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Benjamin Liaw - One of the best experts on this subject based on the ideXlab platform.
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* Corresponding author (Ali Seyed Yaghoubi) AN EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THICKNESS EFFECT ON CROSS-PLY GLARE 5 FML PLATES SUBJECTED TO BALLISTIC IMPACT
2020Co-Authors: Seyed A Yaghoubi, Benjamin LiawAbstract:ABSTRACT GLARE 5 fiber-metal laminated (FML) plates of dimensions: 152.4 mm × 101.6 mm with various thicknesses, ranging from 1.12 mm up to 4.37 mm, were impacted by a 0.22 caliber bullet-shaped Projectile using a high-speed gas gun. A high-speed camera was used to measure the Projectile Velocity along its ballistic trajectory. The post-impact damage characteristics were evaluated using both nondestructive ultrasonic and destructive mechanical sectioning techniques. Only the contour of the entire damage area could be obtained using ultrasonic C-scan; whereas more details of the damage were provided through the mechanical cross-sectioning technique. As expected, thicker GLARE 5 offered higher impact resistance. It was found that by increasing the specimen thickness, the damage contour increased. In addition, the results showed that for a given specimen thickness, the damage contour was maximized near its ballistic limit Velocity. The 3D dynamic nonlinear finite element (FE) software, LS-DYNA, was used to validate the experimental results. Good agreement between experimental and FE results was obtained
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influences of thickness and stacking sequence on ballistic impact behaviors of glare 5 fml plates part ii numerical studies
Journal of Composite Materials, 2014Co-Authors: Seyed A Yaghoubi, Benjamin LiawAbstract:This two-part article examines the effects of thickness and stacking sequence of GLARE 5 (2024-T3 aluminum alloy-unidirectional S2-glass/epoxy) fiber–metal laminated (FML) plates subjected to ballistic impact. Part I presented experimental observations of damage development in the specimens, C-scan damage contours, Projectile Velocity profiles and ballistic limit velocities (V50). Part II concerns with finite element (FE) modeling of the FML plates. The 3D FE code, LS-DYNA, was used to model and validate the experimental results. Experimentally obtained incident Projectile impact Velocity versus the residual Velocity (Vi∼Vr), damage patterns and bullet residual length were used to validate the FE model. Good agreement was achieved between experimental and numerical results. It was found that for a given specimen thickness/stacking-sequence, by increasing the Projectile incident Velocity up to its V50 value, the maximum contact force increased. By further increasing the Projectile Velocity above its V50, t...
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thickness influence on ballistic impact behaviors of glare 5 fiber metal laminated beams experimental and numerical studies
Composite Structures, 2012Co-Authors: Seyed A Yaghoubi, Benjamin LiawAbstract:Abstract This paper presents experimental and numerical investigations on ballistic impact behaviors of GLARE 5 fiber-metal laminated (FML) beams of various thicknesses. A high-speed camera was used to measure impact and residual/rebound velocities and also to assess damage evolution in the FMLs. The incident Projectile impact Velocity versus the residual Velocity ( V I – V R ) was plotted and numerically fitted according to the classical Lambert–Jonas equation for the determination of ballistic limit Velocity, V 50 . The results showed that the V 50 varied in a parabolic trend with respect to the metal volume fraction (MVF) and specimen thickness. The interfacial debonding as well as bending and stretching in aluminum layers played the significant roles in dissipating the impact energy in the GLARE 5 FML beams. The 3D finite element (FE) code, LS-DYNA, was used to model and validate the experimentally obtained results. Good agreement between experimental and numerical results was achieved. It was found that for a given specimen configuration, by increasing the Projectile incident Velocity up to its V 50 , the maximum contact force increased. By further increasing the Projectile Velocity above its V 50 , the maximum contact force was relatively invariant with respect to an increase in the Projectile incident Velocity.
Seyed A Yaghoubi - One of the best experts on this subject based on the ideXlab platform.
