bluuebunny/crossref_metadata_2025 huggingface dataset:
Podometrics: A New Methodology for Foot Typing
Authors: Rossi WA
Published: February 2009

Podometrics is an original and innovative system to establish cartographical and geometrical parameters for the human foot: a methodology for “mapping” the foot to determine foot types by anthropometrical classification. A methodology has long been evasive because of the challenging complexities of the foot with its unique shapes, components and many converging contours and angles. Foot typing efforts to date have not been particularly productive or effective because the emphasis has been mostly on external features rather than on both internal and external features; and also because the main focus has been on numerical measurement data rather than geometrical design. Further, foot typing has often included both structural and functional features, which sometimes tend to be conflicting and confusing by intermixing structural and functional types.

Podometrics has numerous potential practical applications in various fields. For example, in orthopaedics and podiatry in establishing foot norms in the diagnosis and therapies of foot disorders; in the shoe industry for the design of shoe lasts and footwear, and enabling the development of a uniform system of shoe sizes for better shoe fit and more efficient biomechanics within the shoe; in physical anthropology for developing an anthropometric system for genetic or racial foot typing; in criminology for detection of body type via foot type obtained from footprints.
Characterization of Early and Modern Wire for an Italian Harpsichord
Authors: Underwood JH , Burr W , Kapusta AA , Rickard CA
Published: February 2009

The characterization of early and modern harpsichord wire is described, part of the musical restoration of a 1610 Italian harpsichord. Three sizes of brass wire believed to the original strings of the harpsichord and one type of steel wire also found with the instrument were characterized using a variety of metallographic tests. Three similar sizes of modern brass wire used in the restoration of the instrument were also characterized and compared with the early wire. Microhardness and microstructure were evaluated using optical microscopy, and the overall and surface appearances and chemical constituents of the wires were determined using scanning electron microscopy. Microhardness results were used to obtain estimates of tensile strength of the wires. Various aspects of the results were discussed in relation to three time periods of the instrument: the early 1600s when it was crafted, the late 1800s when it may have been fraudulently repressented as a mid-1500s instrument, and its corrent use as a restored instrument.
Testing the Superplastic Flow Characteristics of Advanced Aluminum Alloys
Authors: Goforth RE , Srinivasan MN
Published: February 2009

Special test equipment is required in order to determine the superplastic flow characteristics of advanced aluminum alloys such as the low-density aluminum-lithium alloys and the high-temperature intermetallics (processed by rapid solidification, mechanically alloying, powder metallurgy techniques). The superplastic flow characteristics under optimum conditions of strain race and temperature are necessary as input data to the computer process model weed to predict optimum pressure-time cycles for the SPF process. Most published tensile flow stress data for superplastic deformation was developed under constant crosshead speeds and at atmospheric pressure. In order to establish accurate flow characteristics, testing must be conducted: (1) at a closely controlled temperature, (2) at a controlled constant true strain rate, and (3) under hydrostatic pressure (to prevent cavitation). This paper discusses the design and development of a test system with these capabilities and also highlights typical results for three aluminum-lithium alloys.
The ASCOR Test: A Simple Automated Method for Stress Corrosion Testing of Aluminum Alloys
Authors: Schra L , Groep FF
Published: February 2009

Alternate immersion stress corrosion testing according to ASTM G 44, Practice for Alternate Immersion Stress Corrosion Testing in 3.5% Sodium Chloride Solution, has proves to be representative for alumimum alloys in natural environments resembling the actual eavironmental conditions for aircraft. A simple automated stress corrosion testing method called the ASCOR (automated stress corrosion ring) test was developed to test aluminum alloys according to ASTM G 44 and using direct stressing as in ASTM G 49. Recommended Practice for Preparation and Use of Direct Tension Stress Corrosion Test Specimens. The method involves testing cylindrical or pin-loaded flat tension test specimens in a loading sing provided with strain gages to measure the load. Initiation of a stress corrosion crack (SCC) results in a small load decrease. During the test the load is measured periodically and stored in a data acquisition system controlled by a personal computer. A specific load decrease is used as the criterion for SCC initiation. The main advantages of the method are that a large number of specimens can be tested simultaneously in a climate chamber and that SCC initiation lives can be determined according to a clearly defined criterion without time consuming and subjective inspections, and without disturbing the test procedure.
Use of a Proposed Test Procedure for Quantifying the Triboelectric Charging Propensity of Packaging Films
Authors: Hall CW , Singh SP , Burgess G
Published: February 2009

This investigation used a proposed test procedure to quantify the triboelectric charging tendencies of conductive, dissipative and insulative packaging films in rolling contact with cylinders made of quartz, brass, and Teflon®. The intent was to simulate the potential build up of static charge on electronic products packaged in these materials during handling or transportation Charging was accomplished by rolling the cylinders down a presenbed length of incline covered with these films.

