A challenging and promising effort toward QNDE for inaccessible and invisible defects; Nonlinear guided wave NDE

Abstract

The use of ultrasonic guided wave, which has been widely accepted as a conventional, screening NDE tool to overcome the inaccessibility of large scale structural integrities is now being extended to early stage damage detection in conjunction with its nonlinear features for more precise material characterization. The status of guided wave based NDE is evolved from detecting geometric defects to monitoring strength related ones. Combining guided wave based NDE schemes with its nonlinearity is challenging due to the existence of multiple modes, the dispersive manner and the need of proper mode tuning. In this paper, some key concepts for the success will be introduced along with recent accomplishments including nonlinear guided wave imaging and application to composites.