bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Computer Program to Aid in Fatigue Precracking of Fracture Toughness Test Specimens
Authors: Sriharsha HK , Anantharaman S , Chatterjee S , Pandey RK 
Published: May 2009

Abstract
Fatigue precracking prior to fracture toughness and fatigue tests ensures a sharp crack ahead of the notch tip. The precracking procedure is outlined in ASTM Standards E 399-78a (Standard Test Method for Plane-Strain Fracture Toughness of Metallic Materials). E813-89 (Standard Test Method for JIC, A Measure of Fracture Toughness), and E-1152-87 (Standard Test Method for Determining J-R Curves). This paper describes an interactive computer program that accepts material properties and specimen dimensions as program input. The program output when plotted graphically suggests an easy and practical precracking procedure adhering to the standards mentioned above. The program is useful in the absence of a computer-controlled testing facility. The program listout is given in the Appendix.
Evaluation of Wear Resistance of Snow Plow Blade Cutting Edges Using the Scratch Test Method
Authors: Wei Y , Nixon WA , Shi Z 
Published: May 2009

Abstract
The scratch test method was used to evaluate the wear resistance of snow plow blade cutting edges. A testing apparatus peculiar to the in situ scratch test of cutting edges was developed. Experimental results indicated that the scratch hardness correlated better to the wear resistance of cutting edges than did the indentation hardness.
Vickers Hardness Indentations Measured with Atomic Force Microscopy
Authors: Jensen CP , Jorgensen JF , Garnaes J , Picotto GB , Gori G 
Published: May 2009

Abstract
Vickers hardness indentations on a steel gage block (-900 HV) with diagonals between 3.4 and 44 µm have been measured with a calibrated atomic force microscope (AFM) and with an opticalbased method. From the AFM images the diagonals were measured from hard copies of diagonal profiles and automatically by image analysis. The combined standard uncertainty for the 3.4-µm diagonals was 10% for the optical-based and only 2.4% for the profile-based measurements (68% confidence level). Indentations with diagonals between 10 and 44 µm had concave shapes, in contrast to the 3.4-µm indentations. We show that optical-based measurements were not made at the level of the background plane, but higher on the indentation ridges.
A Neural-Based Analog IC Parametric Fault Diagnostic System with Discriminant Simulation Sampling
Authors: Wu A 
Published: May 2009

Abstract
This article presents experimental results that show feedforward neural networks are well suited for analog IC parametric fault diagnosis. It describes a discriminant sampling method for analog IC parametric faults simulation for a neural-based diagnostic system to reduce the computational overhead of the neural network training phase. Analog circuit fault simulation has not achieved the same degree of success as its digital counterpart owing to the difficulty in modeling the more complex analog behavior. Analog circuit fault simulation does rely on time-consuming circuit simulations on a large number of sampled points subject to various process deviations to emulate the actual faulty conditions. The proposed algorithm uses an effective importance sampling strategy to capture the parametric acceptance boundaries of the circuit under test. It makes use of circuit simulations effectively to relate each circuit performance to the process disturbances and to establish response functions that are accurate at the transition boundaries of the acceptance region. With the proposed approach, simulation samples can be generated for fault simulations mostly at the boundaries of the acceptance region to institute the discriminant functions for parametric faults testing using a neural network approach. The proposed algorithm is more computationally effective when compared to the Monte Carlo method.
An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of Water Vapor Transmission Properties
Authors: Kumaran MK 
Published: May 2009

