bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of Wood Resistance Sensors for Measurement of Humidity
Authors: Carll C , TenWolde A
Published: February 2009

This work was undertaken to evaluate the accuracy of wood resistance sensors for measurement of relative humidity and to identify sources of error in this use. Relative humidity can be expressed as a function of the logarithm of the sensor's electrical resistance and of its temperature. We found that single-point calibration of each sensor compensates for most between-sensor variation, although care must be exercised during calibration. With careful calibration readings, error in relative humidity readings made with these sensors can be limited to ± 10% relative humidity under most conditions. The literature indicates that a lower degree of error than this is anticipated when electrical resistance is used to estimate moisture content measurements. Our data suggest that sorption hysteresis and sensor memory are significant contributors to this (± 10%) relative humidity error.
Fly Ash as a Pre-Filter Material for the Retention of Lead Ions
Authors: Pandian NS , Rajasekhar C , Sridharan A
Published: February 2009

Clay liners have been widely used to contain toxic and hazardous waste materials. Clays absorb contaminant cations due to their exchange capacity. To improve the performance of the clay liner, fly ash, a waste material arising from the combustion of coal has been studied as a pre-filter material. In particular, the retention of lead by two different fly ashes was studied. The influence of pH on retention as well as leaching characteristics are also examined. The results obtained from the retention experiments by the permeameter method indicate that fly ash retains the lead ions through precipitation in the pores as well as onto the surface when the ambient pH value is more than 5.5, and through adsorption when the pH value is less than 5.5. It has been observed that fly ash did not release the retained lead ions when the pH value is between 3.5 and 10.0. Hence, the retention of lead ions by fly ash is likely to be permanent since the pH of most of the municipal landfill leachates are within 3.7 to 8.8. However, for highly acidic or alkaline leachates, the retained ions can get released.
Preliminary Characterization of Thermal Diffusivity for Carbon-Carbon Composites Through Pulsed Video Thermal Imaging
Authors: Kulkarni MR , Brady RP
Published: February 2009

Many times complete knowledge of thermal transport properties is needed before a material can be employed in a thermal application. One property of primary concern is thermal diffusivity. What is desirable is not only the magnitude of thermal diffusivity, but also the determination of its non-uniformity. The currently used standard test method by industry is the (ASTM) Standard Test Method for Thermal Diffusivity of Solids by the Flash Method, which measures diffusivity at one point. This method also requires the destructive removal of a small sample for examination, special ad hoc machinery for surface scanning, and is not suitable for quality assessment in a manufacturing environment. There is substantial industrial demand for the nondestructive, rapid, on-line evaluation of the thermal diffusivity of an entire part's surface. Pulsed Video Thermography (PVT) is an emerging thermal wave imaging technique that shows promise for meeting those demands. In this work a brief description of the theory behind PVT and a sample application are given. Preliminary results show that the PVT thermal diffusivity values for a carbon-carbon composite plate compare favorably with those obtained by the widely used laser flash diffusivity method.
A Fracture Test Method for Mode I Fracture Of Thin Metal Materials
Authors: Cotterell B , Sim MC , Amrutharaj G , Teoh SH
Published: February 2009

A method of testing Mode I K dominated fractures in thin materials using a constrained short center notched tension specimen that is clamped along the loaded edge is described. Poisson's effect induces a lateral tension on the specimen that eliminates the buckling problems associated with thin materials. Furthermore, the stress intensity factor over a significant range of crack lengths and specimen geometries is dependent only on the nominal strain, making the test very suitable for crack-growth experiments under a constant-stress intensity factor. A very accurate approximate expression for the stress intensity factor is presented. A test using this method to measure the crack-growth resistance of Kapton 300HN polyimide film is described.
Improved Indentation-Depth Method of Hardness Measurement
Authors: Ezhov YV
Published: February 2009

In the determination of the indentation hardness of a metal by pressing a ball into its surface, it is shown that the use of a modified procedure that compensates for testing-instrument backlash when measuring indentation depths gives good reproducibility of measurement, approaching the reproducibility found when measuring indentation diameters. This suggests that the need to measure the indentation diameter in the standard Brinell hardness test may be unnecessary, since comparable precision can be obtained by measuring the indentation depth, overall a simpler procedure.
Review of Durability Testing of Building Stone with Annotated Bibliography
Authors: Carr DD , Strickland J , McDonald WH , Bortz S
Published: February 2009

The search for a method to test the durability of building stone has been in practice for centuries. There is no universally accepted method of testing all building stone. The differences in mineralogical, chemical, and physical properties of rocks are too great to have one test evaluate all. The standard ASTM physical tests for building stone contribute, in their own way, to the analysis of durability.

