National Advisory Committee for Aeronautics (NACA) - 44 Matching Results

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Adaptor for Measuring Principal Strains With Tuckerman Strain Gage

Description: Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error … more
Date: June 1943
Creator: McPherson, A. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Bearing strengths of bare and alclad XA75S-T and 24S-T81 aluminum alloy sheet

Description: From Introduction: "A report was recently issued covering an investigation of the bearing properties of the wrought aluminum alloys commonly used in aircraft construction (reference 1). Since this work was undertaken, two new materials, XA75S-T and 24S-T81, have been developed to the commercial stage for aircraft use. The objection of this investigation was to determine the bearing yield and ultimate strengths of these new materials in the form of bare and alclad sheet."
Date: December 1943
Creator: Moore, R. L. & Wescoat, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Bearing strengths of some wrought-aluminum alloys

Description: From Introduction: "Although a number of investigations of the bearing strength of aluminum alloys have been made, the problem remains one of considerable interest to the aircraft industry. For this reason it has seemed advisable to make additional tests of the commonly used aircraft alloys in an effort to establish a better basis for the selection of allowable bearing values. Current design practice does not recognize the effect of edge distance upon bearing strengths, and for this reason edge… more
Date: August 1943
Creator: Moore, R. L. & Wescoat, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Bearing tests of magnesium-alloy sheet

Description: From Summary: "Bearing tests of AM-3S, AM-52S, and AM-C57S magnesium-alloy sheet in various thicknesses and tempers were made. Bearing yield and ultimate strengths were determined and compared for various edge distances and for various ratios of loading-pin diameter to sheet thickness. Tensile strengths were determined and ratios of average bearing yield and ultimate strength to tensile strength are given."
Date: June 1943
Creator: Sharp, W. H. & Moore, R. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Certain Mechanical Strength Properties of Aluminum Alloys 25S-T and X76S-T

Description: Note presenting tests made to determine certain mechanical strength properties of 25S-T aluminum alloy. Results are presented from static tests in tension and torsion, bending fatigue tests employing three different types of testing machines, and from impact tests of notched and unnotched specimens in tension as well as Charpy impact tests made at several low temperatures. These are made in order to study the stresses that propeller blades experience.
Date: October 1943
Creator: Dolan, Thomas J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Column Strength of Magnesium Alloy AM-57S

Description: Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.
Date: July 1943
Creator: Holt, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Description of Stress-Strain Curves by Three Parameters

Description: "A simple formula is suggested for describing the stress-strain curve in terms of three parameters; namely, Young's modulus and two secant yield strengths. Dimensionless charts are derived from this formula for determining the stress-strain curve, the tangent modulus, and the reduced modulus of a material for which these three parameters are given. Comparison with the tensile and compressive data on aluminum-alloy, stainless-steel, and carbon-steel sheet in NACA Technical Note No. 840 indicates… more
Date: July 1943
Creator: Ramberg, Walter & Osgood, William R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of Fillers and of Mixing Procedure on the Strength of Plastic Materials

Description: Note presenting a study to prepare a series of molding powders with the use of a given plastic and given fillers in varying proportions and to determine the effect of the differences in composition of the molding powders on certain physical properties of standard test pieces molded from them.
Date: January 1943
Creator: Kynoch, William & Patronsky, L. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effect of inlet-valve design, size, and lift on the air capacity and output of a four-stroke engine

Description: Report presenting a series of performance tests made with a CFR engine at constant inlet pressure and temperature and constant exhaust pressure. Special cylinder heads with different sizes and designs of inlet valve and port were used.
Date: November 1943
Creator: Livengood, James C. & Stanitz, John D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of Rivet Pitch Upon the Fatigue Strength of Single-Row Riveted Joints of 0.025- to 0.025-Inch 24S-T Alclad

Description: "S-N curves at the range ratio of 0.2 were experimentally obtained for each of the following values of rivet pitch P as used in a single-row lap joint of 0.025- to 0.025-inch 24S-T alclad with one-eight AN430 round-head rivets: p=0.5, 0.75, 1.0, 1.5. Families of constant rivet pitch curves, which define the fatigue life for specimens studied, were developed. Curves showing the variation of the effective stress concentration factor in fatigue with rivet pitch and maximum load per rivet were also… more
Date: July 1943
Creator: Seliger, Victor
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effect of Surface Finish on the Fatigue Performance of Certain Propeller Materials

Description: Report presenting an investigation of the effect of various surface finishes on the endurance of normalized X4130 and 4140 steels and 25S-T aluminum alloy. All mechanically formed surfaces tested were stronger than electropolished surfaces.
Date: December 1943
Creator: Russell, H. W.; Gillett, H. W.; Jackson, L. R. & Foley, G. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effect of the type of specimen on the shear strengths of driven rivets

Description: Report presenting tests of various types of riveted joint composed of 24S-T sheet and 1/8-inch A17S-T rivets in order to determine the effects of specimen type on shear strengths. The results indicated that there was only a slight variation in shear strength with considerable variation in the types of specimen.
Date: November 1943
Creator: Sharp, W. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effects of Prior Fatigue-Stressing of the Impact Resistance of Chromium-Molybdenum Aircraft Steel

Description: Note presenting a study of the impact behavior of normalized SAE X4130 steel after a variety of repeated stress treatments. Fatigue specimens of several types were used and the effects of surface finish, rest periods, stress amplitude, mean stress, stress concentration, and temperature during repeated stress received consideration.
Date: March 1943
Creator: Kies, J. A. & Holshouser, W. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Exact Solution of Shear-Lag Problems in Flat Panels and Box Beams Assumed Rigid in the Transverse Direction

