A fast Fourier transform micromechanical upscaling method for the study of the thermal expansion of a TATB-based pressed explosive

摘要

This paper presents the first phase of development of a multiscale numerical method oper- ating at the microstructureal level for a TATB-based pressed plastic-bonded explosive. It uses a virtual model of microstructure mimicking the grain size distribution of the actual material, and a Fourier-based numerical scheme. At present, the method works with sim- plified microstructure and linear anisotropic thermoelastic behavior for the constituents. Neglecting the inter-granular binder leads to fairly overestimated values for isotropic elas- tic moduli and volumetric coefficient of thermal expansion. A first attempt to include the binder yielded much more realistic predictions for elastic moduli, but not for the volumet- ric thermal expansion coefficient. The origin of this discrepancy is thought to lie in the behavior of constituents.