The research found that there was no significant difference between the various film material classifications in their ability to limit triboelectric charging. There was however a significant difference between cylinder materials with Teflon acquiring the highest negative charge on all film materials. Cylinder weight was also found to be important as the heavier brass cylinder attained more charge on some film materials than a hollow brass cylinder the same size A greater angle of incline in general produced a greater charge on the cylinders for all film materials.
Performance of Hybrid Reinforcements in PVC Composites: Part I—Use of Surface-Modified Mica and Wood Pulp as Reinforcements
Authors: Maldas D , Kokta BV
Published: February 2009

In the present study, the hybird behavior of surfacetreated mica and hardwood chemithermomechanical pulp (CTMP) in PVC composites was investigated. In order to improve the compatibility of wood fibers with PVC and surface-coated mica, CTMP was subjected to different surface modifications by pretreating the fibers with maleic anhydride (MA), a mixture of MA and Na-silicate, and with an inocyanate (PMPPIC). The effect exerted by the concentration of reinforcements, composition of hybrid as well as the treatment of CTMP, on the mechanical properties of the hybrid composites were evaluated. In general, these properties improved compared to those of uncoated CTMP/mica-filled composites. Moreover, PMPPIC treatment renked best followed by MA — and MA + silicat treatments. The optimal concentrations of reinforcements and their compositions, which provided superior properties, varied according to the nature of the trestment of CTMP and of the individual mechanical properties themselves.
The Effect of Moisture on Laboratory-Prepared Asphalt Mixtures
Authors: Akili W
Published: February 2009

This paper presents the results of a laboratory study conducted to examine the water-induced damage of compacted and loose asphalt-aggregate mixtures from Riyadh, Saudi Arabia. One asphalt cement and two typical aggregate sources (A and B) were used to prepare asphalt mixtures. Test methods used included the Marshall stability ratio, the wet-dry indirect tensile test (Lottman). and coating and stripping tests of uncompacted mixtures (ASTM D 1664, Test Method for Coating and Stripping of Bitumen-Aggregate Mixtures, and ASTM D 3625. Test Method for Effect of Water on Bituminous-Coated Aggregate-Quick Field Test).

The test results have shown superior performance of mixtures prepared from Source A aggregate in comparison with Source B Differences in physical properties of the fine fraction between the two sources appear to be responsible for the noted difference in behavior However, mixtures with water susceptible aggregate (Source B) have exhibited improved performance when natural sand. used routinely in combination with crushed sand, is reduced or eliminated.

The partial replacement of the crushed limestone filler by cement or lime had positive effects on performance of water-susceptible mixtures. Distinct improvements in 24-h Marshall stability were exhibited when 2% hydrated lime was added.

Based on the results, the test methods deployed in this study appear to do a reasonable job in detecting moisture-susceptible pavement mixtures and in evaluating the relative effectiveness of additives in minimizing water damage potential.
The Effect of Wet Abrasive Wear on the Tensile Properties of Cotton and Polyester-Cotton Fabrics
Authors: Ukponmwan JO
Published: February 2009

The tensile properties of cotton and polyester-cotton woven fabrics have been analyzed in terms of the breaking load, breaking extension, breaking elongation, and elongation at 1 kg (1% full-scale-deflexion (FSD)) using the Instron Tensile Tester, Model 1026. Changes in tensile properties of the woves fabrics as a consequence of wear using the Accelerotor Abrasion Tester in wet conditions are illustrated. The tensile properties before and after abrasion and the effect of abrasion damage on the tensile properties were determined. The Spearman rank correlation coefficient was used to determine the interrelationship between the tensile properties and percentage loss in weight. Relationships between the tensile properties, mass, thickness, density, and specific volume of these fabrics before abrasion are also reported. A significant positive correlation (at 5% and 1% levels) was obtained between breaking load, breaking extension, and breaking elongation, and between breaking extension and breaking elongation in both wet and damp abrasion. Determination of a simple paired t-test showed that there was no significant difference between the unabraded and abraded fabrics (wet and damp), or between wet and damp abraded fabrics at the 95% confidence interval with respect to tensile properties.
Axial-Torsional Fatigue: A Study of Tubular Specimen Thickness Effects
Authors: Bonacuse PJ , Kalluri S
Published: February 2009

A room-temperature experimental program was conducted on AISI type 316 stainless steel to determine the effect of wall thickness on the cyclic deformation behavior and fatigue life of thinwall, tubular, axial-torsional fatigue specimens. The following experimental variables were examined in this study: the depth of the surface work-hardened layer produced in specimen machining, and the effects of strain range and axial-torsional strain phassing. Tubular fatigue specimens were fabricated with wall thicknesses of 1.5, 2.0, and 2.5 mm. One as-fabricated specimen from each wall thickness was sectioned for microstructural examination and microhardness measurement. A specimen of each wall thickness was tested at each of three conditions—high strain range in-phase, low strain range inphase, and low strain range out-of-phase—for a total of nine axialtorsional fatigue experiments. Little or no variation in the fatigue life or deformation behavior as a function of wall thickness was observed. The machining-induced work-hardened zone, as a percentage of the gage section material, was found to have a minimal effect on both deformation behavior and fatigue life. Out-of-phase fatigue tests displayed shorter fatigue lives and more cyclic hardening than in-phase tests.
Effects of Wash Temperature on Bacterial Survival and Strength Retention of Cotton Fabrics
Authors: Perenich TA , Moore MA
Published: February 2009

