Experimental and numerical study of the fragmentation of expanding warhead casings by using different numerical codes and solution techniques

Moxnes, John F.; Prytz, Anne K.; Frøyland, Øyvind; Klokkehaug, Siri; Skriudalen, Stian; Friis, Eva; Teland, Jan Arild; Dørum, Cato; Ødegårdstuen, Gard

doi:10.1016/j.dt.2014.05.009

Cited by 22 publications

(16 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Two different shots (loadings) were studied numerically and experimentally by varying the thickness of the brass cylinder to achieve different expansions velocities of the steel rings. The steady state numerical velocities were found to be 190 m/s and 630 m/s and in good agreement with the measurements (Moxnes et al, 2015 [32]). The parameters of the two different loadings are seen in Table 1.…”

Section: The Experimental Set Up and Geometrical Datasupporting

confidence: 71%

“…Meyer and Brannon (2012) [30] concluded that further studies were warranted to ensure mesh independence of the predictions and accuracy in a variety of applications. Moxnes et al (2014) [31] show by using SPH that increasing the resolution (i.e. reducing the particle size) increased the number of fragments.…”

Section: Introductionmentioning

confidence: 98%

“…It was concluded that proper ways to incorporate sub scale physical effects in strength and fracture models remains a subject of research. Moxnes et al (2014) [32] show by using smoothed particle hydrodynamics (SPH) that randomness increased the number of fragments.…”

Section: Introductionmentioning

confidence: 99%

“…Another research issue is whether numerical noise is useful without any stochastic fracture model (Diep et [31], 2015 [32]). The interesting aspect of numerical noise is that it does not require any artificial seeding of fracture sites within the material as a part of the initial conditions of the problem.…”

Section: Introductionmentioning

confidence: 99%

“…In the current work, the initial particle distribution is either Cartesian or polar structured so that we can investigate to what extent the initial particle structuring affects the fragmentation behavior. The experimental part of the study is mostly reported in Moxnes et al (2015) [32]. Fig.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Simulation of natural fragmentation of rings cut from warheads

Moxnes

Børve

2015

Defence Technology

Self Cite

View full text Add to dashboard Cite

Natural fragmentation of warheads that detonates causes the casing of the warhead to split into various sized fragments through shear or radial fractures depending on the toughness, density, and grain size of the material. The best known formula for the prediction of the size distribution is the Mott formulae, which is further examined by Grady and Kipp by investigating more carefully the statistical most random way of portioning a given area into a number of entities. We examine the fragmentation behavior of radially expanding steel rings cut from a 25 mm warhead by using an in house smooth particle hydrodynamic (SPH) simulation code called REGULUS. Experimental results were compared with numerical results applying varying particle size and stochastic fracture strain. The numerically obtained number of fragments was consistent with experimental results. Increasing expansion velocity of the rings increases the number of fragments. Statistical variation of the material parameters influences the fragment characteristics, especially for low expansion velocities. A least square regression fit to the cumulative number of fragments by applying a generalized Mott distribution shows that the shape parameter is around 4 for the rings, which is in contrast to the Mott distribution with a shape parameter of ½. For initially polar distributed particles, we see signs of a bimodal cumulative fragment distribution. Adding statistical variation in material parameters of the fracture model causes the velocity numerical solutions to become less sensitive to changes in resolution for Cartesian distributed particles.

show abstract

Section: The Experimental Set Up and Geometrical Datasupporting

confidence: 71%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Simulation of natural fragmentation of rings cut from warheads

Moxnes

Børve

2015

Defence Technology

Self Cite

View full text Add to dashboard Cite

show abstract

Data‐driven nonlocal model for fragmentation in the crushing of solids

Silling

2024

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

A technique is proposed for reproducing particle size distributions in three‐dimensional simulations of the crushing and comminution of solid materials. The method is designed to produce realistic distributions over a wide range of loading conditions, especially for small fragments. In contrast to most existing methods, the new model does not explicitly treat the small‐scale process of fracture. Instead, it uses measured fragment distributions from laboratory tests as the basic material property that is incorporated into the algorithm, providing a data‐driven approach. The algorithm is implemented within a nonlocal peridynamic solver, which simulates the underlying continuum mechanics and contact interactions between fragments after they are formed. The technique is illustrated in reproducing fragmentation data from drop weight testing on sandstone samples.

show abstract