Over the last 60 years, laminated composite materials have attracted the attention of several advanced industries including aerospace, motorsport and energy due to the excellent ratio between in-plane mechanical properties and low density. However, due to the fragile nature and the lack of reinforcement along their through-the-thickness direction, these materials are sensitive to impact loading conditions and are prone to damage generation within the composite structure leading to the decreased performance and eventual catastrophic failure of the structure. The original contribution of this thesis is the systematic presentation of three different hybridisation processes aiming to improve the impact properties of laminated composite materials through the introduction of an additional phase or reinforcement within the composite structure and, at the same time, to enable important non-structural properties which can significantly increase reliability of the structure and the appeal of these materials for advanced sectors. Three were investigated in this work. The first consisted of the introduction of metal wires as secondary reinforcement to improve maximum tolerated contact force whilst enabling structural monitoring (sensing ability and IR damage detection), de-icing and anti-icing safety procedures. The second investigated the effect of the introduction of resin pockets along fibres length creating a 3D discontinuities pattern whilst activating additional failure mechanisms typical of biological organisms to increase the toughness of the laminate and enhance drapability. The final hybridisation process investigated was the introduction of polymeric coating on the impact surface to mitigate the impact damage generated within the structure by increasing the amount of dissipated impact energy via damping mechanisms whilst increasing erosion resistance. Experimental impact testing was carried out to characterise and evaluate the benefits of hybridisation on laminated materials and reported improvement in each of the evaluated properties demonstrating the potential of these materials to be used in increasing performance, reliability and safety for advanced applications.
|Date of Award||22 Jul 2020|
|Supervisor||Michele Meo (Supervisor) & Fulvio Pinto (Supervisor)|
- Damage resistance
- structural health monitoring
- hybrid laminates