Effects of temperature and strain rate on the dynamic responses of three polymer-bonded explosives

Abstract

Polymer-bonded explosives (PBXs) are typical particulate composites of energetic crystals in a polymer matrix, which have a volume fraction of 60% to 95%. They are engineered to provide reliable performance and maximum safety envelopes through reduction of their sensitivity. There are three kinds of polymer-bonded explosive materials; namely, PBX1, PBX2, and PBX3. The last two polymer-bonded explosives were recently invented, in search of the more insensitive polymer-bonded explosive but with high detonation energy also. To investigate the dynamic response of new materials, the uniaxial compressive stress-strain behavior of the three polymer-bonded explosives was investigated as a function of temperature and strain rate. Constant and non-constant strain rate loading experiments were conducted in the use of pulse shapers. By comparing two different loads, the strain rate effect of these materials was found to depend on the instantaneous strain rate. The variations in failure stress, and failure strain with temperature, strain rate, and material composition were examined. The dependence of compressive strength on temperature and strain rate can be attributed to the Young's modulus and fracture surface energy according to Griffith criteria for fracture. The axial splitting caused by brittle fracture for most conditions was also investigated. Another failure mode of PBX2 agreed with the Mohr's failure mode criterion. All results show that PBX2 has more stable mechanical behavior and higher detonation performance.

Wide range temperature-dependent deformation and fracture mechanisms for 8701 under dynamic and static loading

“…11 Li et al investigated the uniaxial compressive stress-strain behavior of three PBXs and found that the yield strength of PBXs is negatively correlated with temperature and positively correlated with strain rate. 12,13 The compressive and tensile properties of PBX9501 and 9502 have been investigated over broad temperature ranges and drastically different loading strain rates. 14 The dynamic response of an aluminized PBX over a temperature range of À55 C to À2 C and under a xed loading strain rate has been tested using the split Hopkinson pressure bar (SHPB).…”

Dynamic Mechanical Properties and Constitutive Relation of an Aluminized Polymer Bonded Explosive at Low Temperatures

“…Some research works on dynamic mechanical properties of PBXs have been done [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The dynamic and static mechanical properties of PBXs were very different [5].…”

“…The dynamic and static mechanical properties of PBXs were very different [5]. Furthermore, researchers have paid more attention to the effect of temperature on dynamic mechanical response of PBXs [6][7][8][9][10][11][12][13][14][15][16]. The stress-strain responses of PBX9501 and mock 9501 were tested under different temperatures and strain rates [6].…”

“…Li et al tested the dynamic compression of three PBXs with three different temperatures at different loading strain rates. Their conclusion was that the compressive yield strength of the PBXs was negatively correlated with temperature and positively correlated with the strain rates [13,14]. By using the split Hopkinson pressure bar (SHPB), Qin et al tested a PBX analog to investigate the effect of temperature and strain rate on mechanical properties [15].…”

The Pore Collapse “Hot-Spots” Model Coupled with Brittle Damage for Solid Explosives

“…The present elastic-viscoplastic collapse models are mostly based on the ductile mechanical property based on Carroll-Holt's model [14]. On the contrary, many experimental results show that explosives, such as PBXs, have typical brittle mechanical properties under impact loading [15][16][17]. The initial defects or damage in the explosives is inevitable in the process of production or usage.…”