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1

Numerical analyses of ceramic/metal ballistic panels subjected to projectile impact

Morka A., Nowak J.

Journal of KONES

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2012

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Vol. 19, No. 4

465-472

EN

The paper concerns research and development on modern, ceramic-based, protective layers used in the armour of tanks, combat vehicles and aeroplanes. A task of ceramic panels is reduction and dispersion of localized kinetic energy before a projectile or its fragment approaches the interior of protected object. The numerical investigations have been performed to determine the ballistic resistance of ceramic/metal panels subjected to projectile impact. The impact of the 7.62mm armour-piercing projectile on the ceramic elements backed by a metal plate was analyzed. The tested panels were composed of a ceramic layer (Al2O3, SiC or B4C) and a metal layer (7017 aluminium alloy, Armox 500T steel or Ti6Al-4 titanium alloy). Different shapes of ceramic elements were analyzed, including hemispheres and pyramids, with respect to standard flat tiles. The influence of the impact point location was also taken into considerations. The computer simulations were performed with the Finite Element Method implemented in LS-DYNA code. Full 3D models of the projectile and targets were developed with strain rate and temperature dependent material constitutive relations. The conclusions presented in the paper can be applied to develop modern impact protection panels in which the appropriate balance between the mass and protection level must be accomplished.

2

On the modelling of penetration/perforation problems

Morka A.

Journal of KONES

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2010

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Vol. 17, No. 1

291-297

EN

The aim of this paper was to present the main aspects of the numerical modelling within the scope of penetration/perforation problems. The most important stages of the computer model development were discussed in detail. They include the study of the hypervelocity impact physics, selection of the numerical solution method, problem discretization in time (time step) and space (mesh/grid), constitutive models consideration, Initial Boundary Conditions (IBC) and finally choice of the results form for analysis and discussion. The Computer simulations were performed with the Element Free Galerkin Method (EFG) implemented in LS-DYNA code. An impact of the 12. 7x108 mm B32 armour piercing projectile on the selected targets was analyzed. Full SD models of the projectile and targets were developed with strain rate and temperature dependent material constitutive relations. The models of the projectile, ceramic and aluminium alloy targets were validated with utilization of the experimental infield tests and data found in literature. The obtained results confirm that EFG method can be considered for numerical solving of the penetration/perforation problems. The errors in Depth of Penetration have not exceeded 20% as compared numerical and experimental results. The conclusions presented in this paper can be applied to develop modern impact protection panels where the appropriate balance between the mass and protection level must be accomplished.

3

Numerical study of the projectile trajectory disturbing during the oblique impacts

Morka A., Niezgoda T.

Journal of KONES

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2010

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Vol. 17, No. 3

307-312

EN

The numerical investigations have been performed to determine the effect of the projectile trajectory disturbing during oblique impacts. An impact of the 14.5x118 mm B32 armour piercing projectile on the A12O3 different shape elements backed by 7017 aluminum alloy plate was analyzed. The oblique impact was realized by different shapes of the frontal ceramic elements, including hemispheres and pyramids, with respect to standard flat tiles. The influence of the impact point location was also under considerations. The Computer simulations were performed with the Element Free Galerkin Method (EFG) implemented in LS-DYNA code. full 3D models of the projectile and targets were developed with strain rate and temperature dependent material constitutive relations. The Johson-Cook model was applied to describe the metallic parts, while the ceramic was modelled by Johnson-Holmquist constitutive relations. The models of the projectile, ceramic and aluminium alloy targets were validated with utilization of the experimental datafound in literature. The obtained results confirmed that the projectile trajectory undergoes essential deviation because of the projectile angular velocity. The conditions for maximizing the value of this angular velocity were studied and it is possible to reach several radians per millisecond. The conclusions presented in this paper can be applied to develop modern impact protection panels where the appropriate balance between the mass and protection level must be accomplished.

4

Numerical study of the shape effect in the ceramic based ballistic panels

Morka A., Jackowska B., Niezgoda T.

Journal of KONES

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2009

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Vol. 16, No. 4

539-548

EN

The numerical investigations have been performed to determine the front surface shape effect in the cer based armour systems. Different shapes of ceramic elements were analyzed, including hemispheres and pyramids with respect to standard flat tiles. The influence of the impact point location was also under considerations. The Computer simulations were performed with the Element Free Galerkin Method (EFG) implemented in LS-D code. An impact of the 14.5xll8mm B32 armour piercing projectile on the A12O3 different shape elements backe 7017 aluminium alloy plate was analyzed. Full 3D models of the projectile and targets were developed with strain, rate and temperature dependent material constitutive relations. The models of the projectile, ceramic and aluminium alloy targets were validated with utilization of the experimental data found in literature. The obtained results confirm, the preliminary presumptions, that the shape of the front surface can significant role in the overall ballistic resistance of the panel. Particularly projectile-target initial contact area st to be important factor as showed by impact point location analysis. The conclusions presented in this paper can be applied to develop modern impact protection panels where the appropriate balance between the mass and protection level must be accomplished.