Reducing tensile stress concentration in perforated hybrid laminate by genetic algorithm

Holes are a common geometric discontinuity in composite structures. Since stress concentrations at a hole can decrease strength, it is desirable that such concentrations be as low as possible. This paper demonstrates ability to minimize tensile stress concentrations in a perforated laminated composite. Synergizing a genetic algorithm optimization method with a specially developed FEM program enables one to optimally orient the fibers locally both within the plies and from ply-to-ply, and thereby significantly reduced the tensile stress concentration associated with a hole. The present evolutionary technique provides more than just a favorable stacking sequence of various rectilinearly orthotropic plies having different fiber orientations.