Description: "A mathematical procedure is herein developed for obtaining exact solutions of shear-lag problems in flat panels and box beams: the method is based on the assumption that the amount of stretching of the sheets in the direction perpendicular to the direction of essential normal stresses is negligible. Explicit solutions, including the treatment of cut-outs, are given for several cases and numerical results are presented in graphic and tabular form. The general theory is presented in a from which… more
Date: June 1943
Creator: Hildebrand, Francis B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Hot-Wire Circuit With Very Small Time Lag

Description: A circuit for a hot-wire anemometer for the measurement of fluctuating flow is presented in the present report. The principal elements of the circuit are a Wheatstone bridge, one branch of which is the hot wire; and an electronic amplifier and a current regulator for the brief current which in combination maintain the bridge balance constant. Hence the hot wire is kept at practically constant resistance and temperature, and the time lag caused by thermal inertia of the wire is thereby reduced. … more
Date: February 1943
Creator: Weske, John R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Large-Deflection Theory for End Compression of Long Rectangular Plates Rigidly Clamped Along Two Edges

Description: "The von Karman equations for flat plates are solved beyond the buckling load up to edge strains equal to eight time the buckling strain, for the extreme case of rigid clamping along the edges parallel to the load. Deflections, bending stresses, and membrane stresses are given as a function of end compressive load. The theoretical values of effective width are compared with the values derived for simple support along the edges parallel to the load" (p. 1).
Date: January 1943
Creator: Levy, Samuel & Krupen, Philip
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Large-Deflection Theory of Curved Sheet

Description: Equations are given for the elastic behavior of initially curved sheets in which the deflections are not small in comparison with the thickness, but at the same time small enough to justify the use of simplified formulas for curvature. These equations are solved for the case of a sheet with circular cylindrical shape simply supported along two edges parallel to the axis of the generating cylinder. Numerical results are given for three values of the curvature and for three ratios of buckle lengt… more
Date: May 1943
Creator: Levy, Samuel
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Least-Work Analysis of the Problem of Shear Lag in Box Beams

Description: The distribution of stress in the cover sheets of thin-wall box beams is analyzed, with regard to the effect of shear deformation in the cover sheets, by the method of least work. Explicit results are obtained for a number of representative cases that show the influence of the following factors on the stress patterns. General conclusions are drawn from the results obtained. Among them the most important one appears to be the fact that the shear-lag effect depends primarily on several tow qualit… more
Date: May 1943
Creator: Hildebrand, Francis B. & Reissner, Eric
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A method for determining the column curve from tests of columns with equal restraints against rotation on the ends

Description: The results are presented of a theoretical study for the determination of the column curve from tests of column specimens having ends equally restrained against rotation. The theory of this problem is studied and a curve is shown relating the fixity coefficient c to the critical load, the length of the column, and the magnitude of the elastic restraint. A method of using this curve for the determination of the column curve for columns with pin ends from tests of columns with elastically restrai… more
Date: August 1943
Creator: Lundquist, Eugene E.; Rossman, Carl A. & Houbolt, John C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Methods of Measurement of High Air Velocities by the Hot-Wire Method

Description: Investigations of strengths of hot wires at high velocities were conducted with platinum, nickel, and tungsten at approximately 200 Degrees Celcius hot-wire temperature. The results appear to disqualify platinum for velocities approaching the sonic range; whereas nickel withstands sound velocity, and tungsten may be used for supersonic velocities under standard atmospheric conditions. Hot wires must be supported by rigid prolongs at high velocities to avoid wire breakage. Resting current measur… more
Date: February 1943
Creator: Weske, John R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Part-Throttle Operation and Control of a Piston-Ported Two-Stroke Cylinder

Description: Report presenting a study of a single-cylinder piston-ported two-stroke engine in order to investigate means of obtaining reliable operation under idling conditions. The fuel-consumption characteristics were also studied over the useful range of speeds and loads. Results regarding illuminating gas, vaporized gasoline, gasoline injection, injected safety fuel, and brake specific fuel consumption are provided.
Date: November 1943
Creator: Rogowski, A. R. & Taylor, C. Fayette
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A portable calibrator for dynamic strain gages

Description: From Summary: "A portable device for calibrating dynamic strain gages is described. The device contains a motor-driven cam, which applies alternating tensile loads to a metal strip 5/8 inch wide and 6 1/4 inches long. The cam is designed to produce a nearly sinusoidal variation of strain with time. Dynamic strain gages with gage lengths up to 5 inches may be calibrated by mounting them on the strip and by changing the frequency and the amplitude of the tensile load. The frequency may be varied … more
Date: February 1943
Creator: McPherson, Albert E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Pressure Distribution on the Fuselage of a Midwing Airplane Model at High Speeds

Description: Report presenting the pressure distribution on the fuselage of a midwing airplane model measured in the 8-foot high-speed wind tunnel at a range of speeds and lift coefficients. The primary purpose of the investigation was to provide data showing the air pressures on various parts of the fuselage for use in structural design.
Date: February 1943
Creator: Delano, James B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Requirements for Auxiliary Stiffeners Attached to Panels Under Combined Compression and Shear

Description: "Panels of aluminum alloy sheets, framed by side and end stiffeners, were subjected to combined loading by means of offset knife edges applying loads to top and bottom end plates with reacting forces against the end plates supplied by laterally acting rollers. The test specimens were 17S-T aluminum alloy shoots 0.040 inch thick in panels of 10-inch width and three different lengths (approximately 10, 26, and 30 inch). Data were obtained for the bowing of transverse and longitudinal ribs of rect… more
Date: September 16, 1943
Creator: Scott, Merit & Weber, Robert L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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