NDTnet 1998 Aug, Vol.3 No.8

Full-Text - Abstract

Fig.: Broken actuator in CFRP laminate

Adaptive materials are able to react to changing environmental conditions. For example, they serve to active vibration damping and geometric stabilisation under alternating thermal andmechanical loading. From the wide variety of material combinations the paper regards CFRP laminates with thin piezoceramic sensors and actuators integrated into the composite.

Non-destructive evaluation of adaptive material systems is aimed onto optimisation of manufacturing techniques. Fibre and resin distribution, actuator and insulation bonding and integrity, interlayer adhesion, absence of massive fibre breaking and impact damage are assumed to be most important quality parameters.
Due to the wide variety of physical properties of the components various non-destructive methods have to be combined to estimate all significant parameters. The paper introduces x-ray, eddy current and ultrasonic methods suitable to characterise the composite. Special sets of specimens have been designed to evaluate typical signals of material imperfections and to optimise test parameters. Concerning practical requirements, a pre-preg system and a DP-RTM system have been chosen for fundamental investigations.

The authors present examples of local fibre and resin concentration, actuator fracture, insulation insufficiencies, fibre curling and impact damage and outline their interpretation. As an example, xray, eddy current and ultrasonic results of internal actuator fracture are displayed on the right side emphasising the complementary character of these NDE methods.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com