The best durability test for a stone is proven use with time. In addition to examining buildings whose construction dates and sources of stone are known, the National Bureau of Standards test wall can be examined. This wall, with 2352 samples of stone, has had about 50 years of weathering in an urban environment.
Creep Testing of Steels at Very High Temperatures
Authors: Lindblom J , Seitisleam F , Henderson PJ
Published: February 2009

This paper describes changes to specimen grips and specimen design in order to creep test steels at temperatures a little below the spalling temperature and at low stresses (long times) where a large amount of oxidation occurs. High ductility and oxidation of a creep specimen often mean that the thermocouples lose contact with the specimen surface and the specimen itself cannot be removed from the grips after testing. The improvements involve the use of corrosion resistant alloys with reasonable high temperature strength for the loading bars and grips, a change in grip design and measuring the temperature inside the specimen.
Ultrasonic Characterization of Interphasial Properties in Sapphire/Haynes 214 Composites
Authors: Huang W , Chu YC , Rokhlin SI , Wright PK
Published: February 2009

This paper reports ultrasonic measurements of elastic properties of Haynes 214 metal matrix composites reinforced with sapphire fibers. The focus of this work is on the effects of the fibermatrix interphases on the composite moduli. Four groups of samples were prepared using fibers with different coatings (including one with no coating). There are two samples in each group: one subjected to one thermal cycle at 1200°C and the other a failed tensile sample tested in transverse-to-fiber direction. Ultrasonic velocity measurements were performed for different wave propagation directions in two incident planes: parallel and perpendicular to the fibers. The velocity data were used to find the elastic constants of the composite. Due to excess matrix material near the sample surface, a matrix/composite layer/matrix laminate model was used to determine the composite layer moduli. A micromechanical model was developed to estimate the interphasial effective elastic moduli from the composite moduli. The transverse moduli of the composite and the fiber are obtained using an averaging scheme to account for material anisotropy in the transverse plane. It was found that for the thermally cycled samples the interphasial moduli are quite similar among different sample groups. However, for the fractured samples the effective interphasial moduli of one group were extremely low, indicating debonding of the interphases before failure, whereas the interphasial moduli of other groups did not significantly differ from those of the thermally cycled samples.
Calibrating Instrument Readings Using a Bivariate Confidence Interval
Authors: McDonald BJ , Trautner JJ
Published: February 2009

A method of calibration that establishes a new bound of confidence for instrument measurements is derived and applied. This bound is named the McDonald-Trautner Interval (MTI). The derivation of the MTI incorporates the bivariate probability distributions of each data point conventionally used to form a regression line. A statistically significant number of parameter measurements on a sample must be made by both the instrument being calibrated and the calibrating medium. When calibration is based solely on regression analysis, the calibrating medium is assumed to be 100% reliable. The MTI includes the variability of the medium. The method is demonstrated on the calibration of a heavy metal detector. The calibrating medium is a chemical process. Compared to the conditional standard deviation bounds of linear regression, it is found that the MTI is a simple means to obtain a more statistically rigorous calibration procedure and is a better indication of the expected value of a variable.
Testing and Design of CMOS D-Latches
Authors: Aissi C , Olaniyan J
Published: February 2009

The CMOS D-latch is an important block in the design of sequential circuits. Thus, a new fully testable CMOS D-latch (FTD) is proposed. A comprehensive test set that includes possible physical failures is developed. This test set is then applied to the FTD. The cost of implementation, analysis, and simulation of the FTD are all presented. Application of the FTD-latch to build a polarity-hold shift register is shown.
Neural Network Approach for Prediction of Wrinkling Limit in Square Metal Sheet Under Diagonal Tension
Authors: Di S , Thomson PF
Published: February 2009

A method of predicting the onset of wrinkling in the Yoshida Buckling Test, devised to simulate the wrinkling behavior in press-forming of sheet metal, has been developed in the present work by using an artificial neural network. The influence of different network architectures, learning parameters, and material coefficients has been investigated. The neural network was trained using data obtained by finite element analysis. The effectiveness of a neural network as a tool for predicting wrinkling limits in sheet metal-forming is examined. It is found that the trained neural network is capable of covering a wide range of material properties and its prediction of nominal strain at the onset of wrinkling is in reasonable agreement with the analytical results.
The Use of the Tortus and the Pendulum with the 4S Rubber for the Assessment of Slip Resistance in the Laboratory and the Field
Authors: Dravitzki VK , Potter SM
Published: February 2009

This study was undertaken to meet a need in New Zealand about five years ago. Earlier an increased use of ceramic tiling and polished natural stones within buildings and on adjacent pavements highlighted what was an existing problem of frequent use of low slip resistance materials for pedestrian areas. A national standard, NZS 5841 “Code of Practice for the Reduction of Slip Hazard—Part 1, Guidelines…”, had been prepared. However, because it was qualitative rather than quantitative in approach, its application was limited. Building regulators wished to have a standard with minimal criteria and appropriate test methods so they could enforce minimum requirements, and there was some support for this approach from architects and materials suppliers. There was, however, uncertainty as to the appropriate test method and, consequently, of the minimum criteria.
Mixed Mode Fiber Pull-Out Equipment: Applications and Results
Authors: Leung CKY , Geng YP
Published: February 2009

