The Design of Double-Overlap Joints Using Thermoplastic-Fibre Composites

Abstract

The present paper considers the adhesive bonding of thermoplastic fibre-composites using an epoxy-paste adhesive. The joint design used for these studies is a double-overlap geometry. Firstly, it is shown that to obtain good joint strengths the thermoplastic fibre-composite substrates need to be subjected to a corona surface treatment prior to bonding. Secondly, it is established that the use of tapered composite substrates and angled adhesive-fillets can substantially increase the joint strength. Indeed, the joint efficiency can approach 100% for such designs of double-overlap joints. Thirdly, finite-element analyses have been employed to study theoretically the various designs of joints, and the results from such analyses are in good agreement with the experimental measurements.