Developing Artificial Olfaction Techniques for Contamination Detection on Aircraft CFRP Surfaces: The Encomb Project

Abstract

Composite materials are already used in the manufacturing of structural components in aeronautics industry. However, the light-weight design of Carbon Fiber Reinforced Polymer (CFRP) primary structures is still limited because of the lack of adequate quality assurance procedures for the realisation of the adhesive bonding, which is the optimum technique for joining CFRP light-weight structures. Hence, the primary objective of ENCOMB is the identification, development, and adaptation of methods suitable for the assessment of adhesive bond quality. The performance of adhesive bonds depends on the physicochemical properties of both adherent surfaces and adhesives. Therefore, a set of advanced non-destructive testing techniques is applied and adapted to the characterization of CFRP bonded structures, the state of adherent surfaces before bonding and the state of the cured and uncured adhesives. Actually, surface contamination by several aeronautics fluids eventually results in weak or kissing bonds. The goal of our research work is to investigate solid state chemical sensors and artificial olfaction techniques (AO) for the detection of CFRP surface contamination by aeronautic fluids. The successful implementation of a reliable quality assurance concept within manufacturing and in-service environments will provide the basis for increased use of light-weight composite materials for highly integrated aircraft structures thus minimizing rivet-based assembly. Herein, we present a first approach on the contamination detection scenario, based on the use of an array of polymer sensors.