MD simulation of HMX rupture under tensile stress

In this contribution, preliminary results of tensile tests on beta-HMX performed in a molecular dynamics simulation are presented. From experimental structure data, an atomistic model is created and a stress versus strain curve is measured during the gradual deformation of a crystalline rod (in the nano-scale) along the crystallographic b-axis. In concordance with experimental findings, the linear elastic deformation of the crystallographic b axis of beta-HMX shows a slope in modulus of roughly 14.4 GPa, until a stress maximum of 0.3 GPa is reached at a strain of 2%. Further strain results in a stress plateau at 0.3 GPa, where molecular rearrangement occurs within a plane perpendicular to the b-axis, at the outer region of a rod-shaped specimen, which corresponds to plastic deformation. At a strain of 0.28, the peel-like rupture is completed.