bluuebunny/crossref_metadata_2025_split huggingface dataset:
Slice Synthesis Technique for an Embedded Crack in Residual Stress Fields
Authors: Nishimura T 
Published: February 2009

AbstractStress intensity factors are obtained for an embedded elliptical crack in a plate subjected to remote tensile and welding induced residual stresses. The three-dimensional crack configuration is reduced to a system of two-dimensional configurations in the crack depth and in crack length directions by using the slice synthesis technique. The algebraic equations on crack face displacements are formulated in terms of unknown coupled tractions acting on the slices. These equations are solved using a multiple linear regression scheme, and the unknown tractions and stress intensity factors are calculated. The accuracy of stress intensity factors is compared with known results from the literature for an embedded elliptical crack in tension and for an embedded penny-shaped crack subjected to welding residual stress. The stress intensity factors are presented for various elliptically shaped cracks embedded in an infinite plate and subjected to three different types of welding residual stresses.
Optimization of Test Parameters for Quantitative Stress Measurements Using the Miniaturized Disk-Bend Test
Authors: Meyers DE , Chen FC , Zhang J , Ardell AJ 
Published: February 2009

Abstract
A recently-developed miniaturized disk-bend test (MDBT) has been successfully used to evaluate the mechanical properties of a variety of materials, using specimens 3 mm in diameter. The load is applied either by a solid ball (the ball-on-ring (BOR) mode), or by a hollow cylinder (the ring-on-ring (ROR) mode). We have reproduced the yield stresses of ordered intermetallic compounds and the fracture toughnesses of several ceramics using analytical solutions to the equations of elasticity theory. Despite this success there are several curious features involved in the analysis of data, for example, in previous tests conducted in the BOR mode correct values of the yield stress were obtained using the equations appropriate to clamped specimens, whether or not they were actually clamped in the test fixture. We show that this is ubiquitous to tests in the BOR mode, and does not arise because of frictional constraints at the supporting ring. We have also completed a thorough evaluation of testing in the ROR mode, in which the yield stresses of cold-rolled or annealed AISI type 302 stainless steel were measured using various combinations of specimen thickness and radii of the loading and supporting rings, and compared to those of tensile specimens machined from the same material. The most accurate and reproducible measurements of the yield strength were obtained for specific combinations of specimen thickness and geometry of the apparatus. We describe these conditions and demonstrate that they provide values that are always within 10% of the tensile results. The errors induced by potential misalignments in the MDBT are also discussed, and are shown to cause no more than a 5% deviation in the measured yield stress.
A Novel Method for Imaging the Damage Pattern in Laminated Plastic Materials Subjected to Ballistic Impact
Authors: Sivakumar K , Ramakrishna YV , Ramanjaneyulu K , Balakrishna Bhat T 
Published: February 2009

Abstract
A new method for assessing the damage in laminated composites upon ballistic impact has been suggested. The proposed method, called infiltration radiography, consists of impregnating a semisolid lubricant mixed with fine metallic powder deep into the damage caused by bullets. The effect of metal content on the quality of image has been studied to determine the minimum required amount of metal powder. The influence of radiographic parameters such as voltage, current, and exposure time has also been studied.
Density Measurement of Cylindrical Specimens Within a Mold by Gamma-Rays
Authors: Tan S-A , Fwa T-F 
Published: February 2009

Abstract
This paper describes a series of tests used to establish a method of nondestructive density measurements of cylindrical specimens contained within a mold by using a twin-probe gamma-ray density gage. Cylindrical specimens within molds are common occurrence in civil engineering practice; examples are soil, concrete, or bituminous cores obtained by in situ sampling or laboratory compaction. In several applications it may be desirable to determine the core densities without removal from the mold, and this can be achieved by the use of a gamma-ray density gage which is an adaptation of a twin-probe direct transmission field gage for laboratory density measurement. It is shown that linear calibration relationships can be obtained by two different procedures. The first case is to use the count ratio between the count rate of specimen with mold to count rate of air plotted against the composite density of the specimen and mold. The composite density is computed using the irradiated volumetric proportions of the specimen and mold. The other case is to use the count ratio between the count rate of specimen and mold to the count rate of mold only plotted against the density of the specimen. Experiments were conducted with three aluminum molds of 116, 119, and 124 mm external diameters and 102 mm internal diameter, for five specimens of 100 mm diameters with density froms 0.87 to 2.70 g/cm3. Based on the radiation attenuation law, a theoretical basis for the linear calibration in the two cases are established. Comparison of the theoretical slopes of the calibration lines with the experimental slopes showed excellent agreement, thus verifying the validity of the calibration procedures.
An Improved Moisture Permeability Measurement Method
Authors: Douglas JS , Kuehn TH , Ramsey JW 
Published: February 2009

