Experimental Investigation of Mechanical Performance of Hybrid Fiber Reinforced polymer Composites for Structural Application

Abstract

Natural fibers which are sourced from plant and animals will have a significant role in developing ‘green’ economy. Because it has attractive features of abundant availability, renewable resources, environmentally friendly, low cost, and biodegradability. Most of these natural fibers are discarded into landfill areas as wastes and removed by open burning that may lead to air pollution. The present study focus on using natural fibers like sheep wool and Enset (Enset Ventricosum) fiber for manufacturing the hybrid fiber composite material (HFCM) for structural application. This HFCM was synthesized by hand lay-up technique with design consideration of principal parameters such as Fiber volume ratio (30%,50%, and 75%), ply arrangement (EWE, WEW) and fiber orientation (MMM, MUM, MRM, URU, RUR). Then mechanical tests, thermal and machining tests were conducted to characterize experimentally beside theoretical studies. In the experimental section, the task was completed in four main stages. In the first stage, the physical properties of the fibers such as the crystallinity index and moisture absorption of HFCM were investigated. The result shows that the 5% Na OH treated fiber enhances the fibers crystallinity and cellulose fibers are more crystal than keratin-based fibers. In the second stage, the thermal stability nature of the fiber was investigated. Almost 5-6% of weight loss was seen in the range of 105-280˚c. It shows that, the stability of fiber and comparable results with others. In the third stage, the mechanical performance investigation of the HFCM was conducted. Tensile, impact and flexural tests were performed. The results showed that increasing fiber content increases the strength of the composite except up to the saturation limit of 56.1% fiber volume ratio. The woven orientation of the fiber also shows better strength than the other. HFCM with MMM fiber orientation, EWE ply arrangement and 56.1 % fiber volume ratio are the optimum model with 22 MPa, 7.12 MPa, and 28 KJ/𝑚2 tensile strength, flexural strength and impact strength respectively. Optimal custom response surface design experimentation with the quadratic model has been intended to model the tensile strength and flexural strength response. Finally, the machinability of the HFCM was investigated. The result shows, cutting quality of the HFCM depends on fiber to matrix adhesive strength and the direction of cutting relative to fiber orientation. After all, the goal of this HFCM is to use as an alternative for structural material. This HFCM suggests being used for refrigerator body, car dashboard, and gas cylinder manufacturing industries.