bluuebunny/crossref_metadata_2025_split huggingface dataset:
Corrosion Fatigue Crack Growth Thresholds for Cast Nickel-Aluminum Bronze and Welds
Authors: Czyryca EJ 
Published: April 2008

Fatigue crack-growth rate tests of cast NAB and NAB weld metal specimens were conducted to determine the threshold for fatigue crack growth (ΔKth). The tests were conducted in accordance with ASTM E 647, Standard Test Method for Measurement of Fatigue Crack Growth Rates, in artificial seawater at a cyclic frequency of 2 Hz at R-ratios of +0.05, +0.40, and +0.60. The specimens were machined from both poor and good quality, as-cast NAB. Production NAB weldments were used for NAB weld metal specimens.
The fatigue crack growth-rate curves for duplicate tests at each R-ratio of cast NAB in seawater were analyzed in the near-threshold regime to determine ΔKth. With increasing stress intensity ratio (R), ΔKth decreased. Compared to the values for cast NAB, higher ΔKth and higher crack closure levels in NAB weld metal tests were noted, due to the residual stress in the weldment. The same fatigue crack growth-rate curve sets were corrected for crack closure, and the near-threshold stress intensity decreased significantly when the closure loads were deducted. The closure-corrected, near-threshold stress intensity, based on ΔKeff, ranged from 4.4 to 6.1 MPa-√m for cast NAB versus 4.4 to 7.4 MPa-√m for NAB weld metal.
Fatigue Crack Growth Thresholds Measurements in Structural Materials
Authors: Lindström R , Lidar P , Rosborg B 
Published: April 2008

Fatigue crack growth thresholds and da/dN-data at low ΔKI-values (&lt;10 MPa√m) have been determined for type 304 stainless steel, nickel-base weld metal Alloy 182, nickel-base metal Alloy 600, and low-alloy steel in air at ambient temperature and in high-temperature water and steam. The stainless alloys have been tested in water with 0.2 ppm O2 at 288°C and the low-alloy steel in steam at 286°C. The fatigue crack growth threshold was defined as the ΔKI-value resulting in a crack growth rate of 10-7 mm per cycle. The measured fatigue crack growth thresholds (at frequencies from 0.5 to 20 Hz) are quite similar independent of the material and the environment.
A relatively inexpensive and time-saving method for measuring fatigue crack growth thresholds, and fatigue crack growth rates at low ΔKI-values, has been used in the tests. The method is a ΔKI-decreasing test with constant KIMax.
Structures and Activities of ASTM Committee D-27
Authors: Kelly JJ , Getz DM 
Published: April 2008

ASTM Committee D-27 on Electrical Insulating Fluids and Gases was formed as Subcommittee IV under Committee D-9 in the year 1916 and was designated as a separate technical committee in 1959. The scope of D-27 is the promotion of knowledge pertaining to insulating liquids and gases, whether synthetic or natural in origin, and the recommendation of standards and specifications pertinent to these materials.
The principal materials included in this arena are oils of petroleum origin, synthetic liquids, and halogenated and other gases when used singularly or as combinations, as electrical insulation or as an environment for electrical insulation in transformers, capacitors, and other electrical equipment.
Standards peculiar to solid insulating materials and varnishes, and the development of standards pertaining to non-electrical uses of liquids and gaseous materials are excluded from our scope.
The D-27 membership is made up of technical people from the refining and chemical industries, electrical equipment manufacturers, electrical utilities, and laboratories that test and analzye both new and used fluids and gases.
The paper presents in some detail the responsibilities of the various subcommittees and the harmonization efforts to work with international standards organizations.
Some specific examples of our work are cited in terms of the events that preceded the need to standardize a procedure.
The Electrochemical Stability of Mineral Insulating Oils
Authors: Sabau J , Stokhuyzen R 
Published: April 2008

