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 [Formula: see text], and crack density [Formula: see text]. Type A configuration had woven carbon fibres and unidirectional flax fibres (i.e. [0–90C2/0F12/0–90C2]), while Type B configuration had woven carbon fibres and ±45 ° obliquely angled flax fibres (i.e. [0–90C2/(±45)F6S/0–90C2]. 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), [Formula: see text] in tension (Type A, 0.085%; Type B, 0.075%) and compression (Type A, 0.086%; Type B, 0.086%), and [Formula: see text] 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.