Integrating Fiber Overbraids in Composites for Enhanced Compressive Performance

Advanced composite materials have become the key to many modern engineering applications due to their material property flexibility and high strength-to-weight ratio. However, achieving optimal compressive performance is still challenging, especially for systems where the ability to maintain the material’s structural integrity under compressive loads is highly important. Overbraids represent a unique form of reinforcement, as they provide additional support and resistance to compressive forces. This paper discusses the process and challenges of overbraiding small-diameter pultruded rods (0.8 mm), with overbraids integration in strut manufacturing from design consideration to manufacturing using a resin transfer moulding (RTM) technique and optimization strategies. A novel and rigorous approach to the attainment of a consistent internal geometry of triaxial overbraids within a composite strut is presented. The micro-CT characterization of composite struts having three different lay lengths (2.5, 4, 6 mm) and braid angles (34, 49, 610) are also presented. The result shows the level of resin infusion with shear support on the surrounding matrix region of the overbraids within the struts. The results from the micro-CT scans show that overbraided rods were fully wetted with epoxy resin with no recorded visible void.