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Showing papers on "Projectile published in 2012"


Journal ArticleDOI
TL;DR: In this paper, a high-speed camera was used to measure impact and residual/rebound velocities and also to assess damage evolution in fiber-metal laminated (FML) beams.

94 citations


Journal ArticleDOI
TL;DR: In this paper, the combined effects of yarn tensile strength, inter-yarn friction, projectile impact location, and fabric clamping conditions on the probabilistic impact response of flexible woven Kevlar KM2 fabrics are studied using a 0.22 caliber spherical projectile.

93 citations


Journal ArticleDOI
TL;DR: In this paper, the impact performance of a hybrid composite made of woven fiber Kevlar-29 and Al2O3 powder/epoxy subjected to high velocity impact is presented both theoretically and experimentally.

70 citations


Patent
30 Jul 2012
TL;DR: In this paper, a subsonic shell casing has an engineered internal propellant cavity built into the internal body of the casing itself that does not depend on the introduction of a separate volume reducing device such as tubing, filler, foam filler and the like.
Abstract: A subsonic ammunition cartridge casing having an engineered internal volume designed to allow for the introduction of precisely the amount of propellant necessary at precisely the desired location to reproducibly produce the desired projectile velocity and internal pressure is provided. The subsonic shell casing has an engineered internal propellant cavity built into the internal body of the casing itself that does not necessarily depend on the introduction of a separate volume reducing device such as tubing, filler, foam filler and the like. This ensures the integrity of the case, does not result in anything being expelled through the muzzle of the weapon other than the projectile, does not have any burning or combusting components, allows for very precise control of the internal volume and thus chamber pressure, and is economical to produce.

70 citations


Journal ArticleDOI
Zitao Guo1, Wei Zhang1, Xinke Xiao1, Gang Wei1, Peng Ren1 
TL;DR: In this article, an analytical cavity model based on the solution to the Rayleigh-Besant problem was developed to describe the cavity dynamics of high-speed horizontal water entry behaviors of flat, ogival and hemispherical-nose projectiles were studied experimentally and theoretically.

68 citations


Patent
30 Mar 2012
TL;DR: In this paper, a method and system for automatically calculating a trajectory of a projectile launched from a weapon includes receiving environmental conditions and determining a distance to a potential target, which is calculated based on the distance and environmental conditions.
Abstract: A method and system for automatically calculating a trajectory of a projectile launched from a weapon includes receiving environmental conditions and determining a distance to a potential target. Determining the distance to the potential target may include calculating distance via optics of the weapon in conjunction with a self correcting reticle module or a video target tracking module. Alternatively, the distance to the potential target may be determined using a laser range finder. A point of impact for the projectile on the potential target may automatically be calculated based on the distance and environmental conditions. A graphical indicator may then be projected on a display device which corresponds to the potential target and indicates the point of impact for the projectile on the potential target. The video target tracking or self correcting reticle module moves the projectile impact point (crosshairs) as the weapon is translated in space by the marksmen.

63 citations


Journal ArticleDOI
TL;DR: In this article, the authors used the LS-DYNA to simulate an HRAM event created by a steel spherical projectile impacting a partially water-filled aluminium square tube, and the ALE formulation was employed to reproduce the event.

52 citations


Journal ArticleDOI
TL;DR: In this paper, the collision of energetic ions and graphene fragments is studied in the framework of real-space finite-difference time-dependent density functional theory (TDDFT) coupled with classical molecular dynamics for nuclei.
Abstract: The collision of energetic ions and graphene fragments is studied in the framework of real-space finite-difference time-dependent density functional theory (TDDFT) coupled with classical molecular dynamics for nuclei. The amount of energy transferred from the projectile to the target is calculated to explore the defect formation mechanisms as a function of the projectile's energy. It is found that creation of defects in graphene due to the interaction of a fast proton with valence electrons is unlikely. In the case of projectiles with higher charges, the transferred energy increases significantly, leading to higher probability of bond breaking.

