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Thomas L Warren - One of the best experts on this subject based on the ideXlab platform.
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penetration of limestone targets by ogive nosed var 4340 steel Projectiles at oblique angles experiments and simulations
International Journal of Impact Engineering, 2004Co-Authors: Thomas L Warren, S J Hanchak, Kevin L PoormonAbstract:Abstract In this paper, we document the results of a combined experimental, analytical, and computational research program that investigates the penetration of steel Projectiles into limestone targets at oblique angles. We first conducted a series of depth-of-penetration experiments using 20.0 g, 7.11-mm-diameter, 71.12-mm-long, vacuum-arc-remelted (VAR) 4340 ogive-nose steel Projectiles. These Projectiles were launched with striking velocities between 0.4 and 1.3 km/s using a 20-mm powder gun into 0.5 m square limestone target faces with angles of obliquity of 15° and 30°. Next, we employed the initial conditions obtained from the experiments with a technique that we have developed to calculate permanent projectile deformation without erosion. With this technique we use an explicit, transient dynamic, finite element code to model the projectile and an analytical forcing function based on the dynamic expansion of a spherical cavity to represent the target. Due to angle of obliquity we developed a new free surface effect model based on the solution of a dynamically expanding spherical cavity in a finite sphere of incompressible Mohr–Coulomb target material to account for the difference in target resistance acting on the top and bottom sides of the projectile. Results from the simulations show the final projectile positions are in good agreement with the positions obtained from post-test castings of the projectile trajectories.
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penetration of 6061 t6511 aluminum targets by ogive nosed var 4340 steel Projectiles at oblique angles experiments and simulations
International Journal of Impact Engineering, 2001Co-Authors: Thomas L Warren, Kevin L PoormonAbstract:Abstract In this paper we present the results from a combined experimental, analytical, and computational penetration program. First, we conducted a series of depth-of-penetration experiments using 0.021 kg, 7.11 mm diameter, 71.12 mm long, vacuum-arc-remelted 4340 ogive-nose steel Projectiles. These Projectiles were launched with striking velocities between 0.5 and 1.3 km/s using a 20 mm powder gun into 254 mm diameter, 6061-T6511 aluminum targets with angles of obliquity of 15°, 30°, and 45°. Next, we employed the initial conditions obtained from the experiments with a new technique that we have developed to calculate permanent projectile deformation without erosion. With this technique we use an explicit, transient dynamic, finite element code to model the projectile and an analytical forcing function derived from the dynamic expansion of a spherical cavity (which accounts for compressibility, strain hardening, strain-rate sensitivity, and a finite boundary) to represent the target. Results from the simulations show the final projectile positions are in good agreement with the positions obtained from post-test radiographs.
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penetration of 6061 t6511 aluminum targets by ogive nose steel Projectiles with striking velocities between 0 5 and 3 0 km s
International Journal of Impact Engineering, 1999Co-Authors: Andrew J Piekutowski, Michael J. Forrestal, Kevin L Poormon, Thomas L WarrenAbstract:Summary We performed a series of depth-of-penetration experiments using 7.11-mm-diameter, 71.12-mm-long, ogive-nose steel Projectiles and 254-mm-diameter, 6061-T6511 aluminum targets. The Projectiles were made from vacuum-arc remelted (VAR) 4340 steel (Rc 38) and AerMet 100 steel (Rc 53), had a nominal mass of 0.021 kg, and were launched using a powder gun or a two-stage, light gas gun to striking velocities between 0.5 and 3.0 km/s. Since the tensile yield strength of AerMet 100 (Rc 53) steel is about 1.5 times greater than VAR 4340 (Rc 38) steel, we were able to demonstrate the effect of projectile strength on ballistic performance. Post-test radiographs of the targets showed three different regions of penetrator response as the striking velocity increased: (1) the Projectiles remained rigid and visibly undeformed; (2) the Projectiles deformed during penetration without nose erosion, deviated from the target centerline, and exited the side of the target or turned severely within the target; and (3) the Projectiles eroded during penetration and lost mass. To show the effect of projectile strength, we present depth-of-penetration data as a function of striking velocity for both types of steel Projectiles at striking velocities ranging from 0.5 and 3.0 km/s. In addition, we show good agreement between the rigid-projectile penetration data and a cavityexpansion model.
Kevin L Poormon - One of the best experts on this subject based on the ideXlab platform.
