bluuebunny/crossref_metadata_2025 huggingface dataset:
Strain Measurement Techniques for Fiber Modulus Determination
Authors: Moore RL , Lepper JK
Published: February 2009

Two techniques were employed to measure the tensile strain of Kevlar-49® organic fiber in an epoxy matrix. One, a direct averaging strain method, uses two linearly variable differential transformers whose hollow cores are supported by glass beads bonded to the fiber strand specimens. The other method is an indirect method using specimens of several gage lengths. The crosshead displacement for selected loads was determined for each gage length and the data were fit to a straight line by a least squares method and the unit strain calculated for each load.

The tensile modulus of the Kevlar-49® fiber strands was determined to be 20 × 106 psi (138 × 106 kPa). The variation of the averages between methods and within methods between specimens was less than five percent.
Heat Transmission in Cellulosic Fiber Insulation Materials
Authors: Tye RP
Published: February 2009

Measurements of heat transmission in a number of different loose fill cellulosic insulations have been made by heat flow meter and guarded hot plate methods. Effect of temperature and density have been studied together with a limited investigation on moisture effects. Variations of up to 18 percent occur in the same nominal materials from different sources. This fact indicates that the raw materials and their processing can have a significant influence on the heat transmission properties.

For the optimum density range of 35 to 40 kg/m3 and above, the different materials have a very similar temperature coefficient of thermal conductivity. Lower density materials have a significant radiation contribution to their total heat transmission characteristics.
New Reference Radiographs for Magnesium Alloy Castings
Authors: Lagowski B
Published: February 2009

With the introduction and increased use of magnesium alloys containing zirconium, rare earth metals, and thorium, predominantly in castings for aircraft and spacecraft applications, it became evident that the existing reference radiographs included in ASTM E 155-64 would require updating to include radiographs for discontinuity types peculiar to these alloys. AFS Committee 2-D was assigned to undertake this project in cooperation with ASTM Section E07.02.02, which was reactivated for that purpose.

Attempts to collect a suitable range of samples for specific reference radiographs from rejected production castings were unsuccessful, and it became obvious that these samples would have to be produced artificially. The metallurgical structure and characteristics of various discontinuities and their radiographic appearance are described. The discontinuity types examined were the following: graded series—(1) eutectic segregation—microshrinkage type, (2) gravity segregation—Zr, Mn, and (3) reacted sand inclusions; and single examples, for identification purposes only—(1) eutectic segregation—hot-tear type, (2) eutectic segregation—pipe-shrink type, and (3) flow line—eutectic depletion.
A Note on Selecting the Better Material in a Paired Comparison Test Program
Authors: Little RE
Published: February 2009

This note deals with the problem of selecting the better material using a sequential paired comparison test program for the case where individual comparisons are qualitative rather than quantitative (namely, where the test outcome for each paired comparison is stated in terms of a preference for A versus B, or vice versa). A simple K series test method strategy is suggested for the selection procedure, and a table is given for the probability that the better material is indeed selected using this strategy. The application of the probability table to the selection of the better material for the cases of nonsequential qualitative paired comparisons and quantitative paired comparisons is also discussed.
Effect of Hydrogen on Iron-Nickel-Cobalt Sealing Alloys
Authors: Thompson AW , Posey WN
Published: February 2009

Two commercial sealing alloys (Kovar® and Ceramvar® were tested in high pressure hydrogen, or after exposure to hydrogen gas for up to 17,500 h. All hydrogen pressures were 69 MPa. In no case was any ductility loss observed. It was therefore concluded that these alloys are probably safe for use in gas handling systems which contain hydrogen.
Fatigue of Nickel-Plated Copper
Authors: McKinnon EA , Sandor BI
Published: February 2009

The fatigue life of nickel-plated copper depends upon the thickness of the nickel coating. Increases in life from 150 to 450 percent were obtained by increasing the thickness of the nickel from 0.0001 to 0.00025 in. (0.00254 to 0.00635 mm). A further increase in thickness to 0.005 in. (0.0127 mm) resulted in an increase in life of 200 percent. Interrupting the current during electroplating produces interfaces within the coating and increases the fatigue life for a given thickness. Increases in life of 110 percent were obtained by applying a 0.0005-in. thick coating in five layers, rather than in a single layer.
Strain Fatigue and Tensile Behavior of Inconel® 718 from Room Temperature to 650°C
Authors: Brinkman CR , Korth GE
Published: February 2009

Results of tensile and fully reversed strain-controlled fatigue tests, conducted on three heats of Incone® 718 that had been subjected to different solution annealing and aging treatments, are presented. Tests were conducted at temperatures ranging from 22 to 650°C, with fatigue tests defining behavior over the cyclic range from 102 to 106 cycles to failure. Average best fit equations defining true stress-strain, strain-controlled fatigue, and cyclic stress-strain behavior are given for the two heat treatments characterized. Heat-to-heat variations in the elevated temperature tensile and fatigue behavior were found. Fatigue lifetime was seen to be dependent upon grain size, particularly at lower strain ranges.
A Study of Cement and Concrete Correlation
Authors: Weaver WS , Isabelle HL , Williamson F
Published: February 2009

American specifications for portland cement require the crushing of mortar cubes for compressive strength of cement and the breaking of cylinder specimens for compressive strength of concrete. It has been assumed that there is a reasonable correlation of mortar and concrete strengths. This has been questioned. A preliminary study of sixty samples showed a significant correlation but indicated a very low order of confidence. A more extensive research was undertaken, which is reported in this paper.

