bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer-Controlled Stress Intensity Gradient Technique for High Rate Fatigue Crack Growth Testing
Authors: Donald JK , Schmidt DW 
Published: February 2009

Abstract
An automated test system utilizing a computer for data acquisition and machine control was used to obtain crack growth rate data from 2.5 × 10−8 to 2.5 × 10−6 m/cycle (1 × 10−6 to 1 × 10−4 in./cycle) on a compact type specimen. The crack length was monitored continuously by using the elastic compliance technique, enabling the stress intensity K to be increased according to the equation ΔK = ΔK exp [C(a − a0)] (where a0 and a are the initial and instantaneous crack lengths and C is a test variable). Crack growth data were obtained on a Ni-Cr-Mo-V rotor steel by using both different, programmed K gradients and the more conventional constant-load-amplitude method where the stress intensity increases as a function of increasing crack length. Excellent agreement was observed between the two test procedures.
A Compact Specimen for Plane Strain Crack Arrest Toughness Testing
Authors: Crosley PB , Ripling EJ 
Published: February 2009

Abstract
A test method is described for measuring plane strain crack arrest toughness KIa with a compact shaped specimen. The method has a number of advantages over those previously used. Rather than a fatigue crack for initiation, a machine-notched, brittle weld is used, which reduces testing costs. A very stiff loading system consisting of a wedge and bushing assembly allows for much higher ratios of initiation to arrest toughness than those allowed with pin-loaded double-cantilever specimens. The use of large initiation values is expected to allow for larger KIa measurements with modest-sized specimens.
Long-Time Creep-Rupture Tests of Aluminum Alloys
Authors: Leslie WC , Jones JW , Voorhees HR 
Published: February 2009

Abstract
Creep-rupture characteristics of aluminum alloys 1100-0, 1100-H14, 5454-0, 5454-H34, and 6061-T651 were determined in the temperature range 93 to 731°C in tests of up to 64 000 h duration. The steady-state creep rates of 1100-0 and 5454-0 alloys are described precisely by a simple power relation that could not be applied to 1100-H14, 5454-H34, and 6061-T651 alloys because their microstructures changed at elevated temperatures. The Larson-Miller extrapolation technique yielded accurate predictions of the long-term rupture strength of 1100-0 and 5454-0 alloys but was not well suited for predicting the long-term rupture strength of aluminum alloys whose microstructures changed during testing. The rupture strength of notched specimens was always greater than that of similar smooth specimens at the same nominal stress.
An Evaluation of the Effect of Low Temperatures on Mechanical Properties of a Commercial Steel to be Used in the Arctic
Authors: Krishnadev MR , Ghosh R , Cutler LR , Prince JR , Gauvin P 
Published: February 2009

Abstract
The effect of low temperatures on the mechanical behavior of a commercial low-alloy high-strength age-hardenable steel, IN-787, has been evaluated. The results indicate that the steel has remarkably good properties (yield strength, ultimate tensile strength, ductility, notch sensitivity ratio, and high cycle fatigue) in low-temperature environments. The steel retains its good mechanical characteristics even in the aged condition although there is an increase in the yield strength. It has been suggested that it would be useful to include the effect of low temperatures (at least the lowest service temperature) on the mechanical properties of materials in the codes and standards used for selecting steels for use in the Arctic.
Development and Correlation of a Variable-Speed Friction Tester
Authors: Whitfield JK , Mullen WG 
Published: February 2009

Abstract
The need for a laboratory variable-speed friction tester was recognized several years ago when emphasis was placed on laboratory test procedures to predict pavement skid resistance in the field. A tester was needed that could provide speed gradients on small samples or speed gradients that are comparable to those obtained by using the locked wheel skid trailer. The variable-speed friction tester measures pavement or pavement sample friction at various speeds and simulates the capability of the ASTM locked wheel skid trailer with which an excellent field correlation has been obtained. The variable-speed friction tester is reasonably portable and may be used to measure friction values on ramps, curves, city streets, and short bridges where towed-type testers usually cannot be used.
Comparisons of Fracture Toughness Measurements by the Short Rod and ASTM Standard Method of Test for Plane-Strain Fracture Toughness of Metallic Materials (E 399-78)
Authors: Barker LM , Baratta FI 
Published: February 2009

