bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Performance of Three Slip Resistance Testers
Authors: Kulakowski BT , Buczek FL , Cavanagh PR , Pradhan P
Published: February 2009

Injuries and deaths from falls due to slipping on walking surfaces have been recognized as a major accident problem in many countries. The safety of walking depends primarily on the surface slip resistance, which is defined as the ratio of (a) the minimum shear force necessary to initiate slipping of a body over the surface to (b) the body's normal force. Several kinds of devices are currently in use to measure slip resistance. In this paper three slip resistance measuring devices are evaluated: the National Bureau of Standards-Brungraber Tester, the Horizontal Pull Slipmeter, and the Pennsylvania Transportation Institute Drag Sled Tester. The testing program consisted of two phases. In the first phase each tester was used to measure the slip resistance of selected surfaces representing a wide range of frictional characteristics of typical indoor and outdoor surfaces. All tested materials were in actual use on walking surfaces. In the mechanical tests the testers were evaluated with respect to their applicability, precision, repeatability, and sensitivity to the operator's measuring technique. The correlation was determined between the results produced by the testers on the same surfaces.

In the second phase of the testing program a series of experiments was conducted with human subjects walking over surfaces having relatively low slip resistance. The objective was to determine whether people will slip more often on surfaces which are measured as having lower slip resistance. In general, the agreement between the results of slip resistance measurements and the results of the biomechanical tests was high. It was observed, however, that the process of slipping involves a considerable randomness.
A Comparison of Test Methods for Shear Properties of the Cores of Sandwich Constructions
Authors: O'Connor DJ
Published: February 2009

ASTM C 273 and BS 4370 single block tests for shear properties of sandwich cores are critically examined. A previous appraisal using finite element modelling is highlighted and extended to include the effects of stress concentrations. Overall performance is assessed by selected laboratory programs and comparisons with panel test and flexural test methods. The ASTM method is shown to give accurate results generally. Modifications are required to the BS 4370 method. Problem areas with regard to theoretical stress concentrations in both methods are identified in relation to the test for shear strength.
Dynamic Reconciliation Algorithm Used on a High-Purity Propylene System
Authors: Bozenhardt H
Published: February 2009

One of the most pervasive and chronic problems in the processing industries is the control of unit operations with substantial dead-time. Dead-time can be the result of large multi-staged or interunit operations. This paper deals with a process that contains both types of dead-time.

All too often dead-time and intertower controllability are problems handled (actually mishandled) by building “safety margins” into targets and allowing the unit's operations to cycle as long as all cycles are within an “acceptable” zone. This paper attacks the dead-time problem with simple, yet effective, methods and demonstrates substantial economic savings. This paper is intended for process control engineers and those in operations management.
Fatigue Performance of AISI 1140 Modified Steel
Authors: Hertzberg RW , Vecchio KS , Schmidt FE
Published: February 2009

A study of the fatigue behavior of modified AISI 1140 resulfurized steel containing manganese (1.05 to 1.25%) and sulfur (0.16 to 0.23%) was conducted at room temperature under load-controlled conditions. Monotonic and cyclic mechanical tests were conducted with samples possessing a “C” shaped ring configuration; a finite element analysis was used to establish the stress levels appropriate to the “C”-ring specimen. Quantitative S-N and Goodman (1) diagrams were determined, based on cyclic stresses representing different fractions of the ultimate strength of the material. A toughening mechanism is postulated that accounts for the interaction between the advancing crack front and the duplex microstructure which includes finely oriented manganese sulfide (MnS) stringers encapsulated in the ferrite phase.
Fractography of AISI 1140 Modified Steel under Static and Cyclic Loading Conditions
Authors: Vecchio KS , Hertzberg RW , Schmidt FE
Published: February 2009

