Microscale hybridization for enhanced impact and post-impact strength in fibre-reinforced composites: A comparative analysis of three hybrid concepts

Fibre-reinforced composites, such as carbon fibre-reinforced polymers (CFRP) and glass fibre-reinforced polymers (GFRP), are widely utilized in engineering applications for their exceptional strength and stiffness. However, their brittle failure and limited impact resistance hinder broader applications, especially in high-impact environments. Improving impact resistance is therefore critical for advancing their performance and expanding their usability. This study explores the development of novel composites with components hybridized on microscale that integrate high-strength fibres (e.g., carbon, glass) with ductile fibres (e.g., steel, aramid) through the fabrication of hybrid yarns featuring highly dispersed fibre components, rather than conventional layer-wise configurations. Three distinct hybrid composite concepts were developed using innovative fibre combinations and manufacturing techniques: Concept 1 (carbon, aramid, and thermoplastic filament yarns), Concept 2 (glass, stainless steel, and polypropylene yarns), and Concept 3 (recycled aramid, carbon, and thermoplastic fibres). The experimental results (tensile and Charpy impact tests) show that by using a specific combination of fibre materials, the properties: tensile strength, impact strength, and energy absorption of the hybrid composite can be specifically modified to meet the needs of the application. Notably, Concept 1 exhibited the highest tensile strength, while Concept 2 excelled in ductility and energy absorption. The hybrid yarns, produced using air texturing and carding techniques, showed optimized tensile properties through fine-tuning of air pressure and overfeed rates during manufacturing. These findings underscore the potential of hybrid composites with highly dispersed components in engineering applications requiring tailored properties.