Crack propagation in fiber reinforced composites is governed by bridging stresses provided by fibers along the crack. To predict the behavior of fiber reinforced structural components under general loading conditions (where mixed mode crack propagation is possible), the normal and shear stresses acting on a crack need to be obtained as a function of crack opening and shearing displacements. In this investigation, a mixed mode fiber pull-out equipment is developed to measure both the normal and shearing bridging forces as a fiber is being pulled and sheared. With slight modifications, the setup can also be employed to study the effect of lateral stresses on fiber pull-out. To demonstrate the applicability of the novel equipment, pull-out tests were carried out with steel fiber reinforced mortar specimens. Experimental results indicate: 1) high sensitivity of fiber pull-out behavior to lateral stresses; 2) dependence of both normal and shear bridging forces on crack opening as well as shearing displacements; and 3) dependence of crack bridging forces on crack opening/shearing displacement history. These experimental observations provide new insights and challenges to the micromechanical modeling of fiber composites.
Analysis of Fatigue Data with Runouts Based on a Model with Nonconstant Standard Deviation and a Fatigue Limit Parameter
Authors: Pascual FG , Meeker WQ
Published: February 2009

The fatigue-limit model studied here contains an unknown fatigue limit parameter. Under this model, specimens tested below this fatigue-limit level of stress will never fail. The model also allows the standard deviation of fatigue life to be a function of stress. Researchers can use this model to describe the standard deviation and stress dependence in fatigue data. To illustrate its application, we use maximum likelihood methods to fit the model to fatigue data on a nickel base superalloy. Modern statistical methods based on likelihood ratio provide confidence intervals for the fatigue limit parameter. We also study the effect that test length has on estimation by analyzing simulated data sets based on this model. Through this simulation study, we gain insight into practical test lengths for future fatigue experiments.
A Modified Normalization Method for Developing J-R and CTOD-R Curves with the LMN Function
Authors: Fortes CJFO , Bastian FL
Published: February 2009

A direct method for obtaining J-R curves and δ-R curves from load-crack mouth opening displacement data is proposed. The method uses the direct method proposed by Landes, Herrera, Zhou, and Lee, based on the geometric normalization suggested by Ernst for deeply cracked bend specimens, to develop calibration curves that relate load, crack mouth opening displacement, and crack length. Given two of these parameters, the third can be calculated from the calibration curves. These curves are developed by assuming a power law plus a straight line functional form with unknown L, M, and N constants and evaluating the unknowns at three calibration points in the test. The method is studied for a HY-80 steel for four test temperatures and 50 mm-width, 25 mm-thickness side-notched single-edge bend specimens.
Consensus Values and Reference Values Illustrated by the Charpy Machine Certification Program
Authors: Wang JC-M , Splett JD
Published: February 2009

We present an overview of consensus values and reference values for various situations and apply the computational methods to data from the Charpy machine certification program administered by the National Institute of Standards and Technology. Candidate Charpy machines are certified by comparing a reference value to the average of a set of verification specimens measured by the candidate machine. Currently, the reference value is the average of three averages observed for measurements taken using three Charpy reference machines. However, the simple average, which does not account for differences among reference machines, may not be the optimal method of computing the reference value for every situation. We describe four different methods based on the simple average, the average weighted by sample size, the weighted average that takes into account machine differences, and the weighted average when machine biases are known, for computing the consensus value and its uncertainty. We also present two methods for computing reference values using weighted and unweighted averages. The techniques and recommendations described in the paper are applicable to consensus value and reference value problems in general.
Evaluation of the Fibrillation Behavior of Oriented Polymer Tapes Using a Tensile Test Method
Authors: Mahajan SJ , Deopura BL
Published: February 2009

Fibrillation (axial splitting) of uniaxially oriented, thin tapes of polyolefin polymers critically affects the production rates and quality of woven sack fabric. A test method based on tensile testing of the twisted tape is described that will prove useful to monitor the day-to-day routine testing of tapes for fibrillation behavior. The test method lends itself to standardization for use in commercial laboratories, requiring simple sample preparation and apparatus. For the general procedure, fibrillation strength of the large number of tapes of various molecular orientation indices were measured using the proposed test method. The results obtained show a good correlation between the molecular orientation index and fibrillation strength of tapes.
Estimating Creep Rates During Tensile Cyclic Loading
Authors: Arbel A
Published: February 2009

A new form is formulated and presented graphically for estimating creep rates during sinusoidal cyclic loading of materials which obey Norton's creep power law. Also, a new closed form expression is derived and presented graphically for the average creep strain rate during ramp-type cyclic loading.
Instantaneous Coefficient of Linear Thermal Expansion—A New Definition
Authors: Bhattachar VS
Published: February 2009

