466 Matching Results

Search Results

Advanced search parameters have been applied.

Advanced composites technology

Description: The development of fiber composite components in next-generation munitions, such as sabots for kinetic energy penetrators and lightweight cases for advanced artillery projectiles, relies on design trade-off studies using validated computer code simulations. We are developing capabilities to determine the failure of advanced fiber composites under multiaxial stresses to critically evaluate three-dimensional failure models and develop new ones if necessary. The effects of superimposed hydrostatic pressure on failure of composites are being investigated using a high-pressure testing system that incorporates several unique features. Several improvements were made to the system this year, and we report on the first tests of both isotropic and fiber composite materials. The preliminary results indicate that pressure has little effect on longitudinal compression strength of unidirectional composites, but issues with obtaining reliable failures in these materials still remain to be resolved. The transverse compression strength was found to be significantly enhanced by pressure, and the trends observed for this property and the longitudinal strength are in agreement with recent models for failure of fiber composites.
Date: October 1, 1998
Creator: DeTeresa, S J; Groves, S E & Sanchez, R J
Partner: UNT Libraries Government Documents Department

Stability of Trilateral Forces: III, Large Unsymmetric Forces

Description: For large unsymmetric forces, at few weapons permissile all forces are reserved, costs are constant, and configurations are stable. At many weapons permissile, no weapons are reserved, and stability degrades. For small unequal forces, the equal sides ignore the smaller forces and deter each other as in bilinear engagements. For large unequal forces, the equal sides ignore each other, commit all forces to the unequal side, and stability indices approach those observed for large triads.
Date: September 18, 1998
Creator: Canavan, G. H.
Partner: UNT Libraries Government Documents Department

The Embudito Mission: A Case Study of the Systematics of Autonomous Ground Mobile Robots

Description: Ground mobile robots are much in the mind of defense planners at this time, being considered for a significant variety of missions with a diversity ranging from logistics supply to reconnaissance and surveillance. While there has been a very large amount of basic research funded in the last quarter century devoted to mobile robots and their supporting component technologies, little of this science base has been fully developed and deployed--notable exceptions being NASA's Mars rover and several terrestrial derivatives. The material in this paper was developed as a first exemplary step in the development of a more systematic approach to the R and D of ground mobile robots.
Date: February 1, 2001
Partner: UNT Libraries Government Documents Department

Less-than-lethal "flashbang" diversionary device.

Description: Diversionary devices such as flashbang grenades are used in a wide variety of military and law-enforcement operations. They function to distract and/or incapacitate adversaries in scenarios ranging from hostage rescue to covert strategic paralysis operations. There are a number of disadvantages associated with currently available diversionary devices. Serious injuries and fatalities have resulted from their use both operationally and in training. Because safety is of paramount importance, desired improvements to these devices include protection against inadvertent initiation, the elimination of the production of high-velocity fragments, less damaging decibel output and increased light output. Sandia National Laboratories has developed a next-generation diversionary flash-bang device that will provide the end user with these enhanced safety features.
Date: November 1, 2003
Creator: Fleming, Kevin James; Melof, Brian Matthew; Ingram, Brian V.; Bender, Susan Fae Ann; Broyles, Theresa A.; Anderson, Heidi M. (K-Tech Corporation, Albuquerque, NM) et al.
Partner: UNT Libraries Government Documents Department