Abstract
A multilaboratory blind comparison testing program evaluated the accuracy of the short rod method of measuring the fracture toughness of metallic materials. Valid comparisons between values measured according to ASTM Standard Method of Test for Plane-Strain Fracture Toughness of Metallic Materials (E 399-78) and values of the plane-strain critical stress intensity factor as measured by the short rod method of fracture toughness measurement (KIcSR) were obtained for several steels, aluminum alloys, and titanium. The KIcSR values measured by the short rod method were consistently low, averaging 6% below the measurements according to ASTM Standard Method E 399. A 4% adjustment in the short rod calibration constant that had been previously evaluated only to ±7% brings the two sets of measurements into very good agreement. The short rod method thus appears to be a viable alternative for measuring the fracture toughness of metallic materials.
Effect of Clamping Pressure on the Fatigue Strength of Dimpled and Undimpled Loaded Holes
Authors: Lohse AK , Shewchuk J 
Published: February 2009

Abstract
The process of dimpling is applied to improve loaded-hole fatigue strength in the presence of surface fretting such as is found in riveted joints. Dimpling introduces residual compressive surface stress into the region of fretting. It is proposed that this compressive stress delays the formation of crack-site pits and reduces the subsequent crack growth rate. An experimental program was carried out to investigate the comparative behavior of dimpled and undimpled loaded-hole connections in the presence of surface fretting. Specimens of 2024-T3 aluminum alloy were loaded as simulated riveted connections at two values of nominal clamping or fretting (rivet-head bearing) pressure. Experimental results indicate that while clamping pressure influences undimpled fatigue strength, it does not significantly affect dimpled fatigue strength. At the higher clamping pressure, the ratio of undimpled to dimpled fatigue strength is 0.95 at 106 cycles to failure. However, at the lower pressure, and at the same life, the ratio drops to 0.77.
Evaluation of theJIc Testing Procedure by Round Robin Tests on A533B Class 1 Pressure Vessel Steel
Authors: Clarke GA 
Published: February 2009

AbstractA round robin test program on the determination of JIc values of ductile materials was conducted by twelve different laboratories, representing five countries. The testing program was conducted under the auspices of the Elastic-Plastic Fracture subcommittee, E24.08, of ASTM Committee E24 on Fracture Testing of Materials. Each laboratory tested one blunt notched and five precracked compact specimens. The results showed very little scatter on JIc values when valid tests are performed. Both single specimen tests and multispecimen tests show excellent agreement.Side grooved specimens were also tested to determine what possible differences exist between side grooved specimens and specimens not side grooved specimens. While the slope of the crack growth resistance (R) lines were different for the two geometries, the JIc values were essentially the same.
Error Analysis of Intrinsic Viscosity Measurements
Authors: Ashar B , Turcotte LR 
Published: February 2009

Abstract
The intrinsic viscosity of polymer solutions is widely used for characterizing the molecular sizes of polymers. The experimental procedure is very involved, and therefore a variety of precautions needs to be observed to eliminate errors. In this paper, a hypothetical case is discussed to demonstrate that the analysis of data can detect the absence or presence of different kinds of errors in the experimental measurements. It is shown that a systematic or constant error in the concentration measurement is the only error that is not reflected anywhere in the analysis and still leads to inaccurate results. Therefore, it is very important to eliminate this error through the automation of instruments.
The Shear Strain to Fracture Characteristics of a Titanium Alloy and an Ultrahigh Molecular Weight Polyethylene Under Complex Loading Conditions
Authors: Grieve RJ , Lawrence R 
Published: February 2009