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penetration of limestone targets by ogive nosed var 4340 steel Projectiles at oblique angles experiments and simulations
International Journal of Impact Engineering, 2004Co-Authors: Thomas L Warren, S J Hanchak, Kevin L PoormonAbstract:Abstract In this paper, we document the results of a combined experimental, analytical, and computational research program that investigates the penetration of steel Projectiles into limestone targets at oblique angles. We first conducted a series of depth-of-penetration experiments using 20.0 g, 7.11-mm-diameter, 71.12-mm-long, vacuum-arc-remelted (VAR) 4340 ogive-nose steel Projectiles. These Projectiles were launched with striking velocities between 0.4 and 1.3 km/s using a 20-mm powder gun into 0.5 m square limestone target faces with angles of obliquity of 15° and 30°. Next, we employed the initial conditions obtained from the experiments with a technique that we have developed to calculate permanent projectile deformation without erosion. With this technique we use an explicit, transient dynamic, finite element code to model the projectile and an analytical forcing function based on the dynamic expansion of a spherical cavity to represent the target. Due to angle of obliquity we developed a new free surface effect model based on the solution of a dynamically expanding spherical cavity in a finite sphere of incompressible Mohr–Coulomb target material to account for the difference in target resistance acting on the top and bottom sides of the projectile. Results from the simulations show the final projectile positions are in good agreement with the positions obtained from post-test castings of the projectile trajectories.
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penetration of 6061 t6511 aluminum targets by ogive nosed var 4340 steel Projectiles at oblique angles experiments and simulations
International Journal of Impact Engineering, 2001Co-Authors: Thomas L Warren, Kevin L PoormonAbstract:Abstract In this paper we present the results from a combined experimental, analytical, and computational penetration program. First, we conducted a series of depth-of-penetration experiments using 0.021 kg, 7.11 mm diameter, 71.12 mm long, vacuum-arc-remelted 4340 ogive-nose steel Projectiles. These Projectiles were launched with striking velocities between 0.5 and 1.3 km/s using a 20 mm powder gun into 254 mm diameter, 6061-T6511 aluminum targets with angles of obliquity of 15°, 30°, and 45°. Next, we employed the initial conditions obtained from the experiments with a new technique that we have developed to calculate permanent projectile deformation without erosion. With this technique we use an explicit, transient dynamic, finite element code to model the projectile and an analytical forcing function derived from the dynamic expansion of a spherical cavity (which accounts for compressibility, strain hardening, strain-rate sensitivity, and a finite boundary) to represent the target. Results from the simulations show the final projectile positions are in good agreement with the positions obtained from post-test radiographs.
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penetration of 6061 t6511 aluminum targets by ogive nose steel Projectiles with striking velocities between 0 5 and 3 0 km s
International Journal of Impact Engineering, 1999Co-Authors: Andrew J Piekutowski, Michael J. Forrestal, Kevin L Poormon, Thomas L WarrenAbstract:Summary We performed a series of depth-of-penetration experiments using 7.11-mm-diameter, 71.12-mm-long, ogive-nose steel Projectiles and 254-mm-diameter, 6061-T6511 aluminum targets. The Projectiles were made from vacuum-arc remelted (VAR) 4340 steel (Rc 38) and AerMet 100 steel (Rc 53), had a nominal mass of 0.021 kg, and were launched using a powder gun or a two-stage, light gas gun to striking velocities between 0.5 and 3.0 km/s. Since the tensile yield strength of AerMet 100 (Rc 53) steel is about 1.5 times greater than VAR 4340 (Rc 38) steel, we were able to demonstrate the effect of projectile strength on ballistic performance. Post-test radiographs of the targets showed three different regions of penetrator response as the striking velocity increased: (1) the Projectiles remained rigid and visibly undeformed; (2) the Projectiles deformed during penetration without nose erosion, deviated from the target centerline, and exited the side of the target or turned severely within the target; and (3) the Projectiles eroded during penetration and lost mass. To show the effect of projectile strength, we present depth-of-penetration data as a function of striking velocity for both types of steel Projectiles at striking velocities ranging from 0.5 and 3.0 km/s. In addition, we show good agreement between the rigid-projectile penetration data and a cavityexpansion model.
Édio Pereira Lima - One of the best experts on this subject based on the ideXlab platform.
