Single crystal model for high rate deformation of β-HMX*

A finite strain thermomechanical model developed by Luscher et al. is advanced and applied to the high rate deformation of β-cyclotetramethylene tetranitramine (β-HMX) single crystals. The model accounts for the plastic deformation due to the dislocation slip and deformation twinning. The viable set of slip systems for β-HMX was evaluated from quasistatic simulations of the Knoop indentation experiments by Gallagher et al. We calibrate the dislocation slip part of the model to the plate impact experiments by Dick et al. For the twinning part of the model we use the phase-field framework proposed by Clayton and Knap. We added anisotropy to the twin interface energy to accurately capture the elongated shape of twins observed in the experiments. We will report predictions of the twin growth for several orientations of β-HMX crystals under shock compression.
Luscher et al., Journal of the Mechanics and Physics of Solids 98 (2017) 63–86
Gallagher et al., Chemistry Central Journal (2015) 9:22
Dick et al., J. Appl. Phys. Vol. 96, No. 1 (2004)
Clayton and Knap, Physica D 240 (2011) 841–858