This research involved 42 job cement samples and twelve repetitions of a monitor cement. Each of the cements in mortar was subjected to the standard 3, 7, and 28-day strength tests, a repeat of the 28-day test, and two accelerated strength tests. The corresponding cements were tested in cylinders of ready-mixed concrete, sampled at both the batching plant and at the job site. Test specimens of these concretes were broken at seven days and at 28 days. Concrete from the job site was also tested after autogenous curing for two days. The same cements were used in two additional concrete batches at the research laboratory, the first using job mix proportions and the second using a standard formulation. Both batches for each cement used job sand and gravel. These latter concretes were tested after standard curing for 7 and 28 days, and other cylinders after accelerated curing under two different sets of conditions.

Much information was obtained concerning the cements, the five mortar tests, the five concrete tests, and their many relationships—mortar/mortar, concrete/concrete, and mortar/concrete. Results were subjected to recognized statistical analysis. The paper includes 25 tables of data, 13 tables of processed information, and 18 figures.

An evaluation of the testing laboratories indicated an acceptable level of competency; an analysis of the cement and concrete variations showed normal good levels of operation. These two factors provided limitations but also gave validity to the conclusions that have been drawn from the research.
The Influence of Interstitial Content on the Ductile-Brittle Transition Temperature of Fe-25Cr Ferritic Stainless Steels
Authors: Plumtree A , Gullberg R
Published: February 2009

The low temperature ductility of several vacuummelted, 25 percent chromium, ferritic stainless steels containing between 300 and 900 ppm total interstitials (C + N + O) has been investigated in the water-quenched condition using impact and tensile tests. In the low interstitial content alloys, the ductile-brittle transition temperature was markedly influenced by changes in interstitial content and grain size, whereas for the high interstitial contents such changes were not as significant. Tensile tests on the same alloys indicated that the yield stress was not sensitive to variations in either interstitial content or grain size.

It is shown that increasing the interstitial content in these high chromium ferritic steels effects an increase in the amount of second phase present, particularly at the grain boundaries. Such particles enhance cleavage fracture by reducing the surface energy. It is observed that the second phase content is a single valued function of the ductile-brittle transition temperature.
Towards the Standardization of Time-Temperature Parameter Usage in Elevated Temperature Data Analysis
Authors: Goldhoff RM
Published: February 2009

A Task Group of the Joint Committee on Effect of Temperature on the Properties of Metals (sponsored by the American Society for Testing and Materials, the American Society of Mechanical Engineers, and the Metal Properties Council) did an extensive study of methods for the extrapolation of short-time rupture data in an effort to decide if any one method might serve as a basis for a standard practice. Emphasis was on the time-temperature parameter.

The following conclusions were reached: 1. Among the computerized techniques the newly introduced minimum-commitment method (MCM) is on the average about as good as the best of the four standard time-temperature parameters studied. 2. In addition, the MCM has other potential merits which make it a candidate for the sought-after standard. Further study and investigative work are required to realize this potential. 3. Experienced analysts can get good results by manual extrapolation methods. These methods are subjective, and because of the limited availability of experienced analysts such methods probably should not be considered for standard practice.

Many recommendations are given in the report for future work toward the goal of defining a standard practice.
Acoustic Emission Produced During Heating of Tin and Zinc Single Crystals
Authors: Papa T , Sette D , Stagni L , Congiu Castellano A
Published: February 2009

Acoustic emission activity has been detected during heating of tin (Sn) and zinc (Zn) single crystals from 0 to 130°C. The emission of Sn occurs copiously only if the heating starts below a temperature of about 18°C, and lasts up to a higher temperature between 60 and 80°C. The results may be interpreted by relating acoustic emission to processes in the α ↔ β phase transformation. Although still qualitative, such a hypothesis permits us to have useful information on the nucleation time of the α-phase and on the temperature hysteresis of the transformation.
Programmed In Situ Melting, Freezing, and Tensile Testing for Laboratory Study of High Temperature Properties of As-Cast Metals
Authors: Batra R , Wilber GA , Breit HF , Childs WJ
Published: February 2009

A technique has been developed for controlled melting and freesing of a steel specimen in a Duffers Gleeble®, combined with a tensile testing capability, in order to obtain subsequent high temperature mechanical properties.
Magnetic Domain Structures in Fe-3.2Si Revealed by Scanning Electron Microscopy—A Photo Essay
Authors: Yakowitz H , Newbury DE
Published: February 2009

