Bamboo fibres for reinforcement in composite materials: Strength Weibull analysis

A recently developed mechanical method for extracting long bamboo fibres opens the possibility to exploit this new material as reinforcement in composite materials for high end uses. The strength distribution of the fibres was characterized in a novel approach to evaluate the effect of defects introduced by the extraction process as function of different scale variables: fibre length, fibre surface area and fibre volume. The modified Weibull distribution, a practical model requiring only three parameters, described accurately the fibre strength distribution of the fibres at different gauge lengths. The average fibre strength decreased with increasing gauge length, from 943 MPa at L = 1 mm to 733 MPa at L = 40 mm and it was nearly independent of the mean fibre volume. The Weibull shape parameter was found to be 7.6 for all tested fibres, showing low strength variability in comparison with other natural fibres and some synthetic fibres, indicating their high quality.