Trans-scale dynamic shear-lag model for the impact performance of fiber-reinforced composites

Abstract

This study proposes a new trans-scale dynamic shear-lag model that integrates the strain gradient linear viscoelasticity theory to investigate the effects of size and viscous softening on the dynamic mechanical properties and energy absorption characteristics of fiber-reinforced composites with micro- and nano-structures. The proposed model clarifies how the strain gradient effect can decrease energy dissipation in the matrix. Our investigation suggests that both classical and higher-order viscosities of the submicron-scale matrix can synergistically optimize energy dissipation. Furthermore, parametric studies demonstrate that the attenuation efficiency of absorbed energy changes non-monotonically with microstructure and constituent properties, such as matrix thickness, strain gradient elasticity parameter, classical viscosity, and high-order viscosity. The trans-scale dynamic shear-lag model advances our understanding of the energy dissipation in the submicron-scale viscoelastic matrix of fiber-reinforced composites and provides valuable guidance for developing composites with micro- and nano-structures that display exceptional dynamic properties.