bluuebunny/crossref_metadata_2025 huggingface dataset:
Decay of Wood and Wood-Based Products Above Ground in Buildings
Authors: Carll CG , Highley TL
Published: February 2009

This paper is an overview of what we know about occurrence of wood decay above ground within buildings. It presents information concerning under what conditions decay may become established. In laboratory tests involving optimum moisture and temperature conditions for decay fungi, and direct contact with large quantities of specific well-developed decay fungi, substantial decay in small specimens of untreated wood of nondurable species can occur in a few weeks. The simultaneous occurrence of optimum conditions for decay and high degree of inoculation with mature decay fungi is probably very rare in buildings. However, spore germination also proceeds rapidly at optimum moisture and temperature conditions. For most decay fungi, optimum moisture conditions mean moisture contents above fiber saturation (usually around 25 to 30% mc,) but well below the waterlogged condition. Optimal temperatures for most decay fungi are in the range of 21 to 32°C. Untreated wood and wood-based products will not decay if intermittently wetted for short periods to moisture contents above fiber saturation or if wetted to such levels for periods of a few months when temperature is low. However, little is known in quantitative terms about decay development under fluctuating conditions. Moisture and temperature conditions are not expected to fluctuate appreciably behind external insulation and finish system (EIFS) claddings. Given this, we can find nothing in the research literature that would contradict the 20% wood moisture content rule for this application.
EIFS Sealant Joint Restoration
Authors: Yarosh KF
Published: February 2009

The successful performance of exterior insulation and finish systems (EIFS) is related directly to the sealants used to weatherseal the EIFS and adjacent materials to EIFS. With millions of square feet of EIFS installed, proper restoration of EIFS joints can help ensure long-term watertight performance of the EIFS wall. A new test method that closely parallels ASTM C 1135—Test Method for Determining Tensile Adhesion Properties of Structural Sealants, is currently under consideration by ASTM Task Group C 24.20.12. This new test method allows sealant joints to be evaluated in many conditions to more closely simulate actual field conditions. This paper will focus on types of EIFS joint failure and possible causes for failure. Different restoration methods will be discussed with particular attention to the use of sealants to overlay failed sealant joints. A modification to the test method under review by ASTM Task Group C 24.20.12 will be used to evaluate various joint conditions with EIFS, including standard square joints, hourglassshaped joints, overlay joints with wet sealants, and overlay joints with performed sealants.
Data Supporting a Provisional American Society for Testing and Materials (ASTM) Method for Metalworking Fluids, Part I: A Solvent Blend with Wide-Ranging Ability to Dissolve Metalworking Fluids
Authors: Glaser RA
Published: February 2009

Data are presented to support modification to a provisional American Society for Testing and Materials (ASTM) sampling and analytical technique for metalworking fluids (ASTM P42-97). The method, tentatively recommended by ASTM Subcommittee D-22.04, involves collection of the aerosolized fluid on a filter and separation of the fluid from co-sampled particulate matter via solvent extraction of that fluid from the filter. The solubilities of nine metalworking fluids were tested in seven solvents: acetone, dichloromethane, ethyl acetate, isopropanol, methanol, toluene, water, and three solvent blends: dichloromethane: methanol, dichloromethane:methanol:toluene, and dichloromethane:methanol:hexane. A ternary blend of dichloromethane: methanol:toluene (1:1:1) was found to dissolve samples of the four classes of metalworking fluids within about 1 min.
The Role of Bearing Plates in the Five-Point Bending Tests of Structural-Size Lumber
Authors: Leichti RJ , Nakhata T
Published: February 2009

The five-point bending test is configured as a continuous two-span beam having point loads at each midspan. It was proposed by others as an approach to evaluating the shear capacity of structural size lumber and engineered wood products because earlier tests with wood-based structural panels yielded shear failure modes. In the tests with structural panels, the thickness/depth ratio was large relative to that in structural lumber, although the length/depth ratios were the same. In addition, the density of the structural panels was greater than that of structural lumber. At the load-bearing positions, rounded bearing surfaces were used for the tests of structural panels, but flat bearing plates have been the practice in tests of structural size lumber. In this study, finite-element analyses of the bearing plates and the resulting stress distributions on structural lumber were conducted, first on an orthotropic half-plane and then in the five-point test geometry for structural lumber. The analyses used linear elastic and nonlinear compressive stiffness perpendicular to the grain and nonlinear shear modulus. Our testing showed that elementary beam theory failed to accurately predict the stresses in the critical region of the specimens. In addition, it appears unlikely that sufficient bearing can be developed in smaller lumber sizes to make the five-point bending method reflective of the true shear capacity.
Evaluation of Wood Poles Using a Free Vibration Technique
Authors: Chui YH , Barclay DW , Cooper PA
Published: February 2009

