bluuebunny/crossref_metadata_2025_split huggingface dataset:
Needs and Challenges in Precision Wear Measurement
Authors: Blau PJ 
Published: February 2009

AbstractAccurate and precise wear measurements are a key element in solving both current wear problems and in facilitating basic wear research. Applications range from assessing the durability of micro-scale components to the accurate screening of surface treatments and thin solid films. The need to distinguish small differences in wear rate presents problems for those who are developing new materials and surface treatments. The sensitivities of methods for measuring wear in ASTM standard test methods are discussed. Errors associated with using alternate methods of wear measurement on the same test specimen are described. Human judgmental factors are a concern in common methods for wear measurement, and the results of an experiment involving measurement of a simulated wear scar by ten different people are described. Precision in wear measurement is limited by both the capabilities of the measuring instruments and by the nonuniformity of wear processes. The advantages and disadvantages of measuring wear using micro- and nano-scale indentations is discussed. The current and future prospects for incorporating advanced, higher-precision wear measurement methods into standards must be evaluated.
The Nonvibrating Kelvin Probe and Its Application for Monitoring Surface Wear
Authors: Zanoria ES , Hamall K , Danyluk S , Zharin AL 
Published: February 2009

Abstract
This paper reports on the design and development of the nonvibrating Kelvin probe that could be used as a noncontact sensor for tribological damage. This device detects surface charge through temporal variation in the electron work function of a material. Experiments are performed to demonstrate the operation of the probe on a rotating aluminum shaft. The probe, made of lead, is placed adjacent (&lt;0.5-mm distance) to the shaft. The two surfaces, which are electrically connected, form a capacitor. Benchmark experiments on the variation of the work function with changes in surface chemistry were performed by coating a segment along the shaft circumference with a colloidal silver paint. As the shaft rotated, the probe senses changes in the contact potential difference with the shaft surface, due to the compositional variation. The temporal variation in the contact potential difference induces a current in an external electrical circuit. This current is amplified and converted to a voltage signal. The magnitude of the signal decreases asymptotically with the electrode-shaft distance and increases linearly with the rotational frequency, as expected. These results are consistent with the theoretical. Preliminary tests to detect mechanical surface damage, using the probe, were also done. These results show that the Kelvin probe can distinguish geometrical features on the surface.
The Significance of Nonlinear Motion in the Wear Screening of Orthopaedic Implant Materials
Authors: Wang A , Polineni VK , Essner A , Sokol M , Sun DC , Stark C , Dumbleton JH 
Published: February 2009

Abstract
Linear reciprocating pin-on-plate-type wear testing has been a standard technique for the screening of orthopaedic implant materials since the early 1980s. This investigation compares a wear screening technique based on linear motion with a modern hip joint simulator based on multi-axial motion. Two groups of differently sterilized UHMWPE samples were tested. The first group of samples was sterilized by ethylene oxide (EtO) gas that caused no structural changes in the UHMWPE. The second group of samples was sterilized in nitrogen by gamma-irradiation and then subjected to a stabilization treatment that resulted in a significant level of crosslinking in the UHMWPE. When tested on the linear reciprocating wear machine, the EtO sterilized specimens (non-crosslinked linear polyethylene) showed an approximately 30% lower wear rate than the gamma-irradiated and stabilized specimens (crosslinked polyethylene). When tested on the hip simulator, the EtO sterilized specimens exhibited two to three times higher wear rates than the gamma irradiated and stabilized specimens. The ranking of wear resistance obtained with the hip simulator was strikingly different than that obtained with the linear reciprocating wear machine. This study indicates that screening wear machines based on linear motion do not correlate with multi-axial joint simulators and may produce misleading results in the prediction of clinical wear performance of UHMWPE bearing materials.
A Tapered Double-Cantilever-Beam Specimen Designed for Constant-KTesting at Elevated Temperatures
Authors: Beres W , Koul AK , Thamburaj R 
Published: February 2009