The mean coefficient of linear thermal expansion is used to define a new “instantaneous coefficient of linear thermal expansion” (ILTE) which is proved to be independent of reference temperatures required to define mean values. Hence it can be considered a true material property. The new ILTE provides a common reference to compare thermal expansion data of different materials. This instantaneous coefficient is different from the instantaneous value defined by ASTM standards. Values of the new coefficient are compared with the widely used mean coefficient values. Accuracy of calculations using the new ILTE is demonstrated using the mean coefficient data of two materials.
Measurement of Load Distribution in Multiple-Bolted Wood Connections
Authors: Stelmokas JW , Zink AG , Loferski JL , Dolan JD
Published: February 2009

Load distribution behavior among multiple-bolts was evaluated using new, instrumented bolt-type connectors. The instrumented shear bolts output an electronic signal proportional to the shear forces transmitted through the bolt in a double-shear connection during loading. Double-shear connections constructed of clear, straight-grained yellow-poplar (Liriodendron tulipifera) were tested in compression parallel to grain. Five different bolt patterns were used to analyze the effect of number of bolts in a vertical row and number of bolts in a horizontal column on load transfer among the bolts. The load distribution among the bolts in the multiple-bolted wood connection was determined effectively using the shear bolts that provided detailed quantitative data concerning which bolt was the major load carrier throughout the entire test and exactly if and when the load was transmitted between the bolts.
Hoechst Celanese Improves Consistency of Cellulose Acetate Through Automated Viscosity Measurement
Authors: Hawley L
Published: February 2009

Hoechst Celanese has improved the precision of viscosity measurements from ±6 to ±2 centipoise by switching from manual to automated testing. Solution viscosity is one of the most critical quality parameters in the production of cellulose acetate flake. In the past, the company used a modified Cannon-Fenske tube for viscosity measurements. Operator influences, including time measurements, start and end points, bath temperature, and other factors, made it impossible to achieve optimal accuracy. Switching to automated differential viscometers eliminated operator influences from the measurement process thus enabling far more precise process control.
Wastewater Sludge Treatment and Utilization in the U.S.S.R.
Authors: Yakovlev SV , Dvinskych EV
Published: February 2009

Among the large number of problems concerning water resources protection from pollution that of treatment and disposal of wastewater sludges is the least developed and the most serious from the engineering and ecological points of view. The importance of the problem arises from the constant increase of sludge masses due to increasing treatment efficiency and the ever increasing amount of wastewaters to be treated. This paper discusses wastewater sludge treatment and utilization in the U.S.S.R.
Repetitive- and Single-Blow Impact Testing of Wear-Resistant Alloys
Authors: Laird G
Published: February 2009

Repetitive-impact and impact toughness tests provide two distinct measures of a material's ability to resist impact-related wear phenomena. These tests are described in detail and results are presented for a variety of cast and forged wear-resistant alloys. In particular, past research at the U.S. Bureau of Mines using the ball-on-block and ball-on-ball repetitive-impact test is reviewed and the wear-related phenomena associated with repetitive impact are described. Impact toughness was measured using a modified dynamic tear test. To account for the heterogeneous and brittle nature of many wear-resistant alloys, a new tear test specimen was developed. Impact energies are presented for a variety of cast alloys and compared against literature values for static and dynamic fracture toughness of similar alloys. It is shown that repetitive-impact and single-blow impact tests allow a unique characterization of the material's behavior to crack initiation and propagation that dominate many wear environments.
High-Speed Compression Testing at Constant True Strain Rates for Hot Working Studies
Authors: Fitzsimons G , Kuhn HA , DeArdo AJ , Semple V
Published: February 2009

A simple device that provides control for constant true strain rate compression (or tension) tests in closed-loop servohydraulic testing machines is described. In the present system, it has been used at strain rates up to 20 s−1. Intended for use in hot working studies, the device allows for single-stroke, change-of-rate, and interrupted sequential tests. In the last of these, interruption times as low as 10 to 20 ms may be achieved.
Development of a Test Setup for Measuring the Deflection of Single-Edge Notched Bend (SENB) Specimens
Authors: Hellmann D , Rohwerder G , Schwalbe K-H
Published: February 2009

A test setup was developed for the measurement of the deflection of single-edge notched bend (SENB) specimens. It avoids the influence of the indentations resulting from the roller pins during the measurement of the deflection. Compliance calibration bend tests were carried out to compare an experimental compliance curve with a theoretical solution.
Some Factors Influencing the Enumeration of Metabolizing Aquatic Bacteria
Authors: Rao SS , Jurkovic AA , Dutka BJ
Published: February 2009

