scholarly journals Cylindrical cavity expansion approximations using different constitutive models for the target material

2017 ◽  
Vol 9 (2) ◽  
pp. 199-225 ◽  
Author(s):  
Joakim Johnsen ◽  
Jens Kristian Holmen ◽  
Thomas L Warren ◽  
Tore Børvik
Keyword(s):  
Strain Hardening ◽  
Cylindrical Cavity ◽  
Constitutive Models ◽  
Target Material ◽  
Cavity Expansion ◽  
Ballistic Limit ◽  
Ductile Metals ◽  
Cylindrical Cavity Expansion ◽  
Expansion Theory ◽  
Cavity Expansion Theory

In this article, we investigate the results obtained using different constitutive models for the solution of the cylindrical cavity expansion problem under plane strain conditions. The cylindrical cavity expansion solutions are employed with the cylindrical cavity expansion approximation to obtain ballistic limit and residual velocities for ductile metals perforated by rigid projectiles. Many of the previously developed cylindrical cavity expansion approximations use simplified constitutive models. However, in the present work, we first extend the cylindrical cavity expansion theory with the Voce strain hardening rule, before we utilize three different strain hardening constitutive models in cylindrical cavity expansion calculations to predict ballistic limit and residual velocities of aluminum and steel target plates struck by rigid projectiles. The results show that when strain hardening is accurately represented by the constitutive models until necking in a uniaxial tension test, all cylindrical cavity expansion models predict ballistic limit velocities that are close to the experimental data.

A Finite Cylindrical Cavity Expansion and Penetration Model of Exponential Strain-Hardening Materials

2013 ◽  
Vol 634-638 ◽  
pp. 2781-2786 ◽  
Author(s):  
Zhi Gang Jiang ◽  
Dian Yi Song ◽  
Fei Liu
Keyword(s):  
Free Boundary ◽  
Strain Hardening ◽  
Penetration Depth ◽  
Cylindrical Cavity ◽  
Radial Pressure ◽  
Radius Ratio ◽  
Cavity Expansion ◽  
Engineering Model ◽  
Finite Radius ◽  
Cylindrical Cavity Expansion

A finite cylindrical cavity expansion model for metal targets was proposed in consideration of the lateral free boundary and strain-hardening effect. Analytical solutions of radial pressure on the cavity wall were obtained. An engineering model for the penetration of rigid sharp-nosed projectiles into thick cylindrical metal targets with finite radius was developed. The influence of the radius ratio of target to projectile on penetration depth was studied. The present engineering model has good agreement with ballistic experiments and numerical simulation. The influence of the lateral free boundary of target on penetration depth needs to be considered for radius ratio of target to projectile less than 20.

Mechanism of High-velocity Projectile Penetration into Concrete

2012 ◽  
Vol 13 (2) ◽  
pp. 137-143
Author(s):  
Hai-Jun Wu
Keyword(s):  
Yield Criterion ◽  
Triaxial Compression ◽  
Target Material ◽  
Cavity Expansion ◽  
Model Parameters ◽  
Compression Tests ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
Triaxial Compression Tests ◽  
Spherical Cavity Expansion

Abstract The penetration depth of rigid projectiles is investigated using the modified spherical cavity expansion theory and the Holmquist–Johnson–Cook (HJC) model for the concrete targets, in which the model parameters used in the Mohr–Coulomb Tresca-limit yield criterion are obtained by the triaxial compression tests. By comparing the cavity expansion pressures of the concrete samples with two different types of aggregate, the influence of the aggregate hardness on the penetration processes is discussed. With the analysis of the tractions acted on the projectile nose, the influences of the projectile and target material properties as well as the projectile structure on the transition impact velocity are also discussed. By comparing the theoretical results with the experimental data, two penetration mechanisms are demonstrated for the ogive-nose projectile penetration into concrete with the striking velocities up to 2.0 km/s.

Dynamic Cylindrical Cavity Expansion of Compressible Strain-Hardening Materials

1991 ◽  
Vol 58 (2) ◽  
pp. 334-340 ◽  
Author(s):  
V. K. Luk ◽  
D. E. Amos
Keyword(s):  
Strain Hardening ◽  
Cylindrical Cavity ◽  
Normal Incidence ◽  
Cavity Expansion ◽  
Cylindrical Cavity Expansion ◽  
Model Predictions ◽  
Cylindrical Cavities ◽  
Compressible Materials ◽  
Aluminum Armor Plates ◽  
Good Agreement

We developed models for the dynamic expansion of cylindrical cavities from zero initial radii for compressible, elastic-plastic, rate-independent materials with powerlaw strain-hardening. Results from cavity-expansion models were used to derive perforation models to predict residual velocities and ballistic limits for rigid, conicalnose projectiles perforating strain-hardening target plates. We compared the numerical results from models for incompressible and compressible materials to show the effect of compressibility. To verify the models, we also compared the model predictions of residual velocities and ballistic limits with the data from terminal-ballistic experiments with tungsten projectiles impacting 5083-H131 aluminum armor plates at normal incidence. Very good agreement was obtained for impact velocities between 200 and 1,200 m/s and 12.7, 50.8, and 76.2-mm thick targets.

