| Department of Defense Standard Family of Tactical Shelters (Rigid/Soft/Hybrid) |
May 2012 |
46 pages |
| Authors:
ARMY NATICK SOLDIER RESEARCH DEVELOPMENT AND ENGINEERING CENTER MA
|
 | This brochure contains information on the Department of Defense (DoD) Standard Family of Tactical Shelters. The standard rigid wall, soft wall, and hybrid shelters shown in this brochure have been approved by the Joint Committee on Tactical Shelters (JOCOTAS) for Department of Defense (DoD) use. |
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| Deceleration of Projectiles in Sand |
Jan 2012 |
5 pages |
| Authors:
Stephan Bless; William Cooper; Keiko Watanabe; Robert Peden; AIR FORCE RESEARCH LAB EGLIN AFB FL
|
| Penetration of projectiles was measured for hemispherical and conical nose shapes penetrating granular media. Targets were beds of Ottawa sand and Eglin sand. Projectiles were rigid metals. Experimental parameters that were varied included velocity (from 300 to 600 m/s), nose shape, sand density, and scale (from 5 mm to 20 mm). Strong evidence for scale effects is found: 5 mm diameter projectiles are less effective penetrators than 12.5, 15, or ... |
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| Numerical Modeling Efforts in Support of 3-D Environmental Variability and Acoustic Vector Field Studies |
Sep 2011 |
15 pages |
| Authors:
Kevin B Smith; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF PHYSICS
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| The goals of this work were multi-faceted, consistent with the various efforts supported by this work. One aspect was the continued study of the effects of three-dimensional (3-D) environmental variability on propagation and the flow of energy in the acoustic field. This included modeling efforts conducted at URI to support analysis of SW06 data sets in the presence of non-linear internal waves (in collaboration with Prof. Jim Miller of URI ... |
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| Synthesis and Properties of Bis(aniline, methyl)siloxy-octaphenylsilsesquioxane Modified Thermosetting Polyimide Oligomers |
19 Aug 2011 |
3 pages |
| Authors:
Gregory R Yandek; Timothy S Haddad; Andrew J Guenthner; Joseph M Mabry; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE SPACE AND MISSILE PROPULSION DIV/PROPULSION MATERIALS APPLICATIONS BRANCH
|
| High performance polyimides are utilized in a number of aerospace and microelectronic applications requiring thin films, wire coatings, adhesives, and matrices for fiber reinforced composites.1-3 In general, thermoplastic polyimides are produced from reactions between aromatic diamines and dianhydrides to form polyamic acids which in turn are thermally imidized to yield desired polymers.1 Due to inter-chain interactions and polymer chain rigidity, such materials are often intractable exhibiting viscosities prohibitive to the ... |
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| Flutter Instability of a Fluid-Conveying Fluid-Immersed Pipe Affixed to a Rigid Body |
Jan 2011 |
12 pages |
| Authors:
Aren Hellum; Ranjan Mukherjee; Andrew J Hull; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
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| A set of simplified boundary conditions for a flexible beam connected to a rigid body at one end and free at the other end is presented and applied to the case of a fluid-conveying, fluid-immersed pipe. These boundary conditions represent an analytically tractable approximation to those of a submersible which uses a combination of jet action and flutter instability induced tail motion to produce thrust. The boundary conditions are made ... |
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| Computational Model of Hydrostatically Coupled Dielectric Elastomer Actuators (Preprint) |
Jan 2011 |
28 pages |
| Authors:
Huiming Wang; Shengqiang Cai; Federico Carpi; Zhigang Suo; HARVARD UNIV CAMBRIDGE MA KAVLI INST FOR BIONANO SCIENCE AND TECHNOLOGY
|
| A hydrostatically coupled dielectric elastomer (HCDE) actuator consists of two membranes of a dielectric elastomer, clamped with rigid circular rings. Confined between the membranes is a fixed volume of a fluid, which couples the movements of the two membranes when a voltage or a force is applied. This paper presents a computational model of the actuator, assuming that the membranes are neo-Hookean, capable of large and axisymmetric deformation. The voltage-induced ... |
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| Modeling Gas Bubble Behaviour and Loading on a Rigid Target due to Close-Proximity Underwater Explosions: Comparison to Tests Conducted at DRDC Suffield |
NOV 2010 |
78 pages |
| Authors:
Mark Riley; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
