BEARING PERFORMANCE IMPROVEMENT OF SINGLE-LAP, SINGLE-BOLT CARBON/BASALT HYBRID FIBER-REINFORCED COMPOSITE JOINTS

Composite materials are assembled in a variety of ways in structural applications, but bolted joints have been commonly used due to their high load-carrying ability. Carbon fibers are widely employed in structural reinforcement. The drawbacks of carbon fibers are its brittleness, non-eco-friendliness, and high cost. Its use in automobiles is therefore restricted. Alternatives to carbon fiber such as basalt fibers are becoming more popular due to growing environmental concerns and the global need for lighter vehicles. However, their mechanical properties are mostly inferior to carbon fibers. Therefore, the primary goal of this research is to propose a cost-effective joint design that outperforms carbon-based joints. To address this, two approaches were used in this study. The first approach exploits the interaction of several design parameters to improve the bearing efficiency of natural basalt composite joints. The second approach comprises of carbon/basalt hybridization at global and local scales. All samples were
fabricated using a vacuum-assisted resin transfer molding process. Based on the bearing analysis, it was shown that when a large washer was used in the place of a small washer, a 5.5% improvement in 0.2% offset strength and a 58% recovery in joint stiffness could be achieved in high torque and high clearance joints, respectively.