Optimized fiber prestress for reduction of free edge stresses in composite laminates (Q5945349)

The authors optimize prestresses in fibers for the reduction of free edge stresses in composite laminates. They consider both thermal changes, piecewise uniform transformation strains in the plies and overal mechanical loads. The thermal and transformation load contributions are decomposed into superpositions of certain uniform fields with mechanical loads. The authors regard the release of fiber prestress as an equivalent uniaxial compression applied at the edge of each prestressed ply. They found optimized distributions of fiber prestress in individual plies such that the stresses in both laminate interior and at the free edges remain within allowable limits. Some specific results are obtained for cross-ply and quasi-isotropic symmetric S-glass/epoxy laminates under tension.