The mechanism and experimental arrangement by which magnetic contrast can be observed from materials of cubic anisotropy are indicated. Transformer alloy Fe-3.2Si is used as an example to illustrate the effects of tensile strain, magnetic field switching, residual stress, and inclusions on magnetic structure.
A Study of Crack Tip Plastic Zone Topography in Beryllium
Authors: Cooper RE
Published: February 2009

Multiple-beam interferometry has been used to study the size and shape of plastic zones both at the tip of subcritical cracks and at the edges of running cracks in rolled ingot and in hot pressed, fully dense and porous beryllium. It is shown that from the zone shape an effective yield stress for the material can be derived and that this stress corresponds to somewhere between the 0.2% proof stress and the microyield stress of the material as measured under uniaxial tension. The relevance of this effective yield stress to practical fracture toughness testing is discussed and it is shown that from the points of view of both overall crack tip plastic zone shape and of the effects of plasticity on elastic stress redistribution, the 0.2% proof stress is probably the best choice.
Strength and Ductility of Cr-Mo-V Steels in Creep at Elevated Temperatures
Authors: Viswanathan R
Published: February 2009

A state-of-the-art survey of literature pertaining to low alloy Cr-Mo-V steels has been completed with a view to elucidate the effects of composition, heat treatment, and microstructure on the creep strength and ductility of the steels. It appears that minor amounts of alloy additions such as boron, titanium, and cerium and impurity elements phosphorus, sulfur, tin, antimony, aluminum, and copper may affect the creep strength or ductility or both of the steels. Higher austenitizing and lower tempering temperatures lead to improved strength at the expense of rupture ductility. An upper bainite microstructure is associated with the highest creep strength and the lowest ductility, for temperatures up to 1050°F (565°C) and for times of at least up to 10,000 h. In bainite-ferrite aggregates, creep and rupture strengths increase in proportion to the amount of bainite, and the difference in strength between the various structures is maintained at least up to 10,000 h at 1070°F (575°C). Stress rupture strengths in general increase linearly with room temperature tensile strength for temperatures up to 1000°F (538°C) and times up to 10,000 h. Variation of rupture strength and minimum creep rate with temperature and time can be adequately described by the Orr-Sherby-Dorn parameter. Activation energies for both creep and for rupture are determined to be about 90 kcal/mole (375 kJ/mole). Further, it is observed that ˙ε × tr ⋍ 3.3 and that tt ⋍ 0.3 tr, where ˙ϵ tt, and tr are the minimum creep rate, time for transition from second- to third-stage creep, and time to rupture, respectively.
A System for Computer Analysis of Stress-Strain Curves
Authors: Olshausen KD , Larsen JK
Published: February 2009

A system for recording and processing of data obtained in tensile tests is described. The electronics (hardware) consists of signal amplifiers (load and elongation), digital voltmeters with binary code decimal output, serializer, and incremental magnetic tape recorder. The operation sequence is controlled by a system of relays, time delays, and an electronic clock.

The computer program calculates not only the typical mechanical properties such as yield stress, ultimate stress, and uniform and total elongation, but also more sophisticated properties such as strain-hardening coefficient and Reed-Hill coefficient, which are difficult to obtain by other means. The computer output is in the form of tabulated data and plotted curves.

The system has been used in over 300 tests of Zircaloy and aluminum samples. Most of the tests were done on irradiated ring samples cut from the cladding of boiling water reactor fuel rods, but also tube- and plate-type samples have been tested. There was good agreement between the computer-generated values and the values calculated by conventional methods.
An Analysis of the Design of Beam Testing Apparatus
Authors: Ducker WL , Vallabhan CVG , McMullin WS
Published: February 2009

A critical evaluation of the mechanical design of beam testing apparatus used to determine the flexural strength of concrete by ASTM methods C 78-64(1972) and C 293-68 is presented. Two approaches were used in the evaluation: (1) an experimental deformation of the concrete beam analysis and (2) a stress-deformation analysis of the same by the finite element method. An alternative design of beam testing fixtures is presented by which the tests can be performed more efficiently and accurately.
Correlation of Damping and Fatigue Properties of an AISI 403 Stainless Steel
Authors: Willertz LE , Moon DM
Published: February 2009

The changes in the damping properties of AISI 403 with cyclical torsional fatigue stressing have been determined in order to define the cyclical stress sensitivity limit (CSSL) of the material. Comparison of the data with observations of changes in surface features and the torsional and push-pull fatigue lives shows that the CSSL is a good indication of the minimum stress which can cause permanent fatigue damage in this material. The type of test used to determine the CSSL is rapid in that less than one day's testing on one specimen is required to define it, whereas the usual fatigue limit requires testing times of several weeks and a number of different specimens.

