bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Performance of the HEART Wheel Load Simulator
Authors: Cho Y-H , Lee K
Published: February 2009

Rutting of hot mixed asphalt (HMA) pavement has been considered a major pavement problem in many countries. Many researchers have tried to predict rutting or permanent deformation in the laboratory. Wheel-tracking devices have been used to evaluate rutting resistance from laboratory testing of HMA over the past several decades. Several studies showed high correlation of pavement performance between the highway and the laboratory results by wheel-tracking tests. Various wheel-tracking devices are available with different testing conditions, like variable temperature and loading conditions. Existing wheel-tracking devices developed by different institutes have some shortcomings such as nonlinear loading speed on the test specimen, fixed wheel path, impossibility of simulating underlayer effects, and so on. Therefore, the HEART Wheel Load Simulator (HWLS) was developed to improve the results the pavement engineers needs. The HWLS is capable of testing various thickness specimens, 50–700 mm, estimate rutting performance by both shear failure and further compaction of pavement substructure, and observe realistic rutting patterns by changing the wheel path using random variables or scattering. In addition, the HWLS has a linear loading speed capability using an oil compressor. Linear kneading compaction was added as an additional function so that it can be used to study rutting behavior under various compaction efforts, especially for conventional flexible pavement. This paper covers an outline of HWLS, calibration of the device, comparison of HWLS with existing wheel-tracking devices, and different behaviors of rutting resistance of typical HMA concrete under lateral distribution of traffic loading.
The Pozzolanic Effect of Fly Ash on the California Bearing Ratio Behavior of Black Cotton Soil
Authors: Pandian NS , Krishna KC
Published: February 2009

Thermal power stations that use pulverized coal as fuel generate large quantities of fly ash, resulting in environmental and disposal problems. Increasing demand for power leads to a greater use of coal and hence a further increase in the quantity of fly ash. These problems can be solved if the fly ash is put to use in an environmentally friendly way. Among the various uses for fly ash, the most massive and effective use is in geotechnical engineering applications. The study of fly ash and its interaction with soil is a must towards this goal. In the present investigation, an attempt has been made to study the engineering properties of fly ash—black cotton (BC) soil mixes with special reference to their use as sub-base materials in pavement construction. The study aims to understand the effect of fly ash on the California bearing ratio (CBR) of BC soil. The CBR variation is observed to depend upon the particle size distribution and pozzolanic nature of fly ash. The study indicates that addition of fly ash increases the CBR of BC soil significantly.
Finite-Element Modeling and Experimental Comparisons of the Effects of Deformable Ball Indenters on Rockwell B Hardness Tests
Authors: Ma L , Low SR , Song J
Published: February 2009

Significant differences occur in Rockwell B hardness (HRB) tests depending on whether the 1.588 mm diameter ball indenter that is used is made of steel or of tungsten carbide (WC). It is important to study and assess the effect of different indenter materials on the HRB tests since the Rockwell hardness test method standards, published by ASTM International and the International Organization for Standardization, now permit the use of either steel or tungsten carbide ball indenters. In this paper, finite-element analysis (FEA) is used to simulate the HRB indentation process using steel and WC ball indenters on the same test materials under the same testing conditions. The influence of the deformable steel and WC indenters on the HRB tests is analyzed by comparing their FEA results with those of a simulated nondeformable rigid indenter. The contact pressure, stress, strain, and deformations of both the indenters and the tested materials during the loading and unloading period are analyzed. The FEA simulation results show that the HRB difference between steel and WC ball indenters is about 0.4 HRB for 40–78 HRB levels, but increases to 0.56 HRB at the 23 HRB level. The FEA simulation results agree with experimental HRB results.
Novel Detection of Welding Seam Parameters Based on Active Infrared Technology
Authors: Jiang J , Ding G , Yan G , Chen T , Gan X
Published: February 2009

How to rapidly and with high precision detect various parameters of welding seams, such as the width, length, and offset is a significant challenge. This article first studies the microstructures and chemical components of welding seams. Then we discuss the effects of different microstructures and chemical components on active infrared images. Through theoretical and experimental analyses, it is well known that active infrared technology can be applied in the investigation of welding seams. Through the adaptive lifting discrete wavelet transform and the simple algorithm of iterative segment, various parameters of welding seams are established. The method put forth in the article is rapid, of high precision, on-line in real time. The precision is up to 0.1 mm. It takes only 0.02 s to segment an active infrared image on a P-III 700 personal computer.
Test Devices for Strength Measurements of Bars Under Contact Loading
Authors: Fett T , Munz D , Thun G
Published: February 2009

Bars loaded by opposite concentrated forces via rollers are appropriate specimens for the determination of strength under contact loading. Measured multiaxial strength values are located in the second quadrant (σ1 > 0, σ2 < 0) of the biaxial failure diagram. In this paper stress solutions for the proposed strength specimens are provided. As practical applications of the proposed specimens, the strengths for two aluminas, an AIN, and a HPSN ceramic, were determined and compared with bending strength results.
Small Punch Testing in Creep Conditions
Authors: Dobeš F , Milička K
Published: February 2009

