Title: Computational electromechanical peridynamics modeling of strain and damage sensing in nanocomposite bonded explosive materials (NCBX)

Naveen Prakash
Engineering Science and Mechanics Dept., Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

Gary D. Seidel,
Dept. of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA

Engineering Fracture Mechanics -- 2017 -- Vol. 177, pp. 180-202

Abstract
Polymer bonded explosives are complex materials which can weaken and more importantly accidentally detonate as a result of microstructural damage if subjected to mechanical insults. It is proposed that dispersing carbon nanotubes within the material will allow for in situ, real time structural health monitoring owing to the unique piezoresistive properties of nanocomposites. To explore this further, a coupled electromechanical peridynamics framework is employed to investigate the deformation and damage sensing capabilities of nanocomposite bonded explosives at the microstructural level. The peridynamics framework enables in capturing key deformation and damage mechanisms associated with this complex material system. Preliminary studies show that CNT content and the electrical conductivity of the grains are important parameters which impact the piezoresistive response. Moreover, these parameters affect the response in the elastic and damage regimes in significantly different ways. Lastly, results from numerical simulations are compared to experimental data on the piezoresistive response of mock NCBX materials, and it is concluded that there is promise in this novel application of nanocomposite based sensing.