Prognostic Analysis of the Tactical Quiet Generator

Description: The U.S. Army needs prognostic analysis of mission-critical equipment to enable condition-based maintenance before failure. ORNL has developed and patented prognostic technology that quantifies condition change from noisy, multi-channel, time-serial data. This report describes an initial application of ORNL's prognostic technology to the Army's Tactical Quiet Generator (TQG), which is designed to operate continuously at 10 kW. Less-than-full power operation causes unburned fuel to accumulate on internal components, thereby degrading operation and eventually leading to failure. The first objective of this work was identification of easily-acquired, process-indicative data. Two types of appropriate data were identified, namely output-electrical current and voltage, plus tri-axial acceleration (vibration). The second objective of this work was data quality analysis to avoid the garbage-in-garbage-out syndrome. Quality analysis identified more than 10% of the current data as having consecutive values that are constant, or that saturate at an extreme value. Consequently, the electrical data were not analyzed further. The third objective was condition-change analysis to indicate operational stress under non-ideal operation and machine degradation in proportion to the operational stress. Application of ORNL's novel phase-space dissimilarity measures to the vibration power quantified the rising operational stress in direct proportion to the less-than-full-load power. We conclude that ORNL's technology is an excellent candidate to meet the U.S. Army's need for equipment prognostication.
Date: September 1, 2008
Creator: Hively, Lee M
Partner: UNT Libraries Government Documents Department

Approximating conductive ellipsoid inductive responses using static quadrupole moments

Description: Smith and Morrison (2006) developed an approximation for the inductive response of conducting magnetic (permeable) spheroids (e.g., steel spheroids) based on the inductive response of conducting magnetic spheres of related dimensions. Spheroids are axially symmetric objects with elliptical cross-sections along the axis of symmetry and circular cross sections perpendicular to the axis of symmetry. Spheroids are useful as an approximation to the shapes of unexploded ordnance (UXO) for approximating their responses. Ellipsoids are more general objects with three orthogonal principal axes, with elliptical cross sections along planes normal to the axes. Ellipsoids reduce to spheroids in the limiting case of ellipsoids with cross-sections that are in fact circles along planes normal to one axis. Parametrizing the inductive response of unknown objects in terms of the response of an ellipsoid is useful as it allows fitting responses of objects with no axis of symmetry, in addition to fitting the responses of axially symmetric objects. It is thus more appropriate for fitting the responses of metal scrap to be distinguished electromagnetically from unexploded ordnance. Here the method of Smith and Morrison (2006) is generalized to the case of conductive magnetic ellipsoids, and a simplified form used to parametrize the inductive response of isolated objects. The simplified form is developed for the case of non-uniform source fields, for the first eight terms in an ellipsoidal harmonic decomposition of the source fields, allowing limited corrections for source field geometry beyond the common assumption of uniform source fields.
Date: October 1, 2008
Creator: Smith, J. Torquil
Partner: UNT Libraries Government Documents Department

Measurement of suspension loads and determination of suspension reliability for a store in the F-111 weapons bay

Description: The dynamic store suspension environment in an open bay of the F-111 aircraft is under investigation. This experimental study was prompted by the uncertainties relative to the loads on the store suspension system which result from the severe aerodynamic environment in the open bay. Because of the complex flow field which exists, the loads on the swaybraces, vertical chocks, horizontal chocks, and lugs are not amenable to accurate analytical predictions. In an effort to verify that a store is capable of withstanding the loads experienced during carriage to the performance limits of the aircraft, an experimental buildup program was undertaken and is currently in progress. This paper discusses the design of the unit which is being used to measure the random loads on the suspension system during open-door carriage and the methods used to establish the reliability of the store suspension system. A numerical example shows that the suspension system of the store under consideration is highly reliable.
Date: January 1, 1977
Creator: Meyer, S.D. & Paez, T.L.
Partner: UNT Libraries Government Documents Department

Statistical Considerations in Designing Tests of Mine Detection Systems: II - Measures Related to the False Alarm Rate

Description: The rate at which a mine detection system falsely identifies man-made or natural clutter objects as mines is referred to as the system's false alarm rate (FAR). Generally expressed as a rate per unit area or time, the FAR is one of the primary metrics used to gauge system performance. In this report, an overview is given of statistical methods appropriate for the analysis of data relating to FAR. Techniques are presented for determining a suitable size for the clutter collection area, for summarizing the performance of a single sensor, and for comparing different sensors. For readers requiring more thorough coverage of the topics discussed, references to the statistical literature are provided. A companion report addresses statistical issues related to the estimation of mine detection probabilities.
Date: August 1, 1998
Creator: Simonson, K.M.
Partner: UNT Libraries Government Documents Department

