AbstractIn this paper the results of both the theoretical and experimental stress analyses of composite materials reinforced with ribbons are presented. The reinforcing materials for such composites are characterized as two‐dimensional elements which are isotropic in planes parallel to the faces. The theoretical work is based on the finite element method. Experimentally, the photoelastic technique is employed to determine the stresses around the glass ribbons embedded in an epoxy matrix. The specimens, containing a number of aligned ribbons, were loaded in tension parallel to the ribbon width. The variation of shearing stress at the ribbon‐matrix interface as well as the pertubation effect on both the ribbon normal stress and interfacial shear due to the discontinuity of the neighboring ribbons are discus