The fracture behavior of modified AISI 1140 resulfurized steel containing manganese (1.05 to 1.25%) and sulfur (0.16 to 0.23%) has been studied under controlled fast fracture and fatigue fracture conditions. “C”-shaped ring samples were machined from tubes hammer forged at 700°C by the GFM process (Gesellschaft für Fertigungstechnik und Maschinenbau [AG] manufactured in Steyr, Austria) so as to develop a highly fibered (axial) microstructure. The microstructure of the material was evaluated and compared with the fracture surface morphology as a function of loading history. It was determined that the MnS inclusion stringers were encapsulated within the ferrite phase and that static fracture progressed along the stringer-ferrite interface. Conversely, fatigue cracks as evidenced by the presence of fatigue striations propagated mainly within the ferrite phase.
Applicability of the Southwell Plot to Shear Deformable Columns
Authors: Koh CG , Kelly JM
Published: February 2009

This paper examines the applicability of the Southwell method to predict the buckling load of columns where the shear deformation cannot be neglected. It is shown by mode superposition that the convergence of the series solution to the buckling mode is slow, since there are two critical loads of the same order associated with the first mode shape for rotation of the cross section. More important, the Southwell plot is not linear even when only one mode shape (corresponding to the lowest critical load in compression) is considered. An example of numerical simulation demonstrates that linearly fitting the Southwell plot can lead to significant errors in the prediction of the buckling load. The accuracy of buckling load determined by the Southwell method for typical elastomeric isolation bearings is also discussed.
The Concept of Filament Strength and the Weibull Modulus
Authors: van der Zwaag S
Published: February 2009

The strength of high-performance filaments is a complex parameter which can not be fully described with a single value. The Weibull model is used to describe the intrinsic statistical nature of the fracture strength. Possibilities and limitations of the Weibull model are illustrated. The relationship between material properties and the parameters in the Weibull model is discussed.
An Encapsulation Technique for Conducting Mechanical Properties Tests of Metallic Specimens in a Controlled Environment without a Retort
Authors: Kschinka BA , Marriott DL , Stubbins JF , Vassos N
Published: February 2009

A novel technique to encapsulate metallic mechanical properties test specimens in a controlled atmosphere has been developed that eliminates the need for cumbersome retort systems. The procedure consists of brazing stainless steel flexible bellows tubing on a test specimen in such a manner that the tubing acts as a miniature retort around the gage section of the specimen. While convenient, this method demands a special correlation relating strain in the gage section to displacement between the specimen shoulders in order to conduct displacement-controlled fatigue tests. Results of such tests using vacuum encapsulated specimens were generally excellent and agreed reasonably well with data from related studies, supporting the validity of both the encapsulation technique and the subsequent correlation.
Rotation Corrections in Three-Point Single Edge Notch Bend Specimens
Authors: Perez Ipiña JE , Santarelli EL
Published: February 2009

In elastic-plastic fracture toughness tests of three-point single edge notch bend (3P-SENB) specimens, very ductile materials suffer significant distortions from their initial geometrical configuration, producing large rotation angles of the arms and causing the rollers to move out and detach themselves. These effects should be taken into account when the Unloading Compliance Method is employed to obtain the slow stable crack growth, because the equations are calculated for the initial condition of null rotation angles.

Experimental measurements of the span change for 3P-SENB specimens with different rotation angles and under several conditions were obtained. The results were compared with other authors' results and with those corresponding to CT specimens. Expressions for the corrected values of span and compliance were deduced, and the errors for not using the corrections were estimated. Conditions that give minimal errors were also documented.
A Method to Obtain Ideal Fatigue Crack Propagation for Steels
Authors: Masuda H , Matsuoka S
Published: February 2009

To predict fatigue crack growth rates under variable loading conditions, a new fatigue test method was developed. Fatigue crack propagation properties were studied for HT80, SM50B, and SUS304 steels. Test results showed that the acceleration of the crack propagation rate occurred at low ΔK regions when the intermittent compressive overload was applied. The maximum acceleration of crack propagation was dependent on both the frequency and amplitude, of the overload. When the compressive overload is frequently applied, the crack propagation rate becomes proportional to the second power of ΔK.

