Hybridization of cotton/bamboo woven fabric epoxy composite laminates: an experimental investigation and optimization

This paper presents the experimental findings on the drilling behavior using a solid twist drill of epoxy composite laminates reinforced with cotton/bamboo (CB) woven fabric. This study focuses on the thrust force generated during drilling with respect to the spindle speed, feed rate and drill diameter. The composite specimens consisted of 45 wt% CB in an epoxy resin matrix. A Box-Behnken Design (BBD) was used to structure the experiments and the results were evaluated using both quadratic models based on Response Surface Methodology (RSM) and the Adaptive Neuro-Fuzzy Inference System (ANFIS). The analysis reveals that the thrust force is minimized with smaller drill diameters, higher cutting speeds and lower feed rates. Additionally, the ANFIS model demonstrated a high degree of accuracy, explaining 98.96% of the variation in thrust force, confirming its effectiveness in capturing the relationship between input parameters and output responses. The impact of this work lies in combining RSM and ANFIS with the significance of developing a robust and precise framework for optimizing drilling conditions in sustainable natural fiber composites. Hybrid CB/epoxy composites were optimized for minimal drilling thrust force. RSM and ANFIS models accurately predicted thrust force during drilling. Lowest thrust achieved with 6 mm drill, 20 mm/min feed, and 2400 rpm speed. ANFIS showed high prediction accuracy with R² = 0.9896 and MAPE = 1.03%. SEM analysis confirmed reduced defects under optimal drilling conditions.