The current method of sorting wood poles is restricted to a visual inspection approach. It has long been recognized that a mechanical sorting approach will be more efficient in properly utilizing the wood pole resources because mechanical methods are generally more capable of segregating wood products into different strength categories. This paper presents a vibrationbased method for evaluating mechanical properties of wood poles. The evaluation parameter is modulus of elasticity. A theory is presented that relates the first natural frequency to the modulus of elasticity of a tapered beam. The method is based on the measurement of the first natural frequency of a wood pole under free vibration. From the first natural frequency the modulus of elasticity is calculated. Comparison of moduli of elasticity of ten wood poles from static bending and the proposed vibration methods reveals a generally strong correlation between the moduli measured by both methods. However, an outlier was noted that, upon examination of the failure mode, suggested that there was prior damage in the pole. This result indicates that the proposed method is not reliable in detecting any poles that have been weakened by internal defects.
Further Evaluation of Automated Stress Corrosion Ring (ASCOR) Testing of Aluminum Alloys
Authors: Schra L , Wanhill RJH
Published: February 2009

In 1991 a simple automated stress corrosion testing method called the ASCOR (automated stress corrosion ring) test was developed to test aluminum alloys according to ASTM Practice for Evaluating Stress Corrosion Cracking Resistance of Metals and Alloys by Alternate Immersion in 3.5% Sodium Chloride Solution (G 44) and using direct stressing as in ASTM Practice for Preparation and Use of Direct Tension Stress-Corrosion Test Specimens (G 49). The present investigation concentrated on evaluating two aspects of the test method: • The SCC initiation criterion (2% load decrease). • The possibility of defining a threshold stress for micro SCC growth in addition to that for macro SCC growth.

It was found that substantial SCC growth had occurred at 2% load decrease. We therefore propose reducing the load decrease criterion to 0.5% to limit the contribution of SCC growth to the SCC initiation life.

Fracture strength ratios (fracture strength of loaded exposed specimens divided by fracture strength of unloaded exposed specimens) less than 100% were found at exposure stresses below the threshold stress for macro SCC growth. Fractographic investigation showed SCC on the fracture surfaces of specimens tested at these exposure stresses. A threshold stress for micro SCC growth was determined and is defined as the exposure stress at and below which the fracture strength ratio is 100%.
Statistical Properties of the Bukit Timah Granite in Singapore
Authors: Wu C , Hao H , Zhou Y
Published: February 2009

The mechanical behavior of rock mass is affected strongly by its material properties. This paper carries out statistical analyses of the material properties of a rock mass. Statistical analyses of the material constants and the initial damage parameter of the rock mass are performed by using both field and laboratory test data. Based on the measured properties of rock specimens, the elastic modulus, uniaxial compressive strength, and the Poisson's ratio of rock are each found to have normal distributions and the tensile strength to have the gamma distribution. By using Monte Carlo simulation, the equivalent critical tensile strain is found to have the normal distribution. The initial damage of the rock mass, which describes the effects of naturally existing geological discontinuities in a rock mass, is estimated using the field-measured longitudinal and transverse elastic wave velocities. It is found to have the beta distribution. These distributions of rock properties can be used in statistical analyses of the rock mass responses to both static and dynamic loads.
A Proposal for Specimen Size Requirements in Toughness Qualification with the Weibull Stress Criterion
Authors: Miyata T , Tagawa T , Yang H
Published: February 2009

The specimen size requirements in toughness qualification are discussed on the basis of a statistical local fracture criterion approach. The Weibull stress criterion for cleavage fracture is applied to the constraint loss field at the crack tip described with the toughness scaling model (TSM). The proposed new model demonstrates that the TSM is a particular case for a material with a particular combination of the Weibull shape parameter, m, and the strain hardening exponent, n. Based on this model, alternative size requirements for ASTM standards are proposed.
Product/Package Interaction: Effect of Physical, Chemical, and Climatic Environments
Authors: Newsham MD , Giacin JR , Singh SP
Published: February 2009

Product/package interactions were evaluated for three product/package systems: a bleach alternative laundry additive, an anti-bacterial surface cleaner, and a glass surface cleaner. The package system was comprised of high-density polyethylene bottles with induction-sealed closures. The physical environment was studied by comparing product/package systems that were exposed to simulated distribution testing with those that were not. The storage environments were ambient conditions at 73°F (23°C), and higher temperatures at 100, 120, and 140°F (38, 49, and 60°C).

Damage caused by distribution testing occurred in the bottle or in the closure component of the package. Bottle defects resulting from distribution testing were dents, abrasions, and creases. Closure defects included sheared-off closures, cracks in the closure body, or nozzle cover damage.

Product/package systems exposed to the four storage environments were inspected for failure, defined as product leaking from the package, during the six-month study. Failures were due to environmental stress cracking. Dents in the shoulder and bottom region of the bottle were the only simulated distribution defects that impacted the storage stability of the product/package systems, which often resulted in reduced shelf life. The primary location of all other failures was near the center of the bottle bottom edge, which was the thinnest region of the bottle. Bleach alternative laundry additive was the most aggressive product, while the two surface cleaners exhibited similar storage stability.

