The effect of including hollow channels (vascules) within cross-ply laminates on static tensile properties and fatigue performance is investigated. No change in mechanical properties or damage formation is observed when a single vascule is included in the 0/90 interface, representing 0.5% of the cross sectional area within the specimen. During tensile loading, matrix cracks develop in the 90° layers leading to a reduction of stiffness and strength (defined as the loss of linearity) and a healing agent is injected through the vascules in order to heal them and mitigate the caused degradation. Two different healing agents, a commercial low viscosity epoxy resin (RT151, Resintech) and a toughened epoxy blend (bespoke, in-house formulation) have been used to successfully recover stiffness under static loading conditions. The RT151 system recovered 75% of the initial failure strength, whereas the toughened epoxy blend achieved a recovery of 67%. Under fatigue conditions, post healing, a rapid decay of stiffness was observed as the healed damage re-opened within the first 2500 cycles. This was caused by the high fatigue loading intensity, which was near the static failure strength of the healing resin. However, the potential for ameliorating (via self-healing or autonomous repair) more diffuse transverse matrix damage via a vascular network has been shown.
Bibliographical noteWelcome to the 2016 Smart Materials and Structures (SMS) Highlights Collection. SMS achieved its highest Impact Factor last year, of 2.769. To recognise some of the outstanding contributions our authors have made to the on-going success of SMS, we have put together this collection of highlight articles published in 2016. The Papers, Letters and Topical Reviews featured in this collection were selected based on their scientific merit, as identified by our reviewers, and represent some of the most downloaded and widely read articles published in 2016. Our thanks go to our authors, reviewers and readers for their support of the journal. We hope you enjoy this overview.
- Fibre reinforced polymers
- cross-ply laminate
- matrix damage