Microelectronics plastic molded packaging

Description: The use of commercial off-the-shelf (COTS) microelectronics for nuclear weapon applications will soon be reality rather than hearsay. The use of COTS for new technologies for uniquely military applications is being driven by the so-called Perry Initiative that requires the U.S. Department of Defense (DoD) to accept and utilize commercial standards for procurement of military systems. Based on this philosophy, coupled with several practical considerations, new weapons systems as well as future upgrades will contain plastic encapsulated microelectronics. However, a conservative Department of Energy (DOE) approach requires lifetime predictive models. Thus, the focus of the current project is on accelerated testing to advance current aging models as well as on the development of the methodology to be used during WR qualification of plastic encapsulated microelectronics. An additional focal point involves achieving awareness of commercial capabilities, materials, and processes. One of the major outcomes of the project has been the definition of proper techniques for handling and evaluation of modern surface mount parts which might be used in future systems. This program is also raising the familiarity level of plastic within the weapons complex, allowing subsystem design rules accommodating COTS to evolve. A two year program plan is presented along with test results and commercial interactions during this first year.
Date: February 1, 1997
Creator: Johnson, D.R.; Palmer, D.W. & Peterson, D.W.
Partner: UNT Libraries Government Documents Department

Statistical Considerations in Designing Tests of Mine Detection Systems: 1 - Measures Related to the Probability of Detection

Description: One of the primary metrics used to gauge the performance of mine detection systems is PD, the probability of detecting an actual mine that is encountered by the sensor. In this report statistical issues and techniques that are relevant to the estimation of PD are discussed. Appropriate methods are presented for summarizing the performance of a single detection system, for comparing different systems, and for determining the sample size (number of target mines) required for a desired degree of precision. References are provided to pertinent sources within the extensive literature on statistical estimation and experimental design. A companion report addresses the estimation of detection system false alarm rates.
Date: August 1, 1998
Creator: Simonson, K.M.
Partner: UNT Libraries Government Documents Department

Crusader Automated Docking System: Technology support for the Crusader Resupply Team. Interim report, Ammunition Logistics Program

Description: The US Army and Team Crusader (United Defense, Lockheed Martin Armament Systems, etc.) are developing the next generation howitzer, the Crusader. The development program includes an advanced, self-propelled liquid propellant howitzer and a companion resupply vehicle. The resupply vehicle is intended to rendezvous with the howitzer near the battlefront and replenish ammunition, fuel, and other material. The Army has recommended that Crusader incorporate new and innovative technologies to improve performance and safety. One conceptual design proposes a robotic resupply boom on the resupply vehicle to upload supplies to the howitzer. The resupply boom would normally be retracted inside the resupply vehicle during transit. When the two vehicles are within range of the resupply boom, the boom would be extended to a receiving port on the howitzer. In order to reduce exposure to small arms fire or nuclear, biological, and chemical hazards, the crew would remain inside the resupply vehicle during the resupply operation. The process of extending the boom and linking with the receiving port is called docking. A boom operator would be designated to maneuver the boom into contact with the receiving port using a mechanical joystick. The docking operation depends greatly upon the skill of the boom operator to manipulate the boom into docking position. Computer simulations at the National Aeronautics and Space Administration have shown that computer-assisted or autonomous docking can improve the ability of the operator to dock safely and quickly. This document describes the present status of the Crusader Autonomous Docking System (CADS) implemented at Oak Ridge National laboratory (ORNL). The purpose of the CADS project is to determine the feasibility and performance limitations of vision systems to satisfy the autonomous docking requirements for Crusader and conduct a demonstration under controlled conditions.
Date: November 1, 1995
Creator: Kring, C.T.; Varma, V.K. & Jatko, W.B.
Partner: UNT Libraries Government Documents Department

The application of microrobotics in warfare

Description: This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project sought to conduct a detailed theoretical study of military microrobot requirements and performance in conflict situations. The study was directed toward construction of a proof-of-concept prototype with attention to its eventual mass manufacture using microlithographic fabrication techniques. The study included design and performance assessment of payloads for the microvehicle, which might include special sensors and data processing equipment for gathering intelligence, or electrical, mechanical, and chemical disrupters of various sorts.
Date: September 1, 1996
Creator: Solem, J.
Partner: UNT Libraries Government Documents Department