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effect of the impact geometry in the ballistic trauma absorption of a ceramic multilayered armor system
Journal of materials research and technology, 2018Co-Authors: Fábio De Oliveira Braga, Fernanda Santos Da Luz, Sergio Neves Monteiro, Édio Pereira LimaAbstract:Abstract Ceramic armors are frequently used for protection against high energy Projectiles, such as the 7.62 mm and 5.56 mm. Recently, it has been demonstrated that a modification in the geometry of the impact face, from flat to convex, enlarges the stress distribution zone created by the projectile-target interaction. This effect raises the projectile's energy absorption and might improve the user's safety. In the present work, the objective is to characterize ceramic armor plates with convex impact face, by means of the NIJ-0101.06 (2008) standard methodology, aiming to provide an eventual application in armor vests. The characterization is based on the measurement of the backface signature, a deformation behind armor imprinted in a reference material that simulates the consistency of the human body. The results showed significant improvement in the ballistic performance after the impact geometry modification.
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Effect of the impact geometry in the ballistic trauma absorption of a ceramic multilayered armor system
Elsevier, 2018Co-Authors: Fábio De Oliveira Braga, Fernanda Santos Da Luz, Sergio Neves Monteiro, Édio Pereira LimaAbstract:Ceramic armors are frequently used for protection against high energy Projectiles, such as the 7.62 mm and 5.56 mm. Recently, it has been demonstrated that a modification in the geometry of the impact face, from flat to convex, enlarges the stress distribution zone created by the projectile-target interaction. This effect raises the projectile's energy absorption and might improve the user's safety. In the present work, the objective is to characterize ceramic armor plates with convex impact face, by means of the NIJ-0101.06 (2008) standard methodology, aiming to provide an eventual application in armor vests. The characterization is based on the measurement of the backface signature, a deformation behind armor imprinted in a reference material that simulates the consistency of the human body. The results showed significant improvement in the ballistic performance after the impact geometry modification. Keywords: Ballistic test, Ceramic armor, Multilayered armor system, Impact geometr
Michael J. Forrestal - One of the best experts on this subject based on the ideXlab platform.
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penetration experiments with 6061 t6511 aluminum targets and spherical nose steel Projectiles at striking velocities between 0 5 and 3 0 km s
International Journal of Impact Engineering, 2000Co-Authors: Michael J. Forrestal, Andrew J PiekutowskiAbstract:We conducted depth of penetration experiments with 7.11-mm-diameter, 74.7-mm-long, spherical-nose, 4340 steel Projectiles launched into 250-mm-diameter, 6061-T6511 aluminum targets. To show the effect of projectile strength, we used Projectiles that had average Rockwell harnesses of R{sub c} = 36.6, 39.5, and 46.2. A powder gun and two-stage, light-gas guns launched the 0.023 kg Projectiles at striking velocities between 0.5 and 3.0 km/s. Post-test radiographs of the targets showed three response regions as striking velocities increased: (1) the Projectiles remained visibly undeformed, (2) the Projectiles permanently deformed without erosion, and (3) the Projectiles eroded and lost mass. To show the effect of projectile strength, we compared depth-of-penetration data as a function of striking velocity for spherical-nose rods with three Rockwell harnesses at striking velocities ranging from 0.5 to 3.0 km/s. To show the effect of nose shape, we compared penetration data for the spherical-nose Projectiles with previously published data for ogive-nose Projectiles.
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penetration of 6061 t6511 aluminum targets by ogive nose steel Projectiles with striking velocities between 0 5 and 3 0 km s
International Journal of Impact Engineering, 1999Co-Authors: Andrew J Piekutowski, Michael J. Forrestal, Kevin L Poormon, Thomas L WarrenAbstract:Summary We performed a series of depth-of-penetration experiments using 7.11-mm-diameter, 71.12-mm-long, ogive-nose steel Projectiles and 254-mm-diameter, 6061-T6511 aluminum targets. The Projectiles were made from vacuum-arc remelted (VAR) 4340 steel (Rc 38) and AerMet 100 steel (Rc 53), had a nominal mass of 0.021 kg, and were launched using a powder gun or a two-stage, light gas gun to striking velocities between 0.5 and 3.0 km/s. Since the tensile yield strength of AerMet 100 (Rc 53) steel is about 1.5 times greater than VAR 4340 (Rc 38) steel, we were able to demonstrate the effect of projectile strength on ballistic performance. Post-test radiographs of the targets showed three different regions of penetrator response as the striking velocity increased: (1) the Projectiles remained rigid and visibly undeformed; (2) the Projectiles deformed during penetration without nose erosion, deviated from the target centerline, and exited the side of the target or turned severely within the target; and (3) the Projectiles eroded during penetration and lost mass. To show the effect of projectile strength, we present depth-of-penetration data as a function of striking velocity for both types of steel Projectiles at striking velocities ranging from 0.5 and 3.0 km/s. In addition, we show good agreement between the rigid-projectile penetration data and a cavityexpansion model.
