Effect of Strain Rate on Fracture Behavior of Nanofiller Reinforced Polymers

Abstract

Nanofiller-reinforced polymers, incorporating carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), or silica nanoparticles, have emerged as high-performance materials with enhanced fracture toughness, stiffness, and energy absorption. Mechanical loading conditions, particularly strain rate, significantly influence fracture behavior, dictating crack initiation, propagation, and energy dissipation mechanisms. This study investigates the effect of strain rate on the fracture performance of nanofiller-reinforced polymer composites through experimental testing, fractographic analysis, and computational modeling. Polymers reinforced with CNTs, GNPs, and silica nanoparticles were subjected to quasi-static, intermediate, and high strain rate loading using tensile, bending, and impact tests. Fracture toughness, interlaminar shear strength, and crack propagation rates were quantified. Results demonstrate that nanofillers enhance fracture resistance at all strain rates, with distinct mechanisms governing low and high strain rate responses. CNTs provide effective crack bridging and pull-out at high strain rates, while GNPs promote crack deflection and energy dissipation under quasi-static loading. Multiscale modeling and cohesive zone analysis elucidate the interplay between strain rate, nanoparticle reinforcement, and fracture mechanisms, providing insights for designing high-performance polymers for dynamic applications.