Nonlinear Resonant Ultrasound Spectroscopy for Predicting Sensitivity to Initiation in Granular High Explosives

Journal Article · Wed Nov 06 00:00:00 EST 2019 · Propellants, Explosives, Pyrotechnics

DOI:https://doi.org/10.1002/prep.201900162· OSTI ID:1573264

Schulze, Peter ^[1]; Pittman, Emily ^[1]; Sjue, Sky ^[2]; Moore, David S. ^[1]; Feagin, Trevor ^[1]; Donahue, Carly ^[3]

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1. Explosive Science and Shock Physics Los Alamos National Laboratory Los Alamos NM USA
2. Physics Los Alamos National Laboratory Los Alamos NM USA
3. Earth and Environmental Sciences Los Alamos National Laboratory Los Alamos NM USA

Abstract Nonlinear Resonant Ultrasound Spectroscopy (NRUS) is a technique that can measure bulk nonlinear coefficients of the nonlinear elastic modulus for a material. NRUS has been used to identify damage in a variety of granular materials including rocks and concrete. Some energetic materials, such as Pentaerythritol Tetranitrate (PETN), are commonly fielded as pressed granular compacts. It is well known that the sensitivity to initiation of these materials is heavily dependent on their microstructure, and that microstructure changes naturally (becomes damaged) over time. In this study, we examine the use of NRUS to identify changes in microstructure between pristine and thermally aged PETN pellets. In particular, we examine the relationship between the bulk hysteretic nonlinearity, α , of the pellets and time spent at temperature, powder specific surface area (SSA), and sensitivity to initiation. We find that, in general, α does not increase uniformly for all pellets within a single thermal aging condition. However, when the pellets are test fired to determine sensitivity to initiation, there is a strong correlation between α and firing voltage threshold. NRUS‐measured α has the added benefit that the measurements can be made in situ and on benchtop scales.

• Sponsoring Organization: USDOE
• OSTI ID: 1573264
• Journal Information: Propellants, Explosives, Pyrotechnics, Journal Name: Propellants, Explosives, Pyrotechnics Vol. 45 Journal Issue: 3; ISSN 0721-3115
• Publisher: Wiley Blackwell (John Wiley & Sons)
• Country of Publication: Germany
• Language: English