Abstract
Thin-walled tubular specimens of titanium alloy and an ultrahigh molecular weight polyethylene are twisted at various strain rates up to approximately 100/s with the simultaneous application of an axial tensile load or compressive load. The strain to fracture of the titanium alloy, that is, the point of instability, is calculated and shown to decrease with an increase in the strain rate. It is also shown to decrease with increasing tensile load and increase with increasing compressive load at all the strain rates. The polyethylene also shows a decrease in strain to fracture with an increase in the strain rate but appears to be independent of axial load.
Studies of Impurity Distribution in Electrolytically Refined Copper Cathodes
Authors: Publicover WE , Taubenblat PW 
Published: February 2009

Abstract
Two studies of impurity distribution within electrolytically refined cathodes show broad disparities in the distribution of impurities within one cathode, between one cathode and another, and between cathodes of differing surface (nodulation) characteristics. The findings bring into question the reliability of results based on sampling discrete locations on cathodes.
The Interactions of Stabilized Scrubber Sludge and Fly Ash with the Marine Environment
Authors: Roethel FJ , Duedall IW , O'Connors HB , Parker JH , Woodhead PMJ 
Published: February 2009

Abstract
Scrubber filter cake (sludge) and fly ash have been stabilized into blocks. These blocks have been submerged in an estuarine environment on the north shore of Long Island, N.Y. for nearly two years and have maintained their structural integrity. The blocks were colonized by a diverse aquatic community of marine plants and animals. The uptake of trace metals from the coal waste blocks by the marine organisms was not greater than that found on concrete reference blocks placed nearby. The initial colonization of the coal waste blocks proceeded somewhat differently at first when compared to the concrete blocks; however, by the end of the first year of submersion both materials supported an almost identical community. Little or no physical abrasion or erosion was observed but biological erosion by the boring clam Barnea truncata was observed to occur. The results indicate that ocean disposal of stabilized scrubber filter cake and fly ash in block form appears to be compatible with the marine environment.
Potential for Utilization of Solid Wastes from Sulfur Oxide Control Processes
Authors: Peterson CH 
Published: February 2009

Abstract
Studies at our laboratory in the last several years in fossil fuel conversion processes have included work on coal gasification, oil gasification, and fluidized bed combustion. A common aspect of these high temperature processes is the production of potentially large quantities of spent limestone or dolomite. This brief presentation describes the logic of the experimental program and presents results of initial bench-scale tests. It was shown that fluidized bed combustion residues could be processed into 5-cm cubes with compressive strengths to 13.8 MPa (2000 psi). Such residues appear to have potential for use in some sectors of the construction industry.
Utilization of Fluidized Bed Combustion Wastes
Authors: Collins RJ 
Published: February 2009

Abstract
Atmospheric fluidized bed (AFB) combustion appears to be a promising means for producing energy from high sulfur coal in an environmentally acceptable manner. The process involves burning crushed coal in a bed of limestone or dolomite that has been fluidized by jets of hot air. The resultant by-products are a dry, sand-size spent bed residue and a relatively high carbon fly ash. This discussion focuses on possible uses for this material, the spent bed residue. The paper is a progress report for a research program sponsored by the U.S. Department of Energy to evaluate potential commercial applications for fluidized bed combustion wastes. Included in the paper are laboratory data related to seven separate residue sources; a discussion of promising approaches to beneficiation; and supporting data on several potential applications involving the use of the relatively high calcium content of the material as a lime substitute or in the form of a cementitious structural product. Specific applications include stabilized road base compositions, masonry block, artificial reefs, partial replacement for portland cement, synthetic aggregate, flue gas desulfurization, neutralization of acid mine drainage, and treatment of industrial trade wastes. Also briefly discussed are efforts to evaluate the environmental impact of AFB waste disposal.
Sludge to Fertile Soil—Research Results
Authors: Briggs RW , Freas RC 
Published: February 2009

