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.

Theoretical Approach in Predicting Perforation of Aluminum Alloy Foam Target against Different Ogive-Nosed Projectile

2010 ◽  
Vol 44-47 ◽  
pp. 3060-3066 ◽  
Author(s):  
Yong Gang Bao ◽  
Nian Mei Zhang ◽  
Gui Tong Yang
Keyword(s):  
Aluminum Alloy ◽  
Kinetic Energy ◽  
Significant Influence ◽  
Theoretical Approach ◽  
Single Layer ◽  
Cavity Expansion ◽  
Resistance Force ◽  
Residual Velocity ◽  
Expansion Theory ◽  
Cavity Expansion Theory

This paper presents a theoretical approach for investigating the perforation of aluminum alloy foam target against rigid ogive-nosed projectile. The target is composited by two different density single-layer aluminum alloy foam boards. The dynamic cavity expansion theory is applied to formulate analytical model. The perforating process can be divided into 8 stages. The effects of shank diameter, shank length and caliber-radius-head (CRH) on perforating resistance force and kinetic energy variation are analyzed. The results demonstrate that velocity limit increases significantly with the raising of shank diameter in the case of fixed mass and CRH has no significant influence on residual velocity and velocity limit. And the residual velocity can be predicted by the known striking velocity and velocity limit.

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.

Comparison of Measured and Back Estimated Cone Penetration Resistance of Sand

2008 ◽  
Author(s):  
Meen-Wah Gui ◽  
Dong-Sheng Jeng
Keyword(s):  
Penetration Resistance ◽  
Cavity Expansion ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Cone Penetration Resistance ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
Penetration Tests

The application of cavity expansion theory in the back estimation of cone penetration tests conducted in calibration chambers has been carried out by many researchers. However, the theory is seldom employed by centrifuge modelers. Based on the work of spherical cavity expansion of previous researchers, this study proposed an analytical solution that incorporates the effects of cone geometry and surface roughness and the effect of compressibility to estimate the cone tip resistance. The calculated results are compared with the measured cone penetration resistance of four cone penetration tests performed in the centrifuge. The cone penetration tests were conducted in granular soil specimens having relative densities ranging between 54% and 89%. The comparison demonstrates the capacity of the cavity expansion theory in the prediction of the centrifuge cone penetration resistance.

Analysis of perforation process into concrete/metal targets by rigid projectiles

2012 ◽  
Vol 227 (7) ◽  
pp. 1454-1468 ◽  
Author(s):  
N Khazraiyan ◽  
GH Liaghat ◽  
H Khodarahmi ◽  
N Dashtian-Gerami
Keyword(s):  
Experimental Data ◽  
Numerical Modeling ◽  
Cavity Expansion ◽  
Velocity Range ◽  
Material Models ◽  
Backing Plate ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
The Impact ◽  
Good Agreement

In this article, a semi-analytical model has been developed for perforation of a hard projectile into a single- and two-layer concrete targets. The model is based on the dynamic cavity expansion theory and the reflection of compressive waves from the end of the concrete targets. The effect of friction coefficient is also investigated in the analysis. Numerical modeling of the problem has been performed in LS-DYNA code. Holmquist–Johnson–Cook, plastic kinematic, and rigid material models have been employed for the concrete, the backing plate, and the projectile, respectively. The impact velocity range, considered in this study, is between 300 and 800 m/s. No projectile erosion is considered in this velocity range. The analytical results of the investigation for both single- and two-layer concrete targets are in a good agreement with numerical simulations and experimental data.

Finite Cylindrical Cavity Expansion Model for Penetration of Steel-Tube-Confined Concrete Targets

2014 ◽  
Vol 1065-1069 ◽  
pp. 1065-1068
Author(s):  
Yang Yue Ye Cao ◽  
Zhi Gang Jiang ◽  
Qing Hua Tan
Keyword(s):  
Cylindrical Cavity ◽  
Steel Tube ◽  
Confined Concrete ◽  
Cavity Expansion ◽  
Strength Theory ◽  
Expansion Process ◽  
Cylindrical Cavity Expansion ◽  
Expansion Model ◽  
Better Than ◽  
Good Agreement

Concrete is a brittle material which cracks under the tension and pulverized when the compressive stress exceeds the ultimate compressive strength. Confined concrete performs better than that of concrete without confinement in resisting penetration. Based on the Griffith strength theory, a quasi-static cylindrical cavity expansion model for the penetration of steel-tube-confined concrete targets is proposed. Numerical results show that ratio of tube wall thickness to tube radius significantly effects cavity expansion stress, which is in proportion to the former ratio. The results are in good agreement with the cavity expansion process.

Sign in / Sign up

Export Citation Format

Share Document