In-situ damage assessment of a novel carbon/flax/epoxy hybrid composite under tensile and compressive loading

Abstract

Damage under progressive load–unload until failure was assessed for a new woven carbon fibre/flax fibre/epoxy hybrid composite via stiffness degradation D, permanent strain ${\varepsilon }_p$ , and crack density ${\rho }_c$ . Type A configuration had woven carbon fibres and unidirectional flax fibres (i.e. [0–90_C2/0_F12/0–90_C2]), while Type B configuration had woven carbon fibres and ±45 ° obliquely angled flax fibres (i.e. [0–90_C2/(±45)_F6S/0–90_C2]. Results were obtained for D in tension (Type A, 0.080; Type B, 0.089) and compression (Type A, 0.178; Type B, 0.207), ${\varepsilon }_p$ in tension (Type A, 0.085%; Type B, 0.075%) and compression (Type A, 0.086%; Type B, 0.086%), and ${\rho }_c$ in tension (Type A, range = 0.12–1.06%; Type B, range = 0.6–1.43%) and compression (Type A, range = 0.65–1.20%; Type B, range = 1.05–2.20%). Failure involved flax fibre bundle cracks and interfacial cracks in the flax fibre/epoxy region.