50 citations


Journal ArticleDOI
TL;DR: In this paper, a microstructure model of 3D orthogonal woven fabric (3DOWF) was established and imported into finite element geometrical preprocessor.
Abstract: The ballistic impact damages of 3D orthogonal woven fabric (3DOWF) penetrated under a conically cylindrical rigid projectile were investigated from experimental tests and finite element simulations. A microstructure model of the 3DOWF was established and imported into finite element geometrical preprocessor. In the microstructure model, the architecture of the 3DOWF has the same spatial configurations with that of the real 3DOWF, including the spatial distributions and cross-sections of warp, weft yarns, and Z-yarns. Mechanical parameters of the yarns were obtained from high-strain rate tests which near to the impact loading condition in ballistic tests. The impact damage evolutions of the 3DOWF were simulated with the commercial finite element code ABAQUS/Explicit. From the comparisons of damage morphologies and residual velocities of the projectile after perforation between experimental and finite element simulation, it was found that the simulation can reflect the impact damage precisely. Furthermore, ...

45 citations



Journal ArticleDOI
TL;DR: In this article, the effects of yarn characteristics on the probabilistic impact response of single-layer fully-clamped flexible woven fabrics are numerically studied using a yarn-level fabric model with a statistical implementation of yarn strengths.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed and demonstrated a highly efficient scheme of acceleration of dense matter in which a projectile placed in a cavity is irradiated by a laser beam introduced into the cavity through a hole and then accelerated in a guiding channel by the pressure of a hot plasma produced in the cavity by the laser beam or by the photon pressure of the ultra-intense laser radiation trapped inside the cavity.
Abstract: Acceleration of dense matter to high velocities is of high importance for high energy density physics, inertial confinement fusion, or space research. The acceleration schemes employed so far are capable of accelerating dense microprojectiles to velocities approaching 1000 km/s; however, the energetic efficiency of acceleration is low. Here, we propose and demonstrate a highly efficient scheme of acceleration of dense matter in which a projectile placed in a cavity is irradiated by a laser beam introduced into the cavity through a hole and then accelerated in a guiding channel by the pressure of a hot plasma produced in the cavity by the laser beam or by the photon pressure of the ultra-intense laser radiation trapped in the cavity. We show that the acceleration efficiency in this scheme can be much higher than that achieved so far and that sub-relativisitic projectile velocities are feasible in the radiation pressure regime.

Journal ArticleDOI
TL;DR: In this article, the effect of configuration and span diameter on the ballistic limit of a 1.5-mm-thick monolithic target was studied with ABAQUS/Explicit finite element code.

Journal ArticleDOI
TL;DR: In this paper, the authors extended the standard linear theory to account for aerodynamic asymmetries caused by actuating canards and proposed an extended linear-projectile theory to address flight stability of projectiles with aerodynamic configuration asymmetry.
Abstract: Driven by the creation of new smart projectile concepts with maneuver capability, projectile configurations with large aerodynamic asymmetries are becoming more common. Standard linear stability theory for projectiles assumes the projectile is symmetric, both from aerodynamic and mass properties perspectives. The work reported here extends standard projectile linear theory to account for aerodynamic asymmetries caused by actuating canards. Differences between standard linear and extended linear theories reported here are highlighted. To validate the theory, time simulation of the extended linear theory and a fully nonlinear trajectory simulation are made for a representative scenario, with excellent agreement noted. The extended linear-projectile theory offers a tool to address flight stability of projectiles with aerodynamic configuration asymmetries.

Journal ArticleDOI
TL;DR: In this paper, the performance of three-dimensional orthogonal woven E-glass/epoxy composites under high velocity impact is analyzed using wave propagation and energy balance between the projectile and the target.
Abstract: Performance of three-dimensional orthogonal woven E-glass/epoxy composites under high velocity impact is presented. The analytical method used is based on wave propagation and energy balance between the projectile and the target. Different damage and energy absorbing mechanisms for a typical three-dimensional orthogonal woven composite are compression of the target directly below the projectile, compression in the surrounding region of the impacted zone, tension in the region consisting of primary yarns, tensile deformation in the region consisting of secondary yarns, shear plugging, bulge formation on the back face of the target, matrix cracking and friction between the target and the projectile. Experimental studies are also presented on high strain rate characterization, shear plugging behavior and high velocity impact behavior. For comparison, studies are also presented on the performance of two-dimensional plain weave E-glass/epoxy composites. A good match is observed between the analytical predictions and experimentally obtained limit velocities for complete penetration. It is observed that limit velocity for complete penetration for three dimensional woven composite is higher than that for two-dimensional plain weave composite.

Journal ArticleDOI
01 Aug 2012-Icarus
TL;DR: In this paper, a simple model based on the transfer of momentum from the projectile to this first target grain was presented, which is capable to explain the results with only a single free parameter, and moreover well determined by previous experiments.