Successful detection of an incipient electrical failure within the windings of power transformers is based upon the possibility of determining the amount and nature of the gases evolved by the oil when subjected to the impact of a strong electric or thermal stress. The cause of the deficiency can be established by analyzing the gases dissolved in the oil. While under normal operating conditions the amount of gas evolved is minimal and therefore of little importance, a significant increase in the concentration of gaseous decomposition products gives cause for concern.
Since a large amount of vulnerable hydrocarbon molecules can also be the source of dissolved gases, the gassing tendency of oil should be taken into consideration. The lack of a reliable procedure capable of establishing a quantitive relationship between laboratory results and the performance of oil in service can influence the interpretation of dissolved gas analysis (DGA). Just as the chemical stability of oil is accepted as an indication of the ability of insulating oils to resist oxidation, the concept of electrochemical stability is introduced as a measure of the capacity of the oil to counteract gas evolution under the impact of electrical stress. Knowledge of the amount of gas generated by a sample of oil, when subjected to the influence of a standard high-voltage field, can improve the interpretation of DGA of that oil. This concept also provides a better understanding of the mechanism by which the high-voltage field negatively affects the chemistry of insulating fluids.
Effect of Clamping Mechanism on Pullout and Confined Extension Tests
Authors: Farrag K , Morvant M 
Published: April 2008

Two different clamping mechanisms are commonly used in pullout and confined extension tests of geosynthetics. The first method consists of extending the clamps inside the soil to a sufficient length that ensures the confinement of the whole specimen length during testing. The frictional resistance of the part of clamping plates inside the soil is subtracted from the results to obtain the resistance of the geosynthetic specimen. The second method consists of clamping the geosynthetic specimen outside the soil. In this method, displacement measurements are taken in the confined part of the specimen in the soil and, hence, the readings are not influenced by the possible slippage of the specimen between the clamps.
A comparison of test results using both installation techniques is presented and the boundary effects associated with both mechanisms are evaluated. In the tests where the clamps were extended inside the soil, earth pressure near the front facing was measured in order to evaluate the frictional resistance of the clamping plates. Soil pressure measurements were taken after applying the confining pressure and during the test to monitor the development of vertical stresses at the vicinity of the clamping plates. The measurements showed an apparent increase of vertical pressure above the clamps. The results were corrected for the increase of the vertical pressure due to frictional resistance of the clamping plates.
When the clamping plates were connected to the specimens outside the box, displacements were measured along the specimen length. These measurements were extrapolated to determine the front displacement of the specimen at the pullout load application point. The use of the extrapolated front displacement resulted in a more reasonable load-displacement relationship for the geosynthetic specimen.
The Effect of Fasteners on the Fatigue Life of Fiber-Reinforced Composites
Authors: Brown CR , Wilson DA 
Published: April 2008

The effects of stress concentrations on the fatigue life of fiber-reinforced graphite epoxy composites play a very important role in the aerospace industry. Primarily stress concentrations refer to the holes. However, fasteners are the primary manufacturing process for attachment of graphite epoxy panels in use in the aerospace industry today. These conditions of composites with and without fasteners greatly affect the fatigue properties of such panels.
In an attempt to understand the stress field created by fasteners in carbon-reinforced graphite composites, and how these stress fields affect the fatigue life of these composites, a fatigue life analysis program was conducted. It compared specimens with machined fastener holes and specimens with fasteners placed in them. In addition to the fatigue analysis performed on the specimens, photoelastic stress analysis is used to determine the stress field created from the use of fasteners. The difference in stress fields of specimens without fasteners compared to specimens with fasteners can be determined to allow designers to prolong the fatigue life of composites.
Algorithm and Computer Code of Group Neutron Spectra Transformation
Authors: Shimansky GA , Tellin AI , Gurevich MI 
Published: April 2008