The influence of temperature, detergent type, and labric finish on bacterial survival and strength retention and clongation in fabrics were investigated in this study. Previous research has shown that temperature is a critical factor in the removal, redeposition, and destruction of microorganisms in the laundering process. The results showed that fabric finish did not have any significant effect on bacterial survival but did influence both strength retention and breaking clongation. Temperature significantly affected bacterial survival and breaking strength and clongation. The addition of a detergent, especially a phosphate detergent, in the laundering process is important in diminishing bacterial survival on fabrics.
Embrittlement of an AISI 8640 Lower Bainite Steel
Authors: Rinnovatore JV , Lukens KF , Reinhold J , Mahon W
Published: February 2009

A study was performed to determine the cause of an abnormally low fracture toughness of an AISI 8640 resulfurized steel. The embrittlement effects of phosphorus and arsenic on this steel heat-treated to a lower bainitic structure were studied by employing fracture toughness tests, Charpy impact tests, X-ray fluorescent spectroscopy, and scanning electron microscopy (SEM). The results showed that the steel was embrittled by phosphorus at prior austenite gram boundaries in a manner similar to the tempered martensite embrittlement (TME) phenomenon. Arsenic is also believed to be involved in the embrittlement effect, specifically as related to producing a reduction in the upper shelf Charpy impact energy. Embrittlement was manifested by a reduced fracture toughness, an increase in the Charpy transition temperature, and intergranular fracture.
Influence of Substrate Deformations on the Thermal Fatigue Life of SMT Solder Joints
Authors: Zafran JB , Sandor BI
Published: February 2009

Previously published expressions based on life data for bulk solder are used in this paper to calculate the number of thermal cycles to failure of the solder joints of leadless chip carriers attached to various substrates. The devices used by Hall in thermal chamber cycling and power cycling are chosen for analysis. The values of deformations in terms of shear strain range and total mismatch are presented and compared. The fatigue lives of the solder joints are predicted based on the deformation data, the test conditions, and the Coffin-Manson expression. Attempts are made to correct some crucial differences in previous work or to fill in for missing information. The resulting predictions are explained according to the specific models used.
Mean Stress Diagrams for Composites Generated Using a Modified Up-and-Down Test Methodology: Part II—Limited Preliminary Data
Authors: Little RE
Published: February 2009

Constant-stress-amplitude axial-load fatigue tests were conducted to generate mean stress data for notched and unnotched specimens of a compression molded thermoset composite material with 27% (by weight) randomly oriented 1.0-in.- (25.4-mm) long E-glass fibers in a (Phase Alpha) polyester matrix. Maximum likelihood point and interval estimates for median fatigue strengths at 107 cycles were computed for four stress ratios R (−1.0, −0.2, +0.2, and +0.6) based on tests conducted following a modified small sample up-and-down methodology appropriate when limited preliminary data are available to aid in test planning.
Characterization of Defects in Graphite Fiber Based Composite Structures Using the Acoustic Impact Technique (AIT)
Authors: Raju PK , Patel JR , Vaidya UK
Published: February 2009

Acoustic Impact Technique (AIT), commonly known as “coin-tapping,” has been applied by previous investigators as a nondestructive evaluation technique to study disbonds in composite honeycomb structures. The experimental configuration adopted by previous investigators was somewhat restricted. In this study, a different approach to AIT is developed. This was done to overcome the experimental constraints encountered in the previous approaches. This paper presents experimental results obtained in the evaluation of defects commonly found in graphite based composite structures, such as delamination, fiber breakage, and misaligned fibers. The experimental approach adopted in this work has two main features. Primarily, the force-time history of the specimen's response to a low magnitude input pulse in different regions of the specimen is compared. Secondly, an Acoustic Emission (AE) wide band sensor was used in conjunction with the conventional acoustic impact technique. The combination of the AE sensor and AIT enabled the study of the material interaction with stress waves generated in the vicinity of the tapped region. Gross defects such as delaminations were identified through the change in the pulse width of the force input, while defects such as fiber breakage and misaligned fibers were successfully identified using AIT in conjunction with AE.
Characterization of Hypervelocity Impact Debris: Naval Research Laboratory Tests
Authors: Fortson BH , Winter JE
Published: February 2009