AbstractA compact, constant stress intensity factor, side grooved, tapered double-cantilever-beam (T-DCB) specimen has been designed for measuring elevated temperature creep and fatigue crack growth rates. This specimen is much smaller than the standard DCB specimen generally used for studying corrosion fatigue in airframe materials and it can be easily accommodated in standard furnaces generally used in elevated-temperature fracture mechanics testing. The specimen possesses a constant-K region of 30 mm. This constant-K crack length range was first established analytically through detailed two- and three-dimensional finite-element analyses and the finite-element calculations were further verified experimentally through quantitative fractographic analysis using the striation measurement technique.
Application of Analysis of Variance (ANOVA) Statistical Methods to Breaking Load Corrosion Test
Authors: Golinkin IA , Ruff DD , Kvam EP , McCabe GP , Grandt AF 
Published: February 2009

Abstract
The breaking load test was used for evaluating the effectiveness of a corrosion preventive compound to protect aluminum alloy 2024-T351 from stress corrosion cracking. This test determines the post-exposure fracture stress of smooth tensile coupons exposed to 3.5% NaCl alternate immersion while held at various stress levels. Three groups of specimens were examined: uncoated specimens, specimens coated before environmental exposure, and specimens coated after one day of exposure. Statistical procedures based on analysis of variance methods were used to analyze the data. This statistical methodology shows much promise as a general approach to analysis of breaking load test data.
Experiments Increase Understanding of Chronic Obstructive Lung Disease
Authors: Kayser B 
Published: February 2009

Abstract
The study of chronic obstructive lung disease shows that the discomfort experienced by sufferers of this disease is largely due to their inability to empty the lungs during expiration. After inducing pulmonary hyperinflation in healthy subjects, researchers studied the results in an attempt to develop new breathing techniques and upper-body strengthening exercises suitable for patients. Extensive instrumentation was required to monitor test subject's breathing patterns. A data acquisition and analysis package that allowed researchers to view, plot and analyze data while the experiment was being run was essential in quantifying the results of the experiments. The complete acquisition, analysis and plotting solution was built in a single software environment.
Dynamic Young's Modulus Measurements in Metallic Materials: Results of an Interlaboratory Testing Program
Authors: Wolfenden A , Harmouche MR , Blessing GV , Chen YT , Terranova P , Dayal V , Kinra VK , Lemmens JW , Phillips RR , Smith JS , Mahmoodi P , Wann RJ 
Published: February 2009

Abstract
The results of a round-robin testing study are presented for measurements of dynamic Young's modulus in two nickel-based alloys. The Interlaboratory Testing Program involved six types of apparatus, six different organizations, and specimens from a well-documented source. All the techniques yielded values of dynamic Young's modulus that agreed within 1.6% of each other. For Inconel alloy 600 the dynamic modulus was 213.5 GPa with a standard deviation of 3.6 GPa; for Incoloy alloy 907 the corresponding values were 158.6 and 2.2 GPa, respectively. No significant effect of frequency over the range 780 Hz to 15 MHz was found.
Flexural and Shear Moduli of Full-Section Fiber Reinforced Plastic (FRP) Pultruded Beams
Authors: Bank LC 
Published: February 2009

Abstract
An experimental methodology is presented for the simutaneous determination of the section flexural modulus and the section shear modulus of thin-walled fiber reinforced polyester and vinylester pultruded beams. A pilot test program, involving four different fiber reinforced plastic (FRP) beams, is described and results are discussed. A slenderness ratio is introduced to characterize the shape of the thin-walled beam, and recommended values of this ratio are suggested for design purposes. With available values of the section moduli the designer has the option of using the Timoshenko beam theory instead of the Euler-Bernoulli beam theory.
Experimental Determination of Hydrostatic Compression versus Volume Change Curves for Cellular Solids
Authors: Fortes MA , Fernandes JJ , Serralheiro I , Rosa ME 
Published: February 2009

