Damage Evaluation of Jute and Jute/Glass Epoxy Composites under Low-Velocity Impact Using Computer Tomography and Shearography

Abstract

Compressed hybrid composite laminates with a thickness of 3 mm were fabricated using a skin–core configuration, employing jute and glass fabrics as reinforcements and epoxy as the matrix material. The impact performance and damage mechanisms of the jute/glass hybrid composites were compared against jute/epoxy composites with the same and variable thicknesses under varying low-velocity impact energies. The incorporation of glass fabric significantly improved the impact resistance of the thinner hybrid laminates. At a higher impact energy of 15 J, the hybrid composites exhibited a rebounding response, indicating superior energy absorption and damage tolerance. Laser shearography was utilized to examine the internal damage evolution, while computed tomography (CT) scanning was employed to quantitatively assess damage. An increase of up to 86% in the maximum impact load was observed from the hybrid composites with thickness of 3 mm when compared with the jute/epoxy laminates. CT scan analysis revealed completely perforated failure in the jute/epoxy composites with progressive crack propagation at different depths. The hybrid composites primarily exhibited localized sliding damage accompanied by surface denting, as observed through shearography. The findings confirmed that jute/glass hybrid composites offered an enhanced low-velocity impact resistance when compared with the pristine jute composites.