Wyniki wyszukiwania - BazTech

1

Numerical and Experimental Comparative Analysis of Ballistic Performance of Packages Made of Biaxial and Triaxial Kevlar 29 Fabrics

Pinkos Justyna, Stempien Zbigniew

Autex Research Journal

|

2020

|

Vol. 20, no. 2

203--219

EN

The objective of this study is a comparative analysis of the ballistic effectiveness of packages made of biaxial and triaxial Kevlar 29 fabrics under the hitting of Parabellum 9×19 bullet. We conduct both numerical simulations using the LS-Dyna program and experimental research in a ballistic research laboratory. Based on the comparative analysis of the results from the numerical and experimental research, demonstrated differences exist in the ballistic effectiveness between the packages made of biaxial fabrics and the packages consisting of triaxial fabrics. For this purpose, the residual velocity of the bullet is analyzed in detail in terms of the maximum deformation cone, the shape of the deformation cone, and the distribution of stress for the textile ballistic packages. It is established that the packages made of triaxial fabric show a considerably smaller deformation cone compared with the packages made of biaxial fabric, a more favorable shape of the deformation cone from the perspective of ballistic trauma and distribution of stress similar to materials with isotropic properties. Poorer properties are recorded for these packages in the case of the minimum number of layers necessary for stopping the bullet, which arises from the open-work structure of the fabric.

2

Microstructure characterization of 7055-T6, 6061-T6511 and 7A52-T6 Al alloys subjected to ballistic impact against heavy tungsten alloy projectile

Khan M. A., Wang Y., Malik A., Nazeer F., Yasin G., Khan W. Q., Ahmad T., Zhang H.

Archives of Civil and Mechanical Engineering

|

2019

|

Vol. 19, no. 4

1484--1496

EN

A spray formed 7055 Al alloy, and traditional formed 6061 Al and 7A52 Al alloy were subjected to extrusion. Later 7055Al and 7A52 treated with T6 and 6061 Al treated with T6511 heat treatment. To investigate the microstructure evolution by optical microscopy (OM), scanning electron microscopy (SEM), electron back scattering diffraction (EBSD) and X-rays diffraction pattern (XRD) analysis were employed to observe the variation in mechanical properties and damages patterns of single layered aluminum alloys impacted by heavy tungsten alloy (WHA) projectile. During impact a substantial increase in temperature inside the target material caused melting on crater wall. The hard metastable intermetallic compound and pores were produced on penetration path owing to diffusion of projectile particles and rapid melt re-solidification. These compounds enhance the hardness (600-650 HV0.1/10) in the middle deformed channels of 7055 Al alloy target. In addition, small size pores, whirl-pool and white adiabatic shear bands were observed in 7A52 and 6061 Al alloys, respectively. The variation in hardness and microstructure of Al alloys target was limited within the 2 mm area from the perforation path. 7055-T6 Al alloy has demonstrated better ballistic protection in terms of strength, mass efficiency (N), depth of penetration (DOP) and penetration path diameter in comparison of other Al alloys.

3

Comparison of numerical and experimental study of armour system based on alumina and silicon carbide ceramics

Chabera P., Boczkowska A., Morka A., Kędzierski P., Niezgoda T., Oziębło A., Witek A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2015

