NONDESTRUCTIVE CHARACTERIZATION OF THE ELASTIC PROPERTIES OF ORTHOTROPIC COMPOSITES WITH ULTRASOUND

摘要

I. INTRODUCTION Due to the increasing use of composite materials in critical applications demanding light weight to high strength ratio, reliable evaluation tools are necessary. The field of ultrasound is a well known non-destructive method, in which the classical C-scan has already proven its usefulness in visualizing defects, delaminations, ... (ref. 1, 2, 3). Though, one of the most critical degradation mechanisms involves fatigue of composite materials, which is attended with a local reduction of the stiffness of the material. Because of the inherent limitations of a C-scan for quantitative characterization (ref. 1), more sophisticated non-destructive tools are needed to monitor complex damage mechanisms.