Application of the Granato-Lücke theory of dislocation damping explains many of the observations of damping and modulus changes encountered.
A High Purity Approach to High Chromium Ferritic Stainless Steels
Authors: Matejka WA , Knoth RJ
Published: February 2009

This paper discusses merits of a high chromium ferritic stainless steel with extremely low levels of carbon and nitrogen. Data are shown on effects of carbon, nitrogen, and other impurity elements on alloy corrosion properties, mechanical properties, mill processing, and fabricability. Properties of Type XM-27, a 26Cr-1Mo high purity ferritic made by electron-beam refining, are discussed for various product forms. Weldability and fabrication characteristics are reviewed with emphasis on heat exchangers and pressure vessels. Use of Type XM-27 in chemical, petroleum, and fertilizer processing equipment is described. Service performance results, in some cases showing 24-month data, are presented.
Neutron Spectrum Analysis from Dosimetry Experiments
Authors: Kam FBK , Stallmann FW
Published: February 2009

A fairly good approximation to a neutron spectrum can be obtained commensurable with the accuracy of the activity and cross-sectional measurements. However, these approximations are valid only in regions where the coverage is determined by the cross sections and spectrum used and may be locally disturbed by poor resolution. Coverage and resolution are two properties which determine the goodness of a given monitor set. The trial spectrum influences the outcome of the unfolding only to the extent that the monitor set fails to provide the necessary coverage and resolution.
Radiation Damage Units for Steel
Authors: Beeler JR
Published: February 2009

Damage units are needed to correlate radiation effects data from different types of radiation sources and to standardize experimental and testing procedures. In the case of radiation-induced changes in the mechanical properties of structural materials, useful damage units are the production rates per unit volume of mobile defects, immobile defect clusters, and interstitial dislocation loops. Quantitative recipes are given for the production of these and other related defects in steel at reactor operating temperatures.
Dosimetry Related to Controlled Thermonuclear Research
Authors: Dudey ND
Published: February 2009

Controlled thermonuclear research (CTR) dosimetry is presently concerned with measurements of neutron flux, fluence, and neutron spectra. This information is being used to (1) correlate radiation effects data, (2) evaluate and describe the irradiation environment of currently available neutron sources, and (3) provide diagnostics for plasma physics studies. Current radiation effects studies are emphasising surface phenonena such as sputtering, and are utilising (d,t) and Be(d,n) reactions as the sources of neutrons. The energy region of 8 to 15 MeV is of most interest for CTR purposes. Experimental constraints necessitate use of the foil activation technique for dosimetry measurements. For the cases of monoenergetic neutron sources (RTNS), accuracies of about 7.5% are being obtained. Cross section uncertainties are limiting the accuracy for broad spectrum measurements, such as from Be-d sources. Because no present neutron source adequately represents the type of radiation environment expected to be encountered in future CTR devices, emphasis must be placed on carefully documenting and standardizing the dosimetry measurements so that the radiation effects data can ultimately be extrapolated to anticipated CTR conditions. Future efforts in CTR dosimetry must develop methods for characterizing charged and neutral particle radiation.
Evaluation of Fracture Energy of Aluminum Alloys
Authors: Johnson FA , Radon JC
Published: February 2009

The fracture toughnesses of some precipitation-hardened aluminum alloys have been evaluated, mainly by the use of precracked three-point bend specimens in instrumented impact testing. A recently developed interpretation of the specific surface energy method has been applied to calculate the initiation values of KIc and these values have been compared with those calculated using stress analysis equations. The value of unity thereby deduced for the geometrical constraint factor in these non-rate-sensitive materials may be appropriate to the type of fracture mode occurring in these alloys, that is, semiductile. The distinction in principle between fracture initiation toughness, expressed as GIc = w/ηA, and the average propagation toughness w/A has been noted and the latter used in studying crack tunnelling during semiductile crack propagation in thick sections of the alloys in the form of large, double-cantilever beam specimens.
New Model Material for Three-Dimensional Stress Analysis
Authors: Hasseem HM , Durelli AJ , Parks VJ
Published: February 2009

This paper describes the manufacturing of a family of epoxies, the Poisson's ratio of which at the critical temperature is on the order of 0.4. The variation of Young's modulus, Poisson's ratio, shear fringe value, and critical temperature as a function of the amount of hardener, the curing temperature, and the curing time for a large range of these variables are presented as parametric curves.

Previously, epoxies used in three-dimensional analysis have all shown a Poisson's ratio of about 0.5, indicating incompressibility. The new compressible material has two advantages: (1) it is closer to the common engineering materials and (2) strains can be measured at interior points to supplement photoelastic analysis, or strain measurements can be used exclusively to obtain stresses throughout the body.
Contamination Damage Avoidance Concepts for Propulsion Feed System Components
Authors: Endicott DL
Published: February 2009

The gain in component reliability for long-term, reusable space vehicles was investigated in a two-part program. Mechanical redesign methods were used to minimize contamination damage of conventional components and a unique type of contamination separator device was developed. The redesign techniques were incorporated into an existing 2-in. (50.8-mn) poppet value and tested for damage tolerance in a full-size open-loop system with gaseous and liquid nitrogen. Cyclic and steady flow conditions were tested with particles of 75 to 200-µm aluminum oxide dispersed in the test fluids. Nonflow cycle life tests (100,000 cycles) were made with three valve configurations in gaseous hydrogen. The redesign valve had an acceptable cycle life and improved tolerance to contamination damage.