Performance criteria of the failed bottles were evaluated to study the impact of package system properties on product/package integrity. Yield strength, modulus of elasticity, and dynamic mechanical properties of failed sample-acquired bottle side panels did not change significantly from those of the control samples. Color changes were monitored by measuring interior and exterior surface yellowness indices of bottle side panels. Although observed spectrophotometrically, these changes were not detected visually.
The U Test for Outlier Detection in Normal Distributions with Known σ
Authors: Wang W , Wang T
Published: February 2009

A new criterion is proposed for testing for outliers when the population standard deviation a is known. The advantage of this criterion is that no table is required and a fixed significance level can be selected. Compared with the current ASTM E 178 criterion for outlier rejection, under the same chance of making a Type I error, the U test has less chance of making a Type II error and therefore is a more powerful test.
Measurement of Anchor Strength in Non-Rigid Substrates
Authors: Farquhar T , Conyers MD , Dixon JT
Published: February 2009

This study provides guidelines for measuring anchor strength in non-rigid substrates. ASTM Standard Test Method for Strength of Anchors in Concrete and Masonry Elements (E 48884) was designed to measure the “strength of anchors in concrete and masonry elements” and was never intended for use in flexible substrates. Hence, the load capacity of anchors installed in thin brittle materials like gypsum wallboard may be overestimated when measured in accordance with E 488. This is because ASTM E 488 imposes a reaction load around the anchor and delays the onset of pullout failure related to substrate bending. In contrast, the alternative test does not constrain the front surface of the substrate and can better reproduce the actual mechanisms of anchor failure in flexible materials.

The pullout strength of five anchor styles of varying rated strengths was determined following the ASTM E 488 method and by the alternative method. In both cases, the anchors were placed in a wallboard panel attached to a rigid wooden framework by suitable screws and adhesive. With no adhesive cure, the strength by the alternative method was up to 31% less than that obtained by the test following ASTM E 488 guidelines. With full adhesive cure, the strength in the alternative test was still up to 30% less than the ASTM test and up to 45% less than the rated strength. The strength differences can be linked to differences in the flexural stiffness of the test panel, and guidelines are given for determining when the substrate is flexible enough to justify the alternative test. The alternative test requires more setup time than ASTM E 488 but provides a more realistic measure of the ultimate load capacity of relatively strong anchors. In addition, the alternative test makes it possible to relate the effects of factors like screw spacing and bonding efficacy to anchor strength.
Modification of ASTM F 1671-97a, Resistance of Materials to Penetration by Blood-Borne Pathogens, for Use with Elastomeric Materials
Authors: Kisielewski RW , Routson LB , Chaput MP , Lytle CD
Published: February 2009

A modification to ASTM F 1671-97a, Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Blood-Borne Pathogens Using Phi-X174 Bacteriophage Penetration as a Test System, was developed to allow evaluation of elastomeric materials having small tears. The original method provides for a flat, open-mesh support screen to prevent expansion of such materials. While natural latex rubber specimens with open, laser-drilled holes ⩾1 µm fail this test by allowing virus penetration, nitrile-butadiene rubber specimens with small tears (20 to 45 µm) pass. A stainless steel wire cloth support screen with a hemispherical-like dome, in lieu of the flat screen, provided controlled expansion and allowed detection of defective specimens with tears. The data also suggest a similar modification to enhance ASTM F 1670-97, Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Synthetic Blood.
Porosity and Wear Resistance in Stone Flooring Tiles
Authors: MacGregor ID , Chiu KY
Published: February 2009

A sorptivity test and a permeability test were used as an assessment of the degree of porosity of stone flooring tiles, where there was particular interest in the surface characteristics. A good correlation was obtained between the two tests; the sorptivity is preferred since it is the easier to perform and could be extended to assess the characteristics of full-sized tiles.

A Taber Abraser was used to compare the likely wear of the stones. Assessment was by weight loss and by groove depth, measured by both a depth micrometer and a laser beam profile meter. Good agreement was achieved among all the wear measurement methods. The laser beam is the least preferred method due to the equipment cost and availability. Mohs' mineralogical scratch method was used to assess hardness, which is possibly related logarithmically to the Taber wear.

The stone types were two granites and two marbles in common use in Hong Kong. One granite had the best properties from all measurements. The other granite and one of the marbles had similar properties, while the remaining marble showed distinctly inferior properties. Flooring specification limits could perhaps be set above those achieved on the poorer marble, but more work is required to set definitive limits. Stone flooring physical property limits do not appear to be specified in Hong Kong, and elsewhere performance specifications seem to be at best limited.
Injuries Due to Traditional and Soft-Core Centered Baseball Impacts: A Review
Authors: Beaumont RD
Published: February 2009

The purpose of this paper is to investigate the increasing use of soft-core centered baseballs and the safety issues that have arisen in comparison to the design and manufacture of traditional hard-core baseballs. This purpose was not to decide whether either of the two types of baseballs was reasonably safe or unreasonably dangerous. Allegations have been made that the hardness of a baseball affects the type and magnitude of injury to a person. Experimental and analytical research has been done exploring that area to determine the validity of those allegations. This paper reviews the models and methodology presented in recent studies attempting to model the mechanism of injury and death related to baseball impacts to the human head and chest regions.