Lynx: A High-Resolution Synthetic Aperture Radar

Description: Lynx is a high resolution, synthetic aperture radar (SAR) that has been designed and built by Sandia National Laboratories in collaboration with General Atomics (GA). Although Lynx may be operated on a wide variety of manned and unmanned platforms, it is primarily intended to be fielded on unmanned aerial vehicles. In particular, it may be operated on the Predator, I-GNAT, or Prowler II platforms manufactured by GA Aeronautical Systems, Inc. The Lynx production weight is less than 120 lb. and has a slant range of 30 km (in 4 mm/hr rain). It has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode. In ground moving target indicator mode, the minimum detectable velocity is 6 knots with a minimum target cross-section of 10 dBsm. In coherent change detection mode, Lynx makes registered, complex image comparisons either of 0.1 m resolution (minimum) spotlight images or of 0.3 m resolution (minimum) strip images. The Lynx user interface features a view manager that allows it to pan and zoom like a video camera. Lynx was developed under corporate finding from GA and will be manufactured by GA for both military and commercial applications. The Lynx system architecture will be presented and some of its unique features will be described. Imagery at the finest resolutions in both spotlight and strip modes have been obtained and will also be presented.
Date: March 8, 1999
Creator: Doerry, A. W.; Hensley, W. H.; Pace, F.; Stence, J.; Tsunoda, S. I.; Walker, B. C. et al.
Partner: UNT Libraries Government Documents Department

Architectural Surety Applications for Building Response to Dynamic Loads

Description: This paper provides a summary introduction to the emerging area of Architectural Surety{trademark} applications for buildings and infrastructures that are subjected to dynamic loads from blast and naturally occurring events. This technology area has been under investigation to assist with the definition of risks associated with dynamic loads and to provide guidance for determining the required upgrading and retrofitting techniques suggested for reducing building and infrastructure vulnerabilities to such dynamic forces. This unique approach involves the application of risk management techniques for solving problems of the as-built environment through the application of security, safety, and reliability principles developed in the nuclear weapons programs of the United States Department of Energy (DOE) and through the protective structures programs of the German Ministry of Defense (MOD). The changing responsibilities of engineering design professionals are addressed in light of the increased public awareness of structural and facility systems' vulnerabilities to malevolent, normal, and abnormal environment conditions. Brief discussions are also presented on (1) the need to understand how dynamic pressures are affected by the structural failures they cause, (2) the need to determine cladding effects on columns, walls, and slabs, and (3) the need to establish effective standoff distance for perimeter barriers. A summary description is presented of selected technologies to upgrade and retrofit buildings by using high-strength concrete and energy-absorbing materials and by specifying appropriately designed window glazing and special masonry wall configurations and composites. The technologies, material performance, and design evaluation procedures presented include super-computational modeling and structural simulations, window glass fragmentation modeling, risk assessment procedures, instrumentation and health monitoring systems, three-dimensional CAD virtual reality visualization techniques, and material testing data.
Date: February 10, 1999
Creator: Matalucci, R.V. & Mayrhofer, C.
Partner: UNT Libraries Government Documents Department

Landmine policy in the near-term: a framework for technology analysis and action

Description: Any effective solution to the problem of leftover landmines and other post-conflict unexploded ordnance (UXO) must take into account the real capabilities of demining technologies and the availability of sufficient resources to carry out demining operations. Economic and operational factors must be included in analyses of humanitarian demining. These factors will provide a framework for using currently available resources and technologies to complete this task in a time frame that is both practical and useful. Since it is likely that reliable advanced technologies for demining are still several years away, this construct applies to the intervening period. It may also provide a framework for utilizing advanced technologies as they become available. This study is an economic system model for demining operations carried out by the developed nations that clarifies the role and impact of technology on the economic performance and viability of these operations. It also provides a quantitative guide to assess the performance penalties arising from gaps in current technology, as well as the potential advantages and desirable features of new technologies that will significantly affect the international community`s ability to address this problem. Implications for current and near-term landmine and landmine technology policies are drawn.
Date: August 1, 1997
Creator: Eimerl, D., LLNL
Partner: UNT Libraries Government Documents Department

