Failure analysis of angle‐ply thin woven <scp>GFRP</scp> composites under low‐velocity impact and low‐temperature

Abstract A comprehensive experimental and analytical study was conducted on quasi‐isotropic woven glass fiber‐reinforced polymer composites with a stacking sequence of [0°/±45°/90°]s, under low‐velocity impact at a low temperature of −50 °C. The results were compared to those at room temperature. The performance of the composite laminate was evaluated using 20 measured parameters for each impact test. Although these parameters may have been identified across dispersed numerous studies on different FRP composite materials, varying temperatures, and different impact levels, often result in scattered findings that complicate establishing accurate conclusions. This highlights the importance of the current study, which deals with 20 impact performance parameters within a single article for a comprehensive analysis. Among the important results of this study is the higher impact energy absorption efficiency of up to 76% at −50 °C, which demonstrates the strong performance of the composite laminates under low‐temperature and impact loads. The increase in energy absorption with impact energy correlates with an increase in impact bending stiffness, delamination threshold force, peak force, and rebound energy. The impact bending stiffness increases linearly with impact energy as the higher strain rate restricts polymer chain mobility, resulting in a stiffer and more brittle response. The predicted delamination threshold force, aided by classical laminate theory, significantly contributes to understanding various damage mechanisms at different impact levels. The prediction of the peak force using the effective peak contact force model and the multivariate regression model revealed strong agreement with the measured values, achieving a coefficient of determination above 0.99. Highlights LVI behavior of woven GFRP composites at low temperatures is vital for aerospace. New insights into damage mechanisms and failure prediction. Correlations of the damage assessment parameters with 20‐impact parameters. Perimeter damage length is a new damage assessment parameter. Explored energies of threshold delamination, damage propagation, and rebound.