Abstract
This paper describes the development of a new method for measuring water vapor transport through common building materials. The method represents an improvement in flexibility over the standard ASTM cup methods in terms of allowing inothermal and nonisothermal testing. The method also accounts for convective boundary layers on both sides of the test material. This paper contains preliminary test results using gypsum board materials. Future testing will attempt to gain transport data for these and other materials under likely operating environments.
Validation of a Corona Discharge Technique to Test Male Latex Condoms for Pinhole Defects
Authors: Herman BA , Carey RF 
Published: February 2009

Abstract
The Center for Devices and Radiological Health, Food and Drug Administration, evaluated a prototype device using novel technology to detect pinholes in male latex condoms. This device uses multiple electrodes, maintained at high positive voltage, which interrogate a latex condom placed on a conducting mandrel. An electric discharge occurs only when a small hole is present in the condom and is sensed by the device. The mandrel is rotated to map out the entire surface of the condom. Using latex condoms with laser-drilled holes ranging from approximately 1 to 30 µm in diameter, we examined the sensitivity of this device. The smallest holes were detected, and the overall false negative rate was 2%.
Cyclic Response and Fatigue of Steels Subjected to Strain Control with Non-Zero Means
Authors: Gong Y , Norton M 
Published: February 2009

Abstract
Baseline fatigue data are presented through a series of strain-controlled tension-compression-type fatigue tests on smooth specimens of a Type S1214 mild steel under various combinations of strain amplitudes and nonzero mean strains. The strain magnitudes were chosen in the upper limit of the elastic range, in the plastic range, or in the transition area between the elastic and the plastic range. Experimental results show that for strain amplitudes in the upper limit of the elastic range, positive mean strains prolong fatigue life and negative mean strains shorten fatigue life. The observations are explained by the analysis of the basic material properties associated with the material concerned. The cyclic response behavior of the materials, namely the Bauschinger effect, the cyclic softening, and the mean stress relaxation processes have been studied also to reveal the underlying fatigue mechanism. Several modified models have been proposed for life prediction under nonzero mean strain and/or mean stress based on experimental observations. The comparison of the experimental results with the predictions made from the proposed models and from an existing model are also presented.
The Influence of Irregularities in the Crack Shape on the Crack Extension Measurement by Means of the Direct-Current-Potential-Drop Method
Authors: Riemelmoser FO , Pippan R , Weinhandl H , Kolednik O 
Published: February 2009

Abstract
The equations used for calculating the crack extension from the change in the potential drop at a fracture mechanics specimen are generally derived for perfectly straight crack fronts. In the practice of fracture mechanics tests the crack, however, usually grows faster in the interior of the specimen than at the exterior, leading to a curved crack front. For such a case we calculate the potential drop by means of a finite difference scheme. It is shown that for curved cracks the usual procedure of the direct-current-potential-drop method underestimates the real crack extension. The same finite difference scheme is then used to account for conductive bars and bridges, which sometimes are left behind the crack front. Finally, the influence of side grooves on the potential drop is investigated.
Experimental System for Simulating Crack Propagation in Asphalt Pavements and Effectiveness of Geosynthetics in Crack Retardation
Authors: Goulias DG , Ishai I 
Published: February 2009

Abstract
This paper presents the pneumatic moving wheel experimental system and its usefulness in simulating the role of geosynthetics (geogrids) in limiting crack propagation. The simultaneous development of rutting through the experiment was studied as well. The performance of the developed loading system showed that: (1) the moving wheel loading device provides a compact, convenient, simple, and rational experimental tool for investigating the effect of pneumatic wheel loading on the mechanical dynamic behavior of asphaltic layers; (2) two of the failure modes of asphaltic pavements, fatigue cracking and permanent deformation, could be assessed and measured simultaneously; and (3) the relative effect of geosynthetics reinforcement on the retardation of the development of the above distresses during service life was successfully measured to verify quantitatively the contribution of interlayer reinforcement toward the reduction of permanent deformation (rutting) and the increase of asphaltic surface layer life by retarding crack propagation.
Data Supporting a Provisional American Society for Testing and Materials (ASTM) Method for Metalworking Fluids, Part 2: Preliminary Report of Evaluation of a Ternary Solvent Blend in a Provisional ASTM Method for Metalworking Fluids (P-42-97)
Authors: Glaser RA , Shulman S , Klinger P 
Published: February 2009