Abstract
The cup methods are used extensively to determine the water vapor transport characteristics of building materials. The dry cup method and the wet cup method prescribe two standardized procedures for this purpose. The dry cup method gives the results as an average value of the property at a mean relative humidity of 25% and the wet cup at 75%. This information is inadequate for detailed hygrothermal analysis of building components. The complete dependence of water vapor permeability on relative humidity is required by most of the current computer models used for hygrothermal analysis. This paper presents an extension of the cup methods in which a series of dry cup and another series of wet cup measurements are suggested at varying relative-humidity levels outside the cup. Also, a detailed procedure for the data analyses to define the dependence of vapor permeability on relative humidity is presented. The methodology is applied successfully to three materials: perlite insulation board, calcium silicate insulation board, and plywood sheathing.
A Testing Device for the Mechanical Characterization of Wood Beams or Plates Under Bending Compression
Authors: Mussot-Hoinard G , Ferron G 
Published: May 2009

Abstract
A bending-compression device has been designed with the help of the ABAQUS/Standard finite element code for studying the mechanical behavior of structural elements under complex loading. A description of the device and its principle are presented. Samples are instrumented with the aim of a better comprehension of the damage mechanisms up to rupture. Current strain on the middle of the upper and lower faces and acoustic emission (AE) signals is collected. A coupled analysis of the mechanical and physical responses are made related to visual observations. Results are illustrated in the case of spruce beams loaded under bending up to rupture with the bending moment along the direction perpendicular to the annual rings.
Evaluation of Three Methodologies for Testing Disposable ENT Endoscope Sheaths as Viral Barriers
Authors: Lytle CD , Clavet CR , Chaput MP , Varney GW , To TM , Carey RF , Baker KH 
Published: May 2009

Abstract
Three methods to determine the barrier function of ENT endoscope sheaths were evaluated: (1) the air deflation test, a candidate quality assurance test, compared differences in pressure between a test sheath and an intact one; (2) a virus barrier test challenged with bacteriophage ΦX174 outside the sheath, with barrier penetration determined by rinsing inside and assaying for penetrated virus; (3) another virus barrier test challenged from inside, with virus penetration determined by assaying a collection/submersion solution. Sheaths with laser-drilled holes or tears generated by acupuncture needles were tested. Five-µm holes and larger were detected by air deflation or inside virus challenge. Outside virus challenge could reliably detect only 30-µm holes. Tears of 35-µm length were detected by inside virus challenge, while all three tests detected 85-µm tears. In addition, air bubbles during submersion detected and located 5-µm holes and larger, suggesting another quality assurance test.
Effect of Construction Adhesive and Joist Variability on the Deflection Behavior of Commercial Wood Floors
Authors: Pellicane PJ , Robinson G 
Published: May 2009

Abstract
A total of 19 440 virtual structural floors of a geometry and material configuration consistent with those used in commercial construction (commercial floors) throughout North America was numerically analyzed to determine deflection characteristics under a constant uniformly distributed load of 95 lbf/ft2 (4.55 kPa). The intent of these analyses was to determine the effect of joist variability on the deflection behavior of floors with and without elastomeric construction adhesive (ECA) between sheathing and joists. The joist property (modulus of elasticity, MOE) was allowed to vary in a systematic fashion between 1250 (8.62) and 3250 (22.4) ksi (MPa) in increments of 250 ksi (1.72 MPa). In addition, the variability of the joists (at each value of MOE) varied between coefficient of variation (COV) values of 0.025 to 0.150 in increments of 0.025. One hundred eighty floors were evaluated with and without ECAs at each mean MOE value and at each COV value for the joists. All other sheathing and connector properties remained constant.
The results indicated that the contribution of the ECA to reducing floor deflection under uniformly distributed loads was dependent in large part on the mean stiffness of the floor joists and to a much lesser extent on the COV of the joists. For joists of lower stiffness, the contribution of ECA had a more pronounced effect on mitigating the floor deflection level. Reductions of nearly 10% were realized when the mean joist MOE was 1250 ksi. For floors made with stiffer joists (mean MOE 4 3250 ksi), floor deflections were reduced by only about 5.5% when adhesive was used. The presence of ECA between joist and sheathing did not have much effect on reducing the variability of floor deflection behavior.
An H2-Optimal Control of Random Loading for a Laboratory Fatigue Test
Authors: Ming L , Bing-Han X , You-Sheng W 
Published: May 2009