Abstract
A floatable solid immersed in a liquid can be made to sink if enough pressure is applied to the liquid to increase the density of the solid to the value of the density of the liquid. If a counterweight, W, is attached to the solid, the sinking pressure is reduced. A simple equation gives the volume of the solid as a function of the sinking pressure for each value of W. This is the basis of an experimental method developed to obtain the volume change, Δ V, of a fairly deformable solid, as a function of pressure, p. The method was applied to cork and two polymer foams; (−Δ V/V0) versus p curves were obtained. These curves are compared with stress-strain curves obtained in uniaxial compression.
Cytotoxicity of Incinerator Fly Ash on Alveolar Macrophages
Authors: Liu WK , Wong MH , Tam NFY 
Published: February 2009

Abstract
Fly ash samples were collected from the electrostatic precipitator of a municipal incinerator in Hong Kong. The physical and chemical properties of fly ash particles of a diameter smaller than 10 μm were studied by a scanning electron microscope incorporated with an X-ray energy dispersive microanalyzer, atomic absorption spectrophotometer, and X-ray powder diffractometer. The particles were very heterogeneous in size and shape and had high levels of trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn).
The cytotoxicity of fly ash particles was assessed using an in vitro culture assay of rat alveolar macrophages. It was found that the particles damaged the surface morphology of the cell, decreased the cell viability and phagocytic activity, and increased the release of cytoplasmic (lactate dehydrogenase) and lysosomal (β-glucuronidase) marker enzymes into the culture medium. No hemolytic effect could be measured on the rat red blood cells, indicating that the plasma membrane is not the target site of the incinerator fly ash.
An Experimental Technique for Studying the Dynamic Stability of Slurry Fuels
Authors: Kesavan SK , Chu ML , Reddy NP , Yazdani S 
Published: February 2009

Abstract
In coal slurry transportation, repeated vertical accelerations larger than the gravitational acceleration are encountered. The sedimentation behavior of the slurry fuels under these conditions is an area of concern in fuel transportation. A laboratory-scale technique has been developed that can be used to study the sedimentation behavior of coal slurry fuels under conditions of repeated vertical accelerations. A coal slurry sample contained in a settling column is subjected to repeated vertical movement using a mechanical shaker. The coal concentration profile along the height of the settling column can be used to quantify the sedimentation behavior of the slurry.
A Compression Test for High Strength Ceramics
Authors: Tracy CA 
Published: February 2009

Abstract
A new uniaxial compression test, developed for high strength ceramics, has successfully measured the strength of 94% alumina (Al2O3). Testing was done using a procedure developed specifically for obtaining strengths to 10 GPa on very difficult to machine ceramics. Strain gage analysis and fractographic observations confirmed that a uniaxial compressive stress state existed. Two existing test methods were also employed to measure the compressive strength of the alumina. Results from these tests are compared with the new methodology.
Fatigue Crack Front Shape and Its Effect on Fracture Toughness Measurements
Authors: Towers OL 
Published: February 2009

AbstractThe shapes of fatigue cracks in fracture toughness test specimens have been reviewed for a sample of approximately 680 three-point bend specimens. Up to 17% of this sample would be rejected for plane strain fracture toughness for Mode I loading KIc test procedures because of fatigue crack front shape. The corresponding rejection rate to crack tip opening displacement (CTOD) procedures is 3%. The results of published work for aluminum alloys indicate that relaxation of the KIc testing standards' restrictions on shape would not cause undue errors. This indication, however, appears to conflict with a computer model of curved crack fronts in a compact tension specimen. The suggestion is therefore made that the calculation procedures for fracture toughness determinations should be made more appropriate to the curved crack fronts usually observed, before the limits quoted in the standards are relaxed. To reduce the number of crack length measurements the removal of one limit on crack front shape is suggested. Finally, experimental justification for the change from the limits on crack front shape of British Standard Draft for Development DD19 [1972]) to those of the current CTOD testing standard, British Standard Methods for Crack Opening Displacement (COD) Testing BS 5762 (1979), is presented.
In-Plane Compression: A New Laboratory Forming Technique to Study the Effect of Large Drawing Deformations in Sheets on Their Subsequent Mechanical Behavior
Authors: Charpentier PL , Piehler HR 
Published: February 2009