Information was obtained from the U.S. Consumer Product Safety Commission, which disseminates mandatory regulations for some consumer products, and the National Operating Committee on Standards for Athletic Equipment, which publishes voluntary industry standards for baseballs and baseball equipment. In addition, studies conducted by a number of organizations, including the Institute for Preventative Sport Medicine, the National Aeronautics and Space Administration, Wayne State University, as well as articles published by The New England Journal of Medicine, were included in the review.
Falling-Weight Deflectometer Sensor Location in the Backcalculation of Concrete Pavement Moduli
Authors: Li S , White TD
Published: February 2009

This paper discusses the principles of two closed-form algorithms, ILLI-BACK and NUS-BACK, for backcalculating layer moduli of concrete pavements and their implications for selecting sensor locations in falling-weight deflectometer tests. It is found that sensor location has an effect on the results backcalculated using these two closed-form algorithms. Use of sensors at large radial distances may produce results with high variations since a small variation in the deflections recorded by these sensors will result in a significant change of layer modulus. Use of close sensor spacing will produce a ratio of deflections recorded by two consecutive sensors close to 1, leading to significant variations in backcalculation results in those cases where errors are involved in deflection measurements. The Strategic Highway Research Program (SHRP) FWD sensor configuration with sensors located at 0, 203, 305, 457, 610, 914, and 1524 mm is examined. Care should be taken in backcalculation analysis of concrete pavements using the SHRP sensor configuration in conjunction with the closed-form algorithms. Backcalculation results from deflections measured by SHRP and on Indiana US52 quantitatively confirm these findings.
Network-Level Pavement Deflection Testing and Structural Evaluation
Authors: Hossain M , Chowdhury T , Chitrapu S , Gisi AJ
Published: February 2009

Structural evaluation provides valuable information about the expected behavior of pavements and can be very useful at the network level of pavement management for project prioritization purposes. However, due to the expense involved in data collection and analysis, structural capacity is usually not determined at the network level. In Kansas, due to limited resources and the large size of the network (10 971 miles), annual network-level structural data collection at the same rate (five to ten tests per mile) as the project level is not realistic. This study was initiated to determine the sample size (% mileage) at the network level as well as the test intervals and frequency that can be used as guides for network-level deflection testing and structural evaluation of pavements.

Falling-weight deflectometer (FWD) data, collected on 571 km (357 miles) of non-interstate asphalt pavements of the Kansas Department of Transportation from 1993 to 1996, were used in the analysis. Three response variables were studied: (1) normalized and temperature-corrected first sensor deflection, (2) backcalculated subgrade resilient modulus (Mr), and (3) effective pavement modulus (Ep). Statistical analysis of these variables showed that the FWD tests up to a three-year interval at the network level yield statistically similar pavement responses and layer properties. At the network level, FWD tests on 20% mileage appear to be a valid statistical choice, and three tests per mile is the minimum test frequency required. An analysis procedure for assessing structural deterioration of pavements at the network level is also demonstrated.
Laboratory Measurements and Analysis of Clogging Mechanism of Porous Asphalt Mixes
Authors: Tan SA , Fwa TF , Guwe VYK
Published: February 2009

A laboratory test to assess the clogging potentials of porous asphalt mixes is useful as part of a rational design procedure of these mixes for the construction of pavement surface friction courses. Following an earlier successful attempt in inducing clogging in porous specimens in the laboratory, this paper describes a project studying the clogging potentials for porous asphalt pavements of different thicknesses under simulated field conditions. The clogging potentials were studied through the monitoring of the deterioration of the permeabilities of the laboratory specimens, made possible by a new falling-head permeameter that measures three-dimensional flow. An attempt was also made to relate the results thus obtained to a simple theoretical model suggested by Giroud for geotextiles. It was found that there was a fairly good comparison between experimental results and theory.
In Situ Measurement of Fatigue Crack Growth Rates in a Silicon Carbide Ceramic at Elevated Temperatures Using a DC Potential System
Authors: Chen D , Gilbert CJ , Ritchie RO
Published: February 2009

The understanding of the mechanisms of fatiguecrack propagation in advanced ceramics at elevated temperatures (>800°C) has in part been hampered by the experimental difficulty in directly measuring crack lengths, and hence crack growth rates, at such high temperatures. In this study, we show how the direct-current (DC) electrical-potential technique, which has been used for such measurements in metallic materials for over 30 years, can be successfully utilized to monitor fatigue crack growth rates in situ in a silicon carbide ceramic at temperatures between 850 and 1300°C, because of the electrical conductivity in SiC at these temperatures. In addition to providing a highly efficient means of collecting such data, this approach offers several significant advantages over the techniques that have been used to date for advanced ceramics, particularly in avoiding artifacts due to thermal fatigue and oxidation from repeated exposure to air and/or lower temperatures while making measurements. Effects of parameters such as load ratio and loading frequency are examined, both on crack growth behavior and the accuracy of measurement. With appropriate considerations, electrical-potential calibrations determined at ambient temperatures in metallic materials can be applied readily to elevated temperature measurements in silicon carbide.
Loss of Compression Strength in Corrugated Shipping Containers Shipped in the Single Parcel Environment
Authors: Singh SP , Pratheepthinthong S
Published: February 2009