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| This study describes recent simulation results for underwater explosions in close-proximity to a rigid target. Simulations were performed using Chinook, an Eulerian computational fluid dynamics (CFD) code. Predicted fluid pressures, impulse loading on the target, gas bubble size and bubble collapse times are compared with measurements taken from a series of experiments and compared to empirical models. The experiments, which were conducted at DRDC Suffield as part of the Force ... |
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| Tents and Shelters |
15 Jul 2010 |
49 pages |
| Authors:
ABERDEEN TEST CENTER MD
|
| This TOP describes procedures for testing rigid wall, soft wall, and hybrid shelters and their accessories, tools and equipment. Tests include Initial Inspection, Safety and Health, Physical Characteristics, Blackout/Infrared Detectability, Roof Load, Durability, Electromagnetic Interference (EMI), Transportability, Environmental, Human Factors Engineering (HFE), Reliability, Availability and Maintainability (RAM), and Final Inspection. |
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| Functionally Graded Adhesives |
Nov-2009 |
22 pages |
| Authors:
Christopher B Stabler; Faye R La Toulan; John J Scala; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| The goal of this project was to increase rubber to metal adhesion in Army materials using the concept of functionally graded interfaces as observed in squid beaks. Through application of adhesive as a graded interface with layers of varying rigidity, exceptional adhesion can be accomplished. 3M Scotch-Weld 847 was chosen as the adhesive because of its flexibility, potential for use on Army weapons platforms, and because it contains no hazardous ... |
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| Biologically Inspired Polymer Microfibrillar Arrays for Mask Sealing |
Apr-2009 |
21 pages |
| Authors:
Eugene Cheung; Metin Sitti; Burak Aksak; CARNEGIE-MELLON UNIV PITTSBURGH PA
|
| Previous work to develop a microfibrillar array to improve mask sealing performance demonstrated increased wet and dry adhesion on rigid and soft smooth substrates using spatulate fibers. The current effort modeled and characterized dry fibrillar adhesion to substrates that more closely approximate human skin. The models for adhesion to soft, textured substrates revealed that the resulting adhesion was simply a fraction of the adhesion to a smooth, rigid substrate. The ... |
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| Decentralized Cooperative Manipulation with a Swarm of Mobile Robots |
2009 |
7 pages |
| Authors:
Joel M. Esposito; NAVAL ACADEMY ANNAPOLIS MD DEPT OF WEAPONS AND SYSTEMS ENGINEERING
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| In this paper we consider cooperative manipulation problems where a large group (swarm) of non-articulated mobile robots is trying to cooperatively control the velocity of some larger rigid body by exerting forces around its perimeter. We consider a second-order dynamic model for the object but use a simplified contact model. We seek solutions that require minimal information sharing among the swarm members. We present a velocity control law that is ... |
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| A Static Aeroelastic Analysis of a Flexible Wing Mini Unmanned Aerial Vehicle |
27 MAR 2008 |
111 pages |
| Authors:
Nathan A. Pitcher; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
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| The static aeroelastic behavior of the Nighthawk mini unmanned aerial vehicle is examined using a combined experimental and computational approach. Three wings are examined. In order of increasing stiffness they are: a flexible wing, a stiff wing, and a fictitious rigid wing with zero deflection. Photogrammetry is used during wind tunnel testing to measure the average deflected shape of the flexible and stiff wings during flight. The independent variables during ... |
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| Modeling the Penetration Behavior of Rigid Into Ballistic Gelatin |
MAR 2008 |
36 pages |
| Authors:
Steven B. Segletes; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| The penetration of 20% ballistic gelatin by rigid steel spheres is studied and analytically modeled. In order to properly capture the response for a wide variety of sphere sizes and impact velocities, a rate-dependent strength formulation is required for the ballistic resistance of gelatin. |
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| Multiscale Modeling of Flows Containing Particles |
01 DEC 2007 |