The creep behavior of low-alloy steel was studied using small punch tests under the action of constant force. Disks with a diameter of 8 mm and a thickness of 0.5 mm were pushed against a die with a bore of 4 mm diameter using a ball of 2.5 mm diameter. The time dependence of the central deflection was registered. The resulting dependence has the sigmoidal shape typical of conventional creep tests but with a very significant primary stage. The conventional constant-stress creep tests were performed for comparison. A simple method for the approximate correlation of the force in punch tests with the stress in conventional creep tests of the same duration is suggested.
Accurate Measurement of Flow Stress Curves at High Temperatures for Low Strain Ranges
Authors: Carmona R , Lacey AJ , Beynon JH , Sellars CM
Published: February 2009

The present paper reports a comparison of flow stresses obtained by tension, plane strain compression, and axisymmetric compression testing in different machines with or without extensometers in the gage length section. Flow stress curves obtained from different test systems suggest machine and specimen geometry dependence, when the strain is computed based on gross specimen deformation. Finite element simulations give some insight into the interpretation and use of each mechanical testing technique, revealing the distribution of the strain field in each case. The results show that careful calibration of every testing machine and, in some cases, finite element modeling of the tests, are essential to give a similar curve for the same nominal deformation conditions.
Laboratory and Field Evaluation of Piezoelectric Weigh-in-Motion Sensors
Authors: Papagiannakis AT , Johnston EC , Alavi S , Mactutis JA
Published: February 2009

This paper presents the results of the laboratory and field evaluation of the piezoelectric weigh-in-motion (WIM) sensors of two manufacturers, namely Vibracoax (VC) and Measurements Specialties Incorporated (MSI). The laboratory evaluation involved fatigue testing of two sensor types for each manufacturer, one factory-encapsulated and the other bare. The fatigue testing involved three contact stresses as well as dry and wet conditions. Significant sensor fatigue was experienced only under wet conditions. The field evaluation of these sensors was carried in both asphalt concrete (AC) and Portland concrete (PC) installations. The facilities at Nevada's WesTrack and at a CalTrans Heavy Vehicle Simulator site were used, respectively. All sensors exhibited high raw signal precision at any given time. Raw signal amplitude seemed to depend on temperature for the sensors installed in the AC pavement. For increasing pavement temperature, the raw signal amplitude of the VC sensors decreased, while that of the MSI sensors increased. The signal-to-noise ratio of the raw signal increased with increasing temperature for the sensors installed in the AC pavement. WIM load measurement precision and sensitivity to temperature varied between sensors. The poor load precision of some of the sensors was attributed to the load calculation algorithm in the WIM data acquisition system, rather than to sensor malfunctioning. During the period of the field tests, no consistent changes in WIM axle load measurements were observed that could be attributed to piezoelectric sensor fatigue.
Static and Dynamic Behavior of Damaged Concrete and Granite in Compression
Authors: Gomez JT , Shukla A
Published: February 2009

Static and dynamic compression experiments were performed on concrete and granite specimens with various levels of induced damage. Damage was induced into the specimens by repeated impacts from a falling weight and quantified as a measure of damage crack surface area per volume using a statistical microscopy technique. The static experiments were performed following ASTM standard procedures. The static compressive strength of both materials decreased with increasing levels of damage. The reduction in strength is due to the induced damage causing the activation and propagation of failure cracks in the specimens.

The dynamic experiments were conducted using a 50.5 mm diameter Split Hopkinson Pressure Bar. The undamaged dynamic compressive strengths of both the concrete and granite were approximately twice their static values at average strain rates of 380/s and 400/s, respectively. However, as the damage levels were increased, the dynamic compressive strength remained unchanged. For the dynamic experiments, the strain energy is stored in the specimen faster than the cracks can develop and coalesce to completely fail the specimen. Therefore, the relatively small amounts of induced damage did not affect the dynamic compressive strength.
On the Recovery Coefficient and Parameter Selection for a New Type of Disk Spring Pile Cap
Authors: Zhou L , Chen J , Zhou X
Published: February 2009

The use of the disk spring pile cap, consisting of a contained group of several stacked disks, because of its high spring constant and high recovery coefficient, can raise pile driving construction efficiency. In order to reach the optimum effect, however, the proper spring arrangement in the stack, the proper composite spring stiffness, and the proper spring recovery coefficient must be selected. The authors have carred out an optimization analysis of these disk spring parameters in order to find the most appropriate set for effective pile driving under given conditions.
Evaluation of a Boron-Nitrogen, Phosphate-Free Fire-Retardant Treatment. Part I. Testing of Douglas-Fir Plywood per ASTM Standard D 5516-96
Authors: Winandy JE , Richards MJ
Published: February 2009

