Showing papers on "Projectile published in 2006"
TL;DR: In this paper, the impact and residual velocities of a hemispherical projectile were measured by using an explicit finite element code (ABAQUS) and the Johnson-Cook elasto-viscoplastic model was used to carry out the analysis.
220 citations
TL;DR: In this article, a 3D finite element analysis model is created using LS-DYNA to simulate the transverse impact of a rigid right circular cylinder onto a square patch of plain-woven Kevlar fabric.
157 citations
TL;DR: In this paper, the dynamic response of monolithic and sandwich beams made from stainless steel is determined by loading the end-clamped beams at mid-span with metal foam projectiles.
156 citations
TL;DR: In this article, the authors conducted experiments with three diameters of concrete targets that had an average compressive strength of 23 MPa (3.3 kg) and 76.2 kg.
133 citations
Patent•
20 Jul 2006
TL;DR: In this article, a sports simulation system includes a tracking apparatus having a display surface on which a visually apparent three-dimensional sports scene is presented, and a launch area sensing unit that is responsive to the data received therefrom to determine the 3D positions, velocity, acceleration and spin of a detected projectile traveling through the tracking region.
Abstract: A sports simulation system includes a projectile tracking apparatus having a display surface on which a visually apparent three-dimensional sports scene is presented The projectile tracking apparatus captures images of a projectile tracking region disposed in front of the display surface to detect a launched projectile traveling through the projectile tracking region towards the display surface A projectile launch area sensing unit captures images of the projectile launch area At least one processing stage communicates with the projectile tracking apparatus and the projectile launch area sensing unit and is responsive to the data received therefrom to determine the three-dimensional positions, velocity, acceleration and spin of a detected projectile traveling through the projectile tracking region The determined three-dimensional positions, velocity, acceleration and spin are used by the at least one processing stage to calculate a trajectory of the launched projectile into the visually apparent three-dimensional sports scene Updated image data is generated by the at least one processing stage that includes a simulation of the launched projectile into the visually apparent three-dimensional sports scene following the calculated trajectory A projection unit coupled to the at least one processing stage receives the image data from the at least one processing stage and presents the visually apparent three-dimensional sports scene, including the simulation, on the display surface
132 citations
TL;DR: In this paper, an underwater shock simulator has been developed for the underwater shock loading of materials and test structures within the laboratory, where a tube is struck at one end by a steel projectile, with the test structure placed at the opposite end of the tube, with peak pressures in the range 15-70 MPa and decay times ranging from 0.1 to 1.5 ms.
Abstract: An underwater shock simulator has been developed for the underwater shock loading of materials and test structures within the laboratory. The tube is struck at one end by a steel projectile, with the test structure placed at the opposite end of the tube. Realistic exponentially decaying pressure pulses are generated in the water with peak pressures in the range 15-70 MPa and decay times ranging from 0.1 to 1.5 ms. The peak pressure and the pulse duration are independently adjusted by varying the projectile velocity and mass, respectively. The underwater shock simulator is used to investigate the one- dimensional fluid-structure interaction of sandwich plates with steel face sheets and an aluminium foam core. The degree of core compression is measured as a function of both the underwater shock impulse and the Taylor fluid-structure interaction parameter. Fully coupled finite element simulations agree well with the measurements while decoupling the fluid-structure interaction phase from the core compression phase within the finite element analysis leads to an under-prediction of the degree of core compression.
122 citations
01 Jan 2006
113 citations
Patent•
25 May 2006
TL;DR: In this article, a system and method for determining the track of a projectile using a thermal signature of the projectile was proposed, where a set of infrared image frames containing spots with characteristics consistent with a projectile in flight were identified.
Abstract: A system and method for determining the track of a projectile use a thermal signature of the projectile. Sequential infrared image frames are acquired from a sensor at a given position. A set of frames containing spots with characteristics consistent with a projectile in flight are identified. A possible projectile track solution for said spots is identified. A thermal signature value for each pixel of each spot of the possible solution is determined. The determined thermal signature is then compared to an actual thermal signature for a substantially similar projectile track to ascertain whether the determined thermal signature substantially matches the actual thermal signature, which indicates that the possible projectile track solution is the correct solution.