Abstract
The authors have proposed an H2-optimal control method of random loading for a fatigue test. The optimal prefilter or optimal controller has been realized, and its system function or frequency response function was derived. The control method was verified by a test, and its use was presented.
Crack-Arrest Testing of Irradiated Nuclear Reactor Pressure Vessel Steels at the Oak Ridge National Laboratory
Authors: Iskander SK , Milella PP , Pini A , Manneschmidt ET 
Published: May 2009

Abstract
Crack-arrest testing of nuclear pressure vessel steels has been conducted at Oak Ridge National Laboratory for many years. Four methods have been used to initiate fast-running cracks in crackarrest specimens: (1) the deposition of a brittle weld bead using hardfacing weld electrodes, (2) water quenching a chevron crack tip, (3) quenching the crack tip by discharging a large current into the crack tip region, and (4) the use of duplex specimens. A problem often encountered with Methods 1 and 4 is the control of the width of the heat-affected zone (HAZ). The HAZ is generally tough and can arrest crack propagation before it has run into the test section. Irradiated crack-arrest specimens were prepared using Methods 1, 3, and 4. Method 1 was the most successful, while Method 4 was the least successful. This paper will discuss some of the reasons for the success, or lack of, as well as the results of testing both a high-copper weldment and a low-copper forging in terms of the shift and shape of the Ka toughness curve compared to the Charpy V-notch shift. The present ASTM Test Method for Determining Plane-Strain Crack-Arrest Fracture Toughness, KIa, of Ferritic Steels (E 1221-88) validity criteria will also be discussed in light of the results.
On the Uncertainties Involved in Quantifying the Fracture Toughness of Al-Li-X Alloys
Authors: McKeighan PC , Hillberry BM 
Published: May 2009

Abstract
The fracture behavior of an extruded Al-2.6Li-0.09Zr alloy in a near peak-aged and over-aged condition was found to be primarily intergranular with formation of non-Mode I, crack-divider delaminations at the crack tip especially in the over-aged temper. This complex, irregular fracture mode results in behavior that cannot be accurately measured using the conventional J- and K-based toughness parameters and testing methods. Other observed fracture characteristics that force reassessment of the traditional testing methodologies include crack length variations, mixed mode fracture from crack deflection, and apparent plasticity. The observed crack length variations through the specimen thickness led to 4 to 8% uncertainty in the K-curve for the specimens used. Furthermore, crack deflection corrections lead to an average 4 to 7% and maximum 15 to 18% apparent toughness increase for the material. The alloy exhibited nonlinear load-displacement behavior during fracture that could be corrected by using a plastic zone size modification. The analyses outlined provide insight into the roles the various mechanisms play in the fracture process of this alloy. However, the conventional toughness measures were inadequate in treating the observed fracture behavior.
R-Curve Generation and CTOD Evaluation Considering Maximum Crack Growth Size and Parabolic Crack Front
Authors: Bhattacharya S , Kumar AN 
Published: May 2009

Abstract
The standard methods of estimating the average size of the slow crack growth region as described in BS 5762 (Crack Opening Displacement (COD)) and ASTM E 1290 (Test Method for Crack-Tip Opening Displacement (CTOD) Fracture Toughness Measurement) are cumbersome, painstaking, time consuming, and dependent on several factors; e.g., section thickness, the nature of crack front profile, and the number of measurements. Often errors are introduced in determining the average crack size which in turn affect the determination of critical CTOD value.
However, several merits are associated with the use of maximum crack size. A theoretical relationship is established between the two physical quantities by assuming a parabolic nature of the slow crack growth front profile, which is supported by experimental data points. In situations of large crack growth, the crack profile tends to change from a parabolic to a semicircular crack front. A new approach is proposed to make use of the maximum crack size to generate R curves that can be extended to yield critical CTOD values. The nonlinear regression analysis of the CTOD-maximum crack size R curve yields critical CTOD values in agreement with the values that may be obtained by BS 5762. However, the linearly regressed and extrapolated critical CTOD values are found to be highly conservative. Alternatively, the average crack size may be obtained theoretically by using maximum crack size data to determine CTOD values following BS 5762.
A Computer Method of Analysis for Tire Wear Characterization, Identification, and Classification
Authors: Changizi K 
Published: May 2009