Journal ArticleDOI
TL;DR: In this article, a high-speed camera with a 1-μs frame speed was used to analyze the trajectories of spherical projectiles launched into detonable mixtures over a wide range of velocity from near to about 1.8 times the Chapman-Jouguet (C-J) velocity.

Journal ArticleDOI
01 Mar 2012
TL;DR: Precision-guided munitions are of interest to the Army as a means of both reducing collateral damage and increasing the chance of desired effect with the first round fired as discussed by the authors. But many technical barriers...
Abstract: Precision-guided munitions are of interest to the Army as a means of both reducing collateral damage and increasing the chance of desired effect with the first round fired. Many technical barriers ...

Journal ArticleDOI
TL;DR: In this article, an experimental investigation into the responses of a woven fabric and a pliable laminate subjected to oblique projectile impact is undertaken, and the influence of impact obliquity on the ballistic limit and energy absorbed are analysed and discussed.

Journal ArticleDOI
TL;DR: In this paper, a smoothed particle hydrodynamics (SPH) method was used to model the impact of a metal sphere on a thin metallic plate with a wide range of velocities (300, 1000, 2000, and 3100 m/s).
Abstract: The modeling of high velocity impact is an important topic in impact engineering. Due to various constraints, experimental data are extremely limited. Therefore, detailed numerical simulation can be considered as a desirable alternative. However, the physical processes involved in the impact are very sophisticated; hence a practical and complete reproduction of the phenomena involves complicated numerical models. In this paper, we present a smoothed particle hydrodynamics (SPH) method to model two-dimensional impact of metal sphere on thin metallic plate. The simulations are applied to different materials (Aluminum, Lead and Steel); however the target and projectile are formed of similar metals. A wide range of velocities (300, 1000, 2000, and 3100 m/s) are considered in this study. The goal is to study the most sensitive input parameters (impact velocity and plate thickness) on the longitudinal extension of the projectile, penetration depth and damage crater.

Journal ArticleDOI
TL;DR: In this article, the entire ballistic impact event considering target performance can be divided into dynamic plastic penetration, spherical bulge formation, bulge advancement, plug formation and exit and projectile exit.

Journal ArticleDOI
TL;DR: In this article, the horizontal water-entry of flat-nose projectiles of two different lengths at impact velocities of 400m/s-600 m/s is studied experimentally and theoretically.
Abstract: In this article, the horizontal water-entry of flat-nose projectiles of two different lengths at impact velocities of 400 m/s-600 m/s is studied experimentally and theoretically. Based on the solution of the Rayleigh-Besant problem, a set of projectile dynamic equations are derived and a cavity model is built to describe the projectile’s water entry dynamics. A parameter in the cavity model is determined by employing the principle of energy conservation. The results indicate that the flat-nose projectiles enjoy a good stability of trajectory, the drag coefficient and the velocity decay coefficient are dependent on the cavitation number, and increase along the penetration distance but with a relatively small variation. The maximum cavity radius decreases monotonically with the penetration distance. Projectiles with the same nose shapes at different initial velocities have a basically consistent cavity dimension before the deep pinching off phenomenon occurs. Good agreements are observed between results obtained by the analytical model and the experimental results.

Journal ArticleDOI
TL;DR: In this article, the impact mechanism and failure of the target are discussed and the ballistic limit equation is verified by the test data and the results show that this empirical equation could be a practical way to estimate the critical velocity.

Journal ArticleDOI
TL;DR: In this article, the authors investigate the evolution of conical structures originating from a supersonic projectile moving through the hot matter of ultrarelativistic particles, using different scenarios for the interaction between a high-energy particle and matter, and different transport properties of the matter.

Journal ArticleDOI
TL;DR: Experimental studies have shown that flexible woven fabrics can absorb significant kinetic energy from both projectile and fragment impacts through a combination of design factors which include yar... as discussed by the authors, and they have been shown that they can absorb a significant amount of kinetic energy.
Abstract: Experimental studies have shown that flexible woven fabrics can absorb significant kinetic energy from both projectile and fragment impacts through a combination of design factors which include yar...

Journal ArticleDOI
TL;DR: In this article, the authors present results of an experimental test and numerical investigation of reinforced concrete blocks' penetration resistance against a steel blunt-nose projectile with a diameter of 23mm and a mass of 175g with striking velocity about 980m/s hitting concrete blocks reinforced by different number of layers of woven wire steel mesh (Ferrocement).

