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Bending tests of a monocoque box

Description: A monocoque box beam consisting of a 24S-T aluminum-alloy sheet reinforced by four bulkheads and by longitudinal stringers and corner posts was subjected to bending loads as follows: pure bending about the lift axis, cantilever bending about the lift axis, and pure bending about both lift and drag axis. Longitudinal strains were measured for loads up to a load at which permanent set became measurable. The loads were sufficient to produce buckling of the sheet between stringers on the compression side of the box. The only noticeable effect of this buckling was a small increase in extreme-fiber strain on the compression side. The measured strains and measured deflections differed less than 10 percent from those computed from the simple beam theory after taking account of the effective width of the buckled sheet. The effect of the bulkheads on the distribution of stringer strain was negligible.
Date: November 1942
Creator: McPherson, Albert E.; Ramberg, Walter & Levy, Samuel
Partner: UNT Libraries Government Documents Department

Stress and distortion measurements in a 45 degree swept box beam subjected to antisymmetrical bending and torsion

Description: Report presenting an untapered aluminum-alloy box beam representing the main structural component of a full-span, two-spar, 45 degree swept wing with a carry-through section subjected to antisymmetrical tip bending and twisting loads such that stresses were kept below the proportional limit. Results regarding stresses due to antisymmetrical bending, stresses due to antisymmetrical torsion, distortions due to antisymmetrical bending, and distortions due to antisymmetrical torsion are provided.
Date: April 1950
Creator: Zender, George W. & Heldenfels, Richard R.
Partner: UNT Libraries Government Documents Department

Stress and distortion analysis of a swept box beam having bulkheads perpendicular to the spars

Description: Report presenting a method for the approximate calculation of the stresses and distortions in a box beam representing the main structural component of a swept wing with a carry-through section and with bulkheads perpendicular to the spars. Results regarding determination of shear-leg effects, effect of bulkhead flexibility, and extension of the method are provided.
Date: November 1950
Creator: Heldenfels, Richard R.; Zender, George W. & Libove, Charles
Partner: UNT Libraries Government Documents Department

An analysis of the stability and ultimate bending strength of multiweb beams with formed-channel webs

Description: From Introduction: "The purpose of the present paper is to develop a simple method of calculating both the stress at which initial wrinkling occurs in muti-web beams and the ultimate bending strength of beams which are susceptible to this mode of instability."
Date: August 1954
Creator: Semonian, Joseph W. & Anderson, Roger A.
Partner: UNT Libraries Government Documents Department

Analytical determination of coupled bending-torsion vibrations of cantilever beams by means of station functions

Description: From Summary: "A method based on the concept of Station Functions is presented for calculating the modes and the frequencies of nonuniform cantilever beams vibrating in torsion, bending, and coupled bending-torsion motion. The method combines some of the advantages of the Rayleigh-Ritz and Stodola methods, in that a continuous loading function for the beam is used, with the advantages of the influence-coefficient method, in that the continuous loading function is obtained in terms of the displacements of a finite number of stations along the beam."
Date: 1951
Creator: Mendelson, Alexander & Gendler, Selwyn
Partner: UNT Libraries Government Documents Department

Fatigue behavior of aircraft structural beams

Description: Report presenting an investigation of the correlation of composite structural fatigue behavior, basic material, and simple-element behavior. Fatigue and static testing were made on aluminum-alloy box beams and I-beams and on elements simulating key failure locations in the two beams.
Date: January 1958
Creator: Hyler, W. S.; Popp, H. G.; Gideon, D. N.; Gordon, S. A. & Grover, H. J.
Partner: UNT Libraries Government Documents Department

Differential equations of motion for combined flapwise bending, chordwise bending, and torsion of twisted nonuniform rotor blades

Description: The differential equations of motion for the lateral and torsional deformations of twisted rotating beams are developed for application to helicopter rotor and propeller blades. No assumption is made regarding the coincidence of the neutral, elastic, and mass axes, and the generality is such that previous theories involving various simplifications are contained as subcases to the theory presented in this paper. Special attention is given the terms which are not included in previous theories. These terms are largely coupling-type terms associated with the centrifugal forces. Methods of solution of the equations of motion are indicated by selected examples.
Date: February 1957
Creator: Houbolt, John C. & Brooks, George W.
Partner: UNT Libraries Government Documents Department

