The constitutive equations of fiber reinforced metal matrix composites.

Abstract

The constitutive equations of unidirectionally fiber reinforced metals were derived. A modified fraction model concept was applied to the matrix and fiber, separately. Equilibrium and compatibility were considered between the matrix and the fiber for deriving the constitutive equations. The proposed theory is expected to describe the inelastic behavior of FRM and the strain rate sensitivity of stress-strain relations. Static and dynamic tensile tests were performed on unidirectional boron/aluminum composites and cross-ply laminated plates. Static and dynamic stress-strain curves were obtained and the effect of the strain rate on tensile strength was investigated. The tensile strength of the 0° and laminated specimens showed no strain rate sensitivity; but the tensile strength of the 45° and 90° specimens increased as the strain rate increased. The validity of the proposed constitutive equations was confirmed by comparing the calculated results with the experimental ones.