Characterization of debris from hypervelocity impact events is an important prerequisite for analytical or empirical predictive modeling of those events. One feature of a useful model would be its ability to predict the characteristics of the debris cloud produced by the impact, and this feature cannot be evaluated without a body of test data with which to compare the analytical predictions. In the current effort, debris produced by hypervelocity impact experiments at the Naval Research Laboratory (NRL) is collected and described. An attempt is also made to construct a parametric model of the data in order to assess the effectiveness of this approach. A model based on a linear relationship is seen to perform well, while a parabolic relationship performs less well, and a bilinear relationship performs poorly. A lognormal distribution is seen to describe the debris more effectively them an exponential distribution. However, the performance of the exponential distribution is seen to improve when the very largest fragments are removed from consideration.
Maximum-Load Predictions in the Dugdale Model Using a Critical CTOA Criterion
Authors: Gu I
Published: February 2009

An engineering method of elastic-plastic fracture analysis is suggested for plane-strain specimens under tension. The condition for an increment of crack extension is set by a critical increment of crakc tip opening displacement (CTOD). The CTOD increment divided by the incremental crack extension is a critical crack tip opening angle (CTOA), assumed to be constant for a material of a given thickness, characterizing the tearing resistance of material. Based on a finite-element analysis of crack tip deformation, a load term in the CTOD equation of the Dugdale strip yield model is modified to accommodate large and small scale yielding, for which cohesive stress in the strip is assumed greater than that for the plane-stress model Approximate generalization of the Dugdale model is suggested for finite-size specimens. A definition of CTOD is reviewed with a round and sharp crack tip. In a successive application of the CTOA criterion at a current extending crack tip, the integration of the incremental crack extensions and load increments after fracture mitration gives a relationship in which a maximum load is either a peak load or a limit load on an unbroken ligament. Material constants are evaluated so that the calculated loads agree with test loads at each crack extension. The proposed method is applied to various specimens of 304 stainless steel for which test data are available.
Laboratory Testing Procedure for Evaluation of Moving Bed Catalyst Attribution
Authors: Doolin PK , Gainer DM , Hoffman JF
Published: February 2009

A laboratory scale attribution test has been designed to simulate particle-particle and particle-wall attrition forces which are similar to those experienced in commercial moving bed units. The modified drum test uses two concentric rotating drums to induce particle breakage. Using this test, the distribution of particle shapes and sizes produced by catalyst attrition in a moving bed unit have been successfully duplicated.
Introduction to Workshop on Accuracy of Load and Strain Measurement of Testing Machines
Authors: Perlov A
Published: February 2009

These questions and others related to the accuracy of test results in material testing were subjects of the papers presented at the workshop on Accuracy of Load and Strain Measurement of Testing Machines, held on 18 November 1992 in Miami, FL.
What's New in Traceability
Authors: Garner EL , Rasberry SD
Published: February 2009

The traditional concept of measurement traceability in the United States has focussed on an unbroken hierarchial pathway of measurement compatisons to national standards Also ingrained in tradition is the tendency to focus on the audit trail rather than on a quality measurement assurance program in which there is sufficient accuracy to accomplish the intended purpose. Evolutionary changes in the U.S. concept of traceability and the forces producing them will be reviewed. Specific examples are used to illustrate the traditional approach to traceability as well as options that might be exercised in the future.
Pressure and Flexible Membrane Effects on Direct-Contact Extensometer Measurements in Axisymmetric Compression Tests
Authors: Mellegard KD , Pfeifle TW , Fossum AF , Senseny PE
Published: February 2009

Axisymmetric compression tests have become routine tests in laboratory experiments on pressure-seasitive materials like geologic material. The usual compression test unes right-circular-cylindrical specimens that are encased in a protective membrane, placed in a pressure vessel, and then subjected to some combination of axial stresses and confining pressures. The best measurement of the resulting specimen deformation can be made by installing pressure-rated instrumentation directly on the specimen. However, responsible experimental practice requires that the effects of pressure and the protective membrane on the deformation measurements be understood. This paper attempts to quantify such effects.

The investigation began with an evaluation of the pressure effects on the instrumentation. Significant pressure effects required that correction factors be introduced. After these pressure effects had been quantified, four types of protective-membrane conditions were tested in three common types of compression tests. The four conditions were: (1) no jacket, (2) thin jacket, (3) thick jacket, and (4) ported jacket. The three compression tests included hydrostatic compression (HC), triaxial compression (TC), and uniaxial strain (US). A single result at each combination of jacket condition and test mode required that twelve tests be performed. The results show that protective membranes can have a very significant effect on the elastic moduli calculated from the deformation measurements, but in some cases the errors can be reduced or eliminated through the use of correction factors or specially designed membranes.
A Comparison of Calculated Geometric Surface Area and Measured BET Surface Area for a Metal Powder
Authors: Schrøder-Pedersen A , Kjøller J , Larsen B
Published: February 2009