109 citations
Journal Article•
TL;DR: In this article, the authors investigate the microscopic mechanism of collisions between energetic protons and graphitic carbon nanostructures and identify not only the amount of energy lost by the projectile, but also the electronic and ionic degrees of freedom of the target that accommodate this energy as a function of the impact parameter and projectile energy.
Abstract: By combining ab initio time-dependent density functional calculations for electrons with molecular dynamics simulations for ions in real time, we investigate the microscopic mechanism of collisions between energetic protons and graphitic carbon nanostructures. We identify not only the amount of energy lost by the projectile, but also the electronic and ionic degrees of freedom of the target that accommodate this energy as a function of the impact parameter and projectile energy. Our results establish validity limits for the Born-Oppenheimer approximation and the threshold energy for defect formation in carbon nanostructures.
109 citations
Patent•
04 Oct 2006TL;DR: In this article, a reactive material composition is defined as a portion of the reactive material that is left exposed to the barrel of a gun or a weapon from which it is launched and similarly exposed to a target with which the projectile subsequently impacts.
Abstract: A munition, such as a projectile formed of at least one reactive material, is provided. In one embodiment, the projectile includes a body portion formed of at least one reactive material composition wherein the at least one reactive material composition defines at least a portion of an exterior surface of the projectile. In other words, a portion of the reactive material may be left “unbuffered” or exposed to the barrel of a gun or weapon from which it is launched and similarly exposed to a target with which the projectile subsequently impacts. In one embodiment, the projectile may be formed with a jacket surrounding a portion of the reactive material to provide additional structural integrity. The projectile may be formed by casting or pressing the reactive material into a desired shape. In another embodiment of the invention, the reactive material may be extruded into a near-net shape and then machined into the desired shape.
90 citations
Patent•
01 Nov 2006
TL;DR: In this paper, the inclination of a line of sight from a vantage point to a target and a line-of-sight range to the target are determined, and an equivalent horizontal range is then determined, wherein the equivalent horizontal ranges is the range at which the trajectory parameter would be expected to occur if the projectile were shot from the vantage point toward a theoretical target located in a horizontal plane intersecting the vantage points.
Abstract: A method for shooting a projectile weapon involves determining the inclination of a line of sight from a vantage point to a target and a line-of-sight range to the target, then predicting a trajectory parameter at the line-of-sight range, for a preselected projectile. Using the trajectory parameter, an equivalent horizontal range may then be determined, wherein the equivalent horizontal range is the range at which the trajectory parameter would be expected to occur if the projectile were shot from the vantage point toward a theoretical target located in a horizontal plane intersecting the vantage point. The equivalent horizontal range may be utilized to compensate for ballistic drop when shooting the projectile weapon. The method may be embodied in a handheld laser rangefinder including a memory for storing ballistic data. Systems for automatic hold over adjustment in a weapon aiming device are also disclosed.
TL;DR: In this paper, a Doppler radar monitored the projectile pre-impact velocity history and a high-speed camera captured the projectile residual velocity for penetration and perforation of high performance concrete targets by steel projectiles.
TL;DR: In this paper, the deformation, penetration, and perforation of composite plates and sandwich panels subjected to quasi-static punch indentation and projectile impact are derived, and a generalized solution methodology for projectile impact is proposed based on three key factors: (i) the contact load duration, (ii) the through-thickness transit time, and (iii) the lateral transit time.
Abstract: Analytical solutions for the deformation, penetration, and perforation of composite plates and sandwich panels subjected to quasi-static punch indentation and projectile impact are derived. Discrete spring-mass models are used to calculate the impact response of the composite plates and sandwich panels. Equivalent load resistance functions are obtained from the quasi-static analysis and adjusted for high strain rate. A generalized solution methodology for projectile impact of composite plates and sandwich panels are then proposed based on three key factors: (i) the contact load duration, (ii) the through-thickness transit time, and (iii) the lateral transit time. A two-dimensional wave propagation model is used to determine the ballistic limits of E-glass/polyester panels and GLARE fiber-metal laminates, and predicted values are found to be within 20 and 13% of the experimental results, respectively. A quasi-static impact model is used to predict the ballistic limit for E-glass/epoxy-aluminum honeycomb sa...
