Material Point Method Simulation of the Equation of State of Polymer-Bonded Explosive under Impact Loading at Mesoscale

Abstract

Mesoscale simulation using the material point method (MPM) was conducted to study the pressure–volume (PV) variations of Octahydro-1,3,5,7-Tetranitro-1,2,3,5-Tetrazocine (HMX)/Estane polymer-bonded explosive (PBX) under impact loading. The PV isotherms and Hugoniot data were calculated for the different porosities and binder volume fractions. The PV isotherms were used to determine the parameters for the Birch– Murnaghan equation of state (EOS) for the PBX. From the EOS, the isothermal bulk modulus (K0) and its pressure derivative (K′0) were calculated. Additionally, the pseudo particle velocity and pseudo shock velocity variations were used to obtain the bulk wave speed c and dimensionless coefficient s for the Mie–Grüneisen EOS. The simulations provide an alternative approach for determining an EOS that is consistent with experimental observations.

Shock Hugoniot Calculations of Newly Designed Thermoplastic Elastomers and Comparison with Classical Binder Estane

“…10 In addition, Hugoniot data for common PBXs (e.g., PBX 9501) is also one of the focuses of experimental research. 11 Given the increasing complexity of the service environment, the quest for better performance of PBXs is endless. For example, IMs for the purpose of greater safety raise the requirements for better polymer binders, including shock performance.…”

“…Bourne et al had also studied the shock response of Estane using 50 and 75 mm bore light gas guns in the range of 0.6–3.5 GPa . In addition, Hugoniot data for common PBXs (e.g., PBX 9501) is also one of the focuses of experimental research …”