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| Authors:
Jamal S. Alrowaijeh; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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 | Multiscale mathematical modeling of flows containing particles is conducted in this study using computational fluid dynamics and molecular dynamics. The first study considered continuous media interaction of macro-scale fluid and micro-scale solid particles using computational fluid dynamics and rigid particle dynamics. This study investigates the potential enhancement of heat transfer properties of particulate fluid as well as the effect of injected particles on fluid profiles, and pressure on walls under ... |
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| Using Computational Fluid Dynamics-Rigid Body Dynamic (CFD-RBD) Results to Generate Aerodynamic Models for Projectile Flight Simulation |
SEP 2007 |
34 pages |
| Authors:
Mark Costello; Stephen Gatto; Jubaraj Sahu; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
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| A method to efficiently generate a complete aerodynamic description for projectile flight dynamic modeling is described. At the core of the method is an unsteady, time-accurate computational fluid dynamics simulation that is tightly coupled to a rigid projectile flight dynamic simulation. A set of short time snippets of simulated projectile motion at different Mach numbers is computed and employed as baseline data. For each time snippet, aerodynamic forces and moments ... |
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| Reactive Conversion of Bioclastic Nanostructures |
JUL 2007 |
8 pages |
| Authors:
Kenneth H. Sandhage; GEORGIA TECH RESEARCH CORP ATLANTA
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| Numerous examples can be found in nature of micro-organisms that assemble oxide nanoparticles into rigid (bioclastic) microstructures with intricate, but well-controlled 3-D shapes and fine (nanoscale) features. Because such self-assembly is under genetic control, a given micro-organism can generate bioclastic replicas with a high degree of fidelity upon biological reproduction. Continuous reproduction (repeated doubling) of such micro-organisms can yield enormous numbers of identically-shaped bioclastic structures. Such genetically-precise and massively-parallel self-assembly ... |
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| The Theory of Canonical Perturbations Applied to Attitude Dynamics and to the Earth Rotation. Osculating and Nonosculating Andoyer Variables |
21 JUN 2007 |
34 pages |
| Authors:
Michael Efroimsky; Alberto Escapa; NAVAL OBSERVATORY WASHINGTON DC
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| In the method of variation of parameters we express the Cartesian coordinates or the Euler angles as functions of the time and six constants. If, under disturbance, we endow the "constants" with time dependence, the perturbed orbital angular velocity will consist of a partial time derivative and convective term that includes time derivatives of the "constants". The Lagrange constraint, often imposed for convenience, nullifies the convective term and thereby guarantees ... |
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| Trials of Transcranial Stimulation for the Treatment of Parkinson's Disease |
MAY 2007 |
6 pages |
| Authors:
Mark Hallett; Mikhail P. Lomarev; Sarah P. Richardson; Eric Wassermann; William Bara; Grisel Lopez; HENRY M JACKSON FOUNDATION FOR THE ADVANCEMENT OF MILITARY MEDICINE ROCKVILLE MD
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| During the first year of the study, we have been mainly working on the protocol "Transcranial Electrical Polarization for the Treatment of Bradykinesia and Rigidity in Patients with Parkinson's Disease". This is one of three protocols of the grant. This protocol was approved by the Office of Research Protections USAMRMC on 03/06/2007. Since then 3 patients were recruited in the protocol. The data was collected in 2 of them during ... |
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| A Test Method to Assess the Foldability of Flexible Structural Materials |
APR 2007 |
14 pages |
| Authors:
Thomas W. Murphey; Gregory E. Sanford; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| A coupon level comparative test method was developed to assess the foldability of thin flexible materials used in deployable structures. The subject materials support tensile and compressive loads; they are not cloth-like. The non-destructive method consists of a tensile stiffness test and a compressive buckling test and reveals changes in coupon properties that could result from locally extreme strains incurred during folding. The test is intended to provide a standardized ... |