AbstractSamples of straight, soluble, semi-synthetic, and synthetic metalworking fluids (MWF) were spiked onto polytetrafluoroethylene (PTFE) membrane filters, stored overnight, and analyzed using a provisional American Society for Testing and Materials (ASTM) method for metalworking fluids. That technique involves collection of aerosolized fluid on PTFE membrane filters and separation of the fluid from co-sampled particulate matter via extraction of the filter with a blend of dichloromethane: methanol:toluene. The extraction of all fluids from the filters was quantitative over the range 200 to 815 µg for the straight fluid, from 223 to 878 µg for the soluble fluid, from 51 to 189 µg for the semisynthetic fluid, and from 102 to 420 µg for the synthetic fluid. For those weights of all four fluids spiked at levels ⩾200 µg, the precision (%relative standard deviation or %RSD) was estimated to be 4% for the total weight procedure and 5% for the extraction procedure. Limits of quantitation, estimated from blanks carried through the entire analytical procedure, were 30 µg for the weighing technique and 60 µg for the extraction technique.
Ultrasonic Measurement of the Dynamic Elastic Moduli of Small Metal Samples
Authors: Slotwinski JA , Blessing GV 
Published: February 2009

Abstract
Ultrasonic velocity measurements were used to determine the dynamic elastic moduli of small metal samples to a 2σ measurement uncertainty of better than 1%. The samples were cylindrical in shape, possessing nominal diameters of 12 mm and thicknesses of 6 mm. Aluminum, titanium, and stainless steel compositions were examined. In the longitudinal wave measurements, a 20-MHz quartz piezoelectric element transducer was employed in pulse-echo mode using a tone-burst excitation. These longitudinal time-of-flight measurements were made with a repeatable 2σ measurement uncertainty of ≤1.0 ns. Shear time-of-flight measurements, using a 10-MHz contact ceramic piezoelectric element transducer subjected to tone-burst excitation, were made with a repeatable 2σ measurement uncertainty of ≈2.0 ns. NIST calibration facilities provided measurements for the density and lengths of these samples, as needed for the moduli calculations. Results indicate that the measurement uncertainties for elastic moduli measurements of this type can be kept quite small.
A Back-Faced Strain Compliance Expression for the Compact Tension Specimen
Authors: Riddell WT , Piascik RS 
Published: February 2009

Abstract
A numerically generated expression to determine crack length in a compact tension specimen from back-faced strain compliance is presented. The numerically generated back-faced strain expression is bounded by two experimentally determined expressions previously published in the literature. Additionally, stress intensity factor and crack-mouth opening expressions are determined. These expressions agree well with previously published results.
A Simple Catapult System for Studying the Small Projectile Impact Resistance of Various Glass Laminates
Authors: Grant PV , Cantwell WJ 
Published: February 2009

Abstract
A catapult arrangement capable of propelling small granite chippings at velocities of between 4 and 20 ms-1 at laminated glass structures similar to those used in car windscreens has been designed and manufactured. The results from a series of studies utilizing this equipment are presented, with the overall aim of reducing the weight of these constructions with no loss in impact resistance. The impact resistance of the laminates has been shown to depend strongly on the thickness of the outer glass layer, while the inner glass layer is of secondary, and in most cases, minor relevance. Tests in which the composition and thickness of the interlayer have been varied have revealed that this layer is of no consequence in terms of the impact resistance of the structure as a whole. Chemical strengthening of the outer glass layer has been carried out, and no improvement in performance is observed due to the nature of the stone geometry. Finally, tests on bilayer systems have been carried out, and these results indicate a potential weight saving for no loss in impact performance.
Water Management and Moisture Transport in Direct-Applied and EIFS Wall Assemblies
Authors: Tonyan TD , Moyer KW , Brown WC 
Published: February 2009

Abstract
An experimental program has been completed investigating water management and moisture transport in direct-applied finish system (DEFS) and exterior insulation and finish system (EIFS) wall assemblies. The first objective of the study was to understand and quantify drainage through water-managed DEFS and EIFS. A second objective was to understand moisture transport through the wall cladding under a variety of climatic conditions. A third objective was to better understand the role of the sheathing membrane on the moisture transport characteristics of the system. A drainage test has been developed, and a variety of water-managed DEFS and EIFS wall assemblies have been tested. Also, DEFS and EIFS wall assemblies have been tested in an environmental chamber using five different sets of climatic conditions to create a vapor drive through the wall. Results from the drainage and environmental chamber testing are presented, along with an evaluation of sheathing membranes with different performance characteristics.
Efficient Mitigation of Edge Effects in Nearest-Neighbor Analysis
Authors: Frost JD , Saussus DR 
Published: February 2009

