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Creep and Relaxation in Metals and Ceramics : A Bibliography, 1950-March 1959

Description: "This is a selected bibliography of books, journal articles and reports published on creep and relaxation in metals and ceramics from 1950 to March 1959. Particular attention has been paid to studies on or applicable to the consideration of creep and relaxation in beryllium oxide. Emphasis has alro been placed on studies of phenomenological materials behavior and high temperature studies."
Date: April 15, 1959
Creator: Maynard, Glenn R. & Lane, Zanier D.
Partner: UNT Libraries Government Documents Department

Mechanism of beneficial effects of boron and zirconium on creep-rupture properties of a complex heat-resistant alloy

Description: Report presenting an investigation of the mechanism by which the addition of boron and zirconium improves the creep-rupture properties of an alloy of 55 percent nickel, 20 percent chromium, 15 percent cobalt, 4 percent molybdenum, 3 percent titanium, and 3 percent aluminum at 1600 degrees Fahrenheit. The creep-rupture properties were improved because the boron and zirconium have a pronounced stabilizing effect on the grain boundaries of the alloy. Results regarding the microstructures in initial condition, changes in microstructure during exposure at 1600 degrees Fahrenheit, interpretation of other microstructural changes, relation of mechanism to published information, causes of effect of boron and zirconium on grain-boundary stability, role of carbon, and generality of results are provided.
Date: August 1958
Creator: Decker, R. F. & Freeman, J. W.
Partner: UNT Libraries Government Documents Department

Creep-Rupture Tests of Beryllium

Description: "A program of creep-rupture tests of several bars of Beryllium has been completed. The tests were made at 1200, 1400, 1550, and 1700 F. in protective atmospheres of tank helium or hydrogen. The results are given in a summary table and by creep and design curves. A description of the test set-up is included."
Date: January 9, 1951
Creator: Manjoine, M. J.
Partner: UNT Libraries Government Documents Department

The Creep of Zirconium in Water

Description: Introduction:"Very little is known about the mechanical properties of zirconium and, in view of this the Atomic Energy Commission requested Sylvania to evaluate the creep characteristics of this metal at various temperatures. Tests at room temperature (25 C) and at 200 C have been completed, the tests having been conducted in air. The data obtained from these tests form the basis of this report. Future tests will be conducted in an atmosphere of water at the desired testing temperature."
Date: 1950
Creator: Brunstetter, D. R. & Alexander, B. H.
Partner: UNT Libraries Government Documents Department

Creep Behavior of Structural Joints of Aircraft Materials Under Constant Loads and Temperatures

Description: "The results of 55 creep and creep-rupture tests on structural joints are presented. Methods are described by which the time to rupture, the mode of rupture, and the deformation of joints in creep may be predicted. These methods utilize creep data on the materials of the joint in tension, bearing, and shear" (p. 1).
Date: January 1957
Creator: Mordfin, Leonard & Legate, Alvin C.
Partner: UNT Libraries Government Documents Department

A variational theorem for creep with applications to plates and columns

Description: A variational theorem is presented for a body undergoing creep. Solutions to problems of the creep behavior of plates, columns, beams, and shells can be obtained by means of the direct methods of the calculus of variations in conjunction with the stated theorem. The application of the theorem is illustrated for plates and columns by the solution of two sample problems.
Date: March 5, 1957
Creator: Sanders, J. Lyell, Jr.; McComb, Harvey G., Jr. & Schlechte, Floyd R.
Partner: UNT Libraries Government Documents Department

A variational theorem for creep with applications to plates and columns

Description: From Summary: "A variational theorem is presented for a body undergoing creep. Solutions to problems of creep bending and creep collapse of plates, columns, beams, and shells can be obtained by means of the direct methods of the calculus of variations in conjunction with the stated theorem. The application of the theorem is illustrated for plates and columns by the solution of two sample problems."
Date: May 1957
Creator: Sanders, J. Lyell, Jr.; McComb, Harvey G., Jr. & Schlechte, Floyd R.
Partner: UNT Libraries Government Documents Department

A summary of NACA research on the strength and creep of aircraft structures at elevated temperatures

Description: Report summarizing research on the strength and creep of aircraft structural elements and components at elevated temperatures. Experimental data for aluminum alloy columns, plates, stiffened panels, and multiweb box beams are presented for temperatures up to 600 degrees Fahrenheit and compared with results predicted from materials data.
Date: May 31, 1956
Creator: Heldenfels, Richard R. & Mathauser, Eldon E.
Partner: UNT Libraries Government Documents Department

Recent research on the creep of airframe components

Description: Report presenting the results of research on the creep of airframe components at elevated temperatures. Experimental lifetime data from creep tests of stainless-steel plates and aluminum-alloy unstiffened circular cylinders are presented and compared with results predicted from isochronous stress-strain curves.
Date: July 1957
Creator: Mathauser, Eldon E.; Berkovits, Avraham & Stein, Bland A.
Partner: UNT Libraries Government Documents Department

