Effect of Alkali Treatment on Mechanical and Buckling Behaviour of Natural Fiber Reinforced Composite Cylinder
Abstract
A structure made from metal, plastic, or ceramic has limited strength, corrosion, and aging tendency. This is overcome by composite or functionally-graded materials. Generally, composites from synthetic fiber reinforcement are widely used. Now-a-days, to meet sustainability, new materials from agricultural or industrial wastes are engineered by the research that has been reported. In this scenario, the replacement of conventional synthetic fiber with natural fiber (bana stem[BS]) and the use of fly ash (FA) increases socio-environmental value. Further, it is evidenced that, most of the researchers had prepared layered rectangular composite parts and studied the usability in different aspects. In contrast to this here, a functionally-graded-hybrid-composite (FGHC) cylinder is fabricated from BS fiber, epoxy, and FA using a designed centrifugal mold. BS-fiber is pulverized to nano size. Further, the effect of alkali treatment is studied by chemically treating BS-fiber and FA (2.5% alkali, 1h), and improvement of interfacial bonding of reinforcements with the matrix is reported. A centrifugal mold is used to prepare FGHC cylinders. Different material testing i.e., hardness test, impact test, buckling test, thermal-analysis, XRD, and SEM tests are conducted to evaluate strength and microstructure. It is evaluated; that the addition of BS fiber induces flexibility with a rise in tensile strength, compressive strength, and hardness. Meanwhile, the addition of FA increases thermal conductivity and stability in FGHC-cylinder. It is demonstrated that alkali treatment can result in up to 38% rise in flexural and compressive strength for interfacial bonding of polymeric-base to fibers. Further, the effect of rotation speeds, and particle size of nano-filler (FA) on mechanical characteristics of FGHC-cylinders is also tested and found to have an evidential effect. Further, finite-element analysis of the FGHC cylinders is conducted to find limiting values of stresses (like hoop stress, longitudinal stress, and buckling stress) to changes in internal pressures, loads, and geometries. It is found that FGHC cylinders or pipes could match the design needs of conventional materials.