On the axial and interfacial shear stresses due to thermal mismatch in hybrid composite sheets

A simple analytical model has been developed which allows the determination of the axial and the interfacial shear stresses which can occur in hybrid fiber composites as a consequence of the mismatch in coefficients of thermal expansion and Young's modulus. The configuration considered is a finite-width hybrid composite monolayer with alternating high- and low-modulus fibers. To account properly for the interfacial shear between fiber and matrix, a modified shear-lag model is used which permits extensional deformation due to thermal expansion of the matrix in the fiber direction. Typical stresses due solely to temperature changes are calculated, and these show steep boundary-layer edge stresses at free corners.