Abstract
The deformation mode or strain path imposed during sheet forming can have a strong influence on the mechanical behavior of materials, both during and after forming. To study strain path effects, laboratory forming techniques capable of producing deformed samples that are flat, of sufficient size, and relatively free from strain gradients are desirable. A new laboratory forming technique, called in-plane compression, has been developed in this study to produce samples in which the strain state approximates that observed in the flange of a partially drawn cylindrical deep-drawn cup, that is, ϵ2 &lt; 0, ϵ1 and ϵ3 &gt; 0, where ϵ1, ϵ2, and ϵ3 are the principal logarithmic strains. These samples exhibit good strain uniformity and are of adequate size (31.8 by 76.2 mm by sheet thickness) to permit subsequent measurement of the postformed mechanical properties. For a 552-MPa (80-ksi) yield-strength high-strength low-alloy (HSLA) steel, it is shown that the postformed tensile properties after in-plane compression agree well with those observed after cup drawing, thus validating the use of in-plane compression to simulate drawing deformations.
Some Factors Affecting Cement Mortar Strength Results Using ASTM Standard Test Methods C 348 and C 349
Authors: Zoldners NG , Carette GG 
Published: February 2009

AbstractThe purpose of this study was to determine the effect of certain factors on test results when using ASTM Methods C 348 and C 349. For this purpose, four series of 3 mortar mixes each were made, and companion test specimens were molded using both hand tamping and vibrating methods. The results showed that, (1) Compaction of mortar test prisms by hand tamping produced densities which increased from the center towards both ends of the prism by an average of 2.1 percent; whereas this increase for prisms which were compacted by vibration averaged only 0.3 percent: (2) Compressive strengths by modified cube tests at the end locations averaged 5.6 percent higher than those at the middle of broken halves of the prisms compacted by hand tamping, but there was only 0.7 percent difference in strengths for the prisms compacted by vibration (Series IV): (3) The density of prisms compacted by vibration was, on the average, 3 percent less than that of tamped prisms. However, their flexural strength, on the average, was 8.5 percent higher than that of prisms compacted by tamping. (4) In comparison with standard 2-in. (50 mm) cube strengths, the compressive strengths of modified cube tests at the middle of broken halves and at the end of the prism averaged 96.0 and 101.7 percent, respectively, for tamped or 96.2 and 96.8 percent, respectively, for vibrated test specimens.
Capillary Porosity in Hardened Cement Paste
Authors: Auskern A , Horn W 
Published: February 2009

Abstract
The porosity and pore size distributions of cement pastes of water/cement ratios of 0.35 and 0.55 were measured by high pressure (50,000 psi) mercury porosimetry. Measurements were made on pastes hydrated from 8 hours to 90 days. The variation of mercury porosity with maturity was found to correlate well with generally held concepts of the hydration of cement paste.
Differences in the pore size distributions between pastes of different water/cement ratio lie mainly in the region of large pores.
Mechanical Testing of Stainless Steel Bone Staples
Authors: Liberace R , Ladin Z 
Published: February 2009

Abstract
Bending characteristics of stainless steel bone staples were examined to determine their possible inclusion in future standards. These characteristics included a measure of the initial slope of the bending curve as the staples were bent in a four-point bending load apparatus and a factor which accounts for the decrease in staple stiffness due to the bends in the staple. Both factors were measured and showed variations as high as 20% when similar size staples from different manufacturers were compared. Material properties such as hardness and tensile strength were also measured, and the resulting values were within 5% of each other for similar size staples. These results suggest that the staples were made from wire with very similar mechanical properties and that the observed variations are probably due to differences in the manufacturing process.
Comparison of Materials for Staple Pull-Out Tests
Authors: Thomas AMC , Pynsent PB , McCombe PF 
Published: February 2009

Abstract
Maximum pull-out forces of 16 mm bridge width staples of 10, 15, 20, and 25 mm leg length were tested in cadaver femoral metaphyseal bone. Pull-out force was related to leg length, but there was a very wide standard deviation. A plastic composite bone and beech hardwood were tested as substitutes and found to be unsuitable. A balsa wood composite was found to provide more reproducible results and is recommended for staple testing.
New Formulae for Determining Fracture Toughness of a Wide Range of Different Materials with Chevron-Notched Short-Rod and Short-Bar Specimens
Authors: Yin XC , Chen TG 
Published: February 2009

