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Production of Large Energetic Neutral Deuteron Beams

Description: Introduction: A proposal for using an energetic neutral deuteron beam for injection into a mirror machine has been made by Eugene Lauer. This report describes an experimental attempt to produce a large neutral deuteron beam. The beam from the NTA ion source was passed through a target of hydrogen gas where the charge exchange mechanics produced a beam of energetic neutral deuterium atoms.
Date: January 24, 1956
Creator: Hester, R. E.
Partner: UNT Libraries Government Documents Department

Secondary Stresses in Thin-Walled Beams With Closed Cross Sections

Description: Note presenting an accurate method of determining secondary stresses in thin-walled, uniform beams of closed cross section. In the first part of the report, the integrodifferential equation governing axial displacements is formulated and solved for a beam without longitudinal stiffeners. In the second part, the corresponding summation-difference equation is developed and solved for a beam with stiffeners.
Date: October 1951
Creator: Benscoter, Stanley Urner
Partner: UNT Libraries Government Documents Department

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

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

Determination of flame temperatures from 2000 to 3000 K by microwave absorption

Description: Report presenting equations derived for the measurement of flame temperatures from the attenuation of a microwave beam by temperature-induced free electrons from chemical elements introduced in the flame. The free electron collision frequency and an effective ionization potential for four alkali elements were determined experimentally. Results regarding the blast burner, liquid propellant burner, and effects of addition of salt solutions on flames are provided.
Date: August 1954
Creator: Kuhns, Perry W.
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

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

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

Investigation of the Vibrations of a Hollow Thin-Walled Rectangular Beam

Description: "Experimental modes and frequencies of an unstiffened hollow beam of rectangular cross section are presented, and comparisons are made between experimental and theoretical frequencies. Theories based on rigid cross sections were found to be sufficiently accurate to predict the frequencies of only the lowest three bending modes. For the higher bending modes and all the torsional modes it was necessary to include the effects of cross-sectional distortions in the calculations" (p .1).
Date: October 1955
Creator: Kordes, Eldon E. & Kruszewski, Edwin T.
Partner: UNT Libraries Government Documents Department

Bending Stresses Due to Torsion in Cantilever Box Beams

Description: "The paper beings with a brief discussion on the origin of the bending stresses in cantilever box beams under torsion. A critical survey of existing theory is followed by a summary of design formulas; this summary is based on the most complete solution published but omits all refinements considered unnecessary at the present state of development. Strain-gage tests made by NACA to obtained some experimental verification of the formulas are described next. Finally, the formulas are applied to a series of box beams previously static-tested by the U.S. Army Air Corps; the results show that the bending stresses due to torsion are responsible to a large extent for the free-edge type of failure frequently experienced in these tests" (p. 1).
Date: June 1935
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

Some Notes on the Numerical Solution of Shear-Lag and Mathematically Related Problems

Description: "The analysis of box beams with shear deformation of the flanges can be reduced to the solution of a differential equation. The same equation is met in other problems of stress analysis. No analytical solutions of this equation can be given for practical cases, and numerical methods of evaluation must be used. Available methods are briefly discussed. Two numerical examples show the application of the step-by-step method of integration to shear-lag problems" (p. 1).
Date: May 1939
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department