TL;DR: In this article, the Lagrangian approach is used to model the characteristics of hypervelocity impact using an algorithm for the automatic conversion of distorted finite elements to mesh-free particles.
TL;DR: In this paper, an algorithm based on the combination of time-derivative preconditioning strategies with low-diffusion upwinding methods is developed and applied to multiphase compressible flows characteristic of underwater projectile motion.
Abstract: An algorithm based on the combination of time-derivative preconditioning strategies with low-diffusion upwinding methods is developed and applied to multiphase, compressible flows characteristic of underwater projectile motion Multiphase compressible flows are assumed to be in kinematic and thermodynamic equilibrium and are modeled using a homogeneous mixture formulation Compressibility effects in liquid-phase water are modeled using a temperature-adjusted Tait equation, and gaseous phases (water vapor and air) are treated as an ideal gas The algorithm is applied to subsonic and supersonic projectiles in water general multiphase shock tubes, and a high-speed water entry problem Low-speed solutions are presented and compared to experimental results for validation Solutions for high-subsonic and transonic projectile flows are compared to experimental imaging results and theoretical results Results are also presented for several multiphase shock tube calculations Finally, calculations are presented for a high-speed axisymmetric supercavitating projectile during the important water entry phase of flight
Patent•
08 Sep 2006TL;DR: In this article, a trajectory control system with a control system having fins that de-spin a section of the control system relative to a projectile or a missile is described. But no electric motor is used in the trajectory control systems, saving weight and increasing reliability.
Abstract: Trajectory is controlled by a control system having fins that de-spin a section of the control system relative to a projectile or missile. The control system also includes aero- surfaces that produce a lift when brought to rotation speed of about 0 Hz relative to a reference fame and a brake that couples the guidance package to the rotational inertia of the projectile or missile. In one example, no electric motor is used in the trajectory control system, saving weight and increasing reliability.
TL;DR: In this article, the deformation mode of a spherical shell was developed by introducing an isometric transformation of surface bending and the Perzyna-Symonds viscoplastic constitutive equations.
TL;DR: In this paper, the effects of the diameter of the steel spherical projectiles and of the material properties of the tubes on cracking and perforation were discussed, and empirical equations of the energies required to perforate the tube wall were derived.
TL;DR: In this article, a 3.0-caliber radius-head steel ogival-nose projectile with a mass of 2.3 kg is fired against a cylindrical concrete target with a striking velocity of 315m/s.
Patent•
19 Jun 2006
TL;DR: In this paper, an electrical discharge weapon with a high efficiency circuit was presented. But the authors did not specify the power level of the circuit, nor the power consumption of the circuits.
Abstract: An electrical discharge weapon projectile for immobilizing a live target that includes a shock circuit having a low power consumption, a high power efficiency, and/or a low weight. In one embodiment, the projectile includes a high efficiency circuit that would reduce the weights of shock circuits while providing a more effective and safer power level, so that the circuits may be entirely contained within the projectile to eliminatethe need for range limiting trailing wires.
Patent•
27 Feb 2006
TL;DR: A projectile retrieval system includes one or more valves disposed to selectively release projectiles from a bullet stop and containment system as mentioned in this paper, where the valves are in pneumatic communication with a tube which utilized a negative air pressure generated by a vacuum to move the projectiles from the valves to a central container.
Abstract: A projectile retrieval system includes one or more valves disposed to selectively release projectiles from a bullet stop and containment system. The valves are in pneumatic communication with a tube which utilized a negative air pressure generated by a vacuum to move the projectiles from the valves to a central container. The projectile retrieval system may also include a vacuum extension which enables the same system to retrieve bullets and casings, fragments and other debris on the range.
TL;DR: In this article, the Lambert W function is used to estimate the time of flight, range and angle which maximizes the range of a moving object in a linear resisting medium with weak and strong damping.
