Shock wave propagation in carbon honeycomb nanostructure and effect of cell vacancies

Abstract

Due to its periodic porous structure and high mechanical strength, carbon honeycomb (CHC), a new carbon allotrope, possesses a high energy absorption capability and thus great potential for the design and fabrication of advanced impact-resistant materials. In this work, the propagation and attenuation of shock waves in CHC are investigated for the first time via molecular dynamics simulation. The simulation results indicate that the propagation speed of shock waves in CHC is highly anisotropic and the shock wave energy decays with the propagation distance exponentially regardless of the direction. In addition, the energy decay is accelerated at elevated temperatures. When vacancies are introduced into CHC, the shock wave propagation in it is significantly impeded due to the large deformations of the vacancies in the form of shrinkage and expansion caused by the shock wave. The calculation of the critical shock wave intensity at which structure failure of CHC initiates shows that the cell axis direction of CHC can sustain a high shock wave intensity which is over two times higher than those for the other two directions. The simulation results obtained in this work are helpful for the design, fabrication, and application of CHC-based and other porous impact-resistant materials.