The Use of Depth of Penetration Testing to Develop Element Erosion Parameters in LS-DYNA Explicit Simulations

Justusson, Brian; Pang, Jenna; Molitor, Matthew; Rassaian, Mostafa; Pereira, Mike

doi:10.2514/6.2019-2056

Cited by 3 publications

(4 citation statements)

References 8 publications

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“…Here, it is difficult to directly resolve the inverse solution of a m by equation (22). However, qualitative analysis of the relation equation above indicates that P(σ c , a m ) will increase as σ c increases but decrease as a m increases, and the influence of increasing σ c on P(σ c , a m ) is much stronger than that of increasing σ t on K(σ t ) in the same kind of rock.…”

Section: Calculation Of the Length Of Primary Cracksmentioning

confidence: 99%

“…However, qualitative analysis of the relation equation above indicates that P(σ c , a m ) will increase as σ c increases but decrease as a m increases, and the influence of increasing σ c on P(σ c , a m ) is much stronger than that of increasing σ t on K(σ t ) in the same kind of rock. erefore, the maximum length of primary cracks a m will increase to meet equation (22), when the rock strength parameters (σ c and σ t ) rise.…”

Section: Calculation Of the Length Of Primary Cracksmentioning

confidence: 99%

“…* MAT_PLASTIC_KINEMATIC model was selected for the rock for the purpose of taking into account the large strain, high strain rate, and the damage under the action of detonation load [21], combined with the * MAT_ADD_EROSION model containing the thresholds of the tensile and compressive failure to acquire the macroscopic effect of fracture [22,23]. Mudstone, sandstone, and granite were chosen as three kinds of rock with different strengths for the simulation.…”

Section: Numerical Simulation Of the Slottedmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Rock Strength on the Propagation of Slotted Cartridge Blasting‐Induced Directional Cracks

Shu

Shao

Dong

et al. 2019

Advances in Civil Engineering

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Based on theories of explosive mechanics and rock fracture mechanics, the influence mechanism of rock strength on the propagation length of the primary crack in the directional fracture blasting with slotted cartridge has been investigated deeply to propose the relation equation between the rock strength and the propagation length of the primary crack. Theoretically, the maximum length am of the primary crack increases with the enhancing rock strength parameters. The explicit dynamic analysis software LS-DYNA has been used to simulate the slotted cartridge blasting in the mudstone, sandstone, and granite with different strengths in order to reveal the effect of rock strength on the propagation length and velocity of the primary crack and the stress distribution characteristics in rock. The numerical results show the primary crack easily bifurcates and attain a much shorter propagation length in the mudstone with the minimum strength, and there are radial cracks appearing in the nonslotted direction. When rock strength rises, the propagation length, velocity, and duration of the primary crack and the concentration degree of effective stress in the slotted direction will all increase in the sandstone and granite, but there is an opposite influence trend of rock strength in the stage of the initial guide crack’s formation. The cracking velocity has an overall oscillation downtrend whose swing amplitude enhances clearly with the increasing rock strength, signifying the more unsteady propagation of the primary crack in the higher strength rock.

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Section: Calculation Of the Length Of Primary Cracksmentioning

confidence: 99%

Section: Calculation Of the Length Of Primary Cracksmentioning

confidence: 99%

Section: Numerical Simulation Of the Slottedmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Rock Strength on the Propagation of Slotted Cartridge Blasting‐Induced Directional Cracks

Shu

Shao

Dong

et al. 2019

Advances in Civil Engineering

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“…The reason is that this model is suited to model isotropic and kinematic hardening plasticity with the option of including rate effects. In EFP penetration calculation, element erosion can be used to remove elements that have reached the critical damage [26]. The FS variable (failure strain for eroding elements) in the plastic-kinematic model was used to control the material failure in the present study.…”

Section: Materials Modelingmentioning

confidence: 99%

Numerical Investigation on the Formation and Penetration Behavior of Explosively Formed Projectile (EFP) with Variable Thickness Liner

Yang

Lin

2021

Symmetry

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Explosively formed projectiles (EFPs) are widely used in civil applications and the military field for their excellent impact performance. How to give full play to the energy accumulation effect of explosives and improve the penetration performance has become the main problem of EFP design. The aim of the present study was to investigate the effect of liner structure on EFP formation and its penetration behavior. In order to achieve this, a finite element (FE) model was first established on the basis of the Lagrange and ALE method. Then, formation and penetration performance tests of EFP were performed to verify the validity and feasibility of the proposed FE model, where the configuration, velocity of EFP, and penetration diameter left on the target plate were compared. Finally, by using the proposed FE model, the entire process of the formation and penetration behavior of EFP with axial symmetrical variable thickness liners were analyzed, where spherical-segment liners with uniform and non-uniform thickness were developed. The results were drawn as follows: the numerical simulation error of EFP velocity was less than 5%, and the simulated penetration diameter was compared to the 8.6% error obtained from the experimental method. It demonstrated that the proposed FE model had higher prediction precision. After the explosive was detonated, a forward-folding EFP was formed by the liner with a thin edge thickness, while the EFP formed by the liner with uniform thickness had a backward-folded configuration. It was also found that the liner with a thin edge thickness gave the largest steady velocity of EFP, and it was the lowest by using the liner with uniform thickness. There were two types of loads generated after the formation of an EFP, those were shock wave loading and an EFP, both causing damage in the target plate during the process of an EFP’s penetration into it. The shock wave induced by liners with non-uniform thickness caused higher damage in the target plate, the maximum value of stress was reached at about 4.0 GPa. The forward-folding EFP formed by the liner with the thinnest edge thickness had the largest penetration ability. The backward-folded EFP, owing to the hollow structure, had the worst penetration ability, which failed to penetrate the target plate.

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An Overview of the NASA Advanced Composites Consortium High Energy Dynamic Impact Phase II Technical Path

Justusson

Pang

Molitor

et al. 2019

AIAA Scitech 2019 Forum

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The Use of Depth of Penetration Testing to Develop Element Erosion Parameters in LS-DYNA Explicit Simulations

Cited by 3 publications

References 8 publications

Influence of Rock Strength on the Propagation of Slotted Cartridge Blasting‐Induced Directional Cracks

Influence of Rock Strength on the Propagation of Slotted Cartridge Blasting‐Induced Directional Cracks

Numerical Investigation on the Formation and Penetration Behavior of Explosively Formed Projectile (EFP) with Variable Thickness Liner

An Overview of the NASA Advanced Composites Consortium High Energy Dynamic Impact Phase II Technical Path

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