Abstract: The time of flight, range and the angle which maximizes the range of a projectile in a linear resisting medium are expressed in analytic form in terms of the recently defined Lambert W function From the closed-form solutions a number of results characteristic to the motion of the projectile in a linear resisting medium are analytically confirmed, and asymptotic and approximate expressions valid within the weak and strong damping limits are developed The problem provides an accessible account of the increasingly applicable Lambert W function and highlights much of the important mathematics associated with this simple yet rapidly emerging ‘implicitly’ elementary function
TL;DR: In this article, the authors investigate fragment clouds generated by hypervelocity impacts (HVIs) on metallic meshes and find that the velocity of the fragment cloud at the cloud center of gravity was up to 35% slower than the impact velocity of a projectile.
Patent•
09 Jan 2006
TL;DR: The axial gas containment chamber (AGC) stores high pressure gas between the inner barrel wall, the outer casing wall, and enclosure bulkheads as mentioned in this paper, and pressure-activated valves along the barrel sequentially release the high-pressure gas contained in the AGC in to the barrel to create a continuously refreshed high energy pressure heads behind the projectile as it moves down the barrel.
Abstract: Launching payloads at high velocity uses high-pressure gas or combustion products for propulsion, with injection of high pressure gas at intervals along the path behind the payload projectile as it accelerates along the barrel of the launcher. An inner barrel has an interior diameter equal to the projectile diameter or sabot containing the projectile. An outer casing surrounds the inner barrel. Structures at intervals attach the outer casing and the inner barrel. An axial gas containment chamber (AGC) stores high pressure gas between the inner barrel wall, the outer casing wall, and enclosure bulkheads. Pressure-activated valves along the barrel sequentially release the high pressure gas contained in the AGC in to the barrel to create a continuously refreshed high energy pressure heads behind the projectile as it moves down the barrel. A frangible cover at the exit end of the barrel allows the barrel to be evacuated prior to launch. The launcher is rapidly recyclable. The valves close automatically after the projectile has exited the barrel, allowing a new projectile to be introduced into the breech and the AGC to be recharged with high-pressure gas.
TL;DR: In this paper, the response of sandwich panels (Glass/Epoxy/PU Foam) to projectile impact in the velocity range of 30-100 m/s was studied, and a mathematical model was proposed to predict the ballistic limit, residual velocity, and the energy absorption based on the energy balance principle.
Abstract: In this paper, the response of sandwich panels (Glass/Epoxy/PU Foam) to projectile impact in the velocity range of 30—100 m/s was studied. Three sets of sandwich plates (WRM/Epoxy/Foam, CSM/Epoxy/Foam, and WRM/CSM/Epoxy/Foam) were used. A piston-type gas gun setup was used to accelerate a cylindro-conical mild steel projectile of mass 558.6 g. From the experimental results, the ballistic limit, residual velocity, and the energy absorption were found. The ballistic limit decreased as the trend moved from WRM to CSM. Debonding was observed in pure WRM/Foam laminates, whereas this was not the case for the other two sets of panels. Plugging occurred when the projectile struck CSM/Foam sandwich panels, which was not observed in the other two sets. A mathematical model was proposed to predict the ballistic limit, residual velocity, and the energy absorption based on the energy-balance principle. The experimental results were compared with the proposed model, which showed good agreement.
Patent•
08 Dec 2006
TL;DR: In this paper, a telescopic sight assembly (100) is described to compensate for deviations in the trajectory of a moving object by adjusting the position of a reticle, which corresponds to a specific characteristic of the object, such as a projectile caliber or a plurality of ballistic curves.
Abstract: A telescopic sight assembly (100) operable to compensate for deviations in projectile trajectory is disclosed. The assembly (100) generally includes a telescopic sight (102) and a plurality of dials (104). The telescopic sight (102) includes a laser range finder (106) for determining a range to a target and an adjustment element (110) for adjusting a reticle (108) position. Each dial corresponds to a projectile characteristic, such as a projectile caliber or one of a plurality of ballistic curves, and may be interchangeably coupled with the adjustment element (110) to facilitate projectile drop compensation.
Journal Article•
TL;DR: In this article, a 5586 GMS MILD STEEL CYLINDROCONICAL PROJECTILE, in the range of 30 { 100m/S, was used to investigate the impact on the performance of the ballistic limit.