The objective of this work was to evaluate (a) the effects of a new boron-nitrogen, phosphate-free fire-retardant (FR) formulation on the initial strength of Douglas-fir AB-grade plywood and (b) the potential of this FR treatment to experience subsequent thermal degradation inservice when exposed to elevated temperatures. Test Method ASTM D 5516 was generally followed. The results of our analysis indicated that treatment and post-treatment redrying with the new boron-nitrogen, phosphate-free FR had a significant negative effect of about 7% on bending strength and a significant negative effect of 26% on energy-related properties, such as work to maximum load. The properties of modulus of elasticity and maximum moment canying capacity were not significantly reduced. Our results indicate that the likelihood of FR-treated plywood to experience in-service reduction in mechanical properties when exposed to elevated temperatures is no different than that of matched untreated plywood. As a result of our analysis, we recommend a revision to the cutting procedure specified by D 5516-96. We recommend that users first cut the specimens, then inspect and cull specimens with defects, and finally allocate specimens to experimental groups prior to FR treatment and redrying. We also recommend the substitution of commercially available grades of higher quality plywood, such as AA or AB, for the custom-made N-grade plywood currently recommended by D 5516-96.
Comparison of Random and Partition Testing Considering the Test Profile
Authors: Zhang L , Luo X , Chen M
Published: February 2009

There has been much interest in the analysis of the effectiveness of partition and random testing. Investigators studied and compared these two strategies from different points of view and came to different conclusions. Some used the probability of detecting at least one failure to quantify the fault-detecting ability of a testing strategy. Some used the expected number of failures detected to assess them. But they did not consider the test profile. Differing from this early work, this paper compares random testing with partition testing by looking at three parameters: the confidence index, the upper confidence bound, and the total number of test cases, considering the test profile. Our results show that random testing generally performs better than partition testing and equally as well as partition testing when the operational profile coincides with the test profile. We also derive the formulas to calculate the three indexes for random and partitional testings.
Test of the Acquisition System in an Analog Gamma Camera
Authors: Besbes H , Bouhlel MS , Salah RB
Published: February 2009

The quality control of an analog gamma camera in our nuclear department concerns exclusively the detection head. To evaluate the acquisition system we use a test system composed of an output card and software called ASST. The test consists of transforming the digital data of a scintigraphic image into three analog signals similar to those delivered by the detection head. These signals are introduced into the acquisition system for reconstructing the image. The software ASST allows comparison between the original and the acquired image in order to evaluate the quality of acquisition.
A Comparison of the Performance Tests Used for Furniture Packaging
Authors: Connolly SM , Marcondes JA , Weigel TG , Lee A
Published: February 2009

ISTA Procedure 2C and two options in NMFCC Item 181, stacked vibration and compression and vibration in separate tests, were compared to determine the equivalency of common U.S. furniture packaging performance tests. Containers constructed of two different corrugated fiberboard specifications were evaluated; Box A: a 32 lb/in. (5.6 kN/m) ECT rated board with a basis weight combination of 35HP/26/35HP, and Box B: a 200 psi (1378.95 kPa) Mullen rated board with a basis weight combination of 42/26/42. Ten corrugated fiberboard containers of each board type were tested following each of the test protocols. After testing, the contents were removed and the residual compression force at failure and deflection at failure of the containers were measured. These data were compared to the compression force and deflection at failure of control samples for the two board grades tested.

Results showed that Item 181 Method A produced significantly different residual compression force at failure when compared to Item 181 Method B and Procedure 2C for both boxes. Item 181 Method B and Procedure 2C were not significantly different. Also, the two boxes showed significantly different residual compression force at failure results for each of the test protocols studied. The percent change in compression force at failure based on control samples, however, was not significantly different between the boxes studied.
Estimation of theCtParameter: Experimental Implications
Authors: Leung C-P , McDowell DL , Saxena A
Published: February 2009

This paper examines the evaluation and interpretation of the Ct parameter that has been proposed for correlating crack growth under non-steady-state creep conditions. The study has been carried out by finite element analysis of the commonly used compact-type fracture specimen with stationary cracks.

It is shown that the loss of constraint of the creep zone growing at the crack tip region due to intense creep at the loading pins can have a significant effect on the results of the load line displacement rate which are used to calculate Ct. Since Ct is identical to C* under extensive creep conditions, these effects also seriously impact determination of other commonly used creep crack growth parameters. This study has given some insight into the proper care that should be taken in obtaining experimentally measured and numerically calculated load line displacement rates in fracture specimens so as to eliminate the undesired effects of intense creep at the loading pins and/or between the crack tip and loading pins. It is shown that compact-type specimens with a crack size to width ratio greater than 0.5 and loaded with a dead weight are best suited for obtaining creep crack growth rate data. A relationship between Ct and the crack tip opening displacement rate has also been derived that provides a more complete framework for the analytical and experimental evaluation of the Ct parameter.
Effect of Compressive Underloads and Tensile Overloads on Fatigue Damage Accumulation in 2024-T351 Aluminum
Authors: Pompetzki MA , Topper TH , DuQuesnay DL , Yu MT
Published: February 2009

