| Analysis and Simulation of Hypervelocity Gouging Impacts |
JUN 2006 |
312 pages |
| Authors:
John D. Cinnamon; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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 | In this work, a summary of past and present research efforts, as well as the theoretical foundation, of hypervelocity gouging is presented. As the Holloman AFB High Speed Test Track (HHSTT) sled's speed has increased to Mach 8.5, material interactions develops which causes "gouging" - this can result in catastrophic failure. A characterization of gouging, including a thermodynamic history, is developed from an examination of a gouged rail. An extensive ... |
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| An Investigation of Sliding Electrical Contact in Rail Guns and the Development of Grooved-Rail Liquid-Metal Interfaces |
DEC 2001 |
54 pages |
| Authors:
Mark T. Adamy; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The barrel life of a solid armature rail gun is a critical issue, Arcing along the barrel pathway at the interfaces between the armature and the rails produces severe damage The ability to protect the rails and yet provide sufficient electrical contact to sustain arc-free high-current flow is desirable, This thesis investigates the use of liquid metal as an interface material between the sliding electrical contact surfaces of the armature ... |
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| Stress Concentration due to Axial Tension of Loaded Nonsymmetric-Shaped Grooves |
NOV 1984 |
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| Authors:
Y. F. Cheng; ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER WATERVLIET NY LARGE CALIBER WEAPON SYSTEMS LAB
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 | Lug and groove connections are frequently found in structures where two components meet and loads are transmitted. These grooves usually have a nonsymmetric shape, i.e., the flank angle at the loaded face is different from that at the free face. While numerous data on stress concentrations for symmetric-shaped grooves (for example, U- or V-shaped) are available, very little information exists for nonsymmetric-shaped grooves. This report describes a photoelastic study on ... |
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| Laser Hot Spot Machining |
MAR 83 |
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| Authors:
R. J. Wallace; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES
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| The first dissertation investigated the shaping of hot pressed S3N4 with a high power CW C02 laser. The laser was used to heat the surface of a workpiece forming a groove by vaporization. Shaping was accomplished by overlapping the grooves. Results are given showing that groove shapes and material removal rates are independent of irradiation environment. This suggests that decomposition is responsible for the removal of material. An analysis of ... |
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| Survivability of Penetrators with Circumferential Shear-Control Grooves |
APR 1981 |
32 pages |
| Authors:
J. C. Schulz; O. E. R. Heimdahl; NAVAL WEAPONS CENTER CHINA LAKE CA
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| Small, cylindrical, steel projectiles containing circumferential grooves were fired against simulated concrete and steel-plate targets to investigate possible effects of shear-control grid placement on the survivability of impacting warheads. The projectiles fired against simulated concrete developed a bulge near the front of the internal cavity. The presence of a groove in this region significantly reduced the breakup velocity, while a groove a short distance to the rear had no effect ... |
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| The Braking Performance of an Aircraft Tire on Grooved Portland Cement Concrete Surfaces. |
JAN 1981 |
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| Authors:
Satish K. Agrawal; Hector Daiutolo; FEDERAL AVIATION ADMINISTRATION TECHNICAL CENTER ATLANTIC CITY NJ
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| Introduction of transverse grooves on runways improves braking and cornering performance of aircraft during operations in wet weather conditions and helps to alleviate hydroplaning. The Federal Aviation Administration (FAA) has recommended 1/4-inch square grooves spaced at 1-1/4 inches for installation on runways where the potential of hydroplaning exists. However, a large number of runways remain nongrooved. The major reasons are the high cost of groove installation and limited evidence as ... |
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| Apparatus for, and Method of, Plunge Grinding. |
30 SEP 1980 |
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| Authors:
James J. Denney; DEPARTMENT OF THE AIR FORCE WASHINGTON DC
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| This patent discloses an apparatus for, and a method of, forming annular grooves in a workpiece by plunge grinding. the preferred embodiment of the apparatus includes; a segmental grinding wheel chuck which further includes a circumferential chuck plate to which a plurality of arcuate-shaped, equally-spaced grinding wheel segment holders are releasably connected, and, grinding wheel segments that are removably attached, by and with the use of eutectic material, to the ... |
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| Noncoplanar High Power FET. |
DEC 1979 |
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| Authors:
S. G. Bandy; D. M. Collins; D. R. Decker; J. H. Dully; R. D. Fairman; VARIAN ASSOCIATES INC PALO ALTO CA SOLID STATE LAB
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| Using a p+ substrate as the gate and employing low-doped V-grooves under the source and drain to reduce parasitic capacitances, a noncoplanar power FET was designed and fabricated which achieved submicron gate lengths with photolithography masks employing a resolution limit of several microns. Device performance was limited by low values of pinch-off voltage and gate breakdown voltage. Ion imlantation or diffusion should enable the breakdown voltage to be raised by ... |
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| Surveys of Grooves in 19 Bituminous Runways. |
MAR 1979 |
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| Authors:
Richard Melone; NAVAL AIR ENGINEERING CENTER LAKEHURST NJ TEST DEPT
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| This report presents the results of a survey of grooves cut into the bituminous runway surfaces at 19 airports throughout the eastern half of the United States. The survey was conducted during the period 20 March 1978 to 25 May 1978. The objectives of the survey were to determine the extent and frequency of problems, such as chipping, cracking, rounding, wearing, distorting, and contaminating of the grooves. A total of ... |
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| Application of Compliance Techniques for Studying the Effect of Side-Grooving on Stress-Corrosion Crack Kinetics of a High Strength Steel. |
APR 1978 |
24 pages |
| Authors:
W. J. Pollock; AERONAUTICAL RESEARCH LABS MELBOURNE (AUSTRALIA)
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| Sub-critical crack growth was estimated from changes in compliance measured during the stress-corrosion cracking of D6AC steel at constant load using 1-T wedge-opening-loading specimens. Agreement of calculated mean crack growth with mean values measured from the fracture surface showed that plastic yielding at the crack tip during loading and subsequent stress-corrosion cracking was negligible. The analysis was then applied to side-grooved specimens where it was demonstrated that, under plane-strain conditions, ... |
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| Laboratory Method for Evaluating Effect of Runway Grooving on Aircraft Tires. |
MAR 1974 |
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| Authors:
G. Wittlin; LOCKHEED-CALIFORNIA CO BURBANK
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| The development of a laboratory technique which simulates an airplane operational touchdown on an existing representative grooved runway landing area is described. The laboratory technique demonstrates that chevron cutting of a 49 inch x 17 inch size tire (KC135, B727) landing on a dry 1/4 inch x 1/4 inch x 1 inch grooved concrete pavement slab is obtained which is representative of tire damage currently being experienced during airplane landings ... |
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| Seal Ring for F-18 Hornet |
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2 pages |
| Authors:
NATIONAL CENTER FOR DEFENSE MANUFACTURING AND MACHINING LATROBE PA
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| The problem was a 303 Stainless Steel Aircraft seal ring with a very small face groove at multiple depths and very thin walls on the outer diameter and inner diameter. The standard manufacturing process produced 18 pieces per hour and used three different tools to process the face groove. The process utilized a rough groove tool, a finish groove tool, and a necking tool for an undercut. The machine spindle ... |
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Reports by Keyword(s)
*GROOVING