The specific surface areas of gas atomized (spherical) metal powder fractionated into 6 size fractions below 125 μm were determined by BET measurements and by geometric derivation from particle size distributions. The areas obtained were compared and a linear correlation was found. Even though the total areas measured were relatively low, in the range of 0.3 m2, the BET measurements followed the areas derived from particle size with a proportionality factor around 1.8. It was concluded that BET surface area measurements represent true area closely, when true area is understood as the envelope best fitting the powder particles. The deviation of the BET measurements from the true area is concluded to be less than 20%, with increasing accuracy for increasing specific surface area.
New Technique for Evaluating Damping of Longitudinal Free Vibration in Wood-Based Materials
Authors: Cai Z , Hunt MO , Fridley KJ , Rosowsky DV
Published: February 2009

Classical log-decrement techniques have been used to evaluate the damping property of materials. However, the consistency and repeatability of the methods when applied to wood and wood-based materials have been found lacking. A different way to view the free vibration of a single-degree-of-freedom system in the x − ˚x plane is presented. A new method that uses all sample points and does not require a knowledge of the initial conditions to determine the damping properties is developed. A comparison between the new method and the classical method is made for three wood-based materials: solid wood, medium density fiberboard (MDF), and particleboard. The results show that the new method is more consistent and repeatable in measuring damping than the classical method. For the six cases examined, there was an absolute average difference of 3.8% in measuring log-decrement between the methods.
Crack Tip Opening Displacement (CTOD) Toughness Evaluation by ASTM E 1290 and BS5762: A Comparative Analysis
Authors: Bhattacharya S , Kumar AN
Published: February 2009

ASTM Committee E-24 on Fracture has recently standardized the crack tip opening displacement (CTOD) measurement method. Three major differences between the ASTM E 1290-89 method and British Standard BS5762:1979 are outlined, and the influence of these differences on the critical crack initiation CTOD value is studied. The study is based on a typical fatigue crack and slow crack growth front profile. A difference of up to 6% in the CTOD values between the two standards, irrespective of the slow crack growth size, was found in the present study. However, a marginal ditterence of only 2% in the initiation CTOD value could be observed for the slow crack growth situation considered.
Critical Assessment of Methods for JIc Determination
Authors: Pandey RK , Sundaram P , Kumar AN
Published: February 2009

Various methods for the evaluation of J-initiation toughness have been compared by conducting investigations on Mo and Cr-Mo steel at different temperatures (i.e., 30 to 460°C) by employing the single-edge-notch bending configuration. The methods investigated include ASTM Standard E 813, a method proposed by the European Group on Fracture (EGF), methods based on a stretch zone approach, and a proposed method of the Japan Society of Mechanical Engineers (JSME). The blunting line approach for toughness determination has been investigated in detail in the light of various propositions made by other investigators, and an equation for the blunting line has been proposed based on the findings from the present work as well as from literature data. A J-resistance curve based on mid-thickness crack growth combined with the stretch zone approach for the blunting line appears to provide a mose comsistent method for toughness determination.
Tensile Stress Relaxation in High-Strength Spring Steel Wire
Authors: Sinha UP , Levinson DW
Published: February 2009

Stress relaxation data were obtained in tension tests using the vibrating string technique (measuring the resonance frequency) in spring steel wire of ASTM Grade A 228 (also known as music wire). The steel wire of 0.56 mm diameter had a 0.29% offset tensile yield strength of 1689 MPa. Tests were conducted at low temperatures in the range of 23 to 140°C, and at initial stress levels of up to 75% of the 0.20% offset yield strength of the wire. The test duration was to 4000 h at 23°C and to 100 h at temperatures to 140°C. The test results indicate a faster rate of stress relaxation during the early stage of stress relaxation, and subsequently a slower rate of stress relaxation rate with increasing time, as is usually observed. An empirical equation has been determined that fits the experimental data very well under the given test conditions.
Accelerated Weathering of Marine Fabrics
Authors: Mooce MA , Epps HH
Published: February 2009

Fabrics designed to be used in marine applications must retain strength and resist color change over prolonged exposure to a variety of potentially degrading factors, including sunlight, variations in temperature and relative humidity, and repeated cycles of wetness and dryness. This research focused on the effects of instrumental weathering on the end-use performance properties of three woven marine fabrics currently available for use as sails. The fabrics were 100% polyester, 100% acrylic, and 100% nylon. Changes in fabric color and tensile properties were analyzed after exposure to three levels of simulated sunlight under both dry and moist conditions.
Fracture Toughness Determination Related to Indentation Problems Avoidance in Three-Point Bend Specimens
Authors: Santarelli EL , Perez Ipiña JE
Published: February 2009

In elastic-plastic fracture toughness of the three-point bend specimens (3P-SENB) test, fracture toughness is obtained as a function of the energy put into the specimen, and it is measured from the area under the load versus load-line displacement record. A fraction of this energy is not developed as a work in the crack tip, but it is expended in plastic deformation near the loading points. There also exists an overestimation of this energy because of spurious displacements involved between measurement points when a remote transducer is used to measure the load-line displacement. Actual standards provide some techniques to discriminate this spurious energy from the total measured energy.