Analytical studies were completed on various types of dynamic separator. A venturi type of particulate separator was fabricated and preliminary testing completed in the gaseous nitrogen test system at 200-ft/s (61-m/s) velocity.
Martian Sandstorms and Their Effects on the 1975 Viking Lander System
Authors: Maegley WJ , Diederich DP
Published: February 2009

A model of a Martian sandstorm has been derived from presently available data. The erosional effects of such a storm on the Viking lander were determined by test, and modifications involving the application of silicone-based protective material were made to insure lander survivability over the planned 60-day mission. Material eroded by windblown sand is expected to provide a source of contaminant for the soil samples used in the organic analysis experiment. Results of analyses predicting the level of such contamination indicate that soil sample contaminant concentration will be below the acceptable maximum.
Contamination Control During Acceptance Testing of Mariner Class Spacecraft Propulsion Hardware
Authors: Nenno RE , Oldland AH
Published: February 2009

In order to insure reliable, leak-free operation of spacecraft propulsion hardware during long-term space missions, it is necessary to maintain hardware internal cleanliness at a level which allows no particles over 100 micrometres in size throughout the acceptance testing and delivery cycle of the hardware. To schieve this goal, it was necessary to derive and use specialized techniques, procedures, processes and hardware.

The spacecraft propulsion hardware involved consists of pressurant control assemblies, propellant isolation assemblies and pyrovalve subassemblies. In the end uses, the assemblies are formed into a system by an induction heating brazing operation on tube stubs to form the Viking Orbiter propulsion system.

Basic requirements for contamination control include a facility with FED-STD-209 Class 100 environments, and personnel trained in clean room practices and disciplines. The specific design, configuration and functions of the spacecraft hardware must then be considered to establish cleaning methods, cleanliness verification methods, and methods of maintaining specified levels of cleanliness. The techniques, methods, hardware designs, and hardware applications used to achieve the required contamination control are described.
Automatic Particle Measurement Systems and Liquid-Handling Techniques for Clean Liquids
Authors: Lieberman A
Published: February 2009

This paper discusses some of the problems in handling liquids that are particularly clean. Practical solutions are provided for problems involved in measuring contamination at low levels and empirically derived methods are given for liquid-handling systems and techniques to minimize artifact introduction. The problems of correlating results from one method to another are discussed. Procedures for calibration of automatic particle counters are considered. Some of the errors that can occur in terms of coincidence and system dynamic range are mentioned. Along with control of solid and liquid artifact introduction, procedures for batch and in-line samples are discussed to minimize bubble effects. The problems involved in sample acquisition and in sample handling are considered.
Evaluation of theJIntegral for the Compact Specimen
Authors: Clarke GA , Landes JD
Published: February 2009

Methods for determining the J integral from an experimental load versus load point displacement curve for the compact specimen are discussed. The original analysis by Merkle and Corten, which accounted for the tension component in the compact specimen, is presented along with a simplified version (of the analysis) that is shown to be essentially equivalent to the original formulation. Based on experimental results from Landes, Walker, and Clarke, a further simplified expression is recommended as the best expression to use for determining J for the compact specimen.
A Rolling Bottle Device for Measuring the Flow of Liquids and Powders
Authors: Winslow DN
Published: February 2009

The apparatus described in this paper is a simple and inexpensive device that allows the rapid measurement of a wide range of properties of both liquids and powders by measuring their flow. The flow is measured by observing the horizontal distance that a bottle, partially filled with a liquid or powder, requires to come to a stop on a runway after it has been allowed to roll down a shallow ramp. When liquids are tested, the apparatus has been found useful for measuring viscosity, temperature effects upon viscosity, and concentrations of dissolved or suspended additives. With powders it is sensitive to factors such as particle size and size distribution, surface area, particle roughness and shape, and surface moisture. It appears to have a wide-ranging applicability as both a research tool and as a test method in many disparate fields.
Stress Relaxation in Bending of Copper-Nickel-Tin Alloy Strip Strengthened by Spinodal Decomposition
Authors: Fox A
Published: February 2009

The stress-relaxation behavior of three copper-nickel-tin alloys strengthened by spinodal decomposition was studied in the temperature range 23 to 204°C (73 to 400°F). The alloys studied were Cu-4%Ni-4%Sn, Cu-9%Ni-6%Sn, and Cu-15%Ni-8%Sn. The resistance to stress relaxation of these alloys at temperatures of 121°C (250°F) and higher is shown to be significantly improved over that of fully precipitation-hardened CA172 (Cu-1.9%Be alloy, condition TH04), a material widely used for connectors and electrical springs requiring high strength at moderately elevated temperatures. Design data that permit an evaluation of spring performance for extended service life applications are presented for these alloys.
A Low-Cycle Fatigue Test for Pipe-Type Power Transmission Cables
Authors: Spillers WR , Greenwood AN , Spiliotis G
Published: February 2009

