3D multi-objective optimization of hybrid composite laminates: Influence of fiber orientation and stacking sequence

Hybrid laminated composites, integrating High Strength (HS) carbon and glass fibers (E, S) within an epoxy matrix, deliver an optimal compromise between lightweight design, mechanical strength, and cost-effectiveness for applications in industrial, aerospace, automotive, and civil engineering sectors. This study presents a three-dimensional optimization of mechanical performance through a multi-objective genetic algorithm (MOGA) under static loading conditions. The design variables encompass the number of plies (6 to 12), fiber orientation angles (-90°≤ θ ≤90°), and ply materials: HS-Carbon/Epoxy (CF-EP), E-Glass/Epoxy (EG-EP) and S-Glass/Epoxy (SG-EP). A constraint mandating 25% CF-EP placement at the core to maximize stiffness while minimizing stresses. The objectives are to enhance the longitudinal modulus (Ex) and reduce von-Mises stress, while ensuring compliance with the Tsai-Wu failure criterion. An analytical model, implemented in MATLAB, incorporates stiffness matrices, Tsai-Wu failure indices, and von-Mises stress calculations, demonstrating a 30% increase in stiffness and effective mitigation of stress concentrations through centralized CF-EP placement. These findings are corroborated by finite element method (FEM) simulations conducted in ANSYS, which exhibit strong agreement with analytical predictions. This hybrid methodology offers a strong framework for developing high-performance laminated composites, significantly impacting applications requiring structural reliability and efficiency.