By checking the experimental setup performance, some differences are evident between the proposed corrections and the real phenomenon during the test. In this paper a simple method for measuring the load-line displacement is proposed, which is able to avoid automatically the spurious energy.

The energy developed by the load components on the outer loading points and its contribution on J is also discussed, and equations to take into account this energy are proposed.
An Evaluation of the Impression Test for Estimating the Tensile Properties of Metallic Materials
Authors: Jones HN
Published: February 2009

The load versus displacement response of a flat-ended cylindrical indenter when pushed into a material at a constant displacement rate, termed the “impression test,” and originally used as a measure of the compressive flow curve of metals, has also been used for estimating the tensile properties of metallic materials. The validity of this test method for determining tensile properties has been studied for five different materials of widely differing tensile flow behaviors. It is demonstrated that the impression test, like all indentation or hardness tests, can be used for the estimation of tensile properties of metallic materials only under very restrictive circumstances. In particular, the test cannot be relied upon alone without calibration and verification by actual tension tests, as it is insensitive to variations in tensile ductility. It was possible, with empirically defined relationships, to obtain reasonable estimates of the tensile yield stress for most of the materials studied. For true tensile strengths of metallic materials the method was less successful. In the case of heterogeneous materials of limited tensile ductility, such as gray cast iron or some particulate reinforced metal matrix composites, the test failed to give a valid characterization of tensile properties. Additionally, it was found to be insensitive to the upper and lower yield point associated with the initiation and propagation of a Luders band which is commonly observed in annealed low-carbon steels.
Temperature Calibration of Thermomechanical Analyzers: Part I—The Development of a Standard Method
Authors: Earnest CM , Seyler RJ
Published: February 2009

Thermomechanical analysis (TMA) is conducted with a variety of configurations involving differing probe geometries under static loading in tension, compression, or flexure. The most frequent assignment made in these applications involving thermomechanical measurements is that of transition temperatures, which include the melt temperature, glass transition, softening point, etc. Assurance of an isothermal study temperature is also a common requirement in TMA experiments. Intrinsic in any of these measurements is the knowledge of the sample temperature; yet, in practice, it is only the temperature in close proximity to the specimen that is known.

The transformation of proximity temperatures recorded in thermomechanical devices to sample transition temperatures is of utmost importance in both basic research and quality control of materials. It is accomplished by an accurate calibration of the TMA sample temperature and should be considered a prerequisite to may other determinations. This paper will discuss the topic of temperature calibration of thermomechanical devices. Efforts which led to the establishment of ASTM E 1363, Test Method for Calibration of Thermomechanical Analyzers, for the calibration of such TMA instruments through ASTM Task Group E37.01.12 will be included.
Temperature Calibration of Thermomechanical Analyzers: Part II—An Interlaboratory Test of the Calibration Procedure
Authors: Seyler RJ , Earnest CM
Published: February 2009

An interlaboratory “round robin” test study was conducted for the calibration method developed by ASTM Task Group E37.01.12, which was described in Part I of this paper. The interlaboratory test protocol was consistent with the requirements outlined in ASTM E 691, Practice for Conducting an Interlaboratory Test Program to Determine the Precision of Test Methods. The results obtained by 10 participating laboratories were used to prepare a precision and bias statement for ASTM E 1363, Test Method for Temperature Calibration of Thermomechanical Analysers. Statistical treatment of the data yielded at the 95% confidence level a repeatability limit r = 1.43904°C, a reproducibility limit R = 4.11475°C, and a bias of 0.0137°C.
Vibration Levels in Commercial Truck Shipments as a Function of Suspension and Payload
Authors: Singh SP , Marcondes J
Published: February 2009

This paper addresses the vibration levels in commercial truck shipments. Data were collected on various truck shipments in the United States over various interstate expressways. Comperisons are shown for effect of suspension, weight of shipment, and road quality. Data are presented in the form of Power Density Spectrums that can be used for simulating tests on electro-hydraulic vibration tables. These plots are composite spectrums showing the average levels observed in these studies from data collected over 16 000 km of road conditions. Specific data for a section of road condition, load configuration, and suspension used may vary from these average levels. The results of these studies were requested by the ASTM D 4728 Task Group on Random Vibration Testing of Shipping Containers, to be recommended for package testing.
Resonance Monitoring of Building Assemblies for Durability Tests
Authors: Hearn G , Testa RB
Published: February 2009

Resonance monitoring is an established method for detecting deterioration in materials in accelerated aging tests Current ASTM practice monitors a single resonance. If more than one resonance is monitored it becomes possible to distinguish localized deterioration from general deterioration, to identify the specific locations of deterioration, and to recognize anticipated deterioration events. Data on location of deterioration is important in durability tests for assemblies where a distinction between materials failures and failures due to stress concentration is needed. Relations for the interpretation of changes in resonance as location of deterioration are developed. A laboratory study of condition monitoring by resonance in fatigue loading of a welded steel frame is reviewed. A potential application for resonance monitoring in building assemblies is outlined.
A Cutting Apparatus to Aid in the Preparation of Ring Specimens for Tensile Testing of Latex Condoms and Other Thin Elastic Films
Authors: Lennon TP , Srisamang V
Published: February 2009

