Effect of Multi-Walled Carbon Nanotubes on Energy Dissipation Behavior of Epoxy Nanocomposites

Carbon nanotubes (CNTs) are widely utilized as nano-reinforcements in polymer matrices owing to their high aspect ratio and outstanding intrinsic mechanical properties. While most previous investigations have primarily focused on stiffness and strength enhancement, the influence of CNT incorporation on energy dissipation behavior in epoxy systems remains less systematically explored. In the present study, the effect of low-content CNT reinforcement (۰.۲۵ wt%) on the energy absorption characteristics of epoxy nanocomposites was experimentally investigated under uniaxial tensile loading. Peak energy values were calculated from stress–strain responses as the area under the curve up to maximum stress. The results indicate that although CNT addition increases the elastic stiffness of the system, it leads to a significant reduction in peak strain and consequently lower peak energy compared to neat epoxy. A decreasing trend in normalized peak energy was observed with increasing nanotube diameter, suggesting a diameter-dependent modification of fracture behavior. The findings demonstrate that stiffness enhancement does not necessarily correspond to improved energy dissipation capacity. Instead, CNT incorporation appears to govern a trade-off between rigidity and ductility, altering crack initiation and propagation mechanisms within the epoxy matrix. Energy-based evaluation provides deeper insight into nano-mechanical interactions than stiffness-centered assessment alone.

کلیدواژه ها:

Multi-Walled Carbon Nanotubes ، Epoxy Nanocomposites ، Polymer Composites ، Energy Dissipation ، Diameter Effect ، Tensile Behavior