Test method to assess interface adhesion in composite bonding

Abstract

This paper introduces a new type of peel tests dedicated to composite bonding: Composite Peel Tests. This test is inspired on the standard floating roller peel test widely used for metal bonding. The aim of this study is to investigate the potential of the Composite Peel Test to assess interface adhesion in composite bonded structures. To this end, peel tests were performed with nine different types of adhesives and at two environmental temperatures, room temperature and +80°C. The results were compared with the standard floating roller peel tests with Aluminium adherends. The results show that when using the Composite Peel Test good interface adhesion results either in cohesive failure of the adhesive or intra-laminar failure of the composite, while bad adhesion results in adhesive failure. In most cases of good interface adhesion, increasing the temperature favors cohesive failure of the adhesive in detriment of intra-laminar failure of the composite. Peel strengths can be used as a quality indicator of interface adhesion only if using exactly the same type of flexible adherend (peeling-off member). Nevertheless, if cohesive failure is the dominant failure mode, the comparison between adhesives’ peel strength is consistent disregarding of the type of peel-off adherend. Composite Peel Tests are suitable to assess interface adhesion of composite bonded structures.

Publication
Applied Adhesion Science
Sofia Teixeira de Freitas
Sofia Teixeira de Freitas
Principal Investigator

Sofia Teixeira de Freitas researches the structural integrity of bonded and layered materials to enable durable, sustainable structures. She is also an accredited group facilitator, committed to building academic environments grounded in cooperation and inclusion—key to overcoming technological limits and addressing the challenges of a truly sustainable society.