Investigation of the quasi-static crash response of circular glass-aramid hybrid composite tubes

This study investigates the quasi-static crashworthiness of circular composite tubes fabricated from glass (G), aramid (A), and hybrid glass-aramid (G/A) fibers embedded within an epoxy resin matrix. The tubes were fabricated using the hand lay-up wet-wrapping technique. Under uniaxial quasi-static compression, the crash load and corresponding energy absorption were recorded as functions of axial displacement, while deformation histories were monitored to characterize failure mechanisms. The crashworthiness evaluation focused on key indicators, including the initial peak load ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal">P</mml:mi> <mml:mtext>ip</mml:mtext> </mml:msub> </mml:mrow> </mml:math> ), total absorbed energy (AE), mean crash load ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal">P</mml:mi> <mml:mtext>avg</mml:mtext> </mml:msub> </mml:mrow> </mml:math> ), crash force efficiency (CFE), and specific energy absorption (SEA). To quantify variability and failure probability, a two-parameter Weibull distribution was fitted using the least-squares method. The results demonstrated that the hybrid configuration 4A/4G exhibited the highest P ip = 9.66 kN, which is approximately 256% higher than that of the pure aramid tube (8A, P ip = 2.71 kN). In contrast, the pure glass tube (8G) achieved the highest AE = 404.93 J, corresponding to an increase of 220% compared to the lowest-performing hybrid (A/2G/2A/2G/A, AE = 126.38 J). Similarly, the 8G specimen recorded the highest <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal">P</mml:mi> <mml:mtext>avg</mml:mtext> </mml:msub> </mml:mrow> </mml:math> = 5.47 kN, 238% greater than that of the lowest (1.62 kN for A/2G/2A/2G/A), and exhibited the highest CFE = 93.71% and SEA = 9.62 J/g, which are approximately 241% and 192% higher than those of the same hybrid, respectively. The 4A/4G hybrid displayed the lowest CFE = 27.47. The failure probability plots provide a practical tool for predicting performance variations and guiding the optimal design of energy-absorbing composite tubes.