Influence of Hollow Glass Microballoons on the Initiation Sensitivity of High Explosives

Additives such as hollow glass microballoons (HGMBs) can be used to tailor high explosive (HE) initiation sensitivity or performance. Similar to pores, HGMB collapse may lead to localized plastic deformation, temperature spikes and subsequent reaction. However, it is important to quantify whether the temperature rise generated by the HGMB offsets the initial energy required to collapse it. Due to this, the influence of HGMBs on the sensitivity of various HEs is not well characterized. In this study, we perform two-dimensional, mesoscale simulations of various HGMB configurations in an HE using LLNL’s multi-physics hydrocode, ALE3D. Shock loading is imparted into the sample via a Kapton thin flyer. The energetic constituent equation of state and chemical kinetics are provided by the thermochemical code, Cheetah. We probabilistically characterize the changes in the extent of chemical reaction in stochastic samples due to microballoon size, material, wall thickness, quantity and location. Predicted changes in material initiation sensitivity are compared to available experimental data.



This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-844173.