Lamb wave characterisation and damage imaging for isotropic plate-like structures using 3D laser vibrometry

Abstract

The scattering of Lamb waves has been adopted for effective detection of different types of mechanical damage in both metal and composite structures. The scattering field from a defect is normally obtained through various types of sensors, which can quantify this field in only one direction. This paper presents experimental investigations adopting 3D laser vibrometry and the root mean square (RMS) of the velocity fields in isotropic plate-like structures. Experimental case studies with defects are considered. The results clearly illustrate the benefits of the method and utilisation of the full 3D characterisations of Lamb wave propagation and scattering.