This study monitored the shipment of corrugated fiberboard shipping containers in the small parcel shipping environment. Similar boxes were also tested in three different laboratories to determine loss of compression strength in actual shipments, and in simulated tests recommended by the International Safe Transit Association and the American Society for Testing and Materials. Safety factors were developed based on the data collected.
The Influence of Specimen Size on the Fracture Behavior of a Structural Steel at Different Temperatures
Authors: Martinez LT , Gonzalez GR , Varela FJB , Biempica CB
Published: February 2009

A broad experimental study was carried out in order to analyze the influence of different geometrical parameters (thickness, width, and crack length) and temperature on the fracture behavior of a structural steel. The J-integral versus crack growth resistance curves (J-R curves) were determined using indirect measurements of the crack size based on the variation of the specimen compliance, together with the physical determination of crack lengths obtained during testing using a color marking procedure. This last technique allows the reliability and accuracy of the data to be improved and provides additional information that can be used to reduce the typical scatter of the results. Only the initial crack size of the specimen has an influence on the J-R behavior of the steel due to the triaxiality modification of the crack tip stress state developed in the specimen. On the other hand, the J-R curve of the steel is also independent of temperature. Temperature affects only the J values at which cleavage or unstable fracture takes place.
DC Potential Drop Calibration in Creep-Fatigue Loading Conditions
Authors: Merah N
Published: February 2009

The direct current potential drop method (DCPD) is used to detect the initiation of cracks and monitor their growth under the conditions of high gross inelastic deformations (plastic and creep). Testing is conducted on flat SS-304 plates with central circular holes of different diameters under fatigue and creep-fatigue loading at 600°C. The potential drop is measured using two pairs of voltage probes across the hole. The variation of the voltage ratio with the number of cycles is considered in order to eliminate the dependency of the DCPD on the current and material resistivity. The visible crack length is measured by a video camera with image processing to assess the reliability of the DCPD technique.

The effects of notch shape and notch plastic zone size prior to initiation are removed by using a special reference voltage ratio. Because of the high inelastic deformations at the crack tip and larger crack opening displacement under fatigue and creep-fatigue conditions at high temperature, the calibration curve developed at room temperature is modified using material property variation with temperature. Furthermore, the variation of notch opening displacement with voltage ratio is employed to correct measured crack length and to determine crack initiation under fatigue with hold time.
Measurement of Apparent Thermal Conductivity by the Thermal Probe Method
Authors: Manohar K , Yarbrough DW , Booth JR
Published: February 2009

Three thermal probes were constructed in accordance with ASTM D 5334 and calibrated using heat-flow metre data. The temperature-time response of the thermal probes for determining apparent thermal conductivity λ under transient state conditions was logged at 1 s intervals. The instrumentation used reduced the determinate error associated with voltage and current measurements to a negligibly small value that made the uncertainty in λ dependent on the uncertainty of the slope dT/dlnt. A test method was run in 1000 s, in which a criterion of 2.5% spread among three consecutive slope values was used to determine the extent of the linear segment of the T–ln t curve.

The probes demonstrated repeatability within ±3.5% but had definite individual bias indicating a need for individual calibration. Using individual probe calibration factors, the experimentally de termined λs for all-purpose sand, sifted sand, and soil were deter mined to be 0.520, 0.445, and 2.11 W/moK, respectively.
Fatigue and Stress Analysis of a Novel Test Coupon Geometry Developed for Hydraulic Pressure Impulse Testing
Authors: Savas TP , Earthman JC
Published: February 2009

Pressure impulse fatigue testing of a novel test coupon geometry was conducted to simulate hydraulic flight con trol manifolds under multiaxial stress conditions. The configuration of the coupon was particularly useful for evaluating complex multiaxial stress states and for comparing the impulse fatigue performance of different types of alloys under conditions of high stress concentration. In this article, three-dimensional linear elastic finite element analyses are presented to quantify the von Mises equivalent and maximum principal stress distributions at the stress-critical regions. Fatigue life results using the present coupon geometry are provided for two high-strength aluminum alloy variants, including Types 7075 and 6013. Post-test macroscopic and scanning electron microscopy examinations are presented to characterize the fatigue fractures and to show that fatigue crack initiation takes place at the maximum stress locations as predicted by finite element analysis.
Leaching Behavior of Indian Fly Ashes by an Oedometer Method
Authors: Pandian NS , Balasubramonian S
Published: February 2009