Intermittent compressive underload and tensile overload tests were carried out on smooth specimens to determine the effect of large stress cycles on the fatigue damage of subsequent small cycles. A load interaction damage model, using a power-law relationship based on crack closure and damage concepts, accurately predicted the test results. The interaction damage was described by assuming that small fatigue cracks in smooth specimens have similar behavior to long cracks. The results indicate that small cycles below the constant amplitude fatigue limit can contribute significantly to damage accumulation, and that conservative damage summations can be made using a modified reference curve based on constant amplitude tests with a minimum stress on the order of the monotonic yield stress.
Bending Strength of Gray Cast Iron
Authors: Noguchi T
Published: February 2009

An experimental and theoretical study was made on the influence of the dimensions and geometry of cross sections on the bending strength of gray cast iron. The experiments revealed that the bending strength varies with specimen height, with higher bending strengths being recorded for smaller heights. This is explained by a region under the beam surface where the stress exceeds the tensile strength of the material. This overstressed depth is about 3 mm in 20 to 30 mm high beams and smaller in thinner beams.

The geometry dependence of bending strength is caused by non-linearity of the stress-strain curve. Numerical simulation by the fracture criterion with a constant overstressed depth showed that the bending strength of round bars is 10% higher than that of rectangular beams. In T cross sections, the influence of the section geometry is more marked. The experiments agreed well with the calculations.
Measurements of Dynamic Young's Modulus in Short Specimens with the PUCOT
Authors: Wickstrom SN , Wolfenden A
Published: February 2009

The piezoelectric ultrasonic composite oscillator technique (PUCOT) was used at frequencies in the range 40 to 150 kHz to measure dynamic Young's modulus for short-length single crystals of copper at temperatures in the range 25 to 650°C and for poly-crystalline copper at room temperature. Corrections to the modulus for variations in l/d (length/diameter) resulted in no loss of precision due to wave velocity dispersion.
Effect of Crystallographic Texture on Flexure Fatigue Properties of Ti-3Al-2.5V Hydraulic Tubing
Authors: Meredith SE , Schemel JH
Published: February 2009

Ti-3Al-2.5V alloy has long been known to have strong anisotropic mechanical properties due to its hexagonal crystal structure. Early workers discovered that tubing made from this alloy had enhanced fatigue resistance when crystals were oriented in a “radial” direction as opposed to the “tangential” direction. The focus of this current work was to test the impact of texture on flexure fatigue strength over a wide texture range and find if an optimum crystallographic texture existed for fatigue resistance. The results show that an optimum crystal orientation does indeed exist and that tubing with a texture either less radial or more radial displays lessened fatigue life.

The lessened fatigue life of highly radial tubing was previously unknown and is not well understood. The findings from this work should be considered by engineers when designing aerospace hydraulic systems and a texture range, not just a minimum, should be specified.
Measurement of Maximum Arrest Force in Performance Tests of Fall Protection Equipment
Authors: Sulowski AC , Brinkley JW
Published: February 2009

Frequency response characteristics for electronic measurement systems and mechanical test fixtures used in tests of fall protection equipment are proposed. The recommendations are based upon the analysis of the dynamic properties of the human body as measured in impact and vibration tests with volunteer subjects. The critical frequencies that are associated with human injury were found to be in the range of 0 to 16 Hz. A corner frequency of 100 Hz is recommended for the measurement system, and a minimum resonant frequency of 200 Hz is recommended for the mechanical test fixture.
Estimation of Characteristic Values of Fracture Toughness
Authors: Slatcher S
Published: February 2009

It is desirable in design codes to characterize material strength by a low fractile of its distribution. This low fractile is known as a characteristic value. The material strength variable considered here is fracture toughness.

Ten realistic fracture toughness distributions were defined, and two characteristic values were estimated on the basis of simulated observations from these parent distributions. The estimates were then compared with the actual characteristic values to evaluate the quality of the estimators. Three estimators were evaluated: one estimator was based on the assumption that the parent distribution was log-normal; the second estimator assumed that it was a two-parameter Weibull distribution with a shape parameter equal to two; and the third was a power limit estimator, which assumed little about the parent distribution's parametric form.

The results suggest that in practical situations the log-normal method gives the best estimator, and that ten is a reasonable number of fracture toughness tests for the purposes of characteristic value estimation by the log-normal method.
Cyclic Stress-Strain Behavior and Low Cycle Fatigue of Ti 6242
Authors: Bui-Quoc T , Gomuc R , Biron A , Nguyen HL , Tadros RN
Published: February 2009

Results of strain-controlled fatigue tests at 329°C on Ti 6242, a potentially important material for aircraft engines, are reported. These tests were carried out under completely reversed strain conditions (strain ratio Rε = −1.0) and with positive strains (Rε = 0.0). Comparisons are made between the stress-strain relations obtained from monotonic tensile tests, at fast and slow strain rates, and those obtained from constant strain amplitude fatigue tests and from increasing multistep fatigue tests. The influence of induced mean stress is discussed.
Relationships Between the Results of Nail Impact Bend Tests and Selected Nail Material Properties
Authors: White MS , McLain TE , Padla D
Published: February 2009