The lateral instability of deep rectangular beams

Description: "Experimental and analytical studies were made of solid and hollow deep rectangular beams to study their lateral instability under various conditions of loading and restraint. The tests were made on bars and tubes of 17ST aluminum alloy. Failure by lateral buckling occurred only in tests on the solid beams. It was found that, within the elastic range, the test results were in agreement with the classical theory for the lateral buckling of deep beams as given by Prandtl, Mitchell, and Timoshenko" (p. 1).
Date: May 1937
Creator: Dumont, C. & Hill, H. N.
Partner: UNT Libraries Government Documents Department

Effects of panel flexibility on natural vibration frequencies of box beams

Description: From Summary: "Effects of local panel oscillations on bending and torsional vibrations of box beams with flexible covers and webs are investigated. Theoretical analyses of simplified models are made in order to shed light on the mechanism of coupling between local and overall vibrations and to derive results than can be used to estimate the coupling effects in box beams."
Date: March 1954
Creator: Budiansky, Bernard & Fralich, Robert W.
Partner: UNT Libraries Government Documents Department

Bending and shear stresses developed by the instantaneous arrest of the root of a cantilever beam rotating with constant angular velocity about a transverse axis through the root

Description: From Summary: "A theoretical investigation was made of the behavior of a cantilever beam in rotational motion about a transverse axis through the root determining the stresses, the deflections, and the accelerations that occur in the beam as a result of the arrest of motion. The equations for bending and shear stress reveal that, at a given percentage of the distance from root to tip and at a given trip velocity, the bending stresses for a particular mode are independent of the length of the beam and the shear stresses vary inversely with the length. When examined with respect to a given angular velocity instead of a given tip velocity, the equations reveal that the bending stress is proportional to the length of the beam whereas the shear stress is independent of the length."
Date: June 1945
Creator: Stowell, Elbridge Z.; Schwartz, Edward B. & Houbolt, John C.
Partner: UNT Libraries Government Documents Department

A Linear, Transparent Beam Integrator

Description: Abstract: "A fast, linear air-ionization chamber has been developed for integrating and monitoring external heavy-particle beams. It consists of a thin-windowed air chamber in which the beam ionization light is viewed by a photomultiplier whose output is fed directly to a standard electrometer."
Date: February 12, 1954
Creator: Kitchen, Sumner W.
Partner: UNT Libraries Government Documents Department

Secondary Stresses in Open Box Beams Subjected to Torsion

Description: In open box beams subjected to torsion, secondary stresses arise owing to lateral bending of the spar caps. The present paper outlines a simple method for estimating the magnitude of these stresses and gives the results of tests of an open box beam in the neighborhood of a discontinuity where the cover changed from the top to the bottom of the box.
Date: November 1944
Creator: Kuhn, Paul; Batdorf, S. B. & Brilmyer, Harold G.
Partner: UNT Libraries Government Documents Department

Practical applications of coherent transition radiation

Description: The predictable nature of transition radiation (TR) emissions has been demonstrated under a wide variety of experimental conditions. The reliable character of TR allows the design of specific practical applications that use emissions from the optical to the x-ray spectral regions. Applications often can be enhanced by the spatial coherence of TR, and some have become highly developed. New applications may be developed through the use of other related radiation mechanisms. 20 refs., 3 figs.
Date: October 2, 1987
Creator: Moran, M.J.
Partner: UNT Libraries Government Documents Department

Possibilities of polarized protons in Sp anti p S and other high energy hadron colliders

Description: The requirements for collisions with polarized protons in hadron colliders above 200 GeV are listed and briefly discussed. Particular attention is given to the use of the ''Siberan snake'' to eliminate depolarizing resonances, which occur when the spin precession frequency equals a frequency contained in the spectrum of the field seen by the beam. The Siberian snake is a device which makes the spin precession frequency essentially constant by using spin rotators, which precess the spin by 180/sup 0/ about either the longitudinal or transverse horizontal axis. It is concluded that operation with polarized protons should be possible at all the high energy hadron colliders. (LEW)
Date: January 1, 1984
Creator: Courant, E.D.
Partner: UNT Libraries Government Documents Department