AbstractNew formulae are presented to re-evaluate plain strain fracture toughness of brittle and ductile materials from previous works on chevron-notched specimens. The fracture toughness KIm from the new formulae agree with values of KIC from ASTM specimens. The KIm measurements are successful in tests of tough aluminum when the fracture toughness exceeds 40 MPa · m1 2 and steel 20G with the plasticity factor p approach 1. It is found that the valid specimen size could be smaller than 1.25(KIC/σS)2 for aluminum alloys, and even less than 0.1(KIC/σS) for steel 20G when the KIm formulae are used.
Time-Domain Ultrasonic Measurement of the Thickness of a Sub-Half-Wavelength Elastic Layer
Authors: Zhu C , Kinra VK 
Published: February 2009

Abstract
This work is motivated by the need to measure the thickness of extremely thin adhesive layers in adhesively bonded joints. The classical method for ultrasonic determination of the thickness of a plate is the so-called “time-of-flight” method. One launches a longitudinal wave normally incident upon an immersed specimen and records the successive reflections from the two walls. The temporal separation between two successive reflections corresponds to the spatial distance between the two walls via the elastic wavespeed. This method breaks down when the specimen thickness (h) is less than three wavelengths (3λ). By combining conventional ultrasonics with the theory of Fourier transforms, Kinra and Dayal developed a technique that worked for h &lt; 3λ. However, their technique runs into a convergence problem when h/λ &lt; 0.5. More recently. Kinra and Iyer have explained the reasons for these convergence problems and refined this technique to the point at which it works satisfactorily down to h/λ = 0(10−2).
The objective of this paper is to report a new technique which accomplishes all of the foregoing objectives without the use of Fourier transforms. The entire ultrasonic nondestructive evaluation (NDE) is carried out in the time domain. Whereas the implementation of the previous technique would require an engineer with a college education, the new technique can be confidently used by a trained technician with no more than a high school education. It is envisioned that the use of the new technique will expand by at least an order of magnitude the technology base in which ultrasonics can be used for thickness measurement.
Dynamic Shear Modulus Measurements with Four Independent Techniques in Nickel-Based Alloys
Authors: Blessing GV , Wolfenden A , Kinra VK , Chen YT , Dayal V , Harmouche MR , Terranova P 
Published: February 2009

AbstractExperimental results are presented, on a round-robin basis, to study the effect of vibrational frequency on the dynamic shear moduli of two metals, Inconel 600 and Incoloy 907. Four separate laboratories, each using a different experimental technique, obtained results over the nominal frequency range of 7 kHz to 10 MHz. A brief discussion and comparison of the four techniques, both resonant and pulse, are included. No significant differences were observed for each alloy's modulus over this frequency range.
Contoured Wood Double Cantilever Beam Specimen for Adhesive Joint Fracture Tests
Authors: River BH , Okkonen EA 
Published: February 2009

Abstract
The strain energy release rate and associated parameters are useful measures of adhesive bond quality. A properly contoured double cantilever beam specimen excels in measuring these properties. However, previous specimen designs presented experimental difficulties resulting in possible bias and poor reproducibility. A new composite specimen is described that overcomes these problems. The specimen is made of oriented strandboard (OSB) and has a concave taper; two contoured beams sandwich a wood laminate having the test bondline at its center. Unlike previous specimen designs, this new specimen allows bonding of the test joint under normal conditions and produces a linear relationship between specimen compliance and crack length. These changes improve the accuracy and reproducibility of the test results with adhesively bonded wood joints. This report describes how the new specimen was developed and how to experimentally determine the compliance and crack-length relationship used to calculate the strain energy release rate of an adhesive joint. Furthermore, the reproducibility of two sets of specimens and the use of the method to analyze differences in actual joint quality are shown and discussed.