Thermal power stations use pulverized coal as fuel, producing enormous quantities of ash as a by-product of combustion. Currently, with very low utilization of the ash produced, the ash deposits at the thermal power stations are increasing rapidly. The disposal problem is expected to become alarming due to the limited space available for ash disposal near most thermal power stations. Among the various applications available for the use of fly ash, geotechnical application offers opportunity for its bulk utilization. However, the possibility of ground and surface water contamination due to the leaching of toxic elements present in the fly ash needs to be addressed. This paper describes a study carried out on two Indian fly ashes. It is found that pH is the controlling factor in the leaching behavior of fly ashes.
Evaluation of the Gavarti Associates-Comprehensive Abrasion Tester
Authors: Burgess G , Singh P , Knudsen E
Published: February 2009

The GA-CAT (Gavarti Associates-Comprehensive Abrasion Tester) was put through sensitivity and repeatability studies to determine the variability associated with the machine. This was done to evaluate its ability to detect differences in quality within a batch of production run labels. The results showed that repeatability was poor so that quality variations in labels could not be assessed. The focus of the study therefore shifted to evaluating the causes of machine variability.
Angle of Internal Friction for Pond Ashes
Authors: Pandian NS , Sridharan A , Srinivas S
Published: February 2009

Thermal power stations use pulverized coal as fuel, producing enormous quantities of ash as a waste product of combustion. Nearly 800 million metric tons of ash is produced each year all over the world. In India, presently 97 million metric tons of ash is produced annually by power stations. The problem of ash disposal is a difficult one due to the limited availability of vacant space around the power plants. In view of the large quantities of ash, its bulk utilization is essential, which is possible only through geotechnical applications such as embankments, back-fill material, subbase material, and the like. For the above applications, one of the important engineering properties is the angle of internal friction, which is determined either by box shear or triaxial shear tests. This paper examines the angle of repose of pond ashes and its relation with the angle of internal friction, using direct shear tests. Determination of the angle of repose is an easy and quick procedure for cohesionless materials. The angles of repose of sand and of quarry dust also are examined for comparison purposes. A relationship between angle of internal friction for materials in the loose, dry condition and the angle of repose is established. Further, a simpler method of measurement of the angle of repose is proposed.
Liquid Limit Determination of Class F Coal Ash
Authors: Sridharan A , Pandian NS , Prasad PS
Published: February 2009

Large production of coal ash, a waste material, demands its bulk utilization. Bulk utilization of these ashes is possible only through geotechnical applications such as embankment construction, as a back-fill material, a subbase material, and the like. Hence their physical and engineering properties need to be determined for effective utilization. Liquid limit is one of the important physical properties. The existing popular methods of liquid limit de termination of soils, namely Casagrande's percussion method and the falling cone method, have limitations for their use in nonplastic materials like coal ash. In this paper, a new method has been proposed to determine the liquid limit of coal ash. The proposed method is based on the premise that at its liquid limit water content, soil/coal ash does not imbibe or give out any water under a particular vertical stress under the Ko condition. This vertical stress is found to be 0.9 kPa. Experimental results are presented to substantiate the proposed method.
Fault Diagnosis Theory: Method and Application Based on Multisensor Data Fusion
Authors: Wang HF , Wang JP
Published: February 2009

This article discusses the elementary theory and method of condition monitoring and fault diagnosis in complex mechanical systems, using multisensor data fusion and integration technology. The basic concept of decision-layer multi-sensor data fusion, i.e., Dempster-Shafer evidence theory, is concisely described. The algorithms and implementation of decision-layer data fusion for condition monitoring and fault diagnosis, based on Dempster-Shafer evidence theory, are studied. We present an approach to diagnose multiple faults of a working diesel engine, based on the above algorithms. The analysis results show that this approach effectively improves the accuracy and reliability of fault diagnosis of the diesel engine.
Development of a Multiple Linear Regression Model to Estimate the Ductile-Brittle Transition Temperature of Ferritic Low-Alloy Steels Based on the Relationship Between Small Punch and Charpy V-Notch Tests
Authors: Saucedo-Muñoz ML , Matsushita T , Hashida T , Shoji T , Takahashi H
Published: February 2009

The transition temperatures of Cr-0.5Mo, Cr-Mo, and Cr-Mo-V steels were determined using the Charpy V-notch (CVN) and the small punch (SP) tests. It was confirmed that there was a linear correlation between the transition temperature of ductile-brittle behavior determined by the Charpy V-notch test and that obtained from the small punch test. However, the estimation of CVN transition temperature by means of this linear equation is not completely reliable because of the large experimental scatter of data. In order to improve the reliability of the transition temperature estimation, a multiple linear regression (MLR) analysis was conducted to evaluate the effect of different variables of the manufacturing process and service conditions. This analysis permitted the determination of the following regression equation: CVNDBTT=1.35SPDBTT−0.84×103d−1∕2+326. This equation enables one to assess more accurately the transition temperature corresponding to the Charpy V-notch test using that of the small punch test and the austenitic grain size, expressed by d−1∕2.
The Effect of Kinematic Viscosity on the Flash Point of Liquids Determined by ASTM D 93 Procedure A, ASTM D 93 Procedure B, and ASTM D 56
Authors: Montemayor RG
Published: February 2009

The flash point of a liquid material is used to classify whether the material is flammable or combustible. ASTM D 93 is used to determine the flash point of various liquids either by Procedure A or Procedure B. There have been reports of flash point depression when viscous materials were tested using ASTM D 93 Procedure A relative to ASTM D 93 Procedure B. A multi-sample interlaboratory study was conducted to determine the effect of the kinematic viscosity of a liquid material on the observed flash point when tested according to ASTM D 93 Procedure A relative to the results when tested according to ASTM D 93 Procedure B. The results of the study indicate that liquid materials with kinematic viscosities greater than 13 mm2/s at 40°C gave lower observed flash points when the flash point was tested using ASTM D 93 Procedure A compared to the flash point tested by ASTM D 93 Procedure B. A possible explanation is a lag in the temperature detected by the temperature-measuring device as the kinematic viscosity of the liquid increases, especially when equilibration of the temperature of the vapor and the bulk of the specimen is not established before the flash point is detected. This temperature lag effect is more pronounced when using D 93 Procedure A than when using D 93 Procedure B. A similar study was conducted with ASTM D 56, another flash point test method. The effect of kinematic viscosity on the observed flash point by D 56 is less apparent than that observed when using D 93 Procedure A.
A Methodology for Determining Rate-Dependent Flow Surfaces for Inconel 718
Authors: Lissenden CJ , Gil CM , Lerch BA
Published: February 2009

A detailed set of experiments has been conducted in an attempt to characterize the inelastic flow behavior of materials used in aeronautics applications. These experiments have shown that aged (precipitate-hardened) Inconel 718 exhibits an initial nonlinear elastic behavior as well as a strength differential in tension and compression at room temperature. This nonlinear elastic behavior correlates reasonably well with a second order stress-strain law that was developed to account for interactions between dislocations and interstitial solute atoms. Flow loci in the axial-shear stress plane at 25 and 650°C have been determined from yield locus data using both inelastic power and equivalent inelastic strain definitions of flow. Flow loci are more theoretically meaningful than yield loci for describing the time-dependent material response. These flow loci are especially important if they are proportional to the dissipation potential since the normality rule is associated with dissipation and not necessarily with a particular yield or flow definition employed in an experiment. A threshold function that depends only on the second deviatoric stress invariant, J2, is inadequate for predicting the threshold surface (initial yield locus) for Inconel 718 due to the difference in flow behavior in tension and compression. Threshold functions including all three stress invariants (I1, J2, and J3) with each term having units of stress raised to the first or third power were equally successful in fitting the initial flow locus. Additionally, both F=aI1+bJ21/2−1 and F=b3J23/2+c3J3−1 are shown to represent the data very well. The outward normals for these two representations of the threshold surface are consistent with experimentally determined directions of the inelastic strain rate vectors.
Early Detection of Fatigue Damage Through Ultrasonic Non-Destructive Evaluation—Part II: Experimental
Authors: Bayer P , Singher L , Notea A
Published: February 2009

Ultrasonic wave velocities (longitudinal and transverse waves) and the attenuation coefficient were used to investigate damage of aluminum 7075-T651 before and after progressive stages of fatigue. Repeated observations under controlled conditions allied to digital signal acquisition, autocorrelation, and regression were used to estimate small velocity and attenuation changes. Although comparatively small uncertainties were observed, the feasibility of utilizing the velocity of ultrasonic waves as a fatigue monitor was not substantiated under actual research conditions. However, careful measurements of the ultrasonic attenuation parameter demonstrated its potential to provide an early assessment of damage during fatigue.

Part I of this work discussed the theoretical approach and described the fatigue testing procedures adopted in this investigation. This is a presentation and discussion of the experimental results.
A New Facility to Simulate Simultaneous Wind and Thermal Effects on Roofing Systems
Authors: Baskaran A , Liu K , Lei W , Delgado A
Published: February 2009

Roofing systems are exposed to wind pressures and thermal stresses. Through a North American roofing consortium (Special Interest Group for Dynamic Evaluation of Roofing Systems—SIGDERS) the National Research Council Canada fabricated a facility to evaluate roof assemblies under simultaneous wind and thermal effects. The overall objective of this paper is to present the commissioning process of the facility based on experimental investigations that were carried out on a single-ply roofing system with a PVC membrane. For this study, roofing system responses were measured under simulated simultaneous wind and heat/cold conditions. A systematic attempt also was made to quantify the system response and to characterize the membrane properties. This was performed on a cold-conditioned system as well as by subjecting the membrane samples to the same cold-conditioning program in a laboratory freezer. Membrane samples were characterized by mechanical and chemical methods. Comparison of laboratory-conditioned membranes and wind-tested systems revealed the effects of cold conditioning and wind loading. Neither the wind uplift nor the mechanical properties (tensile breaking strength, elongation at break, tear strength, and seam strength) nor the chemical properties (glass transition temperature and weight loss) were affected by the selected cold conditioning. Based on these findings, directives for further studies are presented for this ongoing project.
Evaluating the Quality of a Mechanical Testing System Using Displacement Field Contours
Authors: Zhao B , Asundi A
Published: February 2009