Abstract
This paper reports on work done by Dravo Lime Co. in the Dravo Corporation Research Facilities with the cooperation of the U.S. Environmental Protection Agency, Project R803999-01-0. The primary purpose of this study has been to combine flue gas desulfurization (FGD) sludges with municipal waste to produce fertile soils. A second objective has been to stabilize and combine coal fine refuse with municipal waste to identify potential stabilization and revegetation techniques. Testing on the FGD municipal waste mixtures has included seedings both under greenhouse conditions and in outdoor test plots. Coal fine refuse-municipal waste sludge mixtures have also been successfully stabilized and have been successfully seeded and tested under greenhouse conditions. Plant varieties that have been growth in these combined waste products include corn, soybeans, oats, ryegrass, and crown vetch.
Computer Data Acquisition Monitoring of the Stress Corrosion Cracking of Depleted Uranium Cantilever Beam Specimens
Authors: Joyce JA , Hasson DF , Crowe CR 
Published: February 2009

AbstractThe objective of this work was to develop and demonstrate a computer data acquisition system to monitor the stress corrosion cracking of laboratory cantilever specimens. Present methods using optical techniques require long time periods to establish the crack growth rate when low crack growth rates are present. These methods also give very limited data and do not show clearly the dependence of the crack growth rate on stress and atmospheric variables. These methods also are incapable of resolving irregularities in the crack growth rate that would exist if oxide-forming and cracking mechanisms were applicable in the material test atmosphere system. The major conclusion of this work is that a computer data acquisition system can be used to evaluate low crack growth rates in relatively short time periods as well as to evaluate the magnitude of variations in crack growth rate about a mean value. Other advantages are that the specimen can be completely enclosed to better control the test atmosphere, other variables like temperature and corrosion potentials can be easily monitored, and a permanent magnetic tape record can be produced for later reanalysis.
The Influence of Some Variables on Extraction Results of Wool Top
Authors: Larsen SA , Kumar R 
Published: February 2009

Abstract
Analyses of test results from interlaboratory tests on extractable matter in wool are reported. A total of ten laboratories were involved in the test that aimed at ascertaining the effect of specimen size, solvent temperature, length of extraction time, and specimen moisture content on the amount of extractable matter. Multiple dependent variable regression analysis of the results using the percentage of extractable matter as a dependent variable showed this to be inversely related (P &lt; 0.01) to specimen size. Extraction time appeared to have some influence, although the relationship was not significant (P &gt; 0.05). It is concluded that the extraction method needs to be revised to specify specimen size.
A Simple Test Method for the Evaluation of Tearing Modulus
Authors: Takahashi H , Khan MA , Suzuki M 
Published: February 2009

AbstractMaterial characterization studies using the multi-specimen J resistance curve procedure have been carried out for a variety of alloy steels. These results along with the data from the literature have been used to demonstrate that the J resistance curves can be normalized to a single R curve. It is shown that J-controlled crack growth is reasonably unvarying with the size of the specimen provided the minimum size requirements to insure a J-based dominance of the crack tip region are satisfied. A relatively simple procedure is proposed to permit an assessment of a critical value of the J integral, the slope of the J integral resistance curve, and the tearing modulus from a single specimen.
A Comparative Study of the Effect of Low Temperature on the Fracture Toughness and Cyclic Properties of Two Candidate High-Strength Low-Alloy Steels for Arctic Pipeline Applications
Authors: Krishnadev MR , Cutler LR , Galibois A 
Published: February 2009

Abstract
Because of the need for a better understanding of the effect of Arctic low temperature environments on the mechanical behavior of high-strength low-alloy (HSLA) steels, a comparative study has been undertaken to evaluate the effect of low temperature on the mechanical properties of two candidate steels, columbium-molybdenum “acicular ferrite” HSLA steel and high-columbium HSLA steel. The paper presents the data relating to the effect of low temperature on the mechanical properties, namely, dynamic fracture toughness KId properties, through instrumented impact testing of precracked Charpy V-notch samples and cyclic properties of the two steels. It also discusses the results in terms of their significance to material specification, selection, and performance criteria for safe and economical transportation of petroleum resources from the Canadian Arctic.
On the Relationship Between Stretch Zone Formation and theJIntegral for High Strain-Hardening Materials
Authors: Mills WJ 
Published: February 2009

