Micromechanics Model of the FRC Subject to Heating High- Velocity Impact Using Continuum Damage Mechanics with Adiabatic Heating

Abstract

The popularities of the composites are increasing growth in manufacturing, with numerous advanced applications ranging from military and civil vehicles to decorative architectural facade. Experiments show that adiabatic heating becomes more noticeable at high strain rate deformation, causing the stress-strain slope to become negative. However, the rate-dependent micromechanics model in Z. Li et al. 2016 lacks the interpreted connection between energy dissipation and adiabatic temperature rise. This work aims to develop a thermal-mechanical model incorporating material heterogeneities to study multi-physics damage and failure of S-glass fiber reinforced epoxy composites under high-velocity impact. This study first established a rate-dependent nonlocal continuum damage model (CDM) with adiabatic heating for composite matrix, e.g., DER 353 Epoxy. A Split- Hopkinson pressure bar (SHPB) experiment from literature are rebuilt in FEM simulation to validates this material model. The research proves that thermal softening became more prominent as the strain rate increases. The new model is then integrated into a micromechanical analysis of composites representative volume elements (RVEs) to study the interaction between stress wave propagation and crack growth in composites RVE subjected to high strain rate deformation. Deformation and failure response of the RVE models exhibiting fiber and matrix damage as well as cohesive interfacial crack. This work is an extension of a broader multiscale work examining glass fiber reinforced composites under high strain rates.