These accelerations of the crack propagation rate under compressive overloading conditions were discussed with respect to the deformation mode at the crack tip.
Flow of Semi-Solid Foods over Inclined Packaging Surfaces as an Index of Traction
Authors: Lai CC
Published: February 2009

A modified tilted plane procedure was evaluated for characterizing the traction property of fluid or semi-solid foods in contact with packaging surfaces. The method was shown to be a useful technique as demonstrated by studying the flow of tomato sauce, salad dressing, and mustard paste over five commonly used polymeric packaging film surfaces.
Establishing Criteria for a Computerized Vision Inspection of Holes Drilled in Carbon Fiber Composites
Authors: Hough CL , Lednicky TE , Griswold N
Published: February 2009

Two basically different carbide bit designs, a dagger bit and a standard twist drill, were tested extensively in graphite/epoxy composite material. A commercially available computer vision system was utilized to evaluate hole quality as the bits wore for fraying, delamination, and hole tolerance. Methods and procedures for establishing acceptance criteria using the vision system are given. Based on manual acceptance criteria, vision system criteria were established for fraying and suggested for entrance delamination.
Fatigue Life Prediction in Flexural Bending of Hollow Cross-Sectional Bars from Axial Fatigue Information
Authors: Muralidharan U
Published: February 2009

Bending fatigue results in the low cyclic life range often differ from those of axial fatigue due to the plastic flow, which alters the linear stress-strain relation normally used to determine the nominal stresses. An approach was presented and an equation derived in earlier work to take into account the plastic flow in calculating nominal bending stress based on actual surface stress for solid rectangular and circular cross-sectional bars. The flexural bending fatigue life prediction of bars with hollow cross sections is addressed in this paper. An equation is derived for calculating the nominal bending stress versus life curve for hollow cross sections that depends directly on the functions derived for the solid section of the same geometry, and k, the ratio of inner to outer dimensions. The nominal bending stress versus life curves are shown for the case of hollow circular sections for six typical materials for various k values.
Chimney Venting Performance Study
Authors: Timusk J , Seskus AL , Selby KA , Rinella J
Published: February 2009

An investigation was undertaken to determine the levels of house depressurization against which naturally vented gas-fired furnaces and domestic water heaters can establish and maintain safe venting of combustion products. Also investigated were the maximum depressurizations of buildings which could be achieved by the installed fans and fireplaces. A test procedure was developed whereby venting failure can be artificially induced by depressurizing the house with a large fan. Results show that it is highly improbable that the maximum depressurizations found in houses by operating all the fans and the fireplaces at the same time will cause the chimney to vent improperly even in conditions under which venting failure would be most likely to occur (cool temperatures, low wind, cold chimney, large number of exhaust fans, weak venting furnace/chimney combination, relatively tight house).
Dynamic Tests on Full-Scale Structures of Glue-Laminated Timber: Theoretical and Experimental Studies
Authors: Ceccotti A , Vignoli A
Published: February 2009

Results obtained by applying free-vibration dynamic tests to a full-scale assembled timber structure are presented. The relationship between the theoretical model and the experimental results is analyzed in order to predict structural behavior and timber quality.
A Microcomputer-Aided Four-Point Bend Test System for Determining Uniaxial Stress-Strain Curves
Authors: Yokoyama T
Published: February 2009

A microcomputer-aided four-point bend test system has been developed for determining the tensile and compressive stress-strain curves, as well as elastic constants, for a material from a single bend test. A special four-point bend fixture has been designed and constructed to minimize loading errors which may occur in the tests. Microcomputer software has been developed for processing the large amount of data obtained from each bend test. Two kinds of cast iron (ASTM A48 and A536), which exhibit different stress-strain characteristics in tension and compression, have been tested to examine the validity of the test system for a limited range of strain. It has been shown that the stress-strain relations derived from the bend tests are in good agreement with those obtained directly from the uniaxial tension and compression tests for strains less than about 5%. The advantages and limitations of the bend tests are also discussed.
J1c Measurements on Single Subsized Specimens of Ferritic Alloys
Authors: Huang F-H
Published: February 2009

Fracture toughness tests on subsized, circular, compact tension specimens of ferritic alloys were performed at temperatures ranging from −192 to 427°C. Test results for 9Cr-1Mo show that the electropotential single specimen method agrees well with the multiple specimen method in determining the upper shelf J1c. The ductile-brittle transition temperature and lower shelf toughness of HT-9, tested at loading rates of 2.1 × 10−5 and 3.2 × 10−2 m/s. were also determined using the J-integral approach. The size criteria for valid J1c values, for a wide range of test temperatures, were satisfied by the subsized specimen used in this work.
Stress Intensity Factors for Notched Configurations
Authors: Baratta FI
Published: February 2009

A method is presented for approximating stress intensity factors for notched-configurations without cracks. It is expected that estimates obtained from such analyses, which are outlined in the text and detailed in the Appendix, should be useful in estimating the failure load in a notched structure behaving in an idealized elastic manner. Additionally, this approach will allow an estimate of the magnitude of load required to precrack fracture toughness specimens having crack starter notches.