A new cutting device has been developed for preparing condom ring specimens for tensile testing. The cutting apparatus requires minimal training and produces a consistent specimen. The device, consisting of a die with replaceable blades and a μg for holding the condom, was designed to be mounted on a conventional high-precision lever press. The underlying principles used in the design of this apparatus may be adapted to improve reliability and quality cutting of any thin elastic material that is difficult to handle.
Probabilistic Model for the Analysis of Dynamic Cone Penetrometer Test Values in Pavement Structure Evaluation
Authors: Divinsky M , Livneh M
Published: February 2009

Reliable analysis and interpretation of the results obtained under testing in pavement design and evaluation require consideration of the nature of the values under study, including construction of the probabilistic model that describes their statistical behavior. The investigation has been focused on the testing data peculiarities related to the dynamic cone penetrometer (DCP), which has become one of the extensively used testing devices in pavement evaluation. Application of the probabilistic models containing the stochastic components in pavement design and evaluation is determined by the nature of the pavement component characteristics, including subgrade soils, formed under the influence of various factors. The probability distribution model for the DCP values has been described based on the analysis of the statistical peculiarities of the observed data. The model reflects the main features and physical essence of the DCP values. Some differences in statistical conclusions based on the models under study have been demonstrated. Models can be recommended that have a positive influence on studying relationships between the DCP characteristics and various pavement design parameters and increase the reliability of estimates and solutions in pavement structure evaluation.
Extrapolation of Creep Strain Data for Pure Copper
Authors: Sandström R
Published: February 2009

High-temperature plants operating in the creep regime are typically designed for a lifetime of 100 000 to 250 000 h. To obtain design data, short time data must be extrapolated to the lifetimes of technical interest. In the present paper a new method for the simultaneous extrapolation of creep strain and rupture data is proposed. This approach has the advantage that it improves the statistical basis for the evaluation and makes it possible to avoid physically impossible results frequently obtained if creep strain data are analyzed separately. The method has successfully been applied to phosphorus-alloyed pure copper.
Effect of Asphalt Mix Design Method on Binder and Gradation Selection
Authors: Sousa JB , Prates M , Barros R , Langlois P , Leclerc AM , Briggs B
Published: February 2009

To investigate the hypothesis that Superpave Volumetric mix design yields superior performing mixes overall, the Portuguese Road Directorate (JAE) compared the performance of Superpave mixes with the performance of other mixes. The comparisons were made with gradations that pass through, above, and below the restricted zone. Performance was evaluated using the Marshall test, the Hveem test, the Repetitive Simple Shear Test at Constant Height, the Four Point Bending Fatigue Test, and the French Wheel Tracking Device. These research efforts led to consideration as to what extent the binder and gradation selections are dependent on the mix design tool. The results indicate that some Superpave mixes yield the lowest laboratory performance in some of the tests.
California Bearing Ratio Test Simplified
Authors: Pandian NS , Sridharan A , Raju PSRN
Published: February 2009

Due to the large volume of soil sample material and effort involved, the conventional California bearing ratio (CBR) tests are laborious and time consuming. Hence, an attempt was made to use the Proctor mold itself with a proportionately smaller plunger to estimate the CBR values. The good agreement between the CBR values obtained using the conventional mold and plunger and the Proctor mold and a smaller plunger (with a correction factor) suggests the feasibility of this approach, especially for fine-grained soils. The recommended minitest apparatus and procedure make the CBR test much simpler.
Observation of the Propagation of Plastic Strain in HSLA 80 Steel
Authors: Du ML , Chiang FP
Published: February 2009

We observed using the in-plane moire method the propagation of plastic strain in a uniform tension specimen made of HSLA 80 steel loaded quasi-statically. The steel shows a localized, heterogeneous type of transition from elastic to plastic deformation. Plastic strain generally initiates at one end of the specimen and gradually propagates toward the other end. The magnitude of plastic strain, once initiated and propagation begun, is about seven times the elastic strain. An interface band of the order of a few millimeters separates the elastic and plastic zones. Since it is a nonuniform deformation, local strain measurement methods such as strain gage, clip gage, etc. are not suitable to characterize the mechanical properties of this material.
Charpy Impact Verification Data (1994–1996): A Summary
Authors: McCowan CN , Wang CM , Vigliotti DP
Published: February 2009

