Search Results

open access

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.
Partner: UNT Libraries Government Documents Department
open access

Device for Measuring Principal Curvature and Principal Strains on a Nearly Plane Surface

Description: Note presenting a device which makes possible the measurement of principal extreme fiber bending strains over a circular area with a radius of 0.94 inch with a systematic error on 0.1-inch sheet of the order of 0.00003. Equations are presented for computing median fiber strains from the measured curvatures and strains at the surface and from the thickness of the sheet.
Date: February 1947
Creator: McPherson, A. E.
Partner: UNT Libraries Government Documents Department
open access

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.
Partner: UNT Libraries Government Documents Department
open access

Normal-pressure tests of circular plates with clamped edges

Description: A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness from 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pr… more
Date: June 1942
Creator: McPherson, Albert E.; Ramberg, Walter & Levy, Samuel
Partner: UNT Libraries Government Documents Department
open access

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 compressio… more
Date: November 1942
Creator: McPherson, Albert E.; Ramberg, Walter & Levy, Samuel
Partner: UNT Libraries Government Documents Department
open access

Effect of Normal Pressure on Strength of Axially Loaded Sheet-Stringer Panels

Description: Note presenting tests under combined axial load and normal pressure on 29 24S-T aluminum alloy sheet-stringer panels. Empirical formulas were derived for predicting the effect of normal pressure on the strain for buckling of sheet between stringers. Results of buckling, sheet load, strains, buckling, and failure are provided.
Date: July 1946
Creator: McPherson, A. E.; Levy, Samuel & Zibritosky, George
Partner: UNT Libraries Government Documents Department
open access

Normal-pressure tests of rectangular plates

Description: From Summary: "Normal-pressure tests were made of 56 rectangular plates with clamped edges and of 5 plats with freely supported edges. Pressure was applied and the center deflection and the permanent set at the center were measured. For some of the plates, strains and contours were measured in addition."
Date: June 1942
Creator: Ramberg, Walter; McPherson, Albert E. & Levy, Samuel
Partner: UNT Libraries Government Documents Department
open access

Effect of rivet and spot-weld spacing on the strength of axially loaded sheet-stringer panels of 24S-T aluminum alloy

Description: Report presenting testing of eighteen 24S-T aluminum alloy sheet-stringer panels in end compression under carefully controlled edge conditions. Results regarding the strains, deflections, failure, and buckling of the sheet are provided.
Date: August 1942
Creator: Levy, Samuel; McPherson, Albert E. & Ramberg, Walter
Partner: UNT Libraries Government Documents Department
open access

Experimental study of deformation and of effective width in axially loaded sheet-stringer panels

Description: From Summary: "The deformation of two sheet-stringer panels subjected to end compression under carefully controlled end conditions was measured at a number of points and at a number of loads, most of which were above the load at which the sheet had begun to buckle. The two panels were identical except for the sheet, which was 0.70-inch 24st alclad for specimen 1 and 0.025-inch 24st aluminum alloy for specimen 6. A technique was developed for attaching Tuckerman optical strain gauges to the shee… more
Date: February 1939
Creator: Ramberg, Walter; McPherson, Albert E. & Levy, Sam
Partner: UNT Libraries Government Documents Department
open access

Compressive Tests of a Monocoque Box

Description: "A monocoque box specimen of aluminum alloy was subjected to end compression and the strains in the stringers were measured up to loads at which permanent set became noticeable. The stringer strains at low loads agreed closely with those computed from the assumption of uniform stress distribution. Buckling of the 0.026-inch sheet between stringers and of the 0.075-inch shear web took place at stresses in accord with theoretical values" (p. 1).
Date: August 1939
Creator: Ramberg, Walter; McPherson, Albert E. & Levy, Sam
Partner: UNT Libraries Government Documents Department
open access

Torsion Tests of a Monocoque Box

Description: Report presenting testing of a monocoque box of aluminum alloy, which had torques applied to the ends. The twist, strain in the stringers, plate, and corner posts, and the buckling load were measured. A new analysis was developed for the twisting of a monocoque box reinforced by stringers, corner posts, and bulkheads, and the measured twist agreed within 10 percent of the analytical value.
Date: November 1942
Creator: Levy, Samuel; McPherson, Albert E. & Ramberg, Walter
Partner: UNT Libraries Government Documents Department
open access

Normal-pressure tests of circular plates with clamped edges

Description: A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness form 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pr… more
Date: October 10, 1941
Creator: McPherson, Albert E.; Ramberg, Walter & Levy, Samuel
Partner: UNT Libraries Government Documents Department
open access

Normal-pressure tests of rectangular plates

Description: Report presents the results of normal-pressure tests made of 56 rectangular plates with clamped edges and of 5 plates with freely supported edges. Pressure was applied and the center deflection and the permanent set at the center were measured. For some of the plates, in addition, strains and contours were measured.
Date: 1942
Creator: Ramberg, Walter; McPherson, Albert E. & Levy, Samuel
Partner: UNT Libraries Government Documents Department
open access

Torsion Test to Failure of a Monocoque Box

Description: Note presenting a torsion test to failure for a monocoque box of 24S-T aluminum alloy. The box had a rectangular section and was reinforced by Z-stringers, antirolls, bulkheads, and corner posts.
Date: October 1944
Creator: McPherson, A. E.; Goldenberg, D. & Zibritosky, G.
Partner: UNT Libraries Government Documents Department
open access

Strength of Wing Beams Under Axial and Transverse Loads

Description: Note presenting wing beams tested under axial compressive loads, transverse loads, and combined axial and transverse loads. Deflections and strains in the elastic range were in general agreement with those computed from the simple beam theory after taking account of the secondary bending moment produced by the axial load as the beam deflected under load.
Date: September 1945
Creator: Ramberg, Walter; McPherson, A. E. & Levy, Samuel
Partner: UNT Libraries Government Documents Department
open access

Influence of wing flexibility on force-time relation in shock strut following vertical landing impact

Description: Report presenting testing to determine the force developed in a shock strut as a function of the flexibility of the attached wing structure. Both the experiment and analysis indicated that wing flexibility had some effect on the shape and peak value of the force-time curve in a shock strut.
Date: November 1949
Creator: McPherson, Albert E.; Evans, J., Jr. & Levy, Samuel
Partner: UNT Libraries Government Documents Department
open access

Effect of Developed Width on Strength of Axially Loaded Curved Sheet Stringer Panels

Description: Report presenting compression tests on six 24S-T aluminum alloy curved sheet-stringer panels 12 inches in length and 24 inches in width, reinforced by six Zeo stringers spaced 4 inches between centers. The increase in developed width had no significant effect on the strain for buckling of sheet between stringers, the strain for buckling of sheet between rivets, the load carried per sheet bay, or the stress at failure.
Date: November 1944
Creator: McPherson, Albert E.; Fienup, Kenneth L. & Zibritosky, George
Partner: UNT Libraries Government Documents Department
Back to Top of Screen