Several notch geometries and loadings are investigated, such as a V-notch, to first illustrate the method of analysis and compare results with those in the literature and to also establish merit and accuracy limits of the method. Two additional cases are then solved, both for finite width tensile sheets, one having symmetric U-notches and the other employing a central slot with finite radii at each end. Both cases are reduced to their end limit: a U-notch in a sheet of semi-infinite width and a circular hole in an infinitely wide sheet. The resulting approximations agree well with limited available data.

Finally, to aid the experimentalist who either uses the compliance approach or a photoelastic analysis to obtain stress intensity factors, the question of how deep or how long a side-edge U-notch or a central slot compared to its radius should be to simulate a crack, is provided.
Effect of Misalignment on the Time to Rupture
Authors: Schmieder AK
Published: February 2009

The materials tested were a low-alloy steel in three conditions of heat treatment and a high-alloy steel in two conditions of heat treatment. The heat treatments were chosen to provide specimens with various notch strength ratios. Notch rupture tests of these five materials were made with various degrees of misalignment. When heat treated to attain the highest notch strength ratio, the low-alloy steel showed no significant change in time to rupture for the range of misalignment tested. The corresponding high-alloy steel specimens showed approximately 3% reduction in time to rupture for each 1% increase in bending strain. For the high-alloy steel, the amount of reduction in time to rupture appears to be almost independent of the notch strength ratio. In contrast, the low-alloy steel showed a reduction in time to rupture of approximately one half that of the high-alloy steel at a notch strength value near unity and almost twice that of the high-alloy steel at the lowest notch strength ratio tested.
Correction of the Results of Standard Fire Resistance Tests
Authors: Harmathy TZ
Published: February 2009

The ASTM Method for Fire Tests of Building Construction and Materials (E 119) empirical formula for correcting the results of fire resistance tests is examined in the light of the normalized heat load concept. The formula, on the whole, does not contradict theoretical conclusions, but its accuracy is questionable. Under practical conditions the corrections is not expected to amount to more than a few minutes.
Poisson's Ratio As Determined for Elastic and Plastic Deformation and for Monotonic and Cyclic Loading—Part I: Critical Review
Authors: Rahka K , Laird C
Published: February 2009

Poisson's ratio is defined strictly on the assumption that the material is homogeneous. In applications of Poisson's ratio to mechanical problems, this assumption can be overlooked. To check whether the assumption applies to monotonic and cyclic loading, we review measurements of Poisson's ratio, or rather the ratio of diametral strain to axial strain. Such measurements are quite rare for cyclic deformation. However, they show that the ratio of diametral strain to axial strain can differ from values expected on the basis of traditional values of Poisson's ratio for elastic and plastic deformation. The technical consequences of this difference are indicated.
R-Curve Round-Robin Program for ASTM Recommended Practice for R-Curve Determination (E 561)
Authors: Pearson HS , McCabe DE
Published: February 2009

A round-robin program sponsored by ASTM Task Group E24.01.02 on Crack Growth Resistance Curves was conducted to establish guidelines on variability for a Precision and Accuracy statement for ASTM Recommended Practice for R-Curve Determination (E 561). Two high strength aluminum alloys were tested by seven participants using the compact configuration specimen. The results of these tests are summarized herein, and a Precision and Accuracy section given along with variability at four levels of effective crack growth.
Determination of Calibration Constants for Hole Drilling Technique Using Special Strain Gage Rosette
Authors: Jayarama Rao G , Ravi Sankar K , Narayanan R
Published: February 2009

Experimental evaluation of calibration constants using a specially designed indigenous strain gage rosette is presented. Performance of this indigenous rosette is compared with an imported rosette and theoