Penetration of Strain-Hardening Targets With Rigid Spherical-Nose Rods

We developed models for the dynamic expansion of spherical cavities from zero initial radii for elastic-plastic, rate-independent materials with power-law strain hardening. The models considered the material as incompressible and compressible. For an incompressible material, we obtained closed-form solutions, whereas the compressible results required the numerical solution of differential equations. A comparison of the numerical results from both models showed the effect of compressibility.

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A Spherical Cavity Expansion Penetration Model for Concrete Based on Hoek–Brown Strength Criterion

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns-2011-099 ◽

2012 ◽

Vol 13 (2) ◽

Author(s):

H. Xu ◽

H. M. Wen

Keyword(s):

Spherical Cavity ◽

Mechanical Response ◽

Plastic Material ◽

Strength Criterion ◽

Cavity Expansion ◽

Forcing Function ◽

Basic Features ◽

Expansion Model ◽

Spherical Cavity Expansion ◽

Good Agreement

AbstractA spherical cavity expansion model for concrete is first proposed by using an elastic-brittle-plastic material law with Hoek–Brown strength criterion. The constitutive model can capture the basic features of the mechanical response of concrete materials including the effects of strain-softening and pressure hardening (pressure-dependent shear strength) and all the parameters used in the model can be determined from material tests. The forcing function obtained from the spherical cavity expansion analysis is then employed to construct a penetration model for concrete targets struck by ogival-nosed projectiles. It transpires that the present model predictions are in good agreement with experimental observations in terms of penetration depth and ballistic limits/residual velocities in the case of perforation.

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Penetration of Aluminum Targets by Ogive-Nosed Projectiles at Oblique Angles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.746 ◽

2013 ◽

Vol 275-277 ◽

pp. 746-750

Author(s):

Yu Tao Hu ◽

Fang Yun Lu ◽

Bang Hai Jiang ◽

Duo Zhang

Keyword(s):

Finite Element ◽

Free Surface ◽

Spherical Cavity ◽

Surface Effects ◽

Cavity Expansion ◽

Finite Element Code ◽

Transient Dynamic ◽

Dynamic Finite Element ◽

Spherical Cavity Expansion ◽

Good Agreement

.In this paper we present the results from a combined experimental, analytical, and computational penetration program. we use an explicit transient dynamic finite element code to model the projectile under an analytical forcing load representing the target. As angle of obliquity is increased free surface effects become significant, The analytical forcing load used here derived from the spherical cavity expansion approach with modifications to account for the free surface effects during oblique penetration. Results from the simulations show the trajectory of the projectile are in good agreement with experiments.

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A Spherical Cavity Expansion Penetration Model for Concrete Based on Hoek–Brown Strength Criterion

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns-2011-0099 ◽

2012 ◽

Vol 13 (2) ◽

Cited By ~ 2

Author(s):

H. Xu ◽

H. M. Wen

Keyword(s):

Spherical Cavity ◽

Mechanical Response ◽

Plastic Material ◽

Strength Criterion ◽

Cavity Expansion ◽

Forcing Function ◽

Basic Features ◽

Expansion Model ◽

Spherical Cavity Expansion ◽

Good Agreement

AbstractA spherical cavity expansion model for concrete is first proposed by using an elastic-brittle-plastic material law with Hoek–Brown strength criterion. The constitutive model can capture the basic features of the mechanical response of concrete materials including the effects of strain-softening and pressure hardening (pressure-dependent shear strength) and all the parameters used in the model can be determined from material tests. The forcing function obtained from the spherical cavity expansion analysis is then employed to construct a penetration model for concrete targets struck by ogival-nosed projectiles. It transpires that the present model predictions are in good agreement with experimental observations in terms of penetration depth and ballistic limits/residual velocities in the case of perforation.

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Penetration of 6061-T651 Aluminum Targets With Rigid Long Rods

Journal of Applied Mechanics ◽

10.1115/1.3173718 ◽

1988 ◽

Vol 55 (4) ◽

pp. 755-760 ◽

Cited By ~ 134

Author(s):

M. J. Forrestal ◽

K. Okajima ◽

V. K. Luk

Keyword(s):

Closed Form ◽

Cylindrical Cavity ◽

Reasonable Agreement ◽

Cavity Expansion ◽

Cylindrical Cavity Expansion ◽

Perfectly Plastic ◽

Engineering Models ◽

Elastic Perfectly Plastic ◽

Penetration Depths

We developed engineering models for forces on rigid, long rods with spherical, ogival, and conical noses that penetrated rate independent, elastic-perfectly plastic targets. The spherical and cylindrical, cavity-expansion approximations simplified the target analyses, so we obtained closed-form penetration equations. To verify our models, we performed terminal-ballistic experiments with 7.1-mm dia., 0.024 kg, marging steel rods and 152-mm dia., 6061-T651 aluminum targets. The models predicted penetration depths that were in reasonable agreement with the data for impact velocities between 0.4-1.4 km/s.

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A Spherical Cavity Expansion Penetration Model for Concrete Based on Hoek–Brown Strength Criterion

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns.2011.099 ◽

2012 ◽

Vol 13 (2) ◽

pp. 145-152

Author(s):

H. Xu ◽

H. M. Wen

Keyword(s):

Spherical Cavity ◽

Mechanical Response ◽

Plastic Material ◽

Strength Criterion ◽

Cavity Expansion ◽

Forcing Function ◽

Basic Features ◽

Expansion Model ◽

Spherical Cavity Expansion ◽

Good Agreement

Abstract A spherical cavity expansion model for concrete is first proposed by using an elastic-brittle-plastic material law with Hoek–Brown strength criterion. The constitutive model can capture the basic features of the mechanical response of concrete materials including the effects of strain-softening and pressure hardening (pressure-dependent shear strength) and all the parameters used in the model can be determined from material tests. The forcing function obtained from the spherical cavity expansion analysis is then employed to construct a penetration model for concrete targets struck by ogival-nosed projectiles. It transpires that the present model predictions are in good agreement with experimental observations in terms of penetration depth and ballistic limits/residual velocities in the case of perforation.

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Analytical Solutions of Spherical Cavity Expansion Near a Slope due to Pile Installation

Journal of Applied Mathematics ◽

10.1155/2013/306849 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Jingpei Li ◽

Yaguo Zhang ◽

Haibing Chen ◽

Fayun Liang

Keyword(s):

Free Boundary ◽

Inclination Angle ◽

Spherical Cavity ◽

Theoretical Method ◽

Cavity Expansion ◽

Sloping Ground ◽

Present Solution ◽

Image Technique ◽

Boussinesq Solution ◽

Spherical Cavity Expansion

Based on the hypothesis that the penetration of a single pile can be simulated by a series of spherical cavity expansions, this paper presents an analytical solution of cavity expansion near the sloping ground. Compared with the cavity expansion in the half-space, the sloping free boundary has been taken into account as well as the horizontal free boundary. The sloping and horizontal free surfaces are considered by the introduction of a virtual image technique, the harmonic function, and the Boussinesq solution. The results show that the sloping free boundary and the variation of the inclination angle have pronounced influences on the distribution of the stress and displacement induced by the spherical cavity expansion. The present solution provides a simplified and realistic theoretical method to predict the soil behaviors around the spherical cavity near the sloping ground. The approach can also be used for the determination of the inclination angle of the slope according to the maximum permissible displacement.

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