A MECHANICS MODEL FOR THE COMPRESSIVE RESPONSE OF FIBER-REINFORCED COMPOSITES

This article presents a model for the uni-axial compressive response of uni-directionally reinforced fibrous composite. The model accounts for the non-linear shear response and the failure strain of the matrix, incorporating both aspects into a non-linear field equation which governs the load-deflection process. In addition, the model considers the effects of two kinds of geometric imperfections, namely, initial fiber waviness and random fiber spacing. it is shown that, under uni-axial compression, random fiber spacing may instigate the formation of severe transverse loadings on the fibers, which suggest the existence of a transitional mechanism from micro-buckling to micro-kinking. Computational results are presented which illuminate the effects of several material and geometric factors on the compressive strength of composites.