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* Corresponding author (Ali Seyed Yaghoubi) AN EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THICKNESS EFFECT ON CROSS-PLY GLARE 5 FML PLATES SUBJECTED TO BALLISTIC IMPACT
2020Co-Authors: Seyed A Yaghoubi, Benjamin LiawAbstract:ABSTRACT GLARE 5 fiber-metal laminated (FML) plates of dimensions: 152.4 mm × 101.6 mm with various thicknesses, ranging from 1.12 mm up to 4.37 mm, were impacted by a 0.22 caliber bullet-shaped Projectile using a high-speed gas gun. A high-speed camera was used to measure the Projectile Velocity along its ballistic trajectory. The post-impact damage characteristics were evaluated using both nondestructive ultrasonic and destructive mechanical sectioning techniques. Only the contour of the entire damage area could be obtained using ultrasonic C-scan; whereas more details of the damage were provided through the mechanical cross-sectioning technique. As expected, thicker GLARE 5 offered higher impact resistance. It was found that by increasing the specimen thickness, the damage contour increased. In addition, the results showed that for a given specimen thickness, the damage contour was maximized near its ballistic limit Velocity. The 3D dynamic nonlinear finite element (FE) software, LS-DYNA, was used to validate the experimental results. Good agreement between experimental and FE results was obtained
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influences of thickness and stacking sequence on ballistic impact behaviors of glare 5 fml plates part ii numerical studies
Journal of Composite Materials, 2014Co-Authors: Seyed A Yaghoubi, Benjamin LiawAbstract:This two-part article examines the effects of thickness and stacking sequence of GLARE 5 (2024-T3 aluminum alloy-unidirectional S2-glass/epoxy) fiber–metal laminated (FML) plates subjected to ballistic impact. Part I presented experimental observations of damage development in the specimens, C-scan damage contours, Projectile Velocity profiles and ballistic limit velocities (V50). Part II concerns with finite element (FE) modeling of the FML plates. The 3D FE code, LS-DYNA, was used to model and validate the experimental results. Experimentally obtained incident Projectile impact Velocity versus the residual Velocity (Vi∼Vr), damage patterns and bullet residual length were used to validate the FE model. Good agreement was achieved between experimental and numerical results. It was found that for a given specimen thickness/stacking-sequence, by increasing the Projectile incident Velocity up to its V50 value, the maximum contact force increased. By further increasing the Projectile Velocity above its V50, t...
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thickness effect on cross ply glare 5 fml beams subjected to ballistic impact
2013Co-Authors: Seyed A Yaghoubi, Enjami LiawAbstract:In this study, GLARE 5 fiber-metal laminates (FMLs) of dimensions: 254mm25.4mm (10″×1″) with various thicknesses were impacted by a 0.22 caliber bullet shaped Projectile using a high-speed gas gun. The specimens were cut transversely through the impact center using a diamond blade cutting wheel for destructive damage evaluation. The results showed that failure pattern was changed as the specimen thickness increased. This was very obvious especially for (5/4) and (6/5) configurations. In addition, a high-speed camera was used to record the damage evolution on the non-impacted side of the specimens. It was found that when impacted ballistically by the same Projectile Velocity, debonding between the bottom (non-impacted side) aluminum layer and its adjacent glass-fiber reinforced epoxy layer was increased by changing the lay-up configuration from (6/5) to (5/4). This phenomenon was demonstrated experimentally using the video footage obtained from the high-speed camera.
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an experimental and numerical investigation of thickness effect on cross ply glare 5 fml plates subjected to ballistic impact
ASME 2012 International Mechanical Engineering Congress and Exposition, 2012Co-Authors: Seyed A Yaghoubi, Enjami LiawAbstract:GLARE 5 fiber-metal laminated (FML) plates of dimensions: 152.4 mm × 101.6 mm with various thicknesses, ranging from 1.12 mm up to 4.37 mm, were impacted by a 0.22 caliber bullet-shaped Projectile using a high-speed gas gun. A high-speed camera was used to measure the Projectile Velocity along its ballistic trajectory. The post-impact damage characteristics were evaluated using both nondestructive ultrasonic and destructive mechanical sectioning techniques. Only the contour of the entire damage area could be obtained using ultrasonic C-scan; whereas more details of the damage were provided through the mechanical cross-sectioning technique. As expected, thicker GLARE 5 offered higher impact resistance. It was found that by increasing the specimen thickness, the damage contour increased. In addition, the results showed that for a given specimen thickness, the damage contour was maximized near its ballistic limit Velocity. The 3D dynamic nonlinear finite element (FE) software, LS-DYNA, was used to validate the experimental results. Good agreement between experimental and FE results was obtained.© 2012 ASME
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thickness influence on ballistic impact behaviors of glare 5 fiber metal laminated beams experimental and numerical studies
Composite Structures, 2012Co-Authors: Seyed A Yaghoubi, Benjamin LiawAbstract:Abstract This paper presents experimental and numerical investigations on ballistic impact behaviors of GLARE 5 fiber-metal laminated (FML) beams of various thicknesses. A high-speed camera was used to measure impact and residual/rebound velocities and also to assess damage evolution in the FMLs. The incident Projectile impact Velocity versus the residual Velocity ( V I – V R ) was plotted and numerically fitted according to the classical Lambert–Jonas equation for the determination of ballistic limit Velocity, V 50 . The results showed that the V 50 varied in a parabolic trend with respect to the metal volume fraction (MVF) and specimen thickness. The interfacial debonding as well as bending and stretching in aluminum layers played the significant roles in dissipating the impact energy in the GLARE 5 FML beams. The 3D finite element (FE) code, LS-DYNA, was used to model and validate the experimentally obtained results. Good agreement between experimental and numerical results was achieved. It was found that for a given specimen configuration, by increasing the Projectile incident Velocity up to its V 50 , the maximum contact force increased. By further increasing the Projectile Velocity above its V 50 , the maximum contact force was relatively invariant with respect to an increase in the Projectile incident Velocity.
