Numerical study of velocity distribution of fragments caused by explosion of a cylindrical cased charge

Grisaro, Hezi Y.; Dancygier, Avraham N.

doi:10.1016/j.ijimpeng.2015.06.024

Cited by 84 publications

(37 citation statements)

References 16 publications

(27 reference statements)

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“…Previous study [22] indicated that the maximum propagation distance of the rarefaction wave was 2r c from the end of initiation and r c from the other end, where r c denotes the outside radius of the explosive charge. Therefore, in their test, the length of the explosive charge was sufficiently large to eliminate the effects of the rarefaction wave from the ends of the warhead on the maximum fragment velocity [22][23][24]. The material parameters in our numerical simulation were adopted from references [20,25].…”

Section: Validation Of Numerical Modelmentioning

confidence: 99%

Fragment Velocity Characteristics of Warheads with a Hollow Core under Asymmetrical Initiation

Dong

Liu

2019

Propellants Explo Pyrotec

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Fragment velocity characteristics of warheads are key issues in the field of explosion technology and protection. However, the fragment velocity characteristics of a warhead with a hollow core under asymmetrical initiation are rarely touched. In this work, the effects of the diameter of the hollow core on the fragment velocities of warheads under asymmetrical initiation were investigated by experimentally verified numerical simulations. The results showed that the fragment velocity‐time curves exhibited a second time acceleration due to the collision of the shock/detonation wave and/or that of the detonation products. For warheads under symmetrical initiation, the second time acceleration becomes stronger, and then becomes slightly weaker with the increase of the diameter of the hollow core, due to the combined effects of bigger hollow core and less explosive charge mass. For warheads under asymmetrical initiation, the second time acceleration becomes more obvious with the increase of the diameter of the hollow core, because the larger shaped charge efficiency enhances the collision of the detonation products. A modified formula was proposed to predict the initial fragment velocity in the aiming direction of a warhead with a hollow core under asymmetrical initiation. Experimentally verified numerical simulations were then used to verify the formula and the results showed that the new formula could predict the velocity very well. This work could offer a good reference for the design of tunable effects warheads and aimable warheads.

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Section: Validation Of Numerical Modelmentioning

confidence: 99%

Fragment Velocity Characteristics of Warheads with a Hollow Core under Asymmetrical Initiation

Dong

Liu

2019

Propellants Explo Pyrotec

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“…The diameter of the charge is 23.6 mm and casing thickness is 3.04 mm. In the numerical model, the Comp B explosive is used as the charge [1,2] and its material parameters are taken from AUTODYN software's material database [17]. The parameters of the casing's material strength, EOS and stochastic failure models are taken from reference [2].…”

Section: Full Papermentioning

confidence: 99%

“…Fragment velocity is an important parameter for fragmentation warheads [1][2][3]. Under constraints on warhead weight and volume, enhancing fragment velocities could increase the utilization of explosive energy and improve the probability of damage to targets.…”

Section: Introductionmentioning

confidence: 99%

New Formula for Fragment Velocity in the Aiming Direction of an Asymmetrically Initiated Warhead

Xiong

et al. 2018

Propellants Explo Pyrotec

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Fragment velocity is an important parameter for fragmentation warheads, but for an asymmetrically initiated warhead, formulas for calculating the fragment velocity in the aiming direction are rare. In this work, new formulas for calculating fragment velocities in the aiming direction and the initiation side of an asymmetrically initiated warhead were established by taking the long element from the warhead section and applying one‐dimensional gas dynamics. Accounting for the assumptions made during the formulas establishing, three experimentally verified warheads modelling of different charge ratios were used to verify the formulas. It is found that the velocity ratios of the modelling to the formulas’ calculations of different warheads are very similar. Hence the fitted curves for the velocity ratios versus the warhead charge ratios were used as correction factors for the established formulas. Finally experiments were designed and conducted to validate the revised formulas, which shows acceptable relative errors of 2.8 % and 9.9 %, better than already existing formulas. The established formulas could be a good reference for the damage evaluation of aimable warheads and for fragment velocity distribution research.

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“…Based on the authors' past experience (e.g. [15]), it was concluded that for this kind of problems, relatively small cells (~2 mm) are required in the vicinity of the charge. However, simulations with a computational domain of a few meters with such small cells are expected to be very expensive in terms of computational resources.…”

Section: Numerical Simulations Of Bare Chargesmentioning

confidence: 99%

“…It is noted that 3D simulations that include detailed modeling of the fragmentation process are very expensive in terms of computational resources and time, because they require a very small cell size to properly model the casing material and obtain correct fragmentation results (e.g. [15,17]). This requirement leads to the use of very small time steps and to timeconsuming simulations.…”

Section: Numerical Simulations Of Cased Chargesmentioning

confidence: 99%

On the problem of bare-to-cased charge equivalency

Grisaro

Dancygier

2016

International Journal of Impact Engineering

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Numerical study of velocity distribution of fragments caused by explosion of a cylindrical cased charge

Cited by 84 publications

References 16 publications

Fragment Velocity Characteristics of Warheads with a Hollow Core under Asymmetrical Initiation

Fragment Velocity Characteristics of Warheads with a Hollow Core under Asymmetrical Initiation

New Formula for Fragment Velocity in the Aiming Direction of an Asymmetrically Initiated Warhead

On the problem of bare-to-cased charge equivalency

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