The transformation of the group neutron spectrum to the differential form or to group spectra with the other scale of energy groups is necessary in many tasks of reactor dosimetry. If the initial spectrum is given in a fine scale of energy groups, e.g., in the scale SAND-2, so for its conversion in a more rough scale and for an evaluation of a differential spectrum, as a rule, there a method of linear interpolation is used. In this case the linear interpolation method ensures an acceptable precision of the transformation results. If the number of groups of initial spectrum energy scale is not large (less than 100), the application of the linear interpolation method can cause a significant error.
In this work a general-purpose algorithm of spectrum transformation developed by the authors is described. Cubic spline is calculated for the initial spectrum in coordinates (Eφ(E),ln(E)), where E—neutron energy, φ(E)—differential function of flux density. As the spline of the spectral function Eφ(E) contains complete information about the differential neutron flux density, it allows to calculate group flux as well as differential values for an arbitrary energy scale.
The algorithm of the corresponding transformation of the spectrum covariance matrix is described. Both algorithms are realized as a computer code for IBM PC.
Characterization and Representation of the HPGE Detector Efficiency
Authors: Sparks MH , Griffin PJ , Flanders TM , Sallee WW , Vehar DW 
Published: April 2008

The feasibility and utility of calculating efficiency curves for HPGe detectors using the MCNP 4B transport code are explored. The calculated curves are compared to experimental data obtained from a 137Cs source counted on a HPGe detector. Efficiency data for the four centimeter reference location are reported in this work. The detector, shield, and counting fixtures are included in the model.
This work also involved extensive sensitivity analyses. Sensitivity studies focused on seven parameters involving the active area of the germanium crystal. Three of the seven variables were found to be significant.
Fatigue Crack Growth Thresholds, Endurance Limits, and Design
Authors: Newman JC , Piascik RS 
Published: April 2008

Description
Leading experts provide 24 papers addressing four areas pertinent to fatigue crack growth thresholds: mechanisms, test procedures, analysis, and applications.
Mechanisms: Three mechanisms that influence thresholds are discussed including: crack-tip closure, environment, and Kmax effects. A simplistic four-parameter model that describes FCG threshold behavior of elastic-plastic materials is also presented.
Test Procedures: Eight papers focus on loading and specimen-type effects with research showing that the resistance-curve (R-curve) method to determine the threshold for fatigue-crack growth should allow more reliable application of ΔKth values to engineering problems.
Analysis: Three papers analyze the behavior of fatigue cracks in the threshold regime using several different analysis methods. These methods were the elastic-plastic finite-element method (FEM), the Dugdale-type mode, the BCS (Bilby, Cottrell and Swinden) model, and a discrete-dislocation model.
Applications: Nine papers address applications of threshold concepts and endurance limits to aerospace and structural materials. The impact of a number of testing variables on the measurement of fatigue-crack-growth thresholds, in particular ASTM E 647, Test Method for Measurement of Fatigue Crack Growth Rates is also discussed.
Pendulum Impact Testing: A Century of Progress
Authors: Siewert TA , Manahan MP 
Published: April 2008

Description
This unique volume examines 23 peer-reviewed papers that represent the latest worldwide technology in pendulum impact testing. Written by 50 U.S. and international experts in their field, these papers are organized into 4 sections:
• Background of Impact Testing
• Reference Energies, Machine Stability, and Calibration
• Impact Test Procedures
• Fracture Toughness Assessment from Impact Test Data
STP 1380 marks the 100 year anniversary of the invention of the pendulum impact test by S. Bent Russell, and the research and standardization efforts of G. Charpy during the early part of the 20th century. As an added bonus, reprints of two landmark papers written by Russell and Charpy are included in this volume, describing the development of the test equipment and procedures.
Marine Corrosion in Tropical Environments
Authors: Dean SW , Delgadillo GH-D , Bushman JB 
Published: April 2008

