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Effect of Rivet Holes on the Ultimate Strength Developed by 24S-T and Alclad 75S-T Sheet in Incomplete Diagonal Tension

Description: Strength tests were made of a number of 24S-T and Alclad 75S-T aluminum-alloy shear webs to determine the effect of rivet or bolt holes on the shear strength. Data were obtained for webs which approached a condition of pure shear stress as well as for webs with well-developed diagonal tension. The rivet factor, (pitch minus diameter) divided by pitch, was varied from approximately 0.81 to 0.62. These tests indicated that the shear stresses on the gross section were nearly constant for all values of the rivet factor investigated if the other properties of the web were not changed.
Date: 1943
Creator: Levin, L. Ross & Nelson, David H.
Partner: UNT Libraries Government Documents Department

Analysis of deep rectangular shear web above buckling load

Description: From Introduction: "An analysis of a square web above the buckling load was presented in reference 1. The analysis of reference 1 therefore was repeated for a shear web with depth/width = 2.5. Comparison of the results with those for the square web then would indicate the effect in the depth-width ratio."
Date: March 1946
Creator: Levy, Samuel; Woolley, Ruth M & Corrick, Josephine N
Partner: UNT Libraries Government Documents Department

An empirical formula for the critical shear stress of curved sheets

Description: Report presenting tests to determine the critical shear stress of curved sheets. The empirical formula derived from the tests is applicable to panels with a ratio of radius to thickness of 300 or greater, a central angle of 1 radian or less, and a ratio of arc length to axial length not greater than 1.
Date: January 1945
Creator: Kuhn, Paul & Levin, L. Ross
Partner: UNT Libraries Government Documents Department

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.
Partner: UNT Libraries Government Documents Department

Critical stress for an infinitely long flat plate with elastically restrained edges under combined shear and direct stress

Description: "A simple interaction curve is presented for evaluating the conditions of combined shear and direct stress under which an infinitely long, flat plate with equal elastic restraints against rotation along the edges will become unstable. The theoretical work that led to the interaction curve is presented in the form of appendixes" (p. 1).
Date: November 1943
Creator: Stowell, Elbridge Z. & Schwartz, Edward B.
Partner: UNT Libraries Government Documents Department

Shear-lag tests of two box beams with corrugated covers loaded to failure

Description: From Summary: "Strain measurements were made on the compression side of two box beams with corrugated aluminum-alloy covers loaded to failure. Angles formed from sheet were used for corner flanges in beam 1; whereas extruded angles were used in beam 2. Failure in each beam occurred in the corner angle at a stress that was above the compressive yield stress for the material."
Date: January 1944
Creator: Chiarito, Patrick T.
Partner: UNT Libraries Government Documents Department

Cold-formed Steel Framed Shear Wall Sheathed with Corrugated Sheet Steel

Description: Incombustibility is one important advantage of the sheet steel sheathed shear wall over wood panel sheathed shear wall. Compared to shear wall sheathed with plywood and OSB panel, shear wall sheathed with flat sheet steel behaved lower shear strength. Although shear wall sheathed with corrugated sheet steel exhibited high nominal strength and high stiffness, the shear wall usually behaved lower ductility resulting from brittle failure at the connection between the sheathing to frames. This research is aimed at developing modifications on the corrugated sheathing to improve the ductility of the shear wall as well as derive practical response modification factor by establishing correct relationship between ductility factor ? and response modification factor R. Totally 21 monotonic and cyclic full-scale shear wall tests were conducted during the winter break in 2012 by the author in NUCONSTEEL Materials Testing Laboratory in the University of North Texas. The research investigated nineteen 8 ft. × 4 ft. shear walls with 68 mil frames and 27 mil corrugation sheet steel in 11 configurations and two more shear walls sheathed with 6/17-in.OSB and 15/32-in. plywood respectively for comparison. The shear walls, which were in some special cutting arrangement patterns, performed better under lateral load conditions according to the behavior of ductility and shear strength and could be used as lateral system in construction.
Date: May 2013
Creator: Yu, Guowang
Partner: UNT Libraries

An approximate method of shear-lag analysis for beams loaded at right angles to the plane of symmetry of the cross section

Description: Report discussing strain measurements made on a box beam of triangular cross section and on two beams of D-section under transverse bending. Information about the arrangement of the beams and experimental and calculated stresses for different boxes.
Date: September 1943
Creator: Kuhn, Paul & Brilmyer, Harold G.
Partner: UNT Libraries Government Documents Department