Effects of incubation time, temperature, and organic substrate on the enumeration of total and metabolizing aquatic bacteria were evaluated with a reduction technique using 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride and formazan. Data indicated that there were no apparent differences in metabolizing bacterial numbers when water samples were incubated for up to 24 h at 4 or 20°C with or without the addition of glucose. However, increasing numbers of detectable metabolizing bacteria were noted when the water samples were incubated at 37°C for 4 h with or without added glucose. Implications of the observations as they relate to point source nutrient discharges on the nearshore-offshore bacterial populations are discussed.
Differential Thermal Analysis of Solid Zirconium
Authors: Zhu YT , Gao YP , Devletian JH , Manthiram A
Published: February 2009

Several observations are made in the differential thermal analysis (DTA) test of solid zirconium (Zr) specimens. It is found that an increasing heating rate generally increases the solid-phase transition temperature for both nondeformed and cold-worked specimens, but to a different extent. Upon cycling the specimen with a constant heating rate, the phase transition temperature decreases initially during the first few runs and then remains constant. Also, holding a specimen for some time just before the phase transition during heating increases the phase transition temperature. Specimen heating history and prior cold work are also found to influence the solid-phase transition temperature.
Creep, Shrinkage, and Mortars in Historic Preservation
Authors: Sickels Taves LB
Published: February 2009

The focus of this research is the theoretical application of laboratory statistics on creep and shrinkage in mortars to historic structures. By utilizing preexisting case studies, conclusions can be tentatively made as to how the tested mortar formulas should react in restoration projects. Mortar specifications, compiled from a variety of sources, are reviewed, and the data related to the laboratory program, enabling additional tables to be compiled and thus contributing to the long-term survival of old buildings.
Fatigue Strength of Adhesive Bonded Aluminum Joints
Authors: Liniecki A , Hsu TR , Li W
Published: February 2009

This paper presents a study involving the assessment of strength of bonded joints. Coupon specimens made of 6061-T6 aluminum alloy were used in the fatigue strength testing experiments. Two sharp grooves were cut on each face of the specimen in order to simulate the cracks in the wind turbine blade. Thin patches made of the same material were adhesively bonded to the surface of the specimen, covering the grooves. All coupon specimens with and without patches were tested under oscillating bending load. Parameters such as the thickness of the adhesive material, the peeling strength and stress distribution between layers were investigated. Failures in the form of patch delamination and subsequent structure fracture were recorded and the numbers of loading cycles which caused these failures were determined. Relationships between the applied loads and the fatigue lives of tested specimens were established. On the basis of the experiments and Finite Element Analysis, an easy-to-use method for estimating the fatigue life of a real wind turbine blade was developed. The proposed method can be extended to applications involving patching of other structures subjected to repeated loads.
Development of Analytical Methods for Quantification of Residual Powder on ‘Powderless’ Latex Gloves
Authors: Chen ET , Hughes-Dillon K , Schroeder LW
Published: February 2009

This paper describes the validation of an analytical method to determine the minimum amount of residual corn starch powder that can reliably be detected on “powderless” gloves. Our procedures are similar to the ASTM D 11.40 method currently under development titled “ASTM D 11.40, Section I Working Draft for Powder-free Glove Method.” The various steps in the procedure were analyzed to determine their limitations and effects on the final results. The ability of the washing steps to remove residual powder from “powderless” gloves was ascertained by conducting recovery studies. An average powder recovery of 81.52% with a relative standard deviation (rsd) value of 8.12% (n = 15) was obtained by the draft ASTM D 11.40 procedure. The efficiency of the filtration and transfer steps was measured. A new device designed in this laboratory received an average yield of 1.51 ± 0.13 mg/glove (n = 15) as compared to the updated draft ASTM D 11.40 method with 0.84 ± 0.11 mg/glove (n = 15). Our new procedure gave an increase of 79% in yield with a rsd value of 8.5%. To enhance yield and powder recovery, it is crucial to rinse the glove surface effectively and reduce the washwater transfer steps.

The use of β-cyclodextrin (β-CD) as an aqueous phase modifier was investigated. The results obtained with (β-CD) increased the powder recovery per glove to 102% with a pooled standard deviation (psd) of 8% (n = 30, 10 level), corresponding to a rsd value of 8% when powder recovery was in the range of 0.5–10 mg. With water alone, the average recovery was 89% with a psd value of 16% in the same range. However, when the range was limited to 1–10 mg, the powder recovery per glove when using water alone was 95% with a psd value of 14%. The 2.7 μm glass microfiber filter collects 96% of the powder applied to it.

