Composite bonds put to the test

The application of adhesive bonding as a joining technology for CFRP aircraft structures is essential for the realization of novel lightweight design concepts.

Composite materials are increasingly being used in the manufacturing of structural components in the aeronautics industry. A consequent lightweight design of carbon-fiber-reinforced plastic (CFRP) primary structures requires adhesive bonding as the optimum joining technique but is limited due to a lack of adequate quality assurance (QA) procedures. The successful implementation of a reliable QA concept for adhesive bonding 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.

The performance of adhesive bonds mainly depends on the physicochemical properties of adherend surfaces. Therefore, a set of advanced nondestructive testing (NDT) techniques is applied and adapted to the characterization of CFRP bonded structures as well as the state of adherend surfaces before bonding within the ENCOMB project. As a medium-scale European Consortium funded within the 7th Framework Program, ENCOMB (Extended Non-Destructive Testing of Composite Bonds) brings together leading experts in aeronautics research and development providing advanced NDT methods for reliable QA of adhesive bonds of CFRP structural components.