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Explosion Mechanics

Innovative Technologies for Controlled Fragmentation Warheads

[+] Author and Article Information
Domenico Villano

e-mail: domenico.villano@otomelara.it

Francesco Galliccia

OTO Melara S.p.A.,
R&D, Guided Ammunition,
via Valdilocchi, 15,
La Spezia 19136, Italy

1Corresponding author.

Manuscript received June 30, 2012; final manuscript received November 10, 2012; accepted manuscript posted January 9, 2013; published online April 19, 2013. Assoc. Editor: Bo S. G. Janzon.

J. Appl. Mech 80(3), 031704 (Apr 19, 2013) (9 pages) Paper No: JAM-12-1287; doi: 10.1115/1.4023341 History: Received June 30, 2012; Revised November 10, 2012; Accepted January 09, 2013

The purpose of this paper is to verify the applicability of innovative technologies for manufacturing controlled fragmentation warheads, with particular attention paid to guided ammunition. Several studies were conducted by the authors during the warhead development of DART and Vulcano family munitions. The lethality of the guided munitions can be considerably increased with controlled fragmentation warheads. This increase can compensate a lower payload of the guided munitions. After introducing the concept of warhead and its natural fragmentation, the paper describes both the elements of fracture mechanics related to the fragmentation and the state of the art of controlled fragmentation. A preliminary evaluation of controlled fragmentation technologies is illustrated along with the numerical models developed for predicting the natural and controlled fragmentations. The most promising technologies are presented in detail and the features of the warheads used for the experiments are defined. A description of the entire experimental phase is provided, including results of arena tests, data analysis and revision of numerical models. The applicability of some innovative technologies for controlled fragmentation warheads is fully demonstrated. Two technologies in particular, the laser microdrilling and the double casing solution, provide a high increase of the reference warhead lethality.

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Copyright © 2013 by ASME
Topics: Lasers , Warheads , Melting
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References

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Figures

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Fig. 1

Fracture types in a cylindrical casing

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Fig. 2

Theoretical (light gray) and real (dark gray) fragments due to secondary fracture trajectories

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Fig. 3

Predicted velocities of fragments along the WH longitudinal axis in case of natural fragmentation

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Fig. 4

Detailed sections of the deep laser melting trajectories obtained with different parameters

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Fig. 5

Holes section obtained by laser microdrilling

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Fig. 6

Casing mass without controlled fragmentation as a function of helix starts number for different technologies

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Fig. 7

Theoretical mass (double line) and real mass (single line) of controlled fragments obtained by simulations

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Fig. 8

Preliminary simulations of the mass distributions of the different technologies in study

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Fig. 9

Layout of the performed arena tests

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Fig. 10

Experimental perforations number obtained on the targets during the arena tests for the different technologies

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Fig. 11

Frequencies of fragments' mass groups in terms of mass percentage

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Fig. 12

Cumulative warhead mass as a function of the fragments' mass groups

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Fig. 13

Pictures of the fragments recovered after the arena tests for each technology performed

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