TOPSIS-Based Performance and Drilling Delamination Assessment of Chemically Treated PALF Composites for Lightweight UAVs.

This study investigates the performance of chemically treated pineapple leaf fiber (PALF) mat-based epoxy composites for potential use in lightweight unmanned aerial vehicles (UAVs). Prior to fabrication, PALF mats were treated with NaOH to enhance fiber-matrix adhesion. The resulting composites showed significant improvements in mechanical properties, with a maximum tensile strength of 25.82 MPa and a tensile modulus of 3938 MPa. Bending tests revealed a peak stress of 21.47 MPa and a modulus of 2418 MPa, corresponding to an approximate 30% increase in strength at 12% alkali treatment. Drilling experiments were performed under varying parameters, and delamination factors were assessed to evaluate the damage tolerance. Quantitative analysis showed that the 12% NaOH-treated composite achieved optimal drilling performance at 2142 rpm, 50 mm/rev feed, and 8 mm drill diameter. Analysis of variance (ANOVA) shows that drill diameter and cutting speed were the dominant factors governing delamination and surface quality. Additionally, the technique for order preference by similarity to ideal solution was applied as a multicriteria decision-making tool to optimize drilling parameters and minimize delamination. The results demonstrate that properly treated PALF composites combine enhanced mechanical performance with improved damage resistance, highlighting their potential for lightweight UAV structural applications.