|

Vol. 63, nr 2

363--367

EN

The main goal of this numerical and experimental study of composite armour systems was to investigate their ballistic behaviour. Numerical simulations were employed to determine the initial dimensions of panel layers before the actual ballistic test. In order to achieve this aim, multivariate computations with different thicknesses of panel layers were conducted. Numerical calculations were performed with the finite element method in the LS-DYNA software, which is a commonly used tool for solving problems associated with shock wave propagation, blasts and impacts. An axisymmetric model was built in order to ensure sufficient discretization. Results of a simulation study allowed thicknesses of layers ensuring assumed level of protection to be determined. According to the simulation results two armour configurations with different ceramics have been fabricated. The composite armour systems consisted of the front layer made of Al2O3 or SiC ceramic and high strength steel as the backing material. The ballistic performance of the proposed protective structures were tested with the use of 7.62 mm Armour Piercing (AP) projectile. A comparison of impact resistance of two defence systems with different ceramic has been carried out. Application of silicon carbide ceramic improved ballistic performance, as evidenced by smaller deformations of the second layer. In addition, one of armour systems was complemented with an intermediate ceramic-elastomer layer. A ceramic-elastomer component was obtained using pressure infiltration of gradient porous ceramic by elastomer. Upon ballistic impact, the ceramic body dissipated kinetic energy of the projectile. The residual energy was absorbed by the intermediate composite layer. It was found, that application of composite plates as a support of a ceramic body provided a decrease of the bullet penetration depth.

4

Numerical and experimental study of armour system consisted of ceramic and ceramic-elastomer composites

Chabera P., Boczkowska A., Morka A., Niezgoda T., Oziębło A., Witek A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2014

|

Vol. 62, nr 4

853--859

EN

The paper presents numerical and experimental results in the study of composite armour systems for ballistic protection. The modelling of protective structures and simulation methods of experiment as well as the finite elements method were implemented in LS DYNA software. Three armour systems with different thickness of layers were analyzed. Discretization for each option was built with three dimensional elements guaranteeing satisfactory accuracy of the calculations. Two selected armour configurations have been ballistically tested using the armour piercing (AP) 7.62 mm calibre. The composite armour systems were made of Al2O3 ceramics placed on the strike face and high strength steel as a backing material. In case of one ballistic structure system an intermediate ceramic- elastomer layer was applied. Ceramic- elastomer composites were obtained from porous ceramics with porosity gradient using pressure infiltration of porous ceramics by elastomer. The urea-urethane elastomer, as a reactive liquid was introduced into pores. As a result composites, in which two phases were interconnecting three-dimensionally and topologically throughout the microstructure, were obtained. Upon ballistic impact, kinetic energy was dissipated by ceramic body The residual energy was absorbed by intermediate composite layer. Effect of the composite shell application on crack propagation of ceramic body was observed.

5

Effect of Velocity of the Structure-Dependent Tension Wave Propagation on Ballistic Performance of Aramid Woven Fabricslication

Stempień Z.

Fibres & Textiles in Eastern Europe

|

2011

|

Vol. 19, no. 4 (87)

74--80

EN

One of the elements defining the effectiveness of soft ballistic protection is the geometric structure of the fabric. In previous research works it was proven that the geometric structure influences the propagation velocity of the tension wave. Thus, fabrics of a geometric structure ensuring a maximum propagation velocity of the tension wave should be selected for the ballistic packets of bullet-proof vests. In such a case, the area of deformation will be larger, which will diminish the probability of local destruction and the acuteness of the ballistic stroke on the user’s body. The aim of the research was to receive a ballistic packet containing layers of fabric ensuring a maximum propagating velocity of the tension wave and verification of its ballistic performance in terms of shooting through, maximum deformation and the ballistic stroke.

PL

Jednym z elementów decydujących o skuteczności miękkich osłon balistycznych jest struktura geometryczna tkaniny. We wcześniejszych badaniach wykazano, że struktura geometryczna ma wpływ na prędkość propagacji fali naprężeń. Istnieje zatem pełne uzasadnienie wyboru struktury geometrycznej tkaniny o maksymalnej prędkości propagacji fali naprężeń na warstwy pakietów balistycznych kamizelek kuloodpornych. W takim przypadku obszar objęty procesem odkształcania będzie rozłożony na większej powierzchni, co zmniejszy możliwość miejscowej destrukcji i wielkość udaru balistycznego na korpus użytkownika. Celem realizowanych badan było uzyskanie pakietu balistycznego zawierającego w swoich warstwach tkaniny o maksymalnej prędkości propagacji fali naprężeń oraz jego weryfikacja balistyczna uwzględniająca efekt przestrzelenia, maksymalną deformację oraz wielkość udaru balistycznego.