Investigation of range extension with a genetic algorithm

Description: Range optimization is one of the tasks associated with the development of cost- effective, stand-off, air-to-surface munitions systems. The search for the optimal input parameters that will result in the maximum achievable range often employ conventional Monte Carlo techniques. Monte Carlo approaches can be time-consuming, costly, and insensitive to mutually dependent parameters and epistatic parameter effects. An alternative search and optimization technique is available in genetic algorithms. In the experiments discussed in this report, a simplified platform motion simulator was the fitness function for a genetic algorithm. The parameters to be optimized were the inputs to this motion generator and the simulator`s output (terminal range) was the fitness measure. The parameters of interest were initial launch altitude, initial launch speed, wing angle-of-attack, and engine ignition time. The parameter values the GA produced were validated by Monte Carlo investigations employing a full-scale six-degree-of-freedom (6 DOF) simulation. The best results produced by Monte Carlo processes using values based on the GA derived parameters were within - 1% of the ranges generated by the simplified model using the evolved parameter values. This report has five sections. Section 2 discusses the motivation for the range extension investigation and reviews the surrogate flight model developed as a fitness function for the genetic algorithm tool. Section 3 details the representation and implementation of the task within the genetic algorithm framework. Section 4 discusses the results. Section 5 concludes the report with a summary and suggestions for further research.
Date: March 4, 1998
Creator: Austin, A. S., LLNL
Partner: UNT Libraries Government Documents Department

TIGER -- A technology to improve the delivery capability of nuclear bombs and the survivability of the delivery aircraft

Description: The TIGER (Terminal guided and Extended-Range) Program was initiated in 1972 to study improved delivery capabilities for stockpiled tactical nuclear bombs. The Southeast Asia conflict fostered the development of air-delivered standoff conventional weapons utilizing terminal guidance systems. SNL initiated the TIGER program to determine if current nuclear bombs could be provided with a similarly accurate standoff capabilities. These conventional weapon delivery techniques, while allowing highly accurate attack, generally require entering the target area at high altitude to establish line of sight to the target. In parallel with the TIGER program, system studies analyzed this concept and showed marked improvement in aircraft and weapon survivability with moderate standoff (10--20 km) if low level deliveries (60 m) could be accomplished. As a result of this work, the TIGER program was redirected in early 1974 to demonstrate a standoff bomb with good accuracy (90 m CEP) when delivered from low flying aircraft. This program redirection resulted in the selection of an inertial guidance system to replace the earlier terminal guidance systems. This program was called the Extended-Range Bomb (ERB). In May 1974, a joint Air Force/DOE study identified the desirability of having a single tactical weapon which could be employed against either fixed, preselected targets, or mobile battlefield targets. Studies conducted on the ERB system showed that the inertially guided weapon could fly not only the standoff mission but also a return-to-target mission against the mobile battlefield targets whose locations are not known accurately enough to use a standoff delivery. The ERB program evolved from these initial investigations into an exploratory program to develop the hardware and demonstrate the technology required to fly standoff and return-to-target trajectories. The application of this technology in the form of field retrofit kits to the B61 bomb is called TIGER II.
Date: December 31, 1980
Partner: UNT Libraries Government Documents Department

Effect of unsymmetric missile force reductions

Description: This note discusses the effect on first strike stability of unsymmetric force reductions, i.e., unilateral reductions from START I levels by one side only. It uses the model for unsymmetric force exchanges, damage, costs, and indices derived in earlier notes. It discusses the effect on first strike stability of unsymmetric fore reductions, i.e., unilateral reductions from START I levels by one side only, using the models for unsymmetric force exchanges, damage, costs, and indices derived in earlier notes. The forces treated are approximations that are assumed to fall in equal decrements from START I to II levels. Attack allocations are determined numerically because of the large initial forces. They are relatively insensitive to fractionation. The decreasing side`s average allocation is about 0. 5; the static side`s allocation is about 0.25.
Date: June 1, 1997
Creator: Canavan, G. H.
Partner: UNT Libraries Government Documents Department