The degree of dependency to which the amount of powder on the glove affects powder recovery was studied using the relative error coefficient (rec). The rec values are less than 0.5%/mg/glove throughout the range of 0.5–10 mg using β-CD. With water alone in the same study range, a rec value of less than 3%/mg/glove was obtained. The correlation coefficients for percent powder recovery versus amount of powder on the glove show much less correlation over these study ranges. β-CD increased the recovery 15% and decreased the dependency of recovery on the amount of powder on the glove by 7.3-fold. The slopes and intercepts of recovered powder versus added powder were 1.01 ± 0.02 and 1.0 × 10−2 ± 1.3 × 10−1 mg for β-CD wash, and 0.95 ± 0.04 and −6.0 × 10−2 ± 2.5 × 10−1 mg for water wash in the range of 0.5–10 mg, respectively.
The Effect of Fiber Coating on the Temperature Dependence of the Elastic and Anelastic Properties of a Fiber-Reinforced Borosilicate Glass Matrix Composite
Authors: Wolfenden A , Thomas HM , Thomas V , Chawla KK
Published: February 2009

Young's modulus and mechanical damping were determined for two borosilicate glass matrix composites reinforced with continuous ceramic fibers for the temperature range of 20–450°C using the piezoelectric ultrasonic composite oscillator technique (PUCOT). Scanning electron microscopy was also performed on the specimens. The effect of having a boron nitride fiber coating 0.2 μm thick on the properties of the composite as a function of temperature was determined. These and other measurements showed that the presence of the boron nitride coating improves the toughness of the composite without any penalty on the elastic modulus and damping characteristics.
Leakers as a Function of Closure Type in Gallon-Size Plastic Bottles in Simulated Small Parcel Test Environment
Authors: Singh SP , Syal VP
Published: February 2009

This study investigated the effects of vertical vibration and drops on gallon-size plastic bottles in simulated small parcel shipping tests. Three types of round and F-style bottles were tested with different finish sizes. Three different types of closures were used on each type of bottle. Six bottles of each type were filled with water and capped with each closure type and packaged in single-wall RSC corrugated boxes with partitions. The packages were subjected to drop and vibration tests after being conditioned for 72 h at normal conditions of 23°C (73.4°F) and 50% relative humidity (RH), and accelerated conditions of 40°C (104°F) and 90% RH. The bottles were checked for application torques before testing and removal torques after testing. The results show the performance of the different types of closures and finish sizes. The larger size finish (63–400) F-style bottle showed the most leaks whereas the smaller finish (33–400) round-style bottles showed the fewest leaks. The bottles that were subjected to higher temperature conditioning showed more leaks and a greater reduction in removal torques.
Comparison of Walkway-Safety Tribometers
Authors: Marpet M
Published: February 2009

The friction between the floor and the pedestrian's shoe bottom is an important factor in walkway safety. There exist a number of instruments, called tribometers, for measuring this quantity. The ASTM F 13.1 Subcommittee on Tribometry, part of the ASTM F-13 Committee on Safety and Traction for Footwear, held a workshop in 1991 at Bucknell University, Lewisberg, PA. At that workshop, a number of commonly used and experimental tribometers were tested under strict laboratory conditions: The ASTM C-1028 horizontal-pull drag sled, Technial Products Model 80 drag sled, Slip Test Mark I Portable Articulated-Strut Tribometer, Slip Test Mark II Portable Inclined-Strut Tribometer, Horizontal Pull Slipmeter drag sled, Tortus dynamic drag sled, Sigler pendulum dynamic tribometer, and the James Articulated-Strut. This paper describes a number of results from that workshop.
Diagnosis of Machinery by Analysis of Running Temperature Data
Authors: Segal L
Published: February 2009

A thermal diagnosis method is proposed for mechanisms and machinery under a transient regime, with a 10–15 minute implementation time.

The suggested diagnostic parameter is the ratio of the maximum rate of increase of the temperature of the mechanism during operation to the time required to reach it. The temperature pattern, processed by computer, yields the overall technical condition of the mechanism and its pre-overhaul service term. For specific mechanisms, statistical data are needed to determine the initial and limiting values of the parameter.

The proposed method is applicable in production as a means of control over the technological process; in overhauls as a means of quality evaluation; and in service for detection of faults and prediction of the service life.
Required Coefficient of Friction Versus Walking Speed: Potential Influences of Footwear and Walkway Surfaces
Authors: Fendley AE , Marpet MI
Published: February 2009

This paper presents data analysis for a representative subject from a pilot study where subjects walked at increasing speeds across a force plate in shoes with the top-piece/outsoles replaced by a variety of test materials, including test-foot materials commonly used in walkway-safety tribometry. The goal of this data analysis was to develop a methodology that can by used in a multi-subject experiment that combines force-plate and video data. More specifically, the objectives were: • To determine how force-plate assessment of required friction for subjects walking in shoes having soles and heels of various shoe-bottom or tribometric reference materials compares to tribometric testing of available friction using similar test-foot materials. • To explore the relationship between μr and walking speed as influenced by specific footwear and walkway surfaces. • To develop hypotheses to guide further data analysis and research.