An apparatus for performing low-cycle flexural fatigue tests on pipe-type power transmission cables with wrapped-tape dielectric is described.
Statistical Analysis of X-ray Residual Stress Measurement Using the Half-Width Method
Authors: Kurita M
Published: February 2009

X-ray stress measurement can be used to nondestructively measure the residual stress in small areas of metallic materials. The equation for calculating the standard deviation of the stress as a result of statistical counting errors σS which are a fundamental source of scatter in X-ray stress measurements, is derived for the half-width method using the preset time technique. This equation shows that σS is independent of the half-width of the diffraction line but is inversely proportional to the slope of the line side. Residual stresses in the three hardened steels, JIS S35C, S45C, and SK3, were determined by three methods, that is, the parabola and the Gaussian curve-fitting methods and the half-width method. The stress values determined by the three methods agreed well with each other. The standard deviation σS determined by the half-width method is smaller than that determined by the curve-fitting methods for most materials, but it becomes larger as the diffraction line broadens.
Nondestructive Magnetic Measurements on Prefabricated Parts
Authors: Kelkar VY
Published: February 2009

A method has been described to compare the magnetic reluctances of prefabricated parts of an electromagnetic system in a nondestructive way. The size and shape of such parts do not allow normal methods of measurement to be used. The method of measurement does not need any special instruments. The same procedure may be extended towards calculation of the B-H curve. The principle of measurement is applicable to both AC and DC excitations. The experimental data is also presented.
A New Scale of Microtension Test for Polymers
Authors: Groves DJ , Sang RD , Scott JT , Scrutton IN , Millie RP , Wigley DA , Hendra PJ
Published: February 2009

Microtension tests on polyethylene, polypropylene, and polyethylene terephthalate are reported for grip separations typically around 10 mm and as little as 4 mm. A waist geometry of uniform radius is used and particular attention to grips and jaw facings is necessary. The results show these microtension specimens to behave in accordance with predictable sources of stress concentration, giving yield and draw processes free from grip influence. There is a small though significant decrease of around 2% when the mean values of yield or draw stress from the microtest are compared with conventional test data, although the testing errors are similar. The mean value of break strength is unaffected whether the microtest or conventional test is used, but the scatter about it is larger with the microtest. For many purposes the differences are small, and the material sample needed is considerably reduced.
Correlation of Data from Standard and Precracked Charpy Specimens with Fracture Toughness Data for HY-130, A517-F, and HY-80 Steel
Authors: Sovak JF
Published: February 2009

Fracture toughness data were obtained for three constructional alloy steels having yield strengths of 958, 752, and 552 MPa (139, 109, and 80 ksi) (HY-130, A517(F) [Unified Numbering System UNS K11576], and HY-80, respectively) by testing conventional Charpy V-notch (CVN), fatigue-precracked Charpy, and plane-strain fracture toughness KIc specimens. The data were used to evaluate proposed correlations between KIc data and data obtained with Charpy-type specimens and to develop additional correlations. Of the five correlations examined, a method based on standard CVN results that incorporated a temperature shift to relate impact to static data gave slightly better estimates of KIc values in the transition temperature region than the others. However, the best results over the widest temperature range were obtained from a correlation method based on a J integral estimation that predicts KIc values from the results of slow-bend tests of fatigue-precracked Charpy-type specimens.
Techniques for Fatigue Testing and Extrapolation of Fatigue Life for Austenitic Stainless Steels
Authors: Manjoine MJ , Landerman EI
Published: February 2009

ASTM has recommended practices for fatigue testing to obtain representative data and to allow comparison of data from different sources. This paper describes testing techniques that follow the guidelines of ASTM but that are modified to study the response of specific materials and to allow an extrapolation of the data to design service lives. The particular material illustrated is a cold-worked type 316 stainless steel (Unified Numbering System [UNS] S31600) in room temperature air. This and other austenitic alloys are characterized by having a relatively stable inelastic strain for a high percentage of life even up to lives beyond 108 cycles.

The testing program included (a) low-cycle tests under fully reversed total-strain control and (b) high-cycle tests under fully reversed stress control. The latter tests were performed in a stress sequence of the staircase method. The test specimen and testing frequency for each type of test were designed to maximize the ability to measure strain and stress and to minimize any instabilities of strain or temperature.

For the high-cycle fatigue tests in room temperature air, the specimen temperature rises as a function of the cyclic work rate. The temperature history was measured and the inelastic strains were estimated from a finite-element heat conduction analysis. Failure was characterized by a continuous increase in temperature but run-out (nonfailure) exhibited an initial rise and a decrease to a stable temperature which was a function of the stress range.

