Design and Optimization of a Hybrid Polyester Composite for Bus Roof Plates Using Jute and Reused PET Fiber Reinforcement

Abstract

The automotive sector faces rising fuel consumption and pollution due to the increasing vehicle numbers. To mitigate these challenges, lightweight materials have become imperative to diminish the weight of automotive components. Additionally, addressing the pervasive issue of plastic pollution necessitates innovative solutions, such as recycling or reusing the primary plastic pollutant, polyethylene terephthalate (PET). This study tackles two interconnected issues: reducing vehicular weight through material substitution and mitigating plastic waste by reusing PET from discarded water bottles. The main objective of this study is to design and optimise a hybrid polyester composite material for bus roof plates for the modified ISUZU NPR71 4570cc, utilizing jute and reused PET fibers as reinforcement. Samples were prepared using the hand lay-up method, with fiber-to-matrix weight fractions ranging from 40% to 60%. Five laminates were created, incorporating alkali-treated jute fibers to enhance interfacial adhesion. Through a series of experimental tests, the tensile, compressive, flexural, impact strengths, density, and water absorption rates were conducted. The TOPSIS method was applied to assess and evaluate the properties of prepared laminate samples. Results indicate that the P-J-J-P orientation of NaOH treated jute fiber stands out as the optimal choice. The NaOH-treated jute fiber reduces water absorption by 47% (1.13% compared to 2.13% for untreated jute). A hybrid composite with a PJ-J-P layup and a 0°-90°-0° orientation was used to design a bus roof plate, optimised using Hyper Works-Optistruct and validated through re-analysis with ABAQUS. The optimised jute/PET hybrid polyester composite roof plate achieved a 34.58% weight reduction compared to a mild steel plate, decreasing from 210.38 kg to 137.63 kg, and saved 0.2765 litres of fuel per 100 km. This demonstrates that jute/PET hybrid polyester composites can effectively replace steel structures, offering significant environmental benefits and fuel savings without compromising performance or vehicle load capacity.