Effects of fiber volume fraction on the elastic stability of specially orthotropic plates

This paper presents an analysis of the effects of fiber volume fraction on the elastic stability of composite plates. Specially orthotropic boron-epoxy plates having various fiber volume fractions and plate geometries are examined in detail. Only the case of in-plane compressive loads is considered. The analysis is done using a computer program that calculates both the material properties and buckling loads of the plates. Micromechanics theory is used first to calculate the physical properties of the plates for the various fiber volume fractions. The buckling loads are then calculated by an equation derived from Reissner's Variational Theorem. This buckling equation accounts for transverse shear deformation, which can significantly affect the buckling loads of composite plates. Results of the analysis show that fiber volume fraction is a considerable factor in a composite plate's ability to withstand buckling. It is concluded that increasing the fiber content of a composite material, within reasonable limits, will enhance the elastic stability of composite plates.