Comparative assessment of design features and their effect on the energy absorption of fiber-reinforced composite tubes

In this work, 87 experimental datasets reported in the literature were analyzed to identify the key factors governing the energy-absorption performance of composite tubes under axial loading. The assessment considered experimental conditions—such as crushing length and axial strain—and load-related parameters obtained from testing, including peak and mean crushing forces. It was also found that longer crushing lengths promote a more complete development of progressive collapse mechanisms, thereby increasing the total absorbed energy. The axial strain interval ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>ε</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">x</mml:mi> </mml:mrow> </mml:msub> </mml:math> ≈ 0.18–0.22) was identified as the range associated with the highest specific energy absorption <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mi>S</mml:mi> <mml:mi>E</mml:mi> <mml:mi>A</mml:mi> </mml:math> values, suggesting the activation of more effective failure modes. A significant positive correlation was proposed between mean crushing force and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mi>S</mml:mi> <mml:mi>E</mml:mi> <mml:mi>A</mml:mi> </mml:math> ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mi>r</mml:mi> </mml:math> = 0.6791), and an even stronger correlation with total absorbed energy ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mi>r</mml:mi> </mml:math> = 0.9737), confirming mean crushing force as a critical design parameter. Specimens with lower mean crushing force ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>F</mml:mi> <mml:mrow> <mml:mi>m</mml:mi> <mml:mi>e</mml:mi> <mml:mi>a</mml:mi> <mml:mi>n</mml:mi> </mml:mrow> </mml:msub> </mml:math> &lt; 30 kN) exhibit greater scatter in their energy-absorption metrics, likely due to variations in manufacturing quality or internal defects. In contrast, specimens with intermediate and high mean force levels show reduced dispersion, indicating more stable and consistent behavior across configurations. Overall, tubes with higher mean strength consistently demonstrate superior energy-absorption capacity. These findings provide a solid foundation for developing predictive models to support the efficient design of composite structures for impact energy-absorption applications.