The data for inelastic and elastic strains and their histories were analyzed and relationships were formulated for extrapolation. From the staircase method of testing, the fatigue strength was statistically determined at 106 cycles and 3.2 × 108 cycles, an interval of 2.5 decades. An extrapolation was made for an equal interval to 1011 cycles. It is proposed that the techniques developed in this paper can be used to generate fatigue data for design of structures using austenitic stainless steels.
Application of Ultrasonic Stress Measurements to Problems in the Electricity Supply Industry
Authors: Williams HD , Armstrong D , Robins RH
Published: February 2009

The potential advantages of an ultrasonic method of stress measurement stem from the speed with which individual determinations can be made, the ability to determine stresses throughout the bulk of a component, and the nondestructive nature of the test. These advantages may be paramount where large numbers of components are involved, where stress contour mapping is required, where quality control is to be exercised over fabrication or structural erection, or where remote measurement is required in hostile environments or inaccessible locations.

The basis of the ultrasonic method is reviewed in terms of the interaction between acoustic wave motion and stress, materials proper ties, and the principle of superposition. Methods of analysis are considered and an assessment made of the practical limitations of the technique.

The application of the technique to problems on pipes, bolts, and electrical rotors is discussed and consideration is given to the work required to provide a rigorous basis for each application.
An Analytical Approach to Reference Samples for Ultrasonic Residual Stress Measurement
Authors: Hsu NN , Proctor TM , Blessing GV
Published: February 2009

While residual stress measurements using ultrasonic techniques have been under development for some time, practical applications are still limited. One of the difficulties is the lack of suitable reference samples for instrument calibration. This paper specifically addresses the question of how to produce a known stress-state reference sample, and ultrasonically determine its zero stress state. The approach was to design and construct a sample possessing residual stresses that can be deduced from established theory. A shrink-fit ring-plug assembly was fabricated from carefully screened aluminum bar stock, forming a disk suitable for both longitudinal and shear wave calibration. Here we report results using longitudinal waves.
Tentative Test Procedure For Determining the Plane Strain JI-R Curve
Authors: Albrecht P , Andrews WR , Gudas JP , Joyce JA , Loss FJ , McCabe DE , Schmidt DW , VanDerSluys WA
Published: February 2009

A tentative test procedure for the determination of the plane strain-crack growth resistance JI-R curve for metallic materials is presented. This procedure was prepared by a Working Group of ASTM Committee E24.08.03. It was evaluated with a round robin test program on HY130 steel, conducted in 1980 to 1981. The results of the testing program were reported in a companion paper, and the experiences were incorporated in this procedure. The procedure is written for the elastic compliance method of developing the plane strain JI-R curve. Recommended specimens are the pin-loaded compact and the three-point bend specimens. Details regarding apparatus, specimen preparation, test system calibration, testing, calculation of J and crack extension, and data qualification are specified.
Evaluation of the Tentative JI-R Curve Testing Procedure by Round Robin Tests of HY130 Steel
Authors: Gudas JP , Davis DA
Published: February 2009

A round robin test program of the tentative test procedure for the determination of the plane strain J-integral crack growth resistance curve was conducted under the auspices of ASTM Committee Section E24.08.03. This test program used HY130 steel and involved 19 participating laboratories in seven countries. Tests were carried out with both 25.4 mm (1-in.) thick compact specimens and three-point bend bar specimens.

The results showed that the tentative procedure is an adequate document to guide JI-R curve testing. The range of scatter in crack length and crack extension measurements was well within prescribed limits. Analysis of compact specimen test data showed that various classifications of test data based upon agreement of crack length prediction and measurement did not significantly change the mean JI-R curves, and the range of scatter. The tentative procedure is seen to result in accurate JI-R curves when testing this specimen geometry. Results of three-point bend tests displayed more scatter than seen with compact specimens. Mean JI-R curves of selected bend bar specimens did not coincide with data from compact specimens. Specific experimental and analytical requirements to enhance the tentative JI-R curve procedure were identified.
Goodness-of-Fit of the Ramberg-Osgood Analytic Stress-Strain Curve to Tensile Test Data
Authors: Papirno R
Published: February 2009

One form of the Ramberg-Osgood analytic approximation of the stress-strain curve, which uses the 0.2% offset yield stress as one of the three parameters, has recently been approved for inclusion in Military Standardization Handbook-5. Using the root-mean-square error as a criterion, the fit of this formulation to data from 2357 tension tests of various materials was found to be excellent. In 90% of the tests, the root-mean-square error in stress was less than 1% of the yield stress and in half the tests the error was less than 0.4% of the yield stress.
Experimental Determination of Lüders Band Parameters from Load-Elongation Data
Authors: Correia MT , Fortes MA
Published: February 2009

Methods for measuring the various parameters of a Lüders band (particularly the width and average strain rate) are developed that use exclusively the load-crosshead displacement curves in tension. Experimental values obtained with these methods agree very well with those determined using extensometers. This allows the identification, in the tensile curve, of the points corresponding to the main events in Lüders band deformation leading to the Type A Portevin-Le Chatelier effect.
Erosion Response of a Turbine Alloy and Its Oxide Scale
Authors: Wenglarz RA , Tabakoff W
Published: February 2009