Selection criteria for nails vary significantly. Some fastener specifications contain criteria based on hardness tests; others are based on yield strength or the results of impact bend tests (MIBANT). Selection may also be based on the carbon content or SAE class of the nail wire. To assist the specifier in the nail selection process, the relationship was studied between the MIBANT angle, an apparent flexural yield strength, the hardness, and the carbon content of nails. Carbon content was found to have a small influence on the mechanical properties of non-hardened nails. Because of apparent variations in work hardening during wire drawing and nail manufacture, carbon content is not a reliable criterion for the selection of non-hardened steel nails. Conversely, carbon content significantly influences the properties of hardened steel nails when the steel carbon content is greater than 0.10%. MIBANT angle, Vickers hardness number, and flexural yield strength are highly correlated for lowcarbon steel nails. Empirical relationships between these properties are presented. MIBANT angle was found to be a better indicator of the flexural yield strength of nails than Vickers hardness number.
Instrumented Impactor for Testing Wood-Base Floor Panels
Authors: McNatt JD , Soltis LA
Published: February 2009

The current ASTM method for evaluating impact resistance (ASTM E 661), which uses a leather bag filled with 14 kg (30 lb) of lead shot, is adequate for comparative rating of panels. Our objective was to obtain a more precise measure of failure initiation. An instrumented steel impactor was developed to evaluate the impact resistance of single-layer wood-base floor panels. Panel materials evaluated were plywood, waferboard (two manufacturers), and oriented strandboard. All were nominally 19 mm (¾ in.) thick with tongue-and-groove edges and were approved for single-layer flooring. Impact resistance tests were conducted on the panels using a 14-kg (30-lb) lead-shot bag, a 14-kg (30-lb) steel impactor, and a 27-kg (60-lb) steel impactor. Floor panel damage was measured by the amount of energy absorbed by the panel, time to maximum deflection, and residual panel deflection (permanent set). The 14-kg (30-lb) impactor proved to be more precise for identifying damage initiation because the 27-kg (60-lb) impactor caused complete failure of some waferboard and oriented strandboard after only two or three drops. For all panel types, the 14-kg steel impactor caused 30 to 40% greater deflection than the 14-kg lead-shot bag for any given drop height.
Stress Intensity Factors for Side-Grooved Fracture Specimens
Authors: Macdonald BD , Pajot JJ
Published: February 2009

Analytical support was sought for using Freed and Krafft's concept of effective thickness, (BBN)1/2, in ASTM plane strain formulas for elastic stress intensity factor, K, for side-grooved fracture specimens. Three-dimensional, elastic, finite-element analysis of various smooth and 20% side-grooved specimens yielded K values which not only supported this idea but also showed it to be slightly conservative. This result was expected to be generally true for all elastic fracture specimens because the finite-element K calculation was based on the elastically singular Gauss point stresses right near the crack front. Constraint at these points was constant through the thickness and nearly equal to its plane strain value. This result was insensitive to the presence of side-grooves and applied to most of the specimen thickness just ahead of the crack. Therefore the use of (BBN)1/2 in K formulas was supported not only for the elastic portion of J-integral testing (ASTM E 813 and E 1152) but for plane strain fracture toughness testing (ASTM E 399).
An Approach to Predicting Long-Term Toughness, Strength, and Ductility of a Cr-Mo-V Steel Alloy Using Short-Term Tests
Authors: Davis DC
Published: February 2009

Within recent years, material science researchers have attempted to develop unified or strain rate sensitive constitutive theories to characterize the mechanical behavior of metal alloys in the creep regime. Some of these theories, such as that by E. W. Hart, employ short-time load relaxation tests to obtain a unique set of material property data relating stress and plastic strain rate. Within the context of these theories, a methodology for assessing the long-term toughness, strength, and ductility of Cr-Mo-V rotor steel alloys is demonstrated in this paper using a series of short-term tests.
A Quality Control Test for Selecting Materials to Arrest Fast-Running, Full-Thickness Cracks
Authors: Crosley PB , Ripling EJ
Published: February 2009

A method for measuring full-thickness crack arrest fracture toughness, Ka, using crack-line wedge-loaded compact specimens is described. The unique feature of the test is that so long as the prescribed test method is followed, the data can be analyzed by a small-scale plasticity procedure, with all validity requirements being met. This simple test and analysis procedure, and the fact that every test gives useful data, makes the method suitable for quality control/quality assurance testing.

The test consists of pre-selecting a value of Ka that must be measured, identified as Kv. The specimen size and allowable limits on mouth opening displacement are selected by using Kv and the material's yield strength. The test is then conducted by driving a wedge into the specimen to develop a run-arrest event, after which the specimen is broken open and the crack length at arrest, af, is measured. If af is between 0.4W and 0.8W, Ka is calculable; if the crack length at arrest 0.5W or 0.8W, Ka Kv or Ka Kv.

Crack propagation in the plates on which the test is expected to be used occurs by tunneling. Hence Ka increases with crack extension, attaining its saturation value when the crack attains its equilibrium shape. Measuring saturation values is not needed for quality control/quality assurance testing, however. This allows the use of smaller specimens, but a K-resistance versus crack extension curve for the type of steel being tested is needed to set acceptance criteria.
Changes in Cotton Fabric Bending Properties As a Result of Laboratory Wear
Authors: Ukponmwan JO
Published: February 2009

The mechanical properties of four woven cotton fabrics have been analyzed in terms of the elastic (Go) and frictional (Co) resistance to bending deformation using a Shirley cyclic bending tester. Changes in bending properties of the cotton fabrics as a consequence of wear using an Accelerotor abrasion tester in the dry condition are illustrated. Statistical correlations between the elastic and frictional parameters of deformation and other parameters such as percentage loss in weight are shown. The correlations are shown to be highly significant between elastic flexural rigidity and frictional coercive couple parameters of the deformation and percentage loss in weight of fabrics given 25 min abrasion time. Correlations between elastic and frictional parameters of deformation before the abrasion test, and with 5 and 25 min abrasion time, are also highly significant. Relations between bending parameters, mass, thickness, density, and specific volume of these fabrics before and after abrasion are reported. The result shows that weight loss may be small as a result of short periods of accelerated wear, but the changes in the bending parameters are large.
Imaging Short Fatigue Cracks with the Gel Electrode
Authors: Baxter WJ
Published: February 2009

A new non-destructive inspection tool is described for tracking and recording crack growth in test coupons and structural components. The current state of development of this device, the gel electrode, is reviewed. This hand-held inspection probe can image surface fatigue cracks in iron, titanium, magnesium, and aluminum alloys. Fatigue cracks only ∼10−2 mm long can be detected, a sensitivity which surpasses that of commercially available techniques by a factor of 100. Images of short fatigue cracks are shown for each of the above alloy systems. The examples are selected to illustrate the good visibility and repeatability of the images, as is required to monitor crack growth. Included are quantitative measurements of the growth kinetics of a short (10−1 to 1 mm) crack in a prototype component.
Standard Reference Materials: NBS-ASTM Cooperation
Authors: Rasberry SD
Published: February 2009

This paper reviews the cooperation between ASTM and the National Bureau of Standards (NBS) in a Research Associate Program to certify and distribute metal Standard Reference Materials (SRMs). Since the initiation of the program in 1975, more than 200 SRM types have been completed and made available to the technical community. Besides describing the cooperative effort, the paper summarizes the status of the metal SRM program at NBS and shows how SRMs, in general, integrate with the standards-writing activities of ASTM. While this shared activity has been very successful over the past 12 years—in fact, a model for industry-government technical cooperation—a difficult technical problem must now be resolved to assure future success. That problem is a growing shortage of classical chemists who are expert in the analytical chemical metrology needed to certify SRMs. A proposal is made that the joint work of ASTM and NBS be expanded to include addressing this serious shortage.
Certification: What It Means for Inhomogeneity and Reference Materials
Authors: Kennedy WR
Published: February 2009

A comparison is made between concepts Americans and foreigners have of the term certification. The paper discusses the requirements for a Standard Reference Material (SRM) Certificate and a Certified Reference Material (CRM) Certificate, and how what appears on the Certificate affects our concepts of homogeneity and inhomogeneity. Also discussed is why who issues a Certificate sometimes is more important than what is on the Certificate. The paper is a challenge to standardize SRM and CRM Certificates.
Metals Analysis in the Plastics Additives Industry: Quality Assurance Considerations
Authors: Nagourney SJ , Madan RK
Published: February 2009

A discussion of the methods used for the atomic spectroscopic determination of barium, cadmium, zinc, and phosphorus in vinyl stabilizers is presented. Comparison with aqueous measurements shows that the determination in organic media by inductively-coupled plasma atomic emission spectroscopy (ICP-AES) is the most desirable analytical approach for these samples. Evaluation of a variety of potential materials shows well-characterized in-house products to be viable, and even preferred, reference materials for the verification of the accuracy of these analyses. Alternative analytical techniques, interlaboratory comparisons, and the use of control charts are also discussed.
Preparation and Certification of Uranium Oxide (U3O8) Spectrometric Reference Materials
Authors: Santoliquido PM
Published: February 2009

This paper describes the preparation, provisional certification, and certification of reference materials for the trace element analysis for uranium oxide (U3O8). The reference materials were prepared by the addition of solution pools containing the trace elements to a dry base of high-purity uranium oxide (U3O8) with subsequent mixing, drying, milling, and blending. Provisional certification was accomplished through an interlaboratory program in which four different laboratories analyzed the reference materials by carrier distillation d-c arc emission spectroscopy. The full certification of these reference material requires concordant results by two independent methods of analysis. Newer methods of analysis, such as graphite-furnace atomic absorption spectrophotometry and inductively-coupled plasma emission spectrometry, unavailable when the last reference material of this type was certified, have figured prominently in the certification of newer reference materials, a project now nearing completion.
Mechanical Behavior of Nailed Joints with Various Side Member Materials
Authors: Pellicane PJ
Published: February 2009

Research was conducted to define and compare the mechanical behavior of nailed joints connecting solid wood to eleven commonly used side member products frequently used in construction. Two hundred twenty eight (228) joints were laterally loaded to the allowable load defined by the National Design Specifications, unloaded to zero, then loaded to failure. Solid-sawn Douglas-fir and Engelmann spruce 2 × 4 nominal dimension lumber was used as the main members, while side member materials consisted of southern pine and Douglas-fir plywood of two thicknesses, oriented strand board (OSB), hardboard, particleboard, waferboard, insulation board, gypsum board, and western red cedar solid wood siding. Nail sizes were 6d and 8d common wire nails.

Experimental load-slip curves were developed for all joints tested. Information reported includes first and second cycle secant slip modulus, loads at 0.003 in. (0.0765 mm) and 0.015 in. (0.381 mm) slip, ultimate load, and ultimate slip. Parameters are also given for empirical equations describing the load-slip behavior of the joints. Comparative statistical analysis was performed using nonparametric multi-response permutation procedures.

The results suggest that for both main member species, the strength and stiffness behaviors of OSB, waferboard, particleboard, and ¾ in. (19.05 mm) nominal southern pine and Douglas-fir plywood were statistically indistinguishable. The stiffness of joints made with the higher specific gravity main member was generally statistically superior to joints made with lower density material. Strength was much less sensitive to this parameter. Joints made with western red cedar, insulation board, and gypsum board were substantially less stiff and strong than those made with the other side member products. Hardboard joints with a 6d nail performed similarly to particleboard, OSB, waferboard, and plywood joints connected with 8d nails. This suggests that hardboard could be used in applications where nail joint resistance is important.
Cryogenic Creep Testing
Authors: McDonald LC , Hartwig KT
Published: February 2009

Cryogenic creep testing methods are examined and evaluated. Because of the difficulty in testing at cryogenic temperatures and the relatively low creep rates that are observed at temperatures below 77 K, cryogenic creep systems must have very sensitive strain measurement capabilities and be extremely stable. A 0.05% change in load or a 0.001 mV change in strain signal over a 200 h test can change the observed creep rate by as much as 10% in high-purity aluminum. An evaluation is made based on experiments using several different loading techniques; comparisons are made to the results of others. Discussions of various data collection methods, test fixtures, strain measurement methods, temperature control methods, and material dependencies are also included.
Nondestructive Density Measurements of Cylindrical Specimens by Gamma-Ray Attenuation
Authors: Tan S-A , Fwa T-F
Published: February 2009

Nondestructive density measurement of cylindrical specimens in the laboratory has several important applications. Many specimens in civil engineering laboratory testing are usually in the form of cylinders; undisturbed soil samples and field cores of concrete and asphaltic materials are primary examples. This paper describes a nondestructive laboratory technique for density measurement that can achieve a 95% confidence limit on the order of ± 0.01 g/cm3 for a useful range of density from 0.8 to 2.7 g/cm3, relevant to the above materials. The technique uses a 5 milliCurie (mCi) Cesium 137 source with a scintillation detector and counter assembly to record the radiation transmitted through the specimen. This is converted to a density value by calibration to an empirical radiation attenuation law. The principles of the method are described with consideration to the variables of the measuring system and the specimen geometry. It is shown that for solid cylindrical specimens of the materials tested, the radiation attenuation law is satisfied to a very high degree. From the law, a diameter ratio to count ratio relationship is established. Thus detailed calibration is only necessary for specimens of one diameter to determine the density of specimens of other diameters.
Comparison of Methods for Measuring Moisture Content of Aggregate and Asphalt-Aggregate Paving Mixtures
Authors: Parker J , Brown ER
Published: February 2009

Residual moisture in hot asphalt-aggregate paving mixtures is a function of aggregate type, environmental conditions, and production rate. This moisture is detrimental to pavement performance. Residual moisture can be controlled, but a simple method is needed to measure the moisture content of asphalt-aggregate paving mixtures during the construction process. Currently the only standardized method for determining moisture content of asphalt-aggregate mixtures is the distillation procedure (ASTM D 1461), a method generally too cumbersome for routine production testing and hence not used in field laboratories. Moisture content measurements on a variety of materials (aggregates and asphalt-aggregate mixtures) with the distillation procedure and with conventional and microwave ovens for drying were compared and analyzed. Drying with a microwave or conventional oven gives slightly higher moisture contents than the distillation procedure. Efficiency of drying is apparently the primary reason for the differences. Considering the magnitude of the observed differences in measured moisture content and the relative difficulty of the D 1461 test procedures, the microwave method is recommended for routine moisture content determination for asphalt-aggregate mixtures.
Effect of Thickness on Elasto-Plastic Deformation and Hysteretic Energy Dissipated at Crack Tip
Authors: Jendoubi K , Ranganathan N , Merah N
Published: February 2009

A study was carried out to verify the influence of thickness on elasto-plastic deformation and the hysteretic energy dissipated at the crack tip. The analysis is based on global energy and local strain measurements that are made on 4,12, and 30 mm thick compact tension specimens. A discussion of fatigue crack growth in the plane stress and plane strain states is presented. The tests were conducted under constant ΔK at R = 0.1 and 0.5 on 2024-T351 aluminum alloy. Experimental results were compared with those obtained from linear elastic fracture mechanics and finite element methods.
Prediction of Fatigue Life of Asphalt Concrete Beams from Fracture Tests
Authors: Ramsamooj DV
Published: February 2009

A substantial amount of experimental data is presented to verify a theoretical solution for predicting the fatigue life of asphalt concrete beams from fracture tests. The theory utilizes the principles of fracture mechanics and covers the full range of loading from low to high. The raw test data extracted from a report by Majidzadeh et al. [1] include dynamic modulus, ultimate tensile strength, critical stress-intensity factor, and fatigue life of asphalt concrete beams fabricated from over 46 different mixtures, consisting of three types of asphalts, five asphalt contents, three filler asphalt ratios, and several gradations. The fracture and fatigue tests were also conducted on one asphalt concrete mix at temperatures ranging from 16 to 35°C (35 to 95°F). The agreement between theory and experiment is excellent.
Materials for Marine Systems and Structures
Authors: Reemsnyder HS
Published: February 2009

The treatise begins with an overview on the theme of materials performance in marine systems and structures. Types and design aspects of, and materials selection for, marine structures are outlined. The welding process, fatigue resistance of weldments, corrosion fatigue of weldments, and the seawater corrosion of reinforced concrete are touched on briefly.
Mechanical Testing
Authors: Westbrook JH
Published: February 2009

This work is the third in a series of seven monographs on the Characterization of High Temperature Materials under the general editorship of M. McLean. Prior volumes related to microstructural and chemical characterization. The present volume represents the proceedings of a December 1988 seminar, sponsored and organized by the Institute of Metals through its committees on Materials Science, Materials Engineering and Continuing Education. The targeted audience is the nonspecialist who needs to know what types of tests are available, how to select the test most appropriate for his purposes, and who needs to have an appreciation of the methods of determination and analysis of the data he uses and knowledge of the status of national and international standards. As the editor points out, while the emphasis is on high temperature materials, the techniques and principles are applicable to many different material classes, and not all tests relevant to high temperature materials are conducted at high temperatures.
Normalization Method for Developing J-R Curves with the LMN Function
Authors: Landes JD , Zhou Z , Lee K , Herrera R
Published: February 2009

The normalization method has been used to develop J-R curves directly from load versus load-line displacement data without the need for on-line crack length measurement. This method, based on the original key curve-method, used the principal of load separation and an assumed functional form for the deformation function to determine a calibration equation for each specimen being evaluated. Originally the functional form was a power law with two unknown constants. A new functional form (the LMN function) containing three unknown constants is proposed for use in the method of normalization. This function requires three calibration points, one more than was needed by the power law function.

The LMN function is described in this paper, and the method for determining the three needed calibration points is given in detail. The procedure for using this new normalization method is describedin a step-by-step manner. Some results are included which show that this approach to normalization gives a J-R curve which agrees well with those developed from the elastic compliance method used in the ASTM test standards.
Detection, Diagnosis, and Prognosis of Rotating Machinery to Improve Reliability, Maintainability, and Readiness Through the Application of New and Innovative Techniques
Authors: Blau PJ
Published: February 2009

The extraordinarily long title, Detection, Diagnosis, and Prognosis of Rotating Machinery to Improve Reliability, Maintainability, and Readiness Through the Application of New and Innovative Techniques, indicates the degree of topic specialization inherent in this book. It is forty-first in a series of proceedings from the Mechanical Failures Prevention Group, an organization dating back to 1967 and primarily devoted to strategies for addressing hardware reliability problems in military, especially naval, equipment. The book consists of thirty-seven articles divided into seven sections: Detection, Diagnosis and Prognosis; Wear; Structural Damage Assessment; Signature Analysis; Monitoring Systems; Failure Mechanisms; and Artificial Intelligence and Expert Systems. This grouping of papers is one of several possible arrangements, because there were elements of some of the papers which could have made them suitable for inclusion in other categories than the ones in which they were placed. However, this kind of organizational problem is common when papers contain interdisciplinary material.
High Temperature Fatigue: Properties and Prediction
Authors: Gabb TP
Published: February 2009

High Temperature Fatigue: Properties and Prediction is a good summary text that reviews the major topics in high temperature fatigue of laboratory specimens and its utilization in structural engineering design. The general subject matter is ferritic and austenitic steels utilized in the power generation fields and particularly smooth bar low cycle fatigue and thermomechanical fatigue response.