57th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference at AIAA SciTech 2016 San Diego, California, USA 4-8 January 2016

AIAA-2016-0155

Multiscale Modeling of Effective Piezoresistivity in Nanocomposite Bonded Explosives

A. Chaurasia and G. Seidel
Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061-0203, USA

The current work aims to explore the eective material properties of polymer bonded explosive (PBX) materials where the polymer medium is reinforced with carbon nanotubes (CNT). In the current work, the effective properties of nanocomposite bound polymer explosives (NCBX) are evaluated using micromechanics based 2-scale hierarchal multiscale models connecting the CNT-Polymer nanocomposite scale (nanoscale) to the grain struc- ture scale (microscale). At the microscale, the binding polymer nanocomposite medium is modeled as cohesive zones between adjacent explosive grains. The cohesive laws for the polymer nanocomposite binder phase are developed based on the effective response of the CNT-polymer nanocomposite at the nanoscale. Eective piezoresistive properties of NCBX materials are evaluated through hierarchal multiscale modeling where the nanoscale effective response of the nanocomposites is evaluated offline using finite elements based micromechanics modeling. The effective properties obtained from homogenization of the nanoscale response are then used to construct microstructure informed cohesive laws which are embedded into the microscale grain boundary problem at the grain interfaces. The results show a significant piezoresistive response when the microscale boundary value problem is subjected to different types of applied deformation.