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| A Value-Focused Thinking Model for the Selection of the Best Rigid Pavement, Partial-Depth Spall Repair Material |
MAR 2007 |
106 pages |
| Authors:
Benjamin G. Speer; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Concrete spalls on airfield pavements generate foreign object debris (FOD) that is damaging to aircraft engines, and may damage landing gear by roughening of the pavement surface. Repairing spalled concrete on aging and deteriorating airfields is essential for its safe operational use. Picking the best repair material from many products on the commercial market is difficult. There is wide variation on material properties, and good performance on certain criteria is ... |
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| Targeting MRS-Defined Dominant Intraprostatic Lesions with Inverse-Planned High Dose Rate Brachytherapy |
FEB 2007 |
42 pages |
| Authors:
Jean Pouliot; I-Chow Hsu; John Kurhanewicz; Sue Noworelski; CALIFORNIA UNIV SAN FRANCISCO
|
| During these three years we have obtained CHR approval (December 2004)from the three step process (G.U. P.R.C. and C.H.R.) committees at UCSF. D.O.D. CHR approval was finally obtained in December 2006. Patient enrollment will begin immediately after receiving UCSF-CHR re-confirmation. We have developed a deformable image registration method to improve the quality of registration of (probe-in) MRSI data for (probe-out) radiation treatment planning. A similarity index (SI) of 98.1 % ... |
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| On the Equilibria of the Extended Nematic Polymers under Elongational Flow |
01-Jan-2007 |
16 pages |
| Authors:
Hong Zhou; Lynda Wilson; Hongyn Wang; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MATHEMATICS
|
| We classify the equilibrium solutions of the Smoluchowski equation for dipolar (extended) rigid nematic polymers under imposed elongational flow. The Smoluchowski equation couples theMaier-Saupe short-range interaction, dipole-dipole interaction, and an external elongational flow. We show that all stable equilibria of rigid, dipolar rod dispersions under imposed uniaxial elongational flow field are axisymmetric. This finding of axisymmetry significantly simplifies any procedure of obtaining experimentally observable equilibria. Copyright 2007 Hong Zhou et ... |
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| Mine-Impact Burial Model (IMPACT35) Verification and Improvement Using Sediment Bearing Factor Method |
Jan 2007 |
17 pages |
| Authors:
Peter C Chu; Chenwu Fan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Recently, a 3-D model (IMPACT35) was developed to predict a falling cylindrical mine's location and orientation in air-water-sediment columns. The model contains the following three components: 1) triple coordinate transform, 2) hydrodynamics of falling rigid object in a single medium (air, water, or sediment) and in multiple media (air-water and water-sediment interfaces), and 3) delta method for sediment resistance with the transient pore pressure. Two mine-impact burial experiments were conducted ... |
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| Measuring the Statutory and Regulatory Constraints on Department of Defense Acquisition. An Empirical Analysis |
2007 |
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| Authors:
Jeffrey A. Drezner; Irv Blickstein; Raj Raman; Megan McKernan; Monica Hertzman; Melissa A. Bradley; Dikla Gavrieli; Brent Eastwood; RAND NATIONAL DEFENSE RESEARCH INST SANTA MONICA CA
|
| Improving the defense acquisition process has been a recurring theme for several decades. Acquisition process reforms often require changes in the body of statutes and regulations governing the acquisition process. Prior research has observed a regulatory pendulum in which statutes and regulations seem to move back and forth from relative flexibility to relative rigidity in response to perceived problems in the acquisition process generally, or in specific weapon system programs. ... |
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| Time-Frequency Modeling of Shallow Water Environments: Rigid vs. Fluid Seabed |
2007 |
6 pages |
| Authors:
Jun Zhang; Bertrand Gottin; Antonia Papandreou-Suppappola; Cornel Ioana; ARIZONA STATE UNIV TEMPE DEPT OF ELECTRICAL ENGINEERING
|
| When the ocean seabed is considered to be rigid, the ideal waveguide model can be used to model the shallow water environment. However, a more realistic ocean waveguide model treats the ocean floor as a boundary between two different fluid media. In this paper, a frequency-domain characterization of shallow water environments is proposed based on this realistic waveguide model with a fluid boundary. First, the time-frequency characteristics of this model ... |