Abstract
A tire's rib profile before and after use can be determined by using two sets of measurements. These measurements are the tire runout values taken along the ribs before and after use. Superimposing these values over a circle with a predetermined constant radius that depends on the overall unloaded diameter of the tire as well as the maximum peak-to-peak runout value of the rib will result in the tire's rib profile. The difference of areas bounded between the rib's profile and the specified circle, before and after use, is a quantitative measure of tire wear along the rib. Therefore, it is the primary objective of this paper to outline a computer method of analysis, not only to generate the tire's rib profile before and after use, but also to provide a quantitative measure of rubber loss around the circumference of each tire rib. The significance of generating the profile is the ability to observe and locate the highest and lowest points of the tire along the rib and to inspect a tire for defects. This can be especially important for the tire manufacturers at their line of production. Among other important characteristics of this proposed method is the potential for predicting the wear nature of a tire rib, after use, by quantifying the loss of the rubber along the rib and by the process of decomposing each rib's profile into the sum of sinusoids with appropriate amplitudes and phase angles. This process of decomposition, which is commonly known as Fourier Analysis, can identify the harmonics with highest contributions to the shape of the profile. Harmonics with highest contributions play an important role in shaping the profile. Two tires with similar or close harmonic contents in their rib's profile, after use, can be classified as tires with identical wear pattern.
Physiologic Challenges Induced by Participation in Ice Hockey—Implications for Training
Authors: Green HJ 
Published: May 2009

Abstract
Training programs for ice hockey players have two fundamental objectives; namely, to optimize performance and to minimize the risk of injury. The design of efficient and successful programs to meet these purposes depends on a careful analysis of the physiological demands of the game and the environment in which it is played. Moreover, if the program is to meet individual needs, the physical and physiological status of the player must be considered. Ice hockey is a demanding sport that involves the recruitment of essentially all of the skeletal muscles of the body in order to perform the diverse skills of the game. These skills are performed over various ranges of movement, at various velocities and loads, and usually involve several large muscles acting synergistically. Moreover the extended nature of the game, performed over three periods, results in numerous repetitions of each task. Collectively, the repeated performance of these tasks impose extreme demands on respiratory, cardiovascular, neural, muscular, metabolic, and thermoregulatory systems of the body. The physiological demands may be further exaggerated given the protective equipment that is worn and the fact that abnormally high temperatures and humidities may be present. Proper preparation can only be realized by exposing the participant to progressive routines designed to systematically challenge each of the physiologic systems in a manner appropriate to game conditions.
Practical Aspects of Dynamic Verification of Extensometers: Part I—The Concepts
Authors: Albright FJ , Annala J 
Published: May 2009

Abstract
Material property studies frequently require the measurement of load and strain. Accurate measurement of both parameters is essential. Methods for accurate static calibration and verification of load transducers and extensometers are well established. More recently, standard practices have been developed for the dynamic calibration of load transducers. Still in its infancy is a standard method for dynamic verification of extensometers.
Dynamic verification introduces a wide range of new issues. These encompass not only the transducer but also the conditioning electronics and actual test machine. Static calibration permits the “elimination” of nearly all dynamics, whereas dynamic verification must be done in the presence of these dynamic effects. This paper outlines the various concepts that need to be understood when performing the dynamic verification of an extensometer. Problems related to computer aided verification are emphasized, issues of aliasing and resolution in particular.
Statics and Strength of Materials, Second Edition
Authors: Shehata IH 
Published: May 2009