Creep buckling of columns

Description: Report presenting formulas for the determination of the creep deflection-time characteristics of an initially curved idealized H-section column. The results were obtained from closed-form solutions of the differential equation of bending of a beam column with creep properties of a nonlinearly viscoelastic nature. Critical time is tabulated and plotted for a wide range of parameters involved.
Date: January 1954
Creator: Kempner, Joseph & Patel, Sharad A.
Partner: UNT Libraries Government Documents Department

Analysis of the Creep Behavior of a Square Plate Loaded in Edge Compression

Description: From Introduction: "In reference 1 results of creep tests and empirical method for predicting collapse times are presented for plates loaded in compression on two opposite edges and with the remaining edges unloaded and supported in V-groove fixtures. Other approximate methods for handling plates having types of edge support are suggested in reference 2; however, experimental verification for these methods is quite limited. In reference 3 an analysis based on small-deflection theory is made of the creep deflection of a simply supported plate composed of a linear viscoelastic material - that is, a material in which the stress and strain and their appropriate time derivatives are related in a linear fashion."
Date: September 1958
Creator: McComb, Harvey G., Jr.
Partner: UNT Libraries Government Documents Department

Creep Bending and Buckling of Linearly Viscoelastic Columns

Description: Note presenting the general dynamic equation of creep bending of a beam loaded laterally and axially as derived for a linearly viscoelastic material whose mechanical properties can be characterized by four parameters. The equation derived was used to obtain the creep bending deflection of a beam in pure bending and of a column with initial sinusoidal deviation from straightness.
Date: January 1954
Creator: Kempner, Joseph
Partner: UNT Libraries Government Documents Department

Interaction of Bearing and Tensile Loads on Creep Properties of Joints

Description: The interaction of bearing and tensile loads on the creep behavior of joints was studied. A specimen was designed for this study which possessed some of the general features of pin and rivet joint connections and an apparatus was constructed to apply both bearing and tensile loads to the joint model. Deformation measurements were made by use of a photogrid printed on the joint model.
Date: October 1956
Creator: Bodine, E. G.; Carlson, R. L. & Manning, G. K.
Partner: UNT Libraries Government Documents Department

Effects of Environment on the Low-Cycle Fatigue Behavior of Type 304 Stainless Steel

Description: The low-cycle fatigue behavior of Type 304 stainless steel has been investigated at 593 degrees C in a dynamic vacuum of better than 1.3 x 10⁻⁶ Pa (10⁻⁸ torr). The results concerning the effects of strain range, strain rate and tensile hold time on fatigue life are presented and compared with results of similar tests performed in air and sodium environments. Under continuous symmetrical cycling, fatigue life is significantly longer in vacuum than in air; in the low strain range regime, the effect of sodium on fatigue life appears to be similar to that of vacuum. Strain rate (or frequency) strongly influences fatigue life in both air and vacuum. In compressive hold-time tests, the effect of environment on life is similar to that in a continuous-cycling test. However, tensile hold times are nearly as damaging in vacuum as in air. Thus, at least for austenitic stainless steels, the influence of the environment of fatigue life appears to depend on the loading waveshape.
Date: December 1979
Creator: Argonne National Laboratory. Materials Science Division.
Partner: UNT Libraries Government Documents Department

Mechanics and Mechanisms of Creep and Ductile Fracture

Description: The main aim of this dissertation is to relate measurable and hopefully controllable features of a material's microstructure to its observed failure modes to provide a basis for designing better materials. The understanding of creep in materials used at high temperatures is of prime engineering importance. Single crystal Ni-based superalloys used in turbine aerofoils of jet engines are exposed to long dwell times at very high temperatures. In contrast to current theories, creep tests on Ni-based superalloy specimens have shown size dependent creep response termed as the thickness debit effect. To investigate the mechanism of the thickness debit effect, isothermal creep tests were performed on uncoated Ni-based single crystal superalloy sheet specimens with two thicknesses and under two test conditions: a low temperature high stress condition and a high temperature low stress condition. At the high temperature, surface oxidation induced microstructural changes near the free surface forming a layered microstructure. Finite element calculations showed that this layered microstructure gave rise to local changes in the stress state. The specimens also contained nonuniform distribution of initial voids formed during the solidification and homogenization processes. The experiments showed that porosity evolution could play a significant role in the thickness debit effect. This motivated a basic mechanics study of porosity evolution in single crystals subjected to creep for a range of stress states. The study was performed using three-dimensional finite deformation finite element analysis of unit cells containing a single initially spherical void in a single crystal matrix. The materials are characterized by a rate-dependent crystal plasticity constitutive relation accounting for both primary and secondary creep. The effect of initial void spacing and creep exponent was also explored. Based on the experimental observations and results of finite element calculations a quantitative mechanistic model is proposed that can account for both bulk and surface ...
Date: August 2013
Creator: Srivastava, Ankit
Partner: UNT Libraries