Abstract
The properties of soils and other civil engineering construction materials are influenced by the microstructural arrangement of the particles. The characterization of the spatial arrangement and distribution of microstructural features are therefore of importance if the mechanical properties of materials commonly used in civil engineering are to be better understood. Numerous statistical methods have been developed to characterize the spatial arrangement of microstructural features. However, care must be taken in implementing these methods using automated imaging systems to analyze finite quantities of features so that bias due to edge effects and other factors is not introduced. A new method for mitigating edge effects when nearest-neighbor analysis is being performed is proposed in this paper. The method is validated using synthetic square and triangular patterns for which the spatial arrangement free of edge effects (unbiased) is already known. Use of the method to analyze a real dataset representing the peripheral packing arrangement of sand particles in triaxial specimens is described. The results indicate that the new method is able to mitigate edge effects and offer substantial savings in terms of efficiency of data collection and analysis.
Experimental and Numerical Study of Delamination Growth Induced by a Transverse Crack in Unidirectional Laminates Subjected to Bending Loads
Authors: Javidrad F 
Published: February 2009

Abstract
This paper presents the results of an experimental and numerical investigation into the mixed-mode delamination growth initiated from a transverse crack in unidirectional laminates under the three-point-bend test condition. The delamination growth was found to be stable both numerically and experimentally. Two data reduction methods, the compliance calibration and the finite element-based data reduction, were used to analyze test results. It was shown that the latter method gives better results. The finite element delamination growth modeling incorporating the linear growth criterion was also used to model the growth of delamination. Very good agreement between numerical and experimental results was achieved. This type of specimen has the advantage of being very easy to prepare. There is no need to implant an artificial delamination as required for most interlaminar tests. The data reduction method using finite element analysis is straightforward. Therefore, this type of test specimen can be used effectively for determination of mixed-mode fracture toughness of laminated composites.
Displacement Ductility of Steel Members under Axial Tension
Authors: Itani AM , Woodgate J 
Published: February 2009

Abstract
This paper discusses the results of an experimental investigation conducted on seven ASTM A 36 steel members subjected to axial tension. The members were chosen with various ratios of net cross-sectional area An to gross cross-sectional area Ag. The specimens were subjected to incremental axial displacement until fracture to determine the displacement ductility of each speci men. The results of this study showed that the displacement ductil ity is highly dependent on the ratio An/Ag and the geometrical shape of the member. It was also found if the ratio An/Ag is less than the specified yield stress to ultimate strength Fy/Fu, the displacement ductility will be close to 1, which means the member will fail in a brittle manner.
Measurement of Young's Moduli for Lead Zirconate Titanate (PZT) Ceramics
Authors: Fett T , Munz D 
Published: February 2009

Abstract
Knowledge of the Young's moduli is necessary for piezoelectric ceramics in order to separate the total deformation into an elastic and a plastic contribution. The methods for the determination of the Young's moduli, well known from conventional ceramics, are much more complicated due to the special electrical boundary conditions. The main aim of the report is to discuss the question in which mechanical tests the conditions of a constant electrical field are fulfilled and in which type of test constant dielectric displacements occur. It will be illustrated that the results from tests with homogeneous stress states are much more trustworthy than results from bending tests.
Stochastic Resonance in Acoustic Emission
Authors: Friesel M 
Published: February 2009

Abstract
Stochastic resonance allows below-threshold signals to be detected because of the presence of favorable background noise. In this paper the author describes stochastic resonance and anti-resonance and presents some examples to illustrate how these affect the detection rates of acoustic emission signals or ultrasonic pulses in low signal-to-noise environments. The author introduces the signal fraction, a measure for quantifying the fraction of detected events that contain a signal that appears to have advantages over the signal-to-noise ratio for certain kinds of data, and a formalism for calculating the probability of signal detection when the noise is a time-dependent sinusoid.
Precision of ASTM D 5821 Standard Test Method for Determining the Percentage of Fractured Particles in Coarse Aggregate
Authors: Hand AJ , Epps JA , Sebaaly PE 
Published: February 2009

Abstract
An interlaboratory study was conducted to develop a precision statement for ASTM D 5821-95, Standard Test Method for Determining the Percentage of Fractured Particles in Coarse Aggregate. The experimental design included ten laboratories, four materials, and three replicates per material per laboratory, resulting in 54 degrees of freedom. Outlier detection was given careful con sideration due to the subjective nature of the method, and resulted in exclusion of one laboratory's data, reducing the degrees of freedom to 48. The materials included three partially crushed gravel blends and one quarry stone blend.
As expected, multilaboratory variability was greater than singleoperator variability. There was also a greater level of variability associated with two or more fractured face determinations than with one or more fractured face determinations. Surprisingly, the greatest variability was observed for the quarry stone rather than for the crushed gravels. The results of the analysis were compared with other available data. The level of variability associated with this study was less than that observed in other studies, due most likely to the highly fractured nature of the materials used in the study.