Thermo-Electromechanical Response of Polymer-Bonded Explosives for Structural Health Monitoring of Energetic Materials

Distributing a carbon nanotube sensing network throughout the binder phase of energetic composites is investigated in an effort for real time embedded sensing of localized heating in polymer bonded explosives (PBXs) through thermo-electromechanical response for in situ structural health monitoring (SHM) in energetic materials. The experimental effort herein is focused on using 70 wt% Ammonium Perchlorate (AP) (solid oxidizer used in solid rocket propellants) crystals embedded into epoxy binder having concentration of 0.1 wt% multi-walled carbon nanotubes (MWCNTs) relative to entire hybrid energetics. Electrical and dielectric properties of neat (i.e. no MWCNTs) energetics and MWCNT hybrid energetics are quantitatively and qualitatively evaluated under localized thermal loading. Electrical and dielectric properties showed variations for both neat energetics and MWCNT hybrid energetics depending on input frequency measurements. Significant thermo-electromechanical response was obtained for MWCNT AP hybrid energetics, providing a proof of concept for thermo-electromechanical sensing for realtime SHM in energetics.