Description
This unique, new ASTM publication details the latest worldwide research on atmospheric corrosion, seawater corrosion, deterioration of concrete, and underground corrosion issues pertaining to tropical environments.
21 peer-reviewed papers cover:
• Mechanisms of corrosion processes.
• Performance of various remedial measures to prevent corrosion damage to steel in concrete.
• Proposal for revision of the ISO atmospheric corrosivity classification.
• New approach to cathodic protection of rebar and concrete.
• Evaluation of stainless steel for rebar in concrete as a long-term solution.
• Protection of underground structures in tropical marine environments.
• Difficulties of coating stainless steels for use in seawater.
Effect of Dilute Alloy Additions of Molybdenum, Niobium, and Vanadium on Zirconium Corrosion
Authors: Sabol GP , Comstock RJ , Nayak UP 
Published: April 2008

An alloy development effort was undertaken to improve the corrosion performance of zirconium-based alloys for high-burnup applications. As part of that effort, three binary alloys were studied to establish the relationship between alloy chemistry, processing, microstructure, and corrosion behavior. the binary additions included molybdenum, niobium, or vanadium at concentrations ranging from 0.1 to 2.5 weight percent. Process variables included cooling rate from the beta phase, aging temperature from 500 to 700°C, and aging times up to 1000 h. The corrosion behavior of these alloys was then studied by testing in 360°C water and 427°C steam and compared to Zircaloy-4.
The effect of alloy content and processing was monitored by characterizing the microstructure of the material. In general, quenching from the beta phase formed martensite for all three alloys with essentially all alloy additions remaining in solution. Subsequent working and aging treatments resulted in precipitation and precipitate growth. These changes in the microstructure were correlated to changes in the corrosion behavior. Typically, corrosion performance initially improved with aging followed by gradual degradation with continued aging. While this trend was observed for all three alloys, the optimum aging treatment was dependent upon alloy chemistry and composition. The results showed that the corrosion behavior was dependent upon the amount of alloying element present in the alpha zirconium matrix, provided the precipitates remained less than a critical size. This critical size was alloy dependent. The vanadium alloy was observed to be more sensitive to heat treatment than the molybdenum and niobium alloys. For all three alloys, corrosion performance superior to Zircaloy-4 could be achieved by an optimum aging treatment.
The details of the relationship between heat-treatment, microstructure, and corrosion response are presented and discussed.
Impact of Second Phase Particles on BWR Zr-2 Corrosion and Hydriding Performance
Authors: Rudling P , Wikmark G , Lehtinen B , Pettersson H 
Published: April 2008

BWR fuel cladding corrosion and hydriding performance may limit the fuel residence time. Historically, out-of-pile high-temperature steam tests have been used to predict the BWR corrosion performance of Zircaloy materials. However, results indicate that no correlation exists in many cases between in-pile and out-of-pile Zircaloy corrosion performance. Concerning BWR hydriding performance there appears to be no reliable out-of-pile test that predicts the BWR Zircaloy hydriding performance.
The Zircaloy corrosion and hydriding performance is a function of: 1. The environment such as the temperature, fast neutron flux, water chemistry. 2. The Zircaloy microstructure, such as texture, dislocation density, matrix chemical composition, and second phase particle SPP characteristics.
One way to solve the problem with the lack of reliable out-of-pile tests is to correlate the BWR Zircaloy corrosion and hydriding performance to the initial microstructure. Such a correlation will of course not predict the impact of temperature, fast flux, and water chemistry on Zircaloy corrosion and hydriding performance.
This paper describes the correlation between the BWR Zircaloy corrosion and hydriding performance and the Zircaloy SPP microstructure. Six Zr-2 fuel cladding rods irradiated in three different reactors to a fuel rod average burnup of &gt;40 MWd/kgU were included in the study. The fuel claddings had varying chemical compositions and were manufactured by three different process routes, resulting in large differences in SPP characteristics. Hot cell examinations including oxide thickness and hydrogen content determinations were performed. Also SPP SEM analyses were done to assess the size distributions of the irradiated materials. In addition, SEM and TEM analyses were performed on non-irradiated achive samples from the same manufacturing lots as the irradiated materials. We further describe how the initial SPP size distribution alters with irradiation and how the BWR Zr-2 corrosion and hydriding performance correlates with the initial SPP size distribution and SPP chemistry.
Interpretations of Tensile Properties of Polyamide 6 and PET Based Thermoplastics Using ASTM and ISO Procedures
Authors: Jia N , Kagan VA 
Published: April 2008

