Youngʹs modulus of unidirectional discontinuous-fibre composites

Youngʹs modulus of a unidirectional discontinuous-fibre composite is derived in the present study by the use of a modified shear-lag model. To achieve this, correct determination of the stress transfer at the fibre ends and selection of the representative volume element in the analytical model are required. The present predicted stress distribution along the fibre length during uniaxial loading of the composite is in excellent agreement with that obtained from a finite-element analysis. Also, by a judicious choice of the representative volume element for the modified shear-lag model, the predicted Youngʹs modulus of the composite is in excellent agreement with those predicted from the Halpin–Tsai semi-empirical equation, the Eshelby model, and numerical analyses. Comparison is also made with experimental measurements of Youngʹs moduli of aligned particulate- or whisker-reinforced SiC/aluminum-alloy composites, and good agreement is obtained.