Critical shear stress of an infinitely long flat plate with equal elastic restraints against rotation along the parallel edges

Description: Report presenting a chart for the values of the coefficient in the formula for the critical shear stress at which buckling may be expected to occur in an infinitely long flat plate with parallel edges. An approximate method for the evaluation of the critical shear stress when the elastic restraints on the two parallel edges are not equal is also presented.
Date: November 1943
Creator: Stowell, Elbridge Z.
Partner: UNT Libraries Government Documents Department

Ultimate stresses developed by 24S-T and Alclad 75S-T aluminum-alloy sheet in incomplete diagonal tension

Description: "Strength tests were made on 24S-T and Alclad 75S-T aluminum-alloy sheet in diagonal tension. These tests indicated that the ultimate shear stress was essentially independent of the rivet factor if the rivet factor was greater than 0.6, which covers most of the practical range. Curves showing the effect of diagonal tension on the ultimate shear stress in the gross section are presented. These curves supersede those given in NACA TN No. 1364" (p. 1).
Date: November 1948
Creator: Levin, L. Ross
Partner: UNT Libraries Government Documents Department

Spectrums and diffusion in a round turbulent jet

Description: "In a round turbulent jet at room temperature, measurement of the shear correlation coefficient as a function of frequency (through bandpass filters) has given a rather direct verification of Kolmogoroff's local-isotropy hypothesis. One-dimensional power spectrums of velocity and temperature fluctuations, measured in unheated and heated jets, respectively, have been contrasted. Under the same conditions, the two corresponding transverse correlation functions have been measured and compared" (p. 1).
Date: July 1950
Creator: Corrsin, Stanley & Uberoi, Mahinder S.
Partner: UNT Libraries Government Documents Department

Nominal Shear Strength and Seismic Detailing of Cold-formed Steel Shear Walls using Steel Sheet Sheathing

Description: In this research, monotonic and cyclic tests on cold-formed steel shear walls sheathed with steel sheets on one side were conducted to (1) verify the published nominal shear strength for 18-mil and 27-mil steel sheets; and (2) investigate the behavior of 6-ft. wide shear walls with multiple steel sheets. In objective 1: this research confirms the discrepancy existed in the published nominal strength of 27-mil sheets discovered by the previous project and verified the published nominal strength of 18 mil sheet for the wind design in AISI S213. The project also finds disagreement on the nominal strength of 18-mil sheets for seismic design, which is 29.0% higher than the published values. The research investigated 6-ft. wide shear wall with four framing and sheathing configurations. Configuration C, which used detailing, could provide the highest shear strength, compared to Configurations A and B. Meanwhile, the shear strength and stiffness of 2-ft. wide and 4-ft. wide wall can be improved by using the seismic detailing.
Date: August 2010
Creator: Chen, Yujie
Partner: UNT Libraries

A Top to Bottom Lithospheric Study of Africa and Arabia

Description: We study the lithospheric structure of Africa, Arabia and adjacent oceanic regions with fundamental-mode surface waves over a wide period range. Including short period group velocities allows us to examine shallower features than previous studies of the whole continent. In the process, we have developed a crustal thickness map of Africa. Main features include crustal thickness increases under the West African, Congo, and Kalahari cratons. We find crustal thinning under Mesozoic and Cenozoic rifts, including the Benue Trough, Red Sea, and East, Central, and West African rift systems. Crustal shear wave velocities are generally faster in oceanic regions and cratons, and slower in more recent crust and in active and formerly active orogenic regions. Deeper structure, related to the thickness of cratons and modern rifting, is generally consistent with previous work. Under cratons we find thick lithosphere and fast upper mantle velocities, while under rifts we find thinned lithosphere and slower upper mantle velocities. There are no consistent effects in areas classified as hotspots, indicating that there seem to be numerous origins for these features. Finally, it appears that the African Superswell has had a significantly different impact in the north and the south, indicating specifics of the feature (temperature, time of influence, etc.) to be dissimilar between the two regions. Factoring in other information, it is likely that the southern portion has been active in the past, but that shallow activity is currently limited to the northern portion of the superswell.
Date: October 31, 2006
Creator: Pasyanos, M
Partner: UNT Libraries Government Documents Department

The Location of the Maximum Temperature on the Cutting Edges of a Drill

Description: This study analyzes the temperature profile along the cutting edges of a drill and describes how the temperature on the chisel edge can exceed the temperature on the primary cutting edges. A finite element model predicts the temperature distribution in the drill, where the heat flux loads applied to the finite element model are determined from analytical equations. The model for the heat flux loads considers both the heat generated on the shear plane and the heat generated on the rake face of the tool to determine the amount of heat flowing into the tool on each segment of the cutting edges. Contrary to the conventional belief that the maximum temperature occurs near the outer corner of the drill, the model predicts that the maximum temperature occurs on the chisel edge, which is consistent with experimental measurements of the temperature profile.
Date: January 7, 2005
Creator: Bono, M J & Ni, J
Partner: UNT Libraries Government Documents Department

qSF wavefront triplication in a transversely isotropicmaterial

Description: Triplication of a wavefront, also classically known as birefringence, can and does occur in transversely isotropic (TI) media. With the growing interest in shear waves, and in particular, converted shear waves, it becomes necessary to study this phenomenon, and the bright spots that accompany it. In a plane that includes the medium's rotational symmetry axis, there may exist a range of angles within which the qSV wave, whose polarization lies in that plane, may propagate at three distinct velocities. The region of the qSV wave curve where this can occur always corresponds to the region of the qSV slowness curve where the closed qSV curve about the origin is concave. When the range of angles is small and the three arrivals are close together, the usual situation, the qSV wave within that small range will be significantly brighter than in other directions. When the range of angles is large, the two cusps of the wave surface, on the borders of the region of triplication will both be bright spots.
Date: June 1, 2004
Creator: Schoenberg, Michael & Daley, Thomas M.
Partner: UNT Libraries Government Documents Department

Tilt sensitivity of the two-grating interferometer

Description: Fringe formation in the two-grating interferometer is analyzed in the presence of a small parallelism error between the diffraction gratings assumed in the direction of grating shear. Our analysis shows that with partially coherent illumination, fringe contrast in the interference plane is reduced in the presence of nonzero grating tilt with the effect proportional to the grating tilt angle and the grating spatial frequencies. Our analysis also shows that for a given angle between the gratings there is an angle between the final grating and the interference plane that optimizes fringe contrast across the field.
Date: January 30, 2008
Creator: Anderson, Christopher N. & Naulleau, Patrick P.
Partner: UNT Libraries Government Documents Department

Development of a Quantitative Method to Predict Critical Shear Stress and Rate of Erosion of Natural Undisturbed Cohesive Soils

Description: The report describes the results of erosion and soil characterization tests performed on cohesive soils. Appendices to the report include plots of shear stress versus erosion rate for remolded and undisturbed soils.
Date: July 1980
Creator: Arulanandan, Kandiah
Partner: UNT Libraries Government Documents Department

Effect of crystal orientation on fatigue-crack initiation in polycrystalline aluminum alloys

Description: Report presenting testing demonstrating that fatigue cracks initiate in preexisting slip bands on planes parallel to planes from tests on large-grained specimens of 1100 and 5052 aluminum alloys. The resolved shear stress on the planes in crystal where fatigue cracks had developed were compared to uncracked crystals. Results regarding the location fatigue cracks, number of stress cycles observed, and differences of the crystals observed in the two types of aluminum alloys are provided.
Date: August 1957
Creator: Weinberg, J. G. & Bennett, J. A.
Partner: UNT Libraries Government Documents Department

Comparison of an approximate and an exact method of shear-lag analysis

Description: Report presenting comparisons between the approximate substitute single-stringer method of shear-lag analysis and the exact solutions, which indicate that for beams of practical proportions the approximate method yields a value for the maximum root stress that exceeds the value obtained by use of the exact solution by less than 10 percent.
Date: January 1944
Creator: Duberg, John E.
Partner: UNT Libraries Government Documents Department

Shear-lag tests of a box beam with a highly cambered cover in tension

Description: Report discusses the results of bending tests on an open box beam designed to fail on the highly cambered tension side. Results in the elastic range and ultimate-strength test are provided. The stringer stresses near the root were in fair agreement with stresses calculated by shear-lag theory and the ultimate tensile strength developed by the beam was only a little higher than the tensile yield stress of the material.
Date: July 1945
Creator: Peterson, James P.
Partner: UNT Libraries Government Documents Department