Erosion response versus angle of particle incidence has been determined for U710 turbine alloy (Unifited Numbering System [UNS] C71000) and a spinel oxide scale developed over 9200 h on the U710 alloy first stage rotor of a large utility turbine operating with natural gas. The approximately 10:1 pressure ratio and 871°C (1600°F) baseload inlet temperature for this machine are suitable for operation with future coal-fired pressurized fluid bed combustor (PFBC) power plants. Erosion test conditions were representative of the environment in the first rotor of the large utility turbine expanding PFB combustion gases after three stages of cyclone cleaning. The test gas velocities of about 457 m/s (1500 ft/s) and test specimen surface temperature of 766°C (1410°F) approached the maximum values in the first rotor and the particles used for the erosion tests were third cyclone fines collected at a PFBC pilot plant.
Concept and Test Method for a Unified Characterization of the Geometric Irregularity of Aggregate Particles
Authors: Ishai I , Tons E
Published: February 2009

The paper describes a concept by which the geometric irregularity (shape, angularity, and surface texture) of aggregate particles is unified and expressed quantitatively by basic and volumetric characteristics that are related to the physical properties of individual particles as well as to the packing behavior of particles in bulk. A test method, the pouring test, was developed for bulk measurements of these characteristics by a fast, simple, and practical procedure. Tests were made on 22 types of aggregate with six sizes of each. It was found that the new geometric parameters can reflect and explain the discernible irregularity of a wide range of aggregate types and sizes. The parameters were highly correlated with the packing specific gravity, asphalt requirement of the particles, optimum asphalt content, and maximum stability of graded bituminous mixtures. The parameters successfully provided physical explanations to marginal and unexpected behavior of unconventional aggregates, while conventional test indexes failed to provide an appropriate explanation.
Correlation Between Leaking Glass/Metal Seals and Wire Defects in Dry Reed Contacts
Authors: Pinnel MR , Bennett JE , Bader FE
Published: February 2009

Considerable variability in the quality of the surface finish on Remendur (equiatomic iron/cobalt with 2.5 to 3.0% vanadium) wire has been experienced and has seemed to have some relationship with the ability to consistently produce gas-tight, glass-to-metal seals. This paper reports on an attempt to develop a significant and quantitative correlation between relevant surface defects and the tendency to produce leaking seals by using optical cross-sectioning and SEM techniques. Results indicate a significant correlation does exist between surface defects observed in cross section and numbers of leaking seals. However, other factors which contribute to leaking tendency, as well as the limits of resolution of an optical cross-sectioning technique, prevent a quantitative analysis of the data sufficient to predict percentages of leaking seals to tenths of one percent. The approach does have application in detecting wire which is likely to produce greater than 1 to 2% leaking seals from that which is subject only to the vagaries of the sealing machines. Observation of the wire surface with a scanning electron microscope is strictly qualitative and appears to be more difficult to correlate with the tendency to produce leaking seals than cross-sectional evaluation.
Bibliography on Clean Glass
Authors: Adams PB
Published: February 2009

A bibliography on glass cleaning has been prepared by a Task Group of Subcommittee C14.03 on Chemical Properties under Committee C-14 on Glass and Glass Products. The bibliography consists of 120 references, accessed by tables on “Specific Contaminants,” “Specific Evaluation Technique,” “Specific Cleaning Methods,” “Specific Products or Processes,” and “Miscellaneous Information.” It is intended to be used as a starting point for designing a rational cleaning procedure.
Thermal Fatigue Testing System for Structural Materials
Authors: Stocker PJ , Morris WL , Robertson WM
Published: February 2009

A materials testing system has been developed for isothermal and differential thermal fatigue testing of metal specimens. A closed-loop thermal cycle is provided by an induction heater and a gas-liquid cooling manifold. Mechanical control of the specimen, as a direct function of temperature, is provided by a closed-loop electrohydraulic system capable of operating in load, stroke, or strain control. A mechanical diametral extensometer was developed to work with soft materials. A unique specimen design and its related hardware make possible the investigation of materials of widely varying properties, including copper alloys and alloy steels.
Nondestructive/Destructive Test Correlations and Fracture Mechanics Analysis
Authors: Tu LKL , Seth BB
Published: February 2009

In view of the recent developments in finite element stress analysis and materials processing and testing, the reliability of fracture mechanics analysis on service life prediction is critically dependent on the estimation of the flaws by nondestructive test (NDT) methods. This paper discusses the correlation between NDT indications and actual sizes of natural flaws determined by destructively examining flaws and shows the importance of this uncertainty on component life predictions. A section of a low-alloy steel forging was ultrasonically inspected, saw-cut into cubes containing flaws, and examined by C-scan and X-ray. Successive metallographic polishing was performed to reconstruct the shape, size, and location of the flaws. The flaws were identified by using electron microprobe energy spectrum analysis. The flaw sizes predicted by ultrasonic inspection were underestimated by up to 6.6 times the actual flaw area. It was demonstrated that underestimation of the sizes of natural flaws by NDT should be properly corrected to make realistic cyclic life predictions.