Insights into the Mechanical-Structural-Energetic Responses of RDX Nanoparticles from Molecular Dynamics Simulation

When the particle size of energetic materials is reduced to the nanoscale, significant changes occur in their properties and behavior. In this work, compression processes of three RDX nanoparticles (A, B, and C) were simulated using ReaxFF-lg. The mechanical, structural, and energetic responses of RDX nanoparticles during compression were revealed and characterized. Simulations reveal that the compression process of the nanoparticles can be divided into three stages: elastic stage, primary damage stage, and sustained damage stage. The temperature increase rate in the elastic phase is much lower than in the primary damage phase. In addition, we found that the smaller nanoparticle B presents a smaller elastic modulus and compressive strength, and it has a slower rate of temperature increase during the primary damage phase. Compared to cuboidal nanoparticles (A and B), the spherical nanoparticle C tends to absorb less energy during the elastic stage and exhibits slower damage rate during the primary damage stage. This is a key factor contributing to the low sensitivity of spherical nanoparticles.