V Madhu - One of the best experts on this subject based on the ideXlab platform.
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an experimental study on ballistic performance of boron carbide tiles
International Journal of Impact Engineering, 2011Co-Authors: S G Savio, K Ramanjaneyulu, V Madhu, Balakrishna T BhatAbstract:Boron carbide is an attractive candidate for use as armour material because of its lower density combined with high hardness. The ballistic performance of boron carbide tiles were evaluated using standard Depth of Penetration (DOP) test method against hard steel 7.62 mm armour piercing (AP) Projectiles. The effect of variation in thickness of tile and the Projectile Velocity on the ballistic efficiency of the material was studied. It has been found that the differential efficiency factor (DEF) increases with increase in Projectile Velocity from 600 to 820 m/s. And an insignificant or marginal increase in efficiency was observed for increase in tile thickness from 5.2 mm up to 7.3 mm. The effect of the type of radial confinement on the residual DOP was also studied. It was found that the steel radial confinement produces lower residual DOP values compared to aluminium alloy and with no radial confinement. Results along with photographs have been presented.
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an experimental study of penetration resistance of ceramic armour subjected to Projectile impact
International Journal of Impact Engineering, 2005Co-Authors: V Madhu, K Ramanjaneyulu, Balakrishna T Bhat, N K GuptaAbstract:Abstract An experimental study has been carried out on the ballistic performance of 95% and 99.5% alumina ceramic tiles backed by metal plates, when subjected to normal impact of hard steel 12.7 mm armour piercing (AP) Projectiles at velocities ranging from 500 to 830 ms−1. Typical damaged targets and broken Projectiles are presented. The depth of penetration is measured in all the experiments, and the ballistic efficiency factor of the ceramic plates are determined. Results show that the efficiency factor increases with increase in Projectile Velocity. With the increase in thickness of the ceramic tile, the ballistic efficiency factor for a given Velocity is observed to decrease in the case of 99.5% grade and increase in the case of 95% grade ceramic. The higher purity alumina (99.5%) shows higher ballistic performance when compared with the 95% alumina. The 99.5% alumina exhibited a predominantly transcrystalline fracture while the 95% alumina showed a less defined fracture surface. Experiments on 7.62 mm AP shots were also done keeping the ( d / t ) ratio same as in 12.7 mm AP experiments and results are presented.
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normal and oblique impact of a kinetic energy Projectile on mild steel plates
International Journal of Impact Engineering, 1992Co-Authors: N K Gupta, V MadhuAbstract:Summary A series of experiments was carried out wherein spinning armour piercing Projectiles of core diameter 6.2 mm were fired on mild steel plates of thicknesses varying from 10 to 25 mm. The Projectile Velocity in all the tests was about 820 ms−1 in both normal and oblique impacts. In successive tests on plates of each thickness, the angle of obliquity was increased from 0° (normal impact) until richochet occurred. The impact velocities in all tests and the residual velocities in tests wherein the plates were perforated, were measured. Velocity drop versus angle of obliquity curves are presented for plates of different thicknesses. The target damage is examined and the conditions at ballistic limit and ricochet are discussed.
N K Gupta - One of the best experts on this subject based on the ideXlab platform.
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an experimental study of penetration resistance of ceramic armour subjected to Projectile impact
International Journal of Impact Engineering, 2005Co-Authors: V Madhu, K Ramanjaneyulu, Balakrishna T Bhat, N K GuptaAbstract:Abstract An experimental study has been carried out on the ballistic performance of 95% and 99.5% alumina ceramic tiles backed by metal plates, when subjected to normal impact of hard steel 12.7 mm armour piercing (AP) Projectiles at velocities ranging from 500 to 830 ms−1. Typical damaged targets and broken Projectiles are presented. The depth of penetration is measured in all the experiments, and the ballistic efficiency factor of the ceramic plates are determined. Results show that the efficiency factor increases with increase in Projectile Velocity. With the increase in thickness of the ceramic tile, the ballistic efficiency factor for a given Velocity is observed to decrease in the case of 99.5% grade and increase in the case of 95% grade ceramic. The higher purity alumina (99.5%) shows higher ballistic performance when compared with the 95% alumina. The 99.5% alumina exhibited a predominantly transcrystalline fracture while the 95% alumina showed a less defined fracture surface. Experiments on 7.62 mm AP shots were also done keeping the ( d / t ) ratio same as in 12.7 mm AP experiments and results are presented.