We present a summary of Charpy impact verification test data that were evaluated by the National Institute of Standards and Technology from January 1994 to December 1996. The Charpy impact machines that met the verification requirements of ASTM Test Methods for Notched Bar Impact Testing of Metallic Materials (E 23) are broken down by year and by reference lot. Based on the data, a proposed verification rule that limits the range of the verification set has been examined. We also present the results for determining whether two energies (lower and upper ends of the machine capacity) or three (lower, middle, and upper) are needed to verify the performance of the large-capacity impact machines; currently E 23 requires three energies to be tested.
Effect of Austempering Variables on the Quasi-Static and Dynamic Fracture Toughness of Austempered Ductile Iron
Authors: Srinivasan MN , Komatsu S
Published: February 2009

Statistical design of experiments was employed to study the effect of austenitizing temperature, austempering temperature, and austempering time on the quasi-static and dynamic fracture toughness of austempered ductile iron of a standard composition. Regression equations were developed to determine the relative significance of the variables in affecting the quasi-static and dynamic fracture toughness of the austempered iron studied.
Ultrasonic Signal-Transmission Techniques for Compact Microtunneling Systems
Authors: Honjoh K , Hoshiya K , Nakano S , Kuwano H
Published: February 2009

This paper describes ultrasonic transmission techniques for sensor signals transmitted through water-filled pilot pipes for underground microtunneling systems. Underwater ultrasonic waves are used for transmitting the orientation and location signals of a remote-controlled machine. We have investigated the relationship between ultrasonic transmission loss and frequency with propagation distance in water-filled pipes. Digital signals can be transmitted at 100 bps for more than 50 m in 80-mm-diameter steel pipes by using underwater ultrasonic pulse waves above 300 kHz. A compact prototype ultrasonic transmitter and receiver were developed, making it possible to transmit and receive 8-bit signals through flowing water in the pilot pipes by processing their signal waveforms. Field trials demonstrated a range of signal transmission of pitching angle data over a 40-m distance for an actual compact microtunneling system.
Estimation with a Few Strain Gages of Stress Fields near a Notch Root of Actual Structures Under In-Plane Loading
Authors: Harada T , Noguchi H
Published: February 2009

In this paper, a simple method is proposed for estimating with a few strain gages stress fields near a notch root in plates under in-plane loading. In the present method, the stress fields are estimated by solving the boundary value problems. Concretely, we use the Airy's stress function for an arbitrary plate with a free circular hole, considering an edge near a notch root as a part of a free circular hole. The unknown coefficients of the Airy's stress function are determined from stress values with strain gages along a certain closed curve so that the Airy's stress function satisfies the boundary conditions at the curve. The strain values are measured only at four points on a circular arc whose radius is 1.5 times as large as the notch root radius. The method of least squares is used for determining the unknown coefficients. We demonstrate the present method using eight types of notched plates. We obtained accurate estimation results except for a few cases.
Failure Analysis Using Microfocus X-ray Imaging
Authors: Bossi RH
Published: February 2009

Failure analysis is an essential element of all engineered products. The goal of failure analysis is the understanding of the root causes of any undesirable effects. Microfocus X-ray imaging (radioscopy and computed tomography) offers detailed information on the internal assembly and material condition of objects under failure analysis investigation. Using advanced systems for the acquisition of radioscopic and computed tomography (CT) images, failure analysis investigations are improved in technical accuracy at a reduced flow time and cost over alternative approaches. A versatile microfocus radioscopic system with CT capability has been implemented successfully as a standard tool in the Boeing Phantom Works Failure Analysis Laboratory. Using this tool, studies of electronic, electromechanical, and composite material items have been performed. Such a system can pay for itself within two years through higher productivity of the laboratory, increased laboratory value to the company, and resolution of critical problems whose worth far exceeds the value of the equipment.
A CTOD Approach to Predicting Crack Extensions in Aluminum Alloys
Authors: Gu I
Published: February 2009

A practical method is proposed to calculate crack extensions during stable and subsequent unstable crack growth conditions in aluminum alloy 7075-T651 specimens. Also for aluminum alloy 2024-T351 specimens, the stable crack growth is calculated up to the limit stress. A crack initiated at a critical CTOD extends stepwise in successive increments of CTOD, so that the ratio of a CTOD increment to a crack-extension increment is a critical value, independent of an initial CTOD. The value attained instantaneously at each step of crack extension is different from measurable total CTOA. Some CTOD functions for MT and CT specimens of various sizes and crack lengths are calculated up to their limit loads using finite element analysis. The functions when plotted against applied stress vary little with crack length over a wide range except near the limit stress. The proposed method is based on the calculated functions for a mechanics solution. There seem to be two types in the final phase of fracture: (1) limit load for the 2024-T351 alloy and (2) fracture instability for the 7075-T651 alloy. When the total of CTOD increments during stable crack growth reaches a critical value, fracture instability occurs that characterizes crack extension without further increment of CTOD. Fracture constants are determined so that the calculations may be fitted to available test data with respect to effective and physical crack lengths. The determined fracture constants are transferred to other specimens to predict the failure loads, in good agreement with test loads. Discussions are made on specimen size effects and crack length measurement in the presence of crack tip tunneling.