A technique using displacement field data to qualify mechanical tests for in-plane deformation is proposed. Contour lines of the displacement fields that result from applied forces in mechanical tests are used for quantitative analysis and graphical representation of quality of the mechanical testing system in the tests. This method can visually, directly, and sensitively detect loading problems, such as misalignment, existing in the tests. A theoretical analysis using a displacement contour map to describe quantitatively the effect of the misalignment in a uniaxial tension test is described in detail. A technique to obtain the displacement contour map from the displacement field data and on-line inspection of some test system misalignment is presented. Several examples, including an eccentric tension test, a tension test with inhomogeneous fixing of a specimen in the grips, and an Iosipescu composite shear test with various degrees and sources of misalignment are analyzed with this contour method.
A Low-Temperature Modification to the Charpy Impact Test, with an Example Study of the Fracture Toughness of Mg-12%Li between 4.2 to 77 K
Authors: Russell AM , Ostenson JE
Published: February 2009

A modification to the Charpy test for measuring impact fracture toughness has been developed that permits the specimen to be bathed in flowing liquid helium while mounted on the testing machine's anvil immediately prior to impact. This method permits samples to be tested at any temperature between 4.2 and 77 K, which extends the Charpy test to temperatures lower than those achievable by the conventional liquid bath immersion technique. A body-centered cubic Mg-12%Li single-phase alloy was tested by this new method and found to have anomalously high impact fracture toughness in the temperature range 4.2 to 77 K.
Effect of Crack Front Curvature and Side Grooving on CTOD δ5 and J-Integral in CT and 3PB Specimens
Authors: Nikishkov GP , Heerens J , Hellmann D
Published: February 2009

Fracture testing on compact tension (CT) and threepoint bend (3PB) specimens is preceded by fatigue precracking. Fatigue cracks have curved crack fronts. Nevertheless, crack front curvature is not taken into account in numerical modeling of fracture toughness testing procedures. In this paper we analyze actual fatigue cracks in CT specimens and show that the difference between crack depth at the center plane and at the surface of specimens is typically 0.01 to 0.03 of the specimen width. Three-dimensional elastic-plastic finite element analyses were performed for CT and 3PB specimens with crack fronts of different curvatures, and the CTOD δ5 and the J-integral were determined. It is found that the ratio δ5C∕δ5 is sensitive to the crack front curvature and strongly affected by side grooves. It is also shown that crack front curvature variations that are within the limits given by the test standards affect to a certain extent the η factor employed for the determination of the experimental value of the J-integral using the area under the force versus load-point displacement record. These facts should be kept in mind when toughness is measured.
Prediction of Permanent Deformation of Asphalt Concrete in Cyclic and Monotonic Loading
Authors: Ramsamooj DV , Ramadan J
Published: February 2009

New theoretical developments are presented to predict the permanent deformation in asphalt concrete caused by constant-load creep and by cyclic loads. The constitutive model utilizes multi-yield surfaces and isotropic hardening. A new hardening law for the changes in the values of the plastic moduli during monotonic or cyclic loading is derived from Rowe's stress-dilatancy theory. A complete description of the permanent deformation of asphalt concrete under constant load creep and cyclic loading is given, including the elastic, viscoelastic, plastic, and microcracking components, to predict the permanent deformation under cyclic loading. The model parameters have clearly defined physical meanings and can be determined from simple conventional laboratory tests. A computer program called RUT determines the permanent deformation. There is good agreement between the model predictions and the experimental data.
Yield of Inconel 718 by Axial-Torsional Loading at Temperatures up to 649°C
Authors: Gil CM , Lissenden CJ , Lerch BA
Published: February 2009

An experimental program has been implemented to determine small offset yield loci for the nickel-base superalloy In conel 718 (IN718) under axial-torsional loading at elevated temperatures. Initial and subsequent yield loci were determined for solutioned IN718 at 23 and 454°C and for aged (precipitation-hardened) IN718 at 23 and 649°C. The shape of the initial yield loci for solutioned and aged IN718 agrees well with the von Mises prediction. However, in general, the centers of initial yield loci are eccentric to the origin due to a strength-differential (S-D) effect that increases with temperature. Subsequent yield loci exhibit kinematic and distortional hardening, and solutioned IN718 shows a weak cross effect. This work demonstrates that it is possible to determine yield surfaces for metallic materials at temperatures up to at least 649°C using multiple probes of a single specimen. The experimental data are first of their kind for a superalloy at these temperatures and will enable a better understanding of multiaxial material response.