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penetration of concrete targets with ogive nose steel rods
International Journal of Impact Engineering, 1998Co-Authors: D J Frew, S J Hanchak, M L Green, Michael J. ForrestalAbstract:Abstract We conducted depth of penetration experiments in concrete targets with 3.0 caliber-radius-head, steel rod Projectiles. The concrete targets with 9.5 mm diameter limestone aggregate had a nominal unconfined compressive strength of 58.4 MPa (8.5 ksi) and density 2320 kg/m3. To explore geometric projectile scales, we conducted two sets of experiments. Projectiles with length-to-diameter ratio of ten were machined from 4340Rc 45 steel, round stock and had diameters and masses of 20.3 mm, 0.478 kg and 30.5 mm, 1.62 kg. Powder guns launched the Projectiles to striking velocities between 400 and 1200 m/s. For these experiments, penetration depth increased as striking velocity increased. When depth of penetration data was divided by a length scale determined from our model, the data collapsed on a single curve. Thus, a single dimensionless penetration depth versus striking velocity prediction was in good agreement with the data at two geometric projectile scales for striking velocities between 400 and 1200 m/s. In addition, we conducted experiments with AerMet 100Rc 53 steel Projectiles and compared depth of penetration and post-test nose erosion data with results from the 4340Rc 45 steel Projectiles.
Andrew J Piekutowski - One of the best experts on this subject based on the ideXlab platform.
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penetration experiments with 6061 t6511 aluminum targets and spherical nose steel Projectiles at striking velocities between 0 5 and 3 0 km s
International Journal of Impact Engineering, 2000Co-Authors: Michael J. Forrestal, Andrew J PiekutowskiAbstract:We conducted depth of penetration experiments with 7.11-mm-diameter, 74.7-mm-long, spherical-nose, 4340 steel Projectiles launched into 250-mm-diameter, 6061-T6511 aluminum targets. To show the effect of projectile strength, we used Projectiles that had average Rockwell harnesses of R{sub c} = 36.6, 39.5, and 46.2. A powder gun and two-stage, light-gas guns launched the 0.023 kg Projectiles at striking velocities between 0.5 and 3.0 km/s. Post-test radiographs of the targets showed three response regions as striking velocities increased: (1) the Projectiles remained visibly undeformed, (2) the Projectiles permanently deformed without erosion, and (3) the Projectiles eroded and lost mass. To show the effect of projectile strength, we compared depth-of-penetration data as a function of striking velocity for spherical-nose rods with three Rockwell harnesses at striking velocities ranging from 0.5 to 3.0 km/s. To show the effect of nose shape, we compared penetration data for the spherical-nose Projectiles with previously published data for ogive-nose Projectiles.
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penetration of 6061 t6511 aluminum targets by ogive nose steel Projectiles with striking velocities between 0 5 and 3 0 km s
International Journal of Impact Engineering, 1999Co-Authors: Andrew J Piekutowski, Michael J. Forrestal, Kevin L Poormon, Thomas L WarrenAbstract:Summary We performed a series of depth-of-penetration experiments using 7.11-mm-diameter, 71.12-mm-long, ogive-nose steel Projectiles and 254-mm-diameter, 6061-T6511 aluminum targets. The Projectiles were made from vacuum-arc remelted (VAR) 4340 steel (Rc 38) and AerMet 100 steel (Rc 53), had a nominal mass of 0.021 kg, and were launched using a powder gun or a two-stage, light gas gun to striking velocities between 0.5 and 3.0 km/s. Since the tensile yield strength of AerMet 100 (Rc 53) steel is about 1.5 times greater than VAR 4340 (Rc 38) steel, we were able to demonstrate the effect of projectile strength on ballistic performance. Post-test radiographs of the targets showed three different regions of penetrator response as the striking velocity increased: (1) the Projectiles remained rigid and visibly undeformed; (2) the Projectiles deformed during penetration without nose erosion, deviated from the target centerline, and exited the side of the target or turned severely within the target; and (3) the Projectiles eroded during penetration and lost mass. To show the effect of projectile strength, we present depth-of-penetration data as a function of striking velocity for both types of steel Projectiles at striking velocities ranging from 0.5 and 3.0 km/s. In addition, we show good agreement between the rigid-projectile penetration data and a cavityexpansion model.