The force plate was covered with polypropylene, a substance expected to cause slipping with some of the test materials. The walking speeds ranged from moderate to as fast as the subject could walk. Required coefficient of friction μr was calculated from force-plate data. Average available coefficient of friction ¯μa was measured using a portable articulated strut tribometer with the test materials used as test feet.

Computerized capture of sequential screens from time-coded videotape recordings of data stored on magneto-optical discs was used to visually assess the kinematics of walking and slipping. Observed slipping was studied in relation to the ratio of μr/¯μa. Profiles of μr versus time during stance were examined relative to top-piece/outsole materials and walking speed. Peak μr at heel contact versus walking speed was evaluated. Positive correlation was seen for certain test materials, while negative correlation was seen with others. The authors hypothesize that biomechanical adaptations of the subject to the footwear/floor-surface combinations account for observed differences. The paper discusses practical problems confounding use of the ratio μr/¯μa as a predictor of slip probability.
Surface Roughness of Footwear Soling Materials: Relevance to Slip Resistance
Authors: Rowland FJ , Jones C , Manning DP
Published: February 2009

The slip resistance of commercial safety boot and experimental footwear solings has been studied over a period of 15 years. Shoes, with experimental solings, were worn in a factory, and the coefficient of friction (CoF) measured at intervals, using a walking traction test. These measurements have shown that a microcellular polyurethane, AP66033 (formerly T66/103) gives the greatest slip resistance of any soling material on wet or oily factory floors and laboratory test surfaces. This performance is attributed to the statistically significant relationship between CoF and mean peak to trough roughness (Rtm). The surface structure of soling materials was examined using Scanning Electron Microscopy, and images compared with Rtm measurements. There is now sufficient experimental evidence to confirm that surface roughness is one of the determinants of CoF on lubricated floors. The wear characteristics of the floor/sole combination must be considered: some soling materials may become polished on certain floors. However, AP66033 cannot be polished.
Comparison of R-Curve Methodologies for Ranking the Toughness of Aluminum Alloys
Authors: Reynolds AP
Published: February 2009

In an effort to determine an optimum method for ranking the fracture toughness of developmental aluminum alloys over a wide range of fracture toughness/strength combinations, five labs performed R-curve testing on aluminum alloy 2024-T3. Middle crack tension and compact tension R-curve specimens were excised from a previously tested 1.5-m wide middle crack tension test specimen. The crack resistance curves generated with the small specimens were compared to the R-curves from 1.5-m wide specimens. The experimental program indicated that effective stress intensity from secant compliance based crack length and stress intensity calculated from J-integral testing were equivalent. Comparison of test results obtained from different specimen sizes and configurations indicated that standard validity requirements for compact tension specimens may be overly restrictive. Improved correlation between specimen types was obtained by plotting Keff or KJ against physical crack extension as compared to effective crack extension.
Effects of Fatigue on Fragility Testing and the Damage Boundary Curve
Authors: Burgess G
Published: February 2009

The original concept behind the damage boundary curve (DBC) and the related shock fragility test, ASTM D 3332, are discussed and used to suggest shortcuts in the test procedure aimed at reducing the number of products that must be damaged. A nondestructive means of evaluating the appropriateness of the DBC in describing product fragility using the results of the test is also described. A new test procedure based on a more realistic model of the product that allows for fatigue failure is then introduced and verified experimentally. The result of the test is a series of DBCs for multiple impacts that would allow the expected number of drops in distribution to be taken into account when designing a cushion for the product. Shortcuts in the new test procedure and a nondestructive means of checking the fit between the product and the new model are also proposed.
Effect of Construction Adhesive and Joist Variability on the Deflection Behavior of Light-Frame Wood Floors
Authors: Pellicane PJ , Robinson G
Published: February 2009

A total of 16,000 light-frame, structural floors of a geometry consistent with those used in residential construction throughout North America was numerically analyzed to determine deflection characteristics under a constant uniformly distributed load of 40 Ibf/ft2 (59.5 Pa). The intent of these analyses was to determine the effect of joist variability on the deflection behavior of light-frame floors and to quantify the contribution of elastomeric construction adhesives (ECA) in reducing the deflection of such systems. The joist property (moudlus of elasticity, MOE) was allowed to vary in a systematic fashion between 750 (5.17) and 3,000 (20.07) 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 0.05 to 0.26 in increments of 0.03. One hundred floors were evaluated at each mean MOE value and at each COV value for the joists. All other sheathing and connector properties [nail slip modulus = 25,500 Ibf/in (4466 N/mm)] remained constant. However, after the 100 floors were analyzed using only nailed connections between joist and sheathing, the same 100 floors were analyzed with ECA used with the nails.

The results indicated that the contribution of the ECA to reduced 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 deflection level of the floors. Reductions of nearly 12% were realized when the mean joist MOE was 750 ksi. For floors made with stiffer joists (mean MOE = 3,000 ksi), floor deflections were reduced by only about 6% when adhesive was used. The presence of ECA between joist and sheathing also had the effect of reducing the variability of floor behavior. When components were connected only with nails, the COV of floor deflections varied between 0.02 and 0.11. However, when ECA were incorporated into the assembly, the COV of floor deflections ranged from less than 0.01 to only about 0.04.