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| Transforming the Structure of the Military: Combat Decisions -- Rank, Responsibility, or Frontline Position? |
2007 |
16 pages |
| Authors:
Bing West; NATIONAL DEFENSE UNIV WASHINGTON DC CENTER FOR TECHNOLOGY AND NATIONAL SECURITY POLICY
|
| This case study raises the questions of whether, in this day of advanced information networks, field grade military officers should be present at the scene of complex tactical battles, and whether net-centric operations allow commanders to operate effectively from the front lines. Many have assumed that new information technologies lift the fog of war and therefore allow commanders to operate with clear vision from rear positions. This study examines the ... |
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| Physics-Based Virtual Fly-Outs of Projectiles on Supercomputers |
NOV 2006 |
44 pages |
| Authors:
Jubaraj Sahu; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This paper describes the development and application of a new multidisciplinary computational capability to compute the flight trajectories and the free flight aerodynamics of projectiles. Advanced computational capabilities both in computational fluid dynamics (CFD) and rigid body dynamics (RBD) have been successfully fully coupled on high performance computing (HPC) platforms for Virtual Fly-Outs of guided munitions identical to actual free flight tests in the aerodynamic experimental facilities. For the first ... |
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| Trajectory Control for Very Flexible Aircraft |
30 OCT 2006 |
47 pages |
| Authors:
Christopher M. Shearer; Cesnik E. Carlos; MICHIGAN UNIV ANN ARBOR
|
| This paper focuses on trajectory control of the 6-DOF body fixed reference frame located on a very flexible aircraft. The 6-DOF equations of motion of a reference point on the aircraft are coupled with the aeroelastic equations that govern the geometrically nonlinear structural response of the vehicle. A low-order strain-based nonlinear structural analysis coupled with unsteady finitestate potential flow aerodynamics form the basis for the aeroelastic model. The nonlinear beam ... |
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| Three Component Velocity Measurements in the Tip Vortex of a Micro-Air-Vehicle |
SEP 2006 |
88 pages |
| Authors:
Hong J. Park; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The purpose of this research was to improve the MAV that will be used for battle damage assessment and reconnaissance or local surveillance through the experiments in AFIT wind tunnel. The experiments were performed to investigate the wing displacement and wing tip vortex interaction. To conduct the experiments, telescopic survey tool and tri-axial hot-wire anemometer was utilized. The results indicate that wing tip displacement of the flexible wing was approximately ... |
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| Time-Accurate Computations of Free-Flight Aerodynamics of a Spinning Projectile With and Without Flow Control |
SEP 2006 |
31 pages |
| Authors:
Jubaraj Sahu; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| This report describes a new multi-disciplinary computational study undertaken to compute the flight trajectories and simultaneously predict the unsteady free flight aerodynamics of a spinning projectile configuration with and without aerodynamic flow control. Actual flight trajectories are computed with an advanced coupled computational fluid dynamics (CFD)-rigid body dynamics (RBD) technique. An advanced time-accurate Navier-Stokes computational technique has been used in CFD to compute the unsteady aerodynamics associated with the free ... |
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| Dynamics and Control of Tethered Satellite Formations for the Purpose of Space-Based Remote Sensing |
AUG 2006 |
296 pages |
| Authors:
Kurt A. Vogel; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| This dissertation assesses the utility of tethered satellite formations for the space-based remote sensing mission. Energy dissipation is found to have an adverse effect on foundational rigid body (Likins-Pringle) equilibria. It is shown that a continuously earth-facing equilibrium condition for a fixed-length tethered system does not exist since the spin rate required for the proper precession would not be high enough to maintain tether tension. The range of required spin ... |
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| Position Analysis of Planar Tensegrity Structures |
AUG 2006 |
108 pages |
| Authors:
Jahan B. Bayat; FLORIDA UNIV GAINESVILLE CENTER FOR INTELLIGENT MACHINES AND ROBOTICS
|
| Tensegrity is an abbreviation of tension and integrity. Tensegrity structures are spatial structures formed by a combination of rigid elements in compression (struts) and connecting elements that are in tension (ties). In three-dimensional tensegrity structures no pair of struts touches, and the end of each strut is connected to non-coplanar ties, which are in tension. In two-dimensional tensegrity structures, struts still do not touch. A tensegrity structure stands by itself ... |
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| Experimental and Analytical Study of the Hydroacoustics of Propellers in Rigid Ducts |
JUL 2006 |
62 pages |
| Authors:
Scott C. Morris; Thomas Mueller; NOTRE DAME UNIV IN DEPT OF AEROSPACE AND MECHANICAL ENGINEERING
|
| This report describes the results of a detailed study of the fluid dynamics and acoustic signature of a rotor operating in a rigid duct. The study focused on the separation of the acoustic source functions and the system response, or transfer function. A new algorithm was developed and quantified to separate these functions from radiated sound measurements. Measurements of the approach flow turbulence and propeller wake turbulence provided insight into ... |
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| Is Systemic Operation Design Capable of Reducing Significantly Bias in Operational Level Planning Caused by Military Organizational Culture? |
25 MAY 2006 |
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| Authors:
Christopher J. Bell; ARMY COMMAND AND GENERAL STAFF COLL FORT LEAVENWORTH KS SCHOOL OF ADVANCED MILITARY STUDIES
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| Bias caused by organizational culture is a constant companion of military planning. Cognitive models dominated by Newtonian, mechanistic, and reductionist thinking have all but fixed bias at the operational level of war where environmental orientation to a rival is rarely more than an ideological mirage. The results are brittle campaign plans that are predictable by any thinking competitor. Systemic Operation Design claims to address this problem by re-orienting users to ... |
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| Experimental Analysis of Propeller Interactions With a Flexible Wing Micro-Air-Vehicle |
23 MAR 2006 |
149 pages |
| Authors:
Brian J. Gamble; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| An investigation into the effects of the propeller slipstream on a flexible wing micro-air-vehicle (MAV) was conducted. The Air Force Research Lab, Munitions Directorate designed a man-portable MAV with a 24 in. wingspan and 6 in. root chord to be used for battle damage assessment and reconnaissance. Two wings have been developed for this MAV. One is a rigid carbon-fiber wing and the other consists of flexible parachute material attached ... |
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| Improving the Development and Utilization of Air Force Space and Missile Officers |
2006 |
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| Authors:
Georges Vernez; Craig Moore; Steven Martino; Jeffrey Yuen; RAND CORP SANTA MONICA CA
|
| Numbering about 3,450 officers during 2001, the 13S career field (space and missile operations) in 1994 merged the separate space and missile career fields. While the nation's intercontinental ballistic missile force has shrunk substantially during the service of many of today 's officers, the space-based systems for navigation, surveillance, warning, and communication have become more numerous. Although missile jobs remain more numerous for junior officers, increasingly more space-oriented jobs are ... |
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| Bomb Strike Experiment for Mine Countermeasure |
2006 |
19 pages |
| Authors:
Peter C. Chu; Greg Ray; Peter Fleischer; Paul Gefken; NAVAL POSTGRADUATE SCHOOL MONTEREY CA NAVAL OCEAN ANALYSIS AND PREDICTION LAB
|
| The Navy's bomb maneuvering model (STRIKE35) predicts the bomb location and trajectory in air and water columns. The Bomb Strike Experiment for Mine Countermeasure Operations, currently sponsored through the Office of Naval Research mine and obstacle breaching technology program, is part of a multi-year, comprehensive effort aimed at enhancing the Navy's fleet naval mine clearance capability and success. The investigation discussed in this thesis examines the experimental and theoretical characteristics ... |
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| Molecular Modeling of Rigid-Rod Polymers Structures Dominated by Electrostatic Interactions |
NOV 2005 |
43 pages |
| Authors:
Natalia V. Lukasheva; RUSSIAN ACADEMY OF SCIENCES SAINT PETERSBURG INST OF MACRO-MOLECULAR COMPOUNDS
|
| This report results from a contract tasking Institute of Macromolecular Compounds of Russian Academy of Science as follows: PBO, a rigid rod polymer developed by the Air Force Materials Laboratory and now commercially available from Toyobo, has considerable promise for applications as separator membranes in advanced fuel cells and batteries. In such applications, the performance of the membrane is intimately related to the structure of the polymer. In PBO as ... |
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| Neural Network Based Adaptive Flow Control for Maneuvering Vehicles |
SEP 2005 |
34 pages |
| Authors:
J. E. Corban; An Glezer; Anthony Calise; GUIDED SYSTEMS TECHNOLOGIES MCDONOUGH GA
|
| This report documents a phase I STIR effort with the objective of developing and demonstrating effective nonlinear adaptive control of the aerodynamic flow about a dynamic body using a distributed array of synthetic jets for actuation. Design of a wind-tunnel test apparatus is presented. Motion of the model is constrained to two degrees of freedom. A conventional elevator is used to trim the model and change its dynamic characteristics. Position ... |
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| Reactive Hyperbranched Polymers as Toughening Processing Aids for Composite Matrices |
09 MAY 2005 |
11 pages |
| Authors:
Patrick T. Mather; CONNECTICUT UNIV STORRS DEPT OF POLYMER PROGRAM AND CHEMICAL ENGINEERING
|
| The overall objective of this proposal is to develop and study for transition new low viscosity thermoset additives - hyperbranched polymers (HBPs) - for use in composites needed for emerging space-based Air Force applications. Specifically, we are studying and developing hyperbranched polymers for use as a new low-viscosity thermoset/thermoplastic additives, which have enormouos applications in rigid spacecraft structures. The particular projects included: (i) Modification of high performance thermoplastics by non-reactive ... |
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| Unsteady Simulation of a Transport Aircraft Propeller Using MEGAFLOW |
25 APR 2005 |
15 pages |
| Authors:
Arne Stuermer; Mark Rakowitz; DLR INST OF AERODYNAMICS AND FLOW TECHNOLOGY BRAUNSCHWEIG (GERMANY)
|
| A series of unsteady CFD simulations have been conducted for an isolated propeller configuration at lowspeed flight conditions using both a structured and an unstructured CFD method. The propeller geometry investigated is representative of a modern eight-bladed design for high-speed turboprop transport aircraft. Two typical low-speed conditions, one at zero and one at ten degrees angle of attack, were investigated and results of the two CFD methods compared with experimental ... |
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| Using Multiple MEMS IMUs to form a Distributed Inertial Measurement Unit |
MAR 2005 |
105 pages |
| Authors:
Rayn Hanson; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| MEMS IMUs are readily available in quantity and have extraordinary advantages over conventional IMUs in size, weight, cost, and power consumption. However, the poor performance of MEMS IMUs limits their use in more demanding military applications. It is desired to use multiple distributed MEMS IMUs to simulate the performance of a single, more costly IMU, using the theory behind Gyro-Free IMUs. A Gyro-Free IMU (GF-IMU) uses a configuration of accelerometers ... |
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| Computational Aeroelastic Analysis of Micro Air Vehicle With Experimentally Determined Modes |
MAR 2005 |
95 pages |
| Authors:
Joshua A. Stults; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| A computational aeroelastic analysis of a micro air vehicle (MAV) is conducted. This MAV has a 24 inch wing span, and is designed for local area reconnaissance. Wind tunnel data for the MAV with a rigid carbon fiber wing and a flexible carbon fiber ribbed nylon wing are compared to CFD results incorporating static and dynamic deformations. We use laser vibrometry to determine the mode shapes of the flexible wing. ... |
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| Toxic Leadership in the U.S. Army |
10 JAN 2005 |
28 pages |
| Authors:
Denise F. Williams; ARMY WAR COLL CARLISLE BARRACKS PA
|
| The extent to which toxic leadership exists in the U.S. Army is a question that demands a thorough examination. While most publications on military leadership focus on the positive aspects of good leadership, this project examines the current literature on destructive leadership styles. The paper sought a definition of toxic leadership, consolidated expert views on the personal characteristics of toxic leaders, and compiled a taxonomy of 18 types of toxic ... |
