrometry is one of the most promising, allowing to extract also small defects and to operate in in-field conditions. The measurement capabilities of vibrometers, such as sensitivity, accuracy and reduced intrusivity, permit to have a very powerful instrument in diagnostic. In this work the recent advances in the experimental diagnostic procedure based on laser Doppler vibrometry are presented. In particular the experimental and numerical techniques developed by the authors in previous works have been validated on different kinds of composite panels with different shapes and structures. The various techniques as well as the different data processing strategies have been tested and compared. Results are analysed in detail, discussing the advantages and the limitations for each particular application.