Detonation Velocity Dependence on Front Curvature for Overdriven Detonation in Solid Explosives

2017 ◽  
pp. 923-925
Author(s):  
Y. Partom
Keyword(s):  
Detonation Velocity ◽  
Velocity Dependence ◽  
Solid Explosives ◽  
Overdriven Detonation ◽  
Front Curvature

scholarly journals The EFP Formation and Penetration Capability of Double-Layer Shaped Charge with Wave Shaper

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4519
Author(s):  
Yakun Liu ◽  
Jianping Yin ◽  
Zhijun Wang ◽  
Xuepeng Zhang ◽  
Guangjian Bi
Keyword(s):  
Detonation Wave ◽  
Double Layer ◽  
Detonation Velocity ◽  
Incidence Angle ◽  
Shaped Charge ◽  
Experimental Simulation ◽  
Detonation Waves ◽  
Forming Process ◽  
Large Length ◽  
Overdriven Detonation

Detonation waves will bypass a wave shaper and propagate in the form of a horn wave in shaped charge. Horn waves can reduce the incidence angle of a detonation wave on a liner surface and collide with each other at the charge axis to form overdriven detonation. Detection electronic components of small-caliber terminal sensitive projectile that are limited by space are often placed inside a wave shaper, which will cause the wave shaper to no longer be uniform and dense, and weaken the ability to adjust detonation waves. In this article, we design a double-layer shaped charge (DLSC) with a high-detonation-velocity explosive in the outer layer and low-detonation-velocity explosive in the inner layer. Numerical and experimental simulation are combined to compare and analyze the forming process and penetration performance of explosively formed projectile (EFP) in DLSC and ordinary shaped charge (OSC). The results show that, compared with OSC, DLSC can also adjust and optimize the shape of the detonation wave when the wave shaper performance is poor. DLSC can obtain long rod EFPs with a large length-diameter ratio, which greatly improves the penetration performance of EFP.

Observations of detonation in solid explosives by microwave interferometry

1958 ◽  
Vol 248 (1255) ◽  
pp. 499-521 ◽  
Keyword(s):  
Activation Energy ◽  
Detonation Velocity ◽  
Fringe Pattern ◽  
Detonation Front ◽  
Beam Theory ◽  
Kcal Mole ◽  
Zone Length ◽  
Solid Explosive ◽  
Interferometric Technique ◽  
Solid Explosives

Detonation processes have been observed in narrow, heavily confined, columns of solid explosive by a new microwave interferometric technique. The technique is described and a multiple-beam theory of fringe shape is given. The location, with respect to the detonation front, of the surface reflecting the microwaves is discussed. Detonation velocity as a function of distance along the column is derived from an oscilloscope display of the fringe pattern. The calculation of the detonation velocity requires a knowledge of the wavelength of the microwaves in the explosive. For this purpose the relative permittivities of a number of explosives are given as a function of their pressed density. The accuracy and applications of the method are discussed. Experiments on tetryl are described in which the technique is evaluated by observing the detonation velocity for a range of densities, and is applied to resolution of the velocity transient during growth to detonation. A simple theory of growth is used to estimate the reaction zone length (0.4 mm) and the activation energy (2 kcal/mole) in the detonation of tetryl.

Investigation of Jet Formation with Overdriven Detonation in High Density Explosive

2007 ◽  
Vol 566 ◽  
pp. 327-332 ◽  
Author(s):  
Hisaatsu Kato ◽  
Kenji Murata ◽  
Shigeru Itoh ◽  
Yukio Kato
Keyword(s):  
Numerical Simulation ◽  
Detonation Velocity ◽  
Tungsten Powder ◽  
High Density ◽  
Shaped Charge ◽  
Detonation Pressure ◽  
Jet Formation ◽  
High Explosives ◽  
Overdriven Detonation ◽  
Penetration Velocity

To increase largely the performance of shaped charge, it is required to generate detonation velocity much higher than CJ velocity or detonation pressure much higher than CJ pressure of existing high explosives. One solution is the application of overdriven detonation phenomena. In this study, the effects of overdriven detonation in tungsten loaded high density explosive on the performance of shaped charge were demonstrated by experiments and numerical simulation. Sample shaped charge was composed of the inner layer tungsten loaded high density PBX and outer layer high velocity PBX. Concentration of tungsten powder in high density PBX was varied from 20 to 60% in mass. The pressure of overdriven detonation in inner layer PBX was measured by PMMA gauge, and was shown to be higher than 50GPa. The experimental results showed that the initial jet velocity and jet penetration velocity in target plates were largely increased by the effects of the overdriven detonation in tungsten loaded high density PBX.

scholarly journals The Non-Stationary Metal Vapour Arc

1973 ◽  
Vol 28 (3-4) ◽  
pp. 428-437
Author(s):  
G. Ecker
Keyword(s):  
Residence Time ◽  
Critical Currents ◽  
Theoretical Studies ◽  
Velocity Dependence ◽  
Metal Vapour ◽  
Energy Characteristics ◽  
Upper Limit ◽  
Physical Background ◽  
Experimental And Theoretical Studies ◽  
Spot Motion

AbstractThe motion is depicted as a sequence of steps of a finite residence time.The spot motion affects essentially only the energy characteristics Te which in comparison to the stationary characteristics Tes are shifted to smaller values. Hereby the critical currents I0, I1 are raised in comparison to the corresponding stationary limits I0s, I1s. Particularly attractive are the phenomena found in connection with the dependence of the spot velocity ʋ on the spot current I. If the spot velocity increases with the spot current stronger than ʋ ∞ I1/2 then the E-diagram reveals the existence of an upper limit lu for the spot current. This result can be used to explain qualitatively the experimentally observed phenomena of "spot multiplicity" and “spot extinction”.Quantitative conclusions are obstructed by the lack of knowledge about the velocity dependence on the spot current, ʋ(I). Experimental and theoretical studies to provide a better understanding of the physical background and the analytical laws describing the motion of the cathode spots are urgently needed.

scholarly journals Frictional properties of anorthite (feldspar): implications for the lower boundary of the seismogenic zone

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Koji Masuda
Keyword(s):  
Dominant Role ◽  
Lower Boundary ◽  
Earthquake Magnitude ◽  
Seismogenic Zone ◽  
Effective Pressure ◽  
Velocity Dependence ◽  
Brittle Deformation ◽  
Frictional Properties ◽  
Depth Extent ◽  
Mineral Constituents

Abstract Earthquake magnitude is closely related to the depth extent of the seismogenic zone, and higher magnitude earthquakes occur where the seismogenic zone is thicker. The frictional properties of the dominant mineral constituents of the crust, such as feldspar-group minerals, control the depth extent of the seismogenic zone. Here, the velocity dependence of the steady-state friction of anorthite, the calcic endmember of the feldspar mineral series, was measured at temperatures from 20 to 600 °C, pore pressures of 0 (“dry”) and 50 MPa (“wet”), and an effective pressure of 150 MPa. The results support previous findings that the frictional properties of feldspar play a dominant role in limiting the depth extent of the seismogenic zone. This evidence suggests that brittle deformation of anorthite may be responsible for brittle fault movements in the brittle–plastic transition zone.

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