Abstract
The second edition of this book, which comes twelve years after the release of the first, mainly targets engineering technology and non-engineering university students with no calculus requirements, as the author states. However, the book may also serve as a reference for courses in materials and materials testing as well as machine and structural design. Two new chapters have been included in this edition: Concurrent Forces in Space (under the Statics branch) and Bolted, Riveted, and Welded Structural Connections (under the Strength of Materials branch). In addition to many changes and improvements throughout all the chapters of the book, this edition contains three new sections: Power Transmission, Flange Couplings (under the chapter named Shear Stresses and Strains; Torsion), and Design of Beams for Strength (under the chapter named Bending and Shearing Stresses in Beams). However, the new chapter Concurrent Forces in Space seems to be very short (it may be described as the five-example and fourteen-problem chapter) and needs to be critically examined.
Fatigue Crack Propagation in a Specimen with a Complicated Cross-Section; Characterization of the Stress Intensity Factor
Authors: Makabe C , Kaneshiro H , Yara H 
Published: May 2009

Abstract
In order to predict the fatigue life of machine equipment, the fatigue crack propagation law has up to now been investigated using specimens with a simple cross-section shape. In this study, a specimen with three grooves cut in the loading direction was used to clarify crack propagation and crack closure behavior at points of discontinuous change in thickness. It was found that the crack propagation curve showed a complicated variation in the vicinity of the grooves and that the variation of crack closure behavior correlated well with it. The stress intensity factor was evaluated using the calibration curve between the crack propagation rate and the effective stress intensity factor range obtained from a similar smooth specimen. Results showed that the stress intensity factor of the grooved specimen was higher in front of the first groove and lower behind it, compared to the smooth specimen. As the crack crossed the first groove, the crack propagation rate exhibited a local maximum as a function of the maximum value of stress intensity factor.
The Use of Fatigue Specimens Precracked in Compression for Measuring Threshold Values and Crack Growth
Authors: Pippan R , Plöchl L , Klanner F , Stüwe HP 
Published: May 2009

Abstract
Precracks generated in purely compressive cycles permit a determination of threshold values ΔKth and crack growth curves with increasing load amplitude only. They also permit to measure the effective threshold ΔKeff th and the dependence of ΔKth on crack length. The production of such precracks is also discussed.
Development of an Improved Compression Specimen Geometry for Unreinforced Polymers
Authors: Odom EM , Adams DF 
Published: May 2009

Abstract
One of the recommended compression specimen geometries for plastics in ASTM D 695, Test Method for Compressive Properties of Rigid Plastics, is a straight-sided cylinder or prism. This end-loaded specimen tends to barrel at high strains. Additionally, if modulus is desired, the standard suggests that the specimen have extra length to avoid end constraints. Therefore, compression specimens for modulus can fail at a different stress level than compression specimens for strength. To overcome these problems, a compression specimen with a gage section of reduced area which is end-loaded but side supported was developed. Additional experimental observations of the thermosetting polymer of interest included a nonlinear compressive stress-compressive strain response which required a parabolic constitutive relationship to model, an observation of a significant anelastic material response, and a material response termed anelastic buckling. These observations of material behavior had not previously been observed.
Back-Face Strain Compliance and Electrical-Potential Crack Length Calibrations for the Disk-Shaped Compact-Tension DC(T) Specimen
Authors: Gilbert CJ , McNaney JM , Dauskardt RH , Ritchie RO 
Published: May 2009

Abstract
Back-face strain compliance and electrical-potential crack length calibrations have been experimentally determined for the disk-shaped compact-tension DC(T) specimen. Finite-element modeling was used to ascertain the back-face strain distribution at several crack lengths to determine the significance of inconsistent gage placement. The numerical solutions demonstrated good agreement with experiment, especially at smaller crack lengths when the back-face strain gradients are minimal. It is concluded that precise gage placement is only critical when the crack tip closely approaches the back of the test specimen.