Impact and fatigue tolerant natural fibre reinforced thermoplastic composites by using non-dry fibres
Farzin Javanshour, Alexandros Prapavesis, Nazanin Pournoori, Guilherme Corrêa Soares, Olli Orell, T. Pärnänen, Mikko Kanerva, Aart Willem Van Vuure, Essi Sarlin
Abstract
This article introduces stiff and tough biocomposites with in-situ polymerisation of poly (methyl methacrylate) and ductile non-dry flax fibres. According to the results, composites processed with non-dry fibres (preconditioned at 50% RH) had comparable quasi-static in-plane shear strength but 42% higher elongation at failure and toughness than composites processed with oven-dried fibres. Interestingly, the perforation energy of flax–PMMA cross-ply composites subjected to low-velocity impact increased up to 100% with non-dry flax fibres. The in-situ impact damage progression on the rear surface of composites was evaluated based on strain and thermal field maps acquired by synchronised high-speed optical and thermal cameras. Impact-induced delamination lengths were investigated with tomography. Non-dry fibres also decreased the tension–tension fatigue life degradation rate of composites up to 21% and altered the brittle failure mode of flax–PMMA to ductile failure dominated by fibre pull-out.