Structural evaluation of flax fiber composite bolted joint

There has been a rising trend of substituting conventional materials like steel and aluminum with synthetic fibers due to the superior ratio of strength-to-weight, which makes them well-suited for use in structural applications. Composites can be easily tailored to meet specific requirements by altering the thickness of sections and the orientation of plies, ensuring they meet the necessary strength criteria. However, synthetic fiber manufacturing has a significant environmental impact, with the carbon footprint of CFRP being 14 times higher than that of steel production. Consequently, researchers are exploring the feasibility of using low-cost, widely available natural fibers such as bamboo, flax, vakka, and banana as a substitute for synthetic fibers. Naturalfibers reinforced with a suitable resin system have demonstrated exceptional mechanical properties. To utilize these composites for structural applications, it is vital to join them and assess the strength of the joints. Metal inserts may be bonded to the composite laminate to enhance joint strength. This project aims to evaluate the tensile strength of a single lap flax fiber laminate bolted jointand quantifying the improvement in its tensile load carrying capacity while using a stainless steel insert around the hole in flax fiberlaminate. Experimental and numerical study is performed to determine the effect of metal inserts on a single lap flax fiber laminate bolted joint. Material properties such as young’s modulus and shear modulus of flax fiber laminate are experimentally determined and are used as material data input for numerical analysis performed using ANSYS 2020 R2. Numerical analysis revealed that a fiber composite bolted joint with an SS insert can increase the joint stiffness by 35%, While experimental analysis showed an increase in joint stiffness of 24%.