As more and more U.S. companies are looking to convert from ASTM to ISO standards for materials development, testing, and analysis in order to gain greater opportunities and compete more effectively in the global market, it has become increasingly important to deal with the concerns raised during the conversion process, so that the differences can be reconciled and harmonies can be brought into the two sets of standards.
This article presents our investigation on several technical issues in the ASTM and ISO standards on the tensile properties of plastics. Using polyamide (PA) 6 and polyethyleneterephthalate (PET) based thermoplastics as examples, our analysis revealed a range of similarities and differences in these two testing procedures. With either procedure — ASTM or ISO — similar results were obtained for material parameters such as tensile strength, tensile strain, and modulus of elasticity, in nonreinforced and short glass fiber reinforced plastics.
The investigation also focused on the role of the system compliance on the tensile strain and modulus measurements, and the effect of grips (wedge- and side-action grips) and gripping on the tensile behavior of the materials. Among the two types of grips, the wedge-action grip was found to cause greater measurement variability, especially in Young's modulus. The analysis of system compliance, on the other hand, reinforced the statements in both testing standards that an accurate strain and modulus measurement would require the use of extensometer. The results in this article went further to indicate how to improve the accuracy in the Young's modulus using the system compliance when the extensometer was not applied during testing. Recommendations were made on the effective use of the testing procedures in product development and design.
Instrumented Pendulum Impact Testing of Plastics
Authors: Manahan MP , Cruz CA , Yohn HE 
Published: April 2008

Conventional impact tests (without instrumentation) are performed to measure the energy required to break a notched specimen under dynamic loading. Instrumented impact tests not only measure the notched specimen breaking energy but also quantify the energy required to form a crack at the root of the notch and the energy required to propagate the crack through the material. Instrumented test systems use strikers which have strain gages so that the load-deflection curve during the impact event can be derived. These data provide load, deflection, and energy data which can be correlated with engineering parameters such as fracture toughness, ductility, and fracture resistance.
This paper compares instrumented impact results obtained using both the Charpy and Izod test procedures. Several possible limitations of the instrumented test procedure have been identified and test procedures to overcome these limitations have been proposed. In addition, an important potential limitation of the Izod test, specimen clamping pressure, has been studied.
Multiple Stressor Effects in Relation to Declining Amphibian Populations
Authors: Linder G , Krest S , Sparling D , Little E 
Published: April 2008

Description
Original research discusses the protocols and approaches to studying the effects of multiple environmental stressors on amphibian populations and gives new perspectives on this complicated subject. This new publication integrates a variety of stressors that can act in concert and may ultimately cause a decline in amphibian populations.
Sixteen peer-reviewed papers cover:
Toxicity Assessment examines methods, which range from long-established laboratory approaches for evaluating adverse chemical effects to amphibians, to methods that link chemicals in surface waters, sediments, and soils with adverse effects observed among amphibians in the field.
Field and Laboratory Studies illustrates studies in the evaluation of multiple stressor effects that may lead to declining amphibian populations. A range of laboratory and field studies of chemicals, such as herbicides, insecticides, chlorinated organic compounds, metals, and complex mixtures are also included.
Causal Analysis demonstrates the range of tools currently available for evaluating "cause-effect" relationships between environmental stressors and declining amphibian populations.
Audience: This new publication is a must-have for scientists and resource management professionals from diverse fields, including ecotoxicology, chemistry, ecology, field biology, conservation biology, and natural resource management.