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| Three-Dimensional Hydrodynamic Model for Prediction of Falling Cylinder Through Water Column |
2005 |
12 pages |
| Authors:
Peter C. Chu; Chenwu Fan; Ashley Evans; Anthony F. Gilles; Peter Fleischer; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY
|
| A three dimensional hydrodynamic model based on triple coordinate systems is developed to predict translation and orientation of falling rigid cylinder through the water column: earth-fixed coordinate (E-coordinate), cylinder 5 main-axis following coordinate (M-coordinate), and hydrodynamic force following coordinate (F- coordinate). Use of the triple coordinate systems and the transforms among them leads to the simplification of the dynamical system. The body and buoyancy forces and their moments are easily ... |
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| 3D Rigid Body Impact Burial Prediction Model (IMPACT35) |
2005 |
11 pages |
| Authors:
Peter C. Chu; Chenwu Fan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA NAVAL OCEAN ANALYSIS AND PREDICTION LAB
|
| Falling of rigid body through air, water, and sediment is investigated experimentally and theoretically. Two experiments were conducted to drop rigid cylinders with the density ratio around 1.8 into shallow water (around 13 m deep) in the Monterey Bay (Exp-1) and into the Naval Postgraduate School s swimming pool (Exp-2). During the experiments, we carefully observe cylinder track and burial depth while simultaneously taking gravity cores (in Exp-1). After analyzing ... |
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| Real-Time Optimal Slew Maneuver Design and Control |
DEC 2004 |
179 pages |
| Authors:
Andrew Fleming; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This thesis considers the problem of time-optimal spacecraft slew maneuvers. Since the work of Bilimoria and Wie it has been known that the time-optimal reorientation of a symmetric rigid body was not the eigenaxis maneuver once thought to be correct. Here, this concept is extended to axisymmetric and asymmetric rigid body reorientations with idealized independent torque generating devices. The premise that the time-optimal maneuver is not, in general, an eigenaxis ... |
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| A Numerical Method for Computing Barge Impact Forces Based on Ultimate Strength of the Lashings between Barges |
AUG 2004 |
220 pages |
| Authors:
Jose R. Arroyo; Robert M. Ebeling; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS INFORMATION TECHNOLOGY LAB
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| In 1993 Headquarters, U.S. Army Corps of Engineers, issued the first formal Corps-wide analysis procedure providing guidance for analyzing the effects of barge impact loading on navigation structures. According to the ETL 1110-2-338 engineering procedure, the magnitude of the impact forces generated by a particular collision event is dependent on the mass including hydrodynamic added mass of the barge train, the approach velocity, the approach angle, the barge train moment ... |
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| The Frequency Response, Impulse Response, and Transfer Function of an Ocean Waveguide |
JUN 2004 |
65 pages |
| Authors:
Walter B. Schulte III; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| In this thesis, the ocean was modeled as a wave-guide with an ideal pressure - release surface, and an ideal rigid bottom. The ocean wave-guide was then treated as a linear, time - invariant, space - variant (TISV) filter or communication channel. The filter is time - invariant because no motion was modeled and because the properties of the ocean were assumed to be constant. The filter is space variant ... |
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| Development of a Nonperiodic Homogenization Method for One-Dimensional Continua |
MAY 2004 |
19 pages |
| Authors:
Michael J. Leany; Peter W. Chung; Raju Namburu; MILITARY ACADEMY WEST POINT NY
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| This work describes a one-dimensional? homogenization method that relaxes the usual assumption of periodicity of microscale displacements. As such this method is appropriate for studying materials with periodic as well as nonperiodic microstructure. Expected applications for the new method include composite rods with manufacturing variability (where material periodicity is destroyed) and rods composed of functionally graded materials. The method is validated through direct comparison with a known exact solution that ... |
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