Simulation of the SRI International test Gun-27 using the PAGOSA code

Description: SRI International conducted a set of impact tests with flat disks hitting water-filled chemical submunitions. One of these tests, called Gun-27, involved a 595 gram disk hitting the side of a submunition at 200 m/s. This test was simulated using the PAGOSA code with a materials model that was a good overall match to the data, and with a sequence of five mesh sizes. It was found that when a mesh was used which had at least five cells across the wall of the submunition, PAGOSA was able to provide reasonably satisfactory agreement with the test results, except for the partial fracture of a welded joint. One feature of the test that was reproduced very well by the simulation that used the finest mesh was the fracture of the diaphragm around its edge. Results are compared for all five simulations so that trends can be seen.
Date: June 23, 1997
Creator: Jacoby, J.J.
Partner: UNT Libraries Government Documents Department

A Field Evaluation of Airborne Techniques for Detection of Unexploded Ordnance

Description: US Defense Department estimates indicate that as many as 11 million acres of government land in the U. S. may contain unexploded ordnance (UXO), with the cost of identifying and disposing of this material estimated at nearly $500 billion. The size and character of the ordnance, types of interference, vegetation, geology, and topography vary from site to site. Because of size or composition, some ordnance is difficult to detect with any geophysical method, even under favorable soil and cultural interference conditions. For some sites, airborne methods may provide the most time and cost effective means for detection of UXO. Airborne methods offer lower risk to field crews from proximity to unstable ordnance, and less disturbance of sites that maybe environmentally sensitive. Data were acquired over a test site at Edwards AFB, CA using airborne magnetic, electromagnetic, multispectral and thermal sensors. Survey areas included sites where trenches might occur, and a test site in which we placed deactivated ordnance, ranging in size from small ''bomblets'' to large bombs. Magnetic data were then acquired with the Aerodat HM-3 system, which consists of three cesium magnetometers within booms extending to the front and sides of the helicopter, and mounted such that the helicopter can be flown within 3m of the surface. Electromagnetic data were acquired with an Aerodat 5 frequency coplanar induction system deployed as a sling load from a helicopter, with a sensor altitude of 15m. Surface data, acquired at selected sites, provide a comparison with airborne data. Multispectral and thermal data were acquired with a Daedelus AADS 1268 system. Preliminary analysis of the test data demonstrate the value of airborne systems for UXO detection and provide insight into improvements that might make the systems even more effective.
Date: March 14, 1999
Creator: Bell, D.; Doll, W.E.; Hamlett, P.; Holladay, J.S.; Nyquist, J.E.; Smyre, J. et al.
Partner: UNT Libraries Government Documents Department

Demonstration of enhanced warhead performance with more powerful explosives

Description: Enhanced warhead performance has been demonstrated for several warhead configurations loaded with more powerful explosives. This paper presents experimental results from several warheads loaded with one of the new more powerful explosives, LX-19. The LX-19 formulation is a volume analog to LX-14 (HMX/Estane) that consists of 95.8 wt.% epsilon CL-20 formulated with 4.2 wt.% Estane binder. The LX-19 formulation, characterization, and evaluation efforts presseted in this paper are the result of several studies that have been ongoing since 1991. The warhead configurations that have been tested include a trumpet lined shaped charge, a hemispherical lined shaped cahrge, an EFP charge, and a fragmentation warhead, Performation improvements have been demonstrated with all configurations that were tested.
Date: December 1, 1997
Creator: Murphy, M.J.; Baum, D.; Simpson, R.L.; Monoto, J.; Montesi, L.; Newman, K. et al.
Partner: UNT Libraries Government Documents Department