Strength and toughness of jade and related natural fibrous materials

Abstract

Room temperature mechanical properties measured for natural fibrous “jade” materials with random fibre orientations were similar to strengths (e.g. ∼ 100 MPa) and toughnesses,K _IC, (e.g. ∼3M Pa m^1/2) in other studies. However, nearly three- and five-fold higher values were found respectively for strength and fracture toughness of “jade” with highly aligned fibres for crack propagation perpendicular to the fibres. Further, the results indicate significantly higher strength and toughness with decreasing fibre diameter and increasing aspect ratio, and an accompanying increase in intrafibre fracture. However, failure was predominantly catastrophic in character for all fibre orientations, indicating some material (i.e. matrix) is necessary for non-catastrophic failure as found in fibre composites.