Proceedings ArticleDOI
09 Jan 2012
TL;DR: In this article, the flow interaction effects from a jet issuing into a supersonic crossflow are investigated using computational fluid dynamic simulations of a basic fin-stabilized projectile at moderate positive and negative angles attack.
Abstract: The flow interaction effects from a jet issuing into a supersonic crossflow are investigated using computational fluid dynamic simulations of a basic fin-stabilized projectile at moderate positive and negative angles attack. Data was generated for a high-pressure ratio jet located at seven locations along the projectile axis. Crossflow Mach numbers of 1.5, 2.5, and 3.5 were investigated for an angle of attack range of -10° ≤ α ≤ 10°. Flowfield visualizations indicated the size of the jet plume and the size of the resulting low-pressure region behind the jet were reduced as Mach number increased. The jet force amplification factor showed more variation as α became more negative. The effective jet location was found to vary little for α > -5° at Mach 2.5 and 3.5. For α > -5°, there was less variation of force amplification factor a Mach number increased. Flight simulations using reaction jet “squibs” were performed to evaluate the sensitivity of the control maneuver to the differences in jet thrust and jet actuation location. These results showed that significant differences in the projectile maneuver control were obtained if the effective jet thrust acting at the effective jet location were used instead of the ideal jet thrust acting at the jet exit location.

Patent
11 Apr 2012
TL;DR: In this article, a semi-physical simulation of a laser terminally guided projectile is presented, where a table body is used for load mounting and an angle measurement element is provided to supply a corner signal to serve as position feedback and speed feedback.
Abstract: The invention relates to a laser terminally guided projectile and particularly discloses a turntable for the semi-physical simulation of the laser terminally guided projectile. The turntable comprises a table body and a control cabinet, wherein the table body is used for simulating a projectile body attitude motion characteristic or a projectile body-target relative motion characteristic, can be used for load mounting and is provided with an angle measurement element so as to supply a corner signal to serve as position feedback and speed feedback; the control cabinet is used for realizing the control over the table body; the control cabinet comprises an upper computer and a lower computer; the upper computer can interact with an operator through a human-machine interface so as to realize control instruction input, configuration data correction, safety protection, system state monitoring, and data receiving and processing for the turntable; and the lower computer can be connected with the upper computer through a high-speed serial interface and connected with the table body through a cable so as to complete the real-time control over the table body.

Proceedings ArticleDOI
15 May 2012
TL;DR: In this paper, an improved synchronous induction coilgun was tested to demonstrate the launch of 120-mm projectiles, and a computer simulation was developed to predict the performance of the launcher system.
Abstract: An improved large-caliber synchronous induction coilgun was tested to demonstrate the launch of 120-mm projectiles. This induction coilgun is made of 15 identical coils. The coils are stacked end-to-end forming a barrel, and each coil is energized by the same pulsed power topology in sequence to generate a magnetic force to accelerate the projectile. Tracking of the projectile location during launching provided precise feedback to control. A computer simulation based on the viewpoint of FEA software is developed to predict the performance of the launcher system. 5-kilogram copper projectiles were accelerated from rest to 220 m/s through the 2.5-m launcher assembly with a projectile kinetic energy to capacitor stored energy efficiency of 14.5 %. The 15-stage induction coilgun provides a significant improvement in the armature capture effect, system efficient and coil structure. Further experiments studies are being continued.

Journal ArticleDOI
TL;DR: In this article, the effects of changes in geometries and material properties of rotating band and long range artillery projectile shell body on gun tube stress are presented based on numerical calculations (finite element analysis, FEA).
Abstract: The effects of changes in geometries and material properties of rotating band and long range artillery projectile shell body on gun tube stress are presented. The results are based on numerical calculations (finite element analysis, FEA). Numerical explicit dynamic analyses were performed assuming elastic–plastic material behavior and nonlinear kinematics. Mechanical loading of shell body was controlled by pressure–time relationship based on the simulation of internal ballistic cycle. One degree slice of projectile and forcing cone section of gun tube was modeled as simplified smooth bore 3D analysis model. The results were in agreement with the measured results in firing trials and also with the results presented in open literature. Although simplified computations were used, the influences of the structural modifications of the rotating band and the shell body were shown.