``Electron Lens`` to Compensate Bunch-to-Bunch Tune Spread in TEV33

Description: In this article we discuss an electron beam lens for compensation of bunch-to-bunch tune spread in the Tevatron antiproton beam. Time-modulated current of an electron beam can produce defocusing forces necessary to compensate effects caused by parasitic beam-beam interactions with proton beam. We estimate maim parameters of the electron beam and consider resulting beam footprint. Emittance growth rate due to the electron current fluctuations is discussed.
Date: October 1, 1997
Creator: Shiltsev, V.
Partner: UNT Libraries Government Documents Department

50x50 GeV Muon Collider Beam Collimation

Description: A summary of different techniques and systems to scrape beam halo in a 50 x 50 GeV {mu}{sup +}{mu}{sup -} collider is presented. Such systems are installed in a special utility section with optics specifically designed to meet both the requirements of the scraping system and of injection. Results froma realistic Monte Carlo simulation (STRUCT-MARS) show that a system consisting of steel absorbers several meters in length suppresses halo-induced backgrounds in the collider detector by more than three orders of magnitude. The heat load in superconducting magnets near the scraper system can be reduced to tolerable levels by appropriate collimator design and location. This reduction applies to both injection and collider mode of operation. Also discussed is extraction of halo particles using electrostatic deflectors and bent crys-tals, although neither appears to be effective for a muon collider at this energy.
Date: April 14, 1999
Creator: Drozhdin, A. I.; Johnstone, C. J.; Mokhov, N. V.; Garen, A. A. & Biryukov, V. M.
Partner: UNT Libraries Government Documents Department

NuTeV SSQT performance

Description: The NuTeV experiment (E815) took data during the 1996-1997 Fermilab fixed target run. The experiment used the sign-selected-quadrupole- train (SSQT) in its neutrino beamline to choose either a neutrino or an anti- neutrino beam. This note summarizes the performance of the SSQT, as measured by the beamline monitoring devices, the observed {nu}{sub {mu}} and {anti {nu}}{sub {mu}} fluxes, and the upper limit on the wrong sign neutrino contamination.
Date: February 1, 1998
Creator: Yu, J. & NuTeV
Partner: UNT Libraries Government Documents Department

Fixed-Target Electron Accelerators

Description: A tremendous amount of scientific insight has been garnered over the past half-century by using particle accelerators to study physical systems of sub-atomic dimensions. These giant instruments begin with particles at rest, then greatly increase their energy of motion, forming a narrow trajectory or beam of particles. In fixed-target accelerators, the particle beam impacts upon a stationary sample or target which contains or produces the sub-atomic system being studied. This is in distinction to colliders, where two beams are produced and are steered into each other so that their constituent particles can collide. The acceleration process always relies on the particle being accelerated having an electric charge; however, both the details of producing the beam and the classes of scientific investigations possible vary widely with the specific type of particle being accelerated. This article discusses fixed-target accelerators which produce beams of electrons, the lightest charged particle. As detailed in the report, the beam energy has a close connection with the size of the physical system studied. Here a useful unit of energy is a GeV, i.e., a giga electron-volt. (ne GeV, the energy an electron would have if accelerated through a billion volts, is equal to 1.6 x 10{sup -10} joules.) To study systems on a distance scale much smaller than an atomic nucleus requires beam energies ranging from a few GeV up to hundreds of GeV and more.
Date: November 2001
Creator: Brooks, William K.
Partner: UNT Libraries Government Documents Department

INTRA-UNDULATOR MEASUREMENTS AT VISA FEL.

Description: We describe a diagnostics system developed, to measure exponential gain properties and the electron beam dynamics inside the strong focusing 4-m long undulator for the VISA (Visible to Infrared SASE Amplifier) FEL. The technical challenges included working inside the small undulator gap, optimizing the electron beam diagnostics in the high background environment of the spontaneous undulator radiation, multiplexing and transporting the photon beam. Initial results are discussed.
Date: August 13, 2000
Creator: MUROKH,A.; FRIGOLA,P.; AL, ET; JOHNSON,E.; WANG,X.J. & YAKIMENKO,V.
Partner: UNT Libraries Government Documents Department