Energy absorption and failure mechanisms of hat-shaped glass/carbon hybrid composites under axial and lateral crushing

The current study examines the axial and lateral crushing properties of composite profiles designed with a hat-shaped configuration, made of pure carbon fiber reinforced polymers (CFRPs), pure glass fiber reinforced polymers (GFRPs), and hybrid configurations including glass-carbon-glass (GCG) and carbon-glass-carbon (CGC). The fabrication of composites was performed by layering woven glass fabric and carbon fiber sheets consisting of twelve plies in the form of an epoxy resin matrix through hand layup method followed by hot press molding. To investigate the mechanical properties of composites under compression, the specimens were subjected to axial and lateral crushing tests using a universal testing machine. It was observed that CFRP composite specimens showed the maximum absorbed energy (EA) value of axial and lateral loads as 232.68 ± 9.36 J and 25.62 J, respectively, due to their superior strength and stiffness properties. For the hybrid configurations, the GCG stacking pattern showed better results compared to the CGC pattern for axial and lateral crushing tests, absorbing approximately 58 % more EA from axial loads and approximately 35 % more from lateral loads. GFRP composites showed the lowest EA values, which were 81.59 J and 8.37 J for axial and lateral loads, respectively. This research showed that CFRP attained the highest SEA of 19.55 J/g under axial loading, while GCG achieved 13.54 J/g (approximately 70 % of CFRP’s value) at a considerably lower material cost.