A resistance force model for spherical projectiles penetrating ballistic gelatin based on cavity expansion theory

2020 ◽  
pp. 095440622096483
Author(s):  
Li Liu ◽  
Yurun Fan ◽  
Pengfei Wang ◽  
Xufang Zhang ◽  
Qianqian Lu
Keyword(s):  
Soft Tissues ◽  
Cavity Expansion ◽  
Resistance Force ◽  
Force Model ◽  
Motion Model ◽  
Cylindrical Cavity Expansion ◽  
Expansion Theory ◽  
Ballistic Gelatin ◽  
Cavity Expansion Theory ◽  
Expansion Model

To investigate the penetration mechanism of spherical projectiles into soft tissues, ballistic gelatin was used as tissue substitute in ballistic tests. A theoretical motion model was established based on the cavity expansion theory. We first presented a quasi-static cylindrical cavity expansion model for the radial stress at the cavity wall of a cracked-hyperelastic material. The pressure on the cavity surface, PS, was also defined as the energy required to open a unit volume in the medium quasi-statically. Based on this interpretation, we proposed an approximate expression for the dynamic pressure, P, acting on the surface of the cavity by analyzing the energy transformation and conservation. Then, based on the analysis and solutions of the cylindrical cavity expansion model, we obtained a resistance force model for spherical projectiles, which consisted of an inertial term and a rate-dependent strength term. Subsequently, ballistic tests, in which gelatin blocks were penetrated by spherical projectiles of different materials and sizes, were analyzed, and the parameters in the resistance model were identified using the test results obtained from the 3 mm steel projectile. Further, the ability of the motion model to describe the motion of spherical projectiles penetrating ballistic gelatin was verified by comparing the calculated and measured results from projectiles of different materials and sizes. The proposed motion model based on the cavity expansion theory can therefore provide a basis for understanding the interaction of small arms ammunition and soft tissues.

Mechanism of High-velocity Projectile Penetration into Concrete

2012 ◽  
Vol 13 (2) ◽  
Author(s):  
Hai-Jun Wu ◽  
Yinan Wang ◽  
Yu Shan ◽  
Feng-Lei Huang ◽  
Qing-Ming Li
Keyword(s):  
Yield Criterion ◽  
Triaxial Compression ◽  
Target Material ◽  
Cavity Expansion ◽  
Model Parameters ◽  
Compression Tests ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
Triaxial Compression Tests ◽  
Spherical Cavity Expansion

AbstractThe penetration depth of rigid projectiles is investigated using the modified spherical cavity expansion theory and the Holmquist–Johnson–Cook (HJC) model for the concrete targets, in which the model parameters used in the Mohr–Coulomb Tresca-limit yield criterion are obtained by the triaxial compression tests. By comparing the cavity expansion pressures of the concrete samples with two different types of aggregate, the influence of the aggregate hardness on the penetration processes is discussed. With the analysis of the tractions acted on the projectile nose, the influences of the projectile and target material properties as well as the projectile structure on the transition impact velocity are also discussed. By comparing the theoretical results with the experimental data, two penetration mechanisms are demonstrated for the ogive-nose projectile penetration into concrete with the striking velocities up to 2.0 km/s.

Mechanism of High-velocity Projectile Penetration into Concrete

2012 ◽  
Vol 13 (2) ◽  
Author(s):  
Hai-Jun Wu ◽  
Yinan Wang ◽  
Yu Shan ◽  
Feng-Lei Huang ◽  
Qing-Ming Li
Keyword(s):  
Yield Criterion ◽  
Triaxial Compression ◽  
Target Material ◽  
Cavity Expansion ◽  
Model Parameters ◽  
Compression Tests ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
Triaxial Compression Tests ◽  
Spherical Cavity Expansion

AbstractThe penetration depth of rigid projectiles is investigated using the modified spherical cavity expansion theory and the Holmquist–Johnson–Cook (HJC) model for the concrete targets, in which the model parameters used in the Mohr–Coulomb Tresca-limit yield criterion are obtained by the triaxial compression tests. By comparing the cavity expansion pressures of the concrete samples with two different types of aggregate, the influence of the aggregate hardness on the penetration processes is discussed. With the analysis of the tractions acted on the projectile nose, the influences of the projectile and target material properties as well as the projectile structure on the transition impact velocity are also discussed. By comparing the theoretical results with the experimental data, two penetration mechanisms are demonstrated for the ogive-nose projectile penetration into concrete with the striking velocities up to 2.0 km/s.

Dynamic finite cylindrical cavity-expansion models for cellular steel tube confined concrete targets normally impacted by rigid sharp-nosed projectiles

2021 ◽  
pp. 204141962110272
Author(s):  
Chaomei Meng ◽  
Dianyi Song ◽  
Qinghua Tan ◽  
Zhigang Jiang ◽  
Liangcai Cai ◽  
...  
Keyword(s):  
Cylindrical Cavity ◽  
Approximate Model ◽  
Steel Tube ◽  
Confinement Effect ◽  
Confined Concrete ◽  
Cavity Expansion ◽  
Depth Of Penetration ◽  
Cylindrical Cavity Expansion ◽  
Infinite Cylindrical Shell ◽  
Response Modes

Cellular steel-tube-confined concrete (CSTCC) targets show improved anti-penetration performance over single-cell STCC targets due to the confinement effect of surrounding cells on the impacted cell. Dynamic finite cylindrical cavity-expansion (FCCE) models including radial confinement effect were developed to predict the depth of penetration (DOP) for CSTCC targets normally penetrated by rigid sharp-nosed projectiles, and stiffness of radial confinement was achieved with the elastic solution of infinite cylindrical shell in Winkler medium. Steady responses of dynamic FCCE models were obtained on the assumption of incompressibility of concrete, failure of comminuted zone with Heok–Brown criterion and two possible response modes of the confined concrete in the impacted cell. Furthermore, a DOP model for CSTCC targets normally impacted by rigid projectiles was also proposed on the basis of the dynamic FCCE approximate model. Lastly, relevant penetration tests of CSTCC targets normally penetrated by 12.7 mm armor piecing projectile (APP) were taken as examples to validate the dynamic FCCE models and the corresponding DOP model. The results show that the DOP results based on dynamic FCCE model agree well with those of the CSTCC targets normally penetrated by rigid conical or other sharp-nosed projectiles.

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