Modeling and Optimization of Alumina Filler-Enhanced Epoxy/Mulberry Fiber Composites Using Stacked Ensemble Modeling and Multi-objective Moth Swarm Algorithm
摘要
This study presents a comprehensive experimental and computational investigation into the mechanical performance optimization of epoxy-based composites reinforced with alkali-treated mulberry fibers and alumina micro-fillers. The primary objective was to enhance tensile strength, flexural strength, and energy absorption while minimizing tensile failure strain, through a hybrid methodology combining experimental design, machine learning, and multi-objective optimization. Composite laminates were fabricated using vacuum-assisted resin transfer molding (VARTM) based on a Taguchi L16 orthogonal design, varying fiber length (0.5-150 mm), fiber content (30-60 wt.%), and filler content (3-12 wt.%). Mechanical characterization was performed per ASTM standards, and predictive modeling was implemented using a stacked ensemble framework integrating Random Forest, Gradient Boosting, and a polynomial meta-learner. The model achieved high predictive accuracy with R2 values of 0.91-0.94 across all responses. Multi-objective Moth Swarm Algorithm (MOMSA) was employed to explore the Pareto front, identifying optimal configurations with superior performance. The knee-point solution yielded a tensile strength of 171.15 MPa, flexural strength of 131.71 MPa, energy absorption of 10.45 J, and tensile failure strain of 1.02%, closely matching model predictions. Fractographic SEM analysis revealed hybrid failure modes including fiber pull-out, filler debonding, and matrix shear yielding, supporting the observed enhancements. The developed framework demonstrates the effectiveness of machine learning-guided multi-objective optimization for tailoring natural fiber-reinforced composites, offering a scalable approach for sustainable material design.