2-Scale Hierarchical Multiscale Modeling of Piezoresistive and Damage Response in Polymer Nanocomposite Bonded Explosive

Abstract

This paper builds on previous work done [1, 2] to explore the effective piezoresistive response of polymer bonded explosive (PBX) materials where the polymer medium is reinforced with carbon nanotubes (CNTs). In the present work, the nanocomposite binder is modeled explicitly as a piezoresistive material whose properties are determined from the nanoscale through a micromechanics based 2-scale hierarchical model connecting the nanoscale to the microscale grain structure. Electromechanical cohesive zones are used to model the interface between the grains and nanocomposite binder in order to characterize interface separation and the resulting piezoresistive effect. The overall microscale piezoresistive effect is measured by using the volume averaged properties of the microscale RVE. The hierarchical framework developed here is used to explore key features of the NCBX microstructure such as the effect of grain conductivity, weight percentage of CNTs used and nanocomposite gage factor.

Computational Micromechanics Investigation of Percolation and Effective Electro-Mechanical Properties of Carbon Nanotube/Polymer Nanocomposites using Stochastically Generated Realizations: Effects of Orientation and Waviness

“…An in-house electro-mechanical 2D finite element code is used to compute the effective electrical and mechanical properties for each realization. This code was previously developed in the Fortran and has been used successfully in several previous works studying CNT/polymer nanocomposite piezoresistivity [ 8 , 25 , 26 , 34 , 36 , 37 , 38 , 39 ] and strain/damage sensing of CNT embedded polymer based energetic materials [ 18 , 40 , 41 , 42 , 43 ].…”

Mesoscale strain and damage sensing in nanocomposite bonded energetic materials under low velocity impact with frictional heating via peridynamics

“…Piezoresistive sensing derived from the addition of carbon nanotube (CNT) inclusions to the polymer binder within the energetic composite has been proposed to develop an embedded structural health monitoring framework applicable to both unfielded and fielded energetic materials. Proof of concept for such embedded sensing has been demonstrated through experiments and computational models [14,[42][43][44][45][46][47][48][49][50]. The new energetic composite with the nanocomposite of polymer and CNTs acting as the binder medium is termed NCBXs [14,42,44].…”