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normal and oblique impact of a kinetic energy Projectile on mild steel plates
International Journal of Impact Engineering, 1992Co-Authors: N K Gupta, V MadhuAbstract:Summary A series of experiments was carried out wherein spinning armour piercing Projectiles of core diameter 6.2 mm were fired on mild steel plates of thicknesses varying from 10 to 25 mm. The Projectile Velocity in all the tests was about 820 ms−1 in both normal and oblique impacts. In successive tests on plates of each thickness, the angle of obliquity was increased from 0° (normal impact) until richochet occurred. The impact velocities in all tests and the residual velocities in tests wherein the plates were perforated, were measured. Velocity drop versus angle of obliquity curves are presented for plates of different thicknesses. The target damage is examined and the conditions at ballistic limit and ricochet are discussed.
Shinichi Maeda - One of the best experts on this subject based on the ideXlab platform.
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initiation and sustaining mechanisms of stabilized oblique detonation waves around Projectiles
Proceedings of the Combustion Institute, 2013Co-Authors: Shinichi Maeda, Satoshi SumiyaAbstract:Abstract Direct initiations and stabilizations of three-dimensional conical detonation waves were attained by launching spheres with 1.06–1.31 times the C–J velocities into detonable mixtures. We conducted high time-resolution Schlieren visualizations of the whole processes over unsteady initiations to stable propagations of the stabilized Oblique Detonation Waves (ODWs) using a high-speed camera. The detonable mixtures were stoichiometric oxygen mixtures with acetylene, ethylene or hydrogen. They were diluted with argon in a 50% volumetric fraction, and a 75% diluted mixture was also tested for the acetylene/oxygen. The direct initiation of detonation by the Projectile and the DDT process like the re-initiation appeared in the initiation process of stabilized ODW. This process eventually led to the stabilized ODW supported by the Projectile Velocity and the ringed shape detonation wave originating in the re-initiation. We modeled the spatial evolution of stabilized ODW after the re-initiation based on its C–J Velocity and angle. The model qualitatively reproduced the measured development rate of stabilized ODW. We also discussed about the detonation stability for the curvature effect arising from the three-dimensional nature of stabilized ODW around the Projectile. The curvature effect attenuated the detonation wave below its C–J Velocity at the vicinity of Projectile. The propagation limits of curvature effect will be responsible for the criticality to attain the stabilized ODWs. By accessing the detailed distributions of propagation velocities and curvature radiuses, the critical curvature radiuses normalized by the cell sizes experimentally revealed to be 8–10 or 15–18 for mixtures diluted with each 50% argon or 75% argon/krypton.
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oblique detonation wave stability around a spherical Projectile by a high time resolution optical observation
Combustion and Flame, 2012Co-Authors: Shinichi Maeda, Jiro Kasahara, Akiko MatsuoAbstract:Abstract Spherical Projectiles were launched into detonable mixtures over a wide range of Projectile velocities from near to about 1.8 times the Chapman–Jouguet (C–J) Velocity. Oblique detonation waves (ODWs) and shock-induced combustions (SICs) stabilized around the Projectiles were visualized with high time and high spatial resolutions using the Schlieren technique and a high-speed camera with a 1-μs frame speed. Unsteady wave structures called Straw Hat type structures consisting of a SIC region followed by a C–J ODW were observed near stabilizing criticalities of a C–J ODW, and they were divided into two propagation types, depending on whether the C–J ODW could be stabilized [11] , [12] , [14] . In the present study, we suggested wave structures of the Straw Hat types based on our examination of dozens of continuous images. Triple points were observed at the intersection of a bow shock, a C–J ODW and a transverse detonation or shock wave when Projectile velocities were slightly higher than C–J velocities. Onsets of local explosions in the SIC region for stabilizing the ODW in the Straw Hat type structures have been reported [14] . We observed this stabilizing mechanism by visualizing onsets of periodical local explosions and their transition to spherical detonation waves when the Projectile Velocity was much higher than the C–J Velocity. We also determined stabilizing criticalities using a stoichiometric acetylene-oxygen mixture diluted with argon or krypton in 50% or 75% volumetric fractions, respectively. We found that the stabilizing criticalities did not depend only on the ratio of the Projectile diameter and the cell size of the mixture.