Abstract: IMPACT ON COMPOSITE STRUCTURES WAS A CRITICAL TOPIC WITH GREAT IMPORTANCE IN THE RECENT PAST IN THIS PAPER, IMPACT ON GLASS/EPOXY AMINATES BY A 5586 GMS MILD STEEL CYLINDROCONICAL PROJECTILE, IN THE RANGE OF 30 { 100M/S, WAS STUDIED COMPOSITE PANELS CONSISTING OF 3 AND 5 LAYERS OF 3 TYPES OF GLASS REINFORCEMENT WITH DIFFERENT COMBINATIONS WERE PREPARED VIZ3 LAYERS OF WRM/EPOXY, CSM/EPOXY, GLASS FABRIC/EPOXY, WRM/CSM/EPOXY, WRM/FABRIC/EPOXY AND CSM/FABRIC/EPOXY LAMINATES TESTS WERE CONDUCTED TO DETERMINE THE BALLISTIC LIMIT AS WELL AS ENERGY ABSORPTION FOR DI®ERENT INITIAL VELOCITY OF THE PROJECTILE USING A PISTON TYPE, GAS GUN LAUNCHER A MATHEMATICAL MODEL BASED ON THE ENERGY BALANCE PRINCIPLE WAS PROPOSED TO PREDICT THE BALLISTIC LIMIT THE WRM/ EPOXY LAMINATES SHOWED HIGHER ENERGY ABSORPTION CAPABILITY AND BETTER BALLISTIC LIMIT WHEREAS CSM/EPOXY SHOWED THE LEAST OF ALL INCREASE IN ENERGY ABSORPTION WAS NOTED UP TO A CERTAIN LIMIT AND THEN DECREASES SLIGHTLY FOR ALL THE 6 TYPES OF PANELS THE DELAMINATION AREA INCREASED WITH INCREASE IN INITIAL VELOCITY UP TO BALLISTIC LIMIT AND A SMALL DECREMENT WAS OBSERVED FROM THEREON THE BALLISTIC LIMIT DETERMINED EXPERIMENTALLY WAS COMPARED WITH THE PROPOSED MODEL AND SHOWED GOOD AGREEMENT WITH THE EXPERIMENTAL VALUE
TL;DR: In this paper, an engineering fragmentation model is presented for the case of hypervelocity impact of a spherical projectile on a thin bumper plate at normal incidence, where the model consists of mainly analytical relationships and a few empirical fit functions, where no analytical formulation was available.
TL;DR: In this paper, the authors performed the analysis of the breakup of {sup 8}B and {sup 11}Be with the aim of analyzing their sensitivity to the projectile description.
Abstract: Calculations of the breakup of {sup 8}B and {sup 11}Be are performed with the aim of analyzing their sensitivity to the projectile description. Several potentials adjusted on the same experimental data are used for each projectile. The results vary significantly with the potential choice, and this sensitivity differs from one projectile to the other. In the {sup 8}B case, the breakup cross section is approximately scaled by the asymptotic normalization coefficient (ANC) of the initial bound state. For {sup 11}Be, the overall normalization of the breakup cross section is no longer solely determined by the ANC. The partial waves describing the continuum are found to play a significant role in this variation, as the sensitivity of the phase shifts to the projectile description changes with the physical constraints imposed to the potential.
Patent•
09 Jun 2006
TL;DR: In this article, a pursuit vehicle carries a projectile with folded barbs that extend once the projectile has entered the tire and which keeps the projectile from flying out of the tire due to centripetal force.
Abstract: A pursuit vehicle carries a projectile housed within a launcher mounted on its front end. The projectile is able to be directed at high speed from the launcher toward a tire of a pursued vehicle. A tether line is coiled about a tether reel within the chase vehicle and is fixed to the projectile. The projectile has folded barbs that extend once the projectile has entered the tire and which keeps the projectile from flying out of the tire due to centripetal force. Being penetrated, the tire quickly looses pressure and deflates while the tether line wraps itself around the wheel's axle and brakes which can cause the wheel to stop spinning.