Optimization of Antisymmetric Angle-Ply Strip for Maximum Strength Including Hygrothermal Effects

The transverse failure load on an antisymmetrically laminated angle-ply strip is maximized with respect to fiber volume ratio. The failure load is determined using the Tsai-Hill failure theory based on initial ply failure criterion. Hygrothermal conditions and the presence of voids in the resin are taken into account in computing the material and strength properties from micromechanical relations. Numerical results are given for graphite, boron and E-glass fibers and the effects of hot-wet conditions and voids are investigated on the efficiency and the fiber content of the optimal designs. Sensitivity of the designs to changes in the design variable is graphically studied.