AbstractThe relationship between stretch zone formation, associated with crack tip blunting, and the J integral was evaluated for materials with high strain-hardening capabilities: Incoloy® 800, Inconel® 600, SA-387 Grade C steel, Type 304 stainless steel, and Alloy A-286. A conventional blunting line commonly used in the construction of a J integral crack growth resistance curve accurately describes stretch zone formation in intermediate and high strength alloys. For low-strength, high strain-hardening materials, however, this conventional blunting line overestimates apparent crack extension associated with stretch zone formation, and it results in an overestimation of ductile fracture toughness values. An alternative blunting line that better describes stretch zone formation in this class of materials is proposed.
Life Testing of Enclosed Heating Elements
Authors: Starr CD 
Published: February 2009

Abstract
Life tests of 80Ni-20Cr, 70Ni-30Cr, and 35Ni-30Cr-35Fe alloys were conducted in enclosed elements. The life to burnout in accelerated tests at double the rate power, 500 W, gave a life of about 500 h, while tests at rated power, 250 W, were stopped after 20,000 h.
The hot and cold resistance of the magnesium oxide changed during the test but the changes were independent of the type of alloy in the heater. The hot and cold resistance change of the heater wire was larger in the accelerated tests than in tests conducted at rated power. This was the result of a larger loss in chromium from the alloys during the accelerated test. The silicon loss during testing was small but was larger for the rated test than for the accelerated test.
Calculations from electrical data and metallographic examination for both accelerated and rated tests disclose the loss in cross-sectional area of the wire due to oxidation was between 2 and 8%. This very minor change is consistent with previous investigations. The mechanism of change of the heater wire is not similar in the accelerated and rated test. Thus, service life cannot be estimated from accelerated life test data.
A New Method of Detecting Fatigue Crack Propagation in Ferromagnetic Specimens
Authors: Bhattacharya S , Schröder K 
Published: February 2009

Abstract
This paper describes a new method for detecting fatigue crack growth in ferromagnetic specimens. This method is similar to the Barkhausen effect type of measurement, where discontinuous voltage pulses are induced in a pickup coil surrounding a specimen when the specimen is magnetized slowly. As a fatigue crack grows, similar voltage pulses are generated. Simultaneous display of the Barkhausen-type magnetic signals and the acoustic emission signals during fatigue crack propagation show that they are correlated.
Failure Load Criteria for Two Collinear Cracks in a Finite Width Strip
Authors: McLellan DL , Goranson UG 
Published: February 2009

Abstract
The failure load characteristics of finite width strips containing eccentrically located collinear cracks have been determined for a variety of crack combinations. In addition to single cracks, the three cases of two edge cracks of unequal lengths, one edge crack with one internal crack, and two internal cracks have been investigated and analyzed. Combined with the confirmed behaviors for the center crack, the single edge crack, and the symmetrical double edge crack, criteria have been developed to characterize the failure loads for each case. Two internal cracks are described by an elliptical failure load surface with limits of single eccentrically located cracks. The elliptical failure load surface also applies to the case of one edge crack with one internal crack. Two edge cracks demonstrate behaviors which are described by a hyperbolic failure load surface, and are limited by the single edge crack condition. The axis of symmetry for this type of surface is the symmetrical double edge crack behavior.
An Extensometer for Circumferential Strains
Authors: Findley WN , Reed RM 
Published: February 2009

Abstract
An instrument is described for measuring circumferential strains in plastic specimens of circular cross section. It consists of four direct-current differential transformers (DCDTs) suitably mounted on an invar ring. The DCDTs probe the position of the surface of the specimen at opposite ends of two mutually perpendicular diameters. Examples of performance are given for creep of a thin-walled tube of polyurethane.
Tricalcium Silicate Hydration in the Presence of Various Salts
Authors: Kantro DL 
Published: February 2009

Abstract
The hydration of tricalcium silicate (C3S) in the presence of various salts has been investigated by means of conduction calorimetry. The salts used have been classified into four groups on the basis of their reactions with C3S. The temperature dependence of hydration has been examined for C3S by itself and in the presence of four salts. The apparent activation energy varies with extent of hydration, decreasing initially to a nearly constant value, and falling off again as diffusion control sets in.