A Critical Look at the Current Status on the Design Regulations for Structural Adhesively Bonded Joints of Fibre Reinforced Polymers

Adhesive bonding is widely recognised as a key technology in many industries, including in particular where composite materials are in the focus. Contradicting this statement is the fact that adhesively bonded joints do unfortunately all too often not meet the requirements placed on them, resulting in failure during service life. In almost all engineering disciplines, codes and standards effectively regulate the design process. What are the reasons behind the noteworthy singularity of adhesive bonding? Both composites as a materials, and adhesive bonding as a joining technique have been widely investigated at several, if not almost all, levels of complexity. Yet this accumulated knowledge has not diffused into useful codes and standards to safely dimension adhesively bonded joints for composite materials. It is posited that this dichotomy between available and implemented knowledge is mainly due to three reasons: lack of specific qualification of designers regarding the new technology and the sheer extension of specific knowledge required; the attempt to clone ""traditional"" codes and standard where uniform approaches are sought after; the lack of specification regarding structural verification procedures. These issues have been recognised in other industries, e.g. railway and automotive, and more general solutions were offered that did not mimic traditional forms of coding, but consider adhesive bonding as a process, and not merely a joint. This paper aims at consider a much broader approach to coding, and offers ways out of the current misery of adhesively bonded joints for composite materials in civil engineering.