Experimental and numerical analysis of a biodegradable hybrid composite under tensile and three-point bending tests

• Published in: Composite structures 2021-10, Vol.273, p.114255, Article 114255
• Main Authors: Beigpour, Reza, Shokrollahi, Hassan, Khalili, S. Mohammad Reza
• Format: Article
• Language: English
• Subjects: Biodegradable; Cotton; Green composites; Kenaf; Mechanical characteristics; Three-point bending
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2021.114255

Kenaf and cotton are agricultural materials used in a variety of applications around the world, and they are undoubtedly one of the most valuable natural fiber plants. Due to their strong tensile properties and high strength-to-weight ratio, polymer composite laminates with natural reinforcing fibers are very common. These composites have been the most popular due to their ease of molding, chemical resistance, physical and mechanical properties, proper bonding of the substrate to the fibers, and the ability to be used in a wide variety of applications. In this research, the mechanical properties of a hybrid green kenaf-cotton composite laminates which were made by using a dissolved mixture of chloroform and Polylactic Acid as matrix material, have been studied experimentally. Besides, the properties of this structure were investigated by finite element method (FEM) simulations, and to validate the research achievements, the results were checked by tensile and three-point bending tests. The experimental results show that by conducting tensile tests, kenaf layers were separated from the middle cotton layers and significate delamination occurred. The tensile strength and Young's modulus of this composite were 19.4 MPa and 1.055 GPa, respectively. The bending test of composite laminate showed that this structure is flexible and has a bending modulus of 450 MPa and a shear modulus of 167 MPa. By magnifying the fracture location of the composite under bending, tortuous crack growth in the matrix surface were observed. Studying the effect of composite thickness parameter using FEM simulations by doubling and halving the thickness of the composite in flexural tests, the amount of force increased by about 660% and decreased by about 87% respectively.