Low amplitude insult project: PBX 9501 high explosive violent reaction experiments

Abstract

The Modified Steven test geometry has been used with several different target designs to investigate the mechanical loading behavior of PBX9501 to a low velocity impact. A 2 kg. mild steel spigot projectile is launched via a new powder driven gun design, from-20 to 105 m/s, at lightly confmed, steel targets. Brief descriptions of the gun design and operation are given. The threshold velocity to reaction for various target designs, different PBX 9501 lots, and different high explosive (HE) thicknesses are reported and compared. Various diagnostics have been employed to evaluate the pressure profile and timing, and target strain behavior relative to projectile impact. The violence of reaction, as measured by both passive and active techniques, is reported relative to a steady state detonation in PBX 9501. Experimental results suggest slightly different ignition mechanisms dominate based on (HE) thickness, resulting in delayed reactions from-0.2-to 2.8ms after impact. Post-test analyses of the PBX 9501 are briefly summarized.

Numerical simulation study on thermal response of PBX 9501 to low velocity impact

“…Simulation models were built according to the configuration at LANL in reference [3] and the one at LLNL in reference [2], simulation models were built. Temperature profile, pressure profile and reaction velocity were obtained.…”

“…Specific to the basic configuration at LANL in reference [3,4], the numerical model is built with the finite element code LS-DYNA [9] . The element type is 14 (Axisymmetric solid-area weighted), and the size of mesh is about 1 mm per cell.…”

“…Subsequently, a series of low velocity impact Steven tests on HMX based explosive were carried out by S K Chidester, D J Idar, R J Scammon, K S Vandersall, S Wortley et al [2][3][4][5][6] . Response of explosives at different impact velocities was obtained, the effect of projectile head and the aging problem of explosive were also considered, and the ignition and growth model was used in numerical analysis.…”

Response of HMX-based HE to low-velocity loading by steel cylindrical impactor

“…Among these investigations, lowvelocity mechanical effect (V imp =10-100 m/s) covers many practical cases (technological loadings, transportation loadings, accident loadings, terrorist attacks, etc.). In this field, significant results were obtained by experts Chidester et al, Vandersall et al, Idar et al from the US National Laboratories (LLNL and LANL) [1][2][3]. However, due to complexity of the explosive transformation process, there is no total data on conditions of its initiation today.…”

LX-04 Violence Measurements-Steven Tests Impacted by Projectiles Shot from a Howitzer Gun

“…Research on the Steven Test has been performed at Lawrence Livermore National Laboratory [1][2][3][4][5][6][7] as well as a modified version of this test at Los Alamos National Laboratory [8][9][10]. Converting overpressure transit data from impact to equivalent point source energy dates back to the Susan Test [11] and is discussed in a prior publication [12].…”