Mechanical characteristics of optimized alkali-treated Similax Zelanica /glass fiber/nanosilica composites in an epoxy matrix: An experimental investigation and numerical study

Abstract

The demand for environmentally conscious materials has led the research on natural fiber composites as an alternative to synthetic materials in various industries. This study focuses on the optimization and preparation of alkali-treated Similax Zelanica/glass fiber and nanosilica-reinforced epoxy composites. The weight % of Similax Zelanica/glass and nanosilica was optimized using the grey relational analysis (GRA) multiparameter optimization technique and DOE of L9 orthogonal was used. Mechanical properties including tensile, flexural, impact, rock well hardness, and dynamic mechanical analysis were evaluated. Results indicate that increasing fiber volume fraction up to 30% enhances mechanical properties, with subsequent declines beyond this threshold. Tensile strength peaked at 30% fiber volume (75 MPa), while flexural strength also peaked at 30% substrate (140 MPa). The impact test showed a maximum of 1.84 kJ/m² at 30% volume fraction. Maximum hardness of 85 RHN is observed for 30% S and 60% E specimens. Weibull distribution plots results, aligned well with the expected distribution pattern, indicating consistent and reliable mechanical behavior. Water absorption rates increase with fiber volume percentage increase, but optimal alkali treatment improves, absorption resistance to some extent. Dynamic mechanical analysis reveals reduced glass transition temperature Tg (97° C) for composite due to their better interaction nature between fiber/silica nanoparticles and matrix. Further characterization reveals thermal stability (374°C), crystalline properties (crystalline index: 56.87%, crystalline size: 21.23 nm), and functional group composition. Numerical analysis using ANSYS validates experimental results, giving confidence in repeatability. Scanning electron microscope analysis confirms good interfacial bonding, crack propagation details, and absence of impurities in the composite. These results like Mechanical properties, thermal stability, crystalline properties, and functional group composition of the composite confirm its suitability for various applications.