It can be concluded that the presence of ECA of the type used in this analysis can reduce light-frame wood floor deflection by 6 to 12% depending on joist stiffness.
Experimental Assessment of Four Composite Material Shear Test Methods
Authors: Adams DF , Lewis EQ
Published: February 2009

Four ASTM standard shear test methods for characterizing composite materials were experimentally investigated: the short beam shear (ASTM D 2344), Iosipescu shear (ASTM D 5379), axial tension of a [±45]ns laminate (ASTM D 3518), and two-rail shear (ASTM D 4255). Six composite material systems were utilized: two thermoset matrix composites; S2 glass/3501-6 epoxy and AS4 carbon/3501-6 epoxy; and four thermoplastic matrix composites, S2 glass/polyetherketoneketone (PEKK), AS4 carbon/PEKK, E-glass/J2 polyamide and AS4 carbon/J2 polyamide.

The results obtained for both shear strength and shear modulus indicate that the various methods each have limitations and inherent inaccuracies, with no one method being clearly superior to the others in all aspects. However, the Iosipescu shear test method does exhibit a number of particularly favorable characteristics.
Symposium on International Advanced Vehicle/Transportation Infrastructure Technology
Authors: Foderberg DC
Published: February 2009

The Symposium was held to develop the concept of and share experiences in integrating the design of vehicles and the transportation infrastructure. Advanced technologies and processes for simultaneous vehicle/transportation infrastructure design were emphasized. In addition, integrated information and control systems along with the technologies involved in the development of smart materials in vehicle and transportation infrastructure construction were included. Three of the twelve papers given at the Symposium are presented here.
Calibration of Weigh-in-Motion Systems Through Dynamic Vehicle Simulation
Authors: Papagiannakis AT
Published: February 2009

This paper describes two methods for calibrating weigh-in-motion (WIM) systems with the aid of dynamic vehicle simulations. A modified version of the vehicle simulation model VESYM, named VESYMF, is used for predicting the dynamic axle load variation exerted by heavy vehicles at a WIM site.

The first method uses test trucks performing controlled runs over a WIM system, while the second method relies on the consistent properties of the steering axle loads of traffic stream 5-axle tractor semi-trailer trucks such as the 3-S2. For the first method, test truck runs are performed at a number of replicate speeds and the WIM measurements of individual axles are plotted versus speed. For a given axle and speed, the variation in WIM measurements is equal to the precision of the WIM system. Combining this source of variation with the dynamics-induced variation calculated through VESYMF, gives the anticipated frequency distribution in WIM measurements for the pavement roughness at a site. This is used for estimating the probability of a particular WIM measurement, which in turn allows the calculation of the weighed average of the axle load WIM measurements obtained at different speeds. Calibration is effected by fitting a zero-intercept linear regression equation between the static and the average WIM axle load measurements.

The second method is based on the consistent properties exhibited by the mean load of the steering axles of traffic-stream 3-S2 trucks. Its combined variance is calculated by adding the variance in static 3-S2 steering axle loads for traffic-stream vehicles to the other two components of variance described previously. This establishes a confidence interval for the mean of the WIM measurements of a number of 3-S2 steering axle loads. The feasibility of these two methods was demonstrated by field experimentation.
Symposium on Needs and Applications in Precision Measurement and Monitoring of Wear
Authors: Blau PJ
Published: February 2009

Wear exacts a high price on our economy, exceeding tens of billions of dollars per year. Anyone who owns an automobile conveyances rolling down the highways, plowing the seas, flying through the skies, and the cost becomes astronomical. Not surprisingly, wear manifests itself in many places—from the grinding of our teeth and the fretting of our joints to the immense turbine drives that power great aircraft carriers and the motors, gears and bearings that run the machines of industry.
Needs and Applications in Precision Measurement and Monitoring of Wear
Authors: Budinski KG
Published: February 2009

Tool wear is one of the most costly problems in many manufacturing companies. Most companies have ongoing programs to try to reduce the cost of tool wear by continually improving tool materials. Part of improving tool life is monitoring the wear that is occurring. In the cutting and perforating of products made from plastic webs, the predominant mode of wear is polishing abrasion. Tool edges start in service with a very small radius which gets progressively larger as tool wear progresses. The minute wear is extremely difficult to quantify. This paper deals with the techniques that can be used to assess changes in tool edge radius produced by polishing abrasion from the product that is being shaped by tools.

Common and the not-so-common assessment techniques are discussed and it is shown that elastomer replicas coupled with microscopic edge inspection can be effective in assessing how tools are wearing with time, so that improvements in tool life can be made.