Effect of overheating on creep-rupture properties of M-252 alloy

Description: Report presenting a study on the influence of periodic overheats of 2-minutes duration to four different temperatures on the creep-rupture properties of M-252 alloy at 1500 degrees Fahrenheit. The purpose of the study was to provide information regarding the estimation of the effects of overheating on creep-rupture performance of gas-turbine parts. Results regarding normal rupture properties of experimental materials, overheats on heat HT-28, overheats on heats 837 and 43642, comparative effects of overheating on S-816, HS-31, and M-252 alloys, mechanism of damage from overheating, interpretation of results in terms of overheating in a turbine, and some limitations of results are provided.
Date: March 1958
Creator: Rowe, John P. & Freeman, J. W.
Partner: UNT Libraries Government Documents Department

Effect of overheating on creep-rupture properties of S-816 alloy at 1,500 degrees F

Description: The effects of overheats to temperatures of 1650, 1800, 1900, and 2000 F were evaluated in terms of the changes in creep-rupture characteristics at 1500 F of S-816 alloy under stresses within the range of rupture strengths of the alloy for 100 to 1000 hours. Overheat periods were predominantly of 2-minute duration and were applied cyclically at approximately 5- or 12-hour intervals. The possible damage from overheating was believed to include internal metal structure changes induced by exposure to the higher temperatures and loss of life by creep if stress was present during the overheats.
Date: December 1957
Creator: Rowe, John P. & Freeman, J. W.
Partner: UNT Libraries Government Documents Department

High-Temperatuer Creep Evaluation in Carbon Dioxide Atmosphere : Summary Report, October 1, 1959 to March 31, 1961

Description: This report follows an investigation made to determine creep-rupture data for three sheet materials. Fourteen of sixteen tests were made in an atmosphere of carbon dioxide within hermetically sealed capsules, analyzing the reaction of the three sheet metals: 347 stainless steel, iron-aluminum-chromium alloy designated 261C, and a zirconium-base alloy, AE1H. Minimum creep rate, per cent elongation, and rupture life were determined and reported.
Date: March 31, 1961
Creator: Domagala, R. F.
Partner: UNT Libraries Government Documents Department

The Mechanical Properties of Beta-Quenched Uranium at Elevated Temperatures

Description: The creep strength and tensile properties-were determined in vacuum for beta-quenched, derby uranium. The stresses to produce a secondary creep rate of- 0.0001 per cent per hr at 100, 250, 400, and 500 deg C were 48,000, sile strengths were 114,500, 35,100, 11,100, and 8,500 psi at temperatares of 28, 300, 500, and 700 deg C, respectively. The creep and tensile strengths decrease quite rapidly with increasing temperature in the temperatare range 250 to 400 deg C.
Date: September 6, 1955
Creator: Shober, Frederic R.; Marsh, Lyle L. & Manning, G. K.
Partner: UNT Libraries Government Documents Department

A linear time-temperature relation for extrapolation of creep and stress-rupture data

Description: Report presenting a time-temperature parameter based on examination of the published stress-rupture data for a variety of materials, rather than on physical theory, is presented in equation form. An examination of published data on 40 materials representing ferritic and sustenitic steels, high-temperature alloys, and aluminum alloys is used to create conclusions.
Date: March 1953
Creator: Manson, S. S. & Haferd, A. M.
Partner: UNT Libraries Government Documents Department

Creep Deformation Patterns of Joints Under Bearing and Tensile Loads

Description: Note presenting an investigation to study the interaction of bearing and tensile loads on the creep behavior of joints. A simplified model was employed which contained many of the features found in riveted connections. Results regarding creep-rupture tests, plate subjected to tension, plate subjected to bearing loads, plate subjected to tensile and bearing loads, and index of joint behavior are provided.
Date: December 1957
Creator: Bodine, E. G.; Carlson, R. L. & Manning, G. K.
Partner: UNT Libraries Government Documents Department

Creep and Creep-Rupture Characteristics of Some Riveted and Spot-Welded Lap Joints of Aircraft Materials

Description: Note presenting a description of equipment and test technique used in the creep testing of lap joints. Riveted aluminum-alloy joints fabricated from 75S-T6 and 24S-T3 sheet with 24S and 24S-T31 rivets were tested at 300, 400, and 500 degrees Fahrenheit. The test results showed that the creep of the riveted joints is considerably greater than the creep of the unriveted sheet although not so large that the creep of the sheet is negligible compared with that of the joints.
Date: June 1955
Creator: Mordfin, Leonard
Partner: UNT Libraries Government Documents Department

Creep Strength of Stabilized Wrought-Aluminum Alloys

Description: Rohn-type equipment has been mounted on rubber blocks, for the purpose of damping the vibrations of the ground and of rendering the plastic yielding of the test bars less subject to outside interferences. New equipment also included three shockproof creep-testing machines with the Martens mirror instruments for recording the strain curve of the fatigue-tested specimens.
Date: November 1940
Creator: Müller, W.
Partner: UNT Libraries Government Documents Department