Abstract (Invited)

Microdamage Diagnostics Using Nonlinear Elastic Wave Spectroscopy

K.Van Den Abeele (Interdisciplinary Research Center, Catholic University Leuven Campus Kortrijk, Kortrijk, Belgium)

e-mail: koen.vandenabeele@kulak.ac.be

Recent advances in modern material technology require the development of non-destructive evaluation (NDE) techniques that quantify micro-scale damage in a variety of materials, both during their production and life cycle in order to ensure products of high quality and safety. In this presentation, a number of powerful macroscopic tools, belonging to the extensive class of Nonlinear Elastic Wave Spectroscopy (NEWS) techniques, will be reviewed. These techniques have been developed to probe the dynamic nonlinear stress-strain behavior of elastically soft (compliant) constituents distributed within a rigid matrix and to analyse their effect on macroscopic wave phenomena. Examples include amplitude excitation dependent resonance experiments, harmonic propagation and intermodulation techniques, dynamic "creep" experiments, nonlinear attenuation measurements etc... The sensitivity of such nonlinear methods to the detection of micro-scale features (dislocation motion, damage, cracks, flaws, etc.) is proved to be far greater than what can be obtained with linear acoustical methods (measures of wavespeed and wave dissipation). We illustrate the sensitivity and consistency of different NEWS techniques on a variety of materials in industrial and biomedical applications.

Section : 3