The role of residual stress at the fibre-matrix interface in composite materials

Abstract It is well known that the fibre-matrix interface plays a key role in defining the mechanical properties of fibre composite materials. The ability to efficiently transfer stress between the matrix and the fibres is critical in ensuring the required performance level needed for advanced composite materials. Stress transfer across the fibre-matrix interface is often reduced to a discussion of ‘adhesion’. Past discussions of thermosetting matrices have typically focussed on the chemistry of the matrix system, specifically the task of maximising the level of chemical bonding between the fibre and the matrix to produce the strongest interface. However, many authors have also commented on the potential for residual radial compressive stresses formed at the interface to be a significant contributor to the strength of the interface. There is still a significant weight of opinion that holds that even if these residual stresses at the interface can contribute to the stress transfer capability, then chemistry and chemical reactions must play an active role in defining their magnitude.

This presentation will explore the research led by Dr Minty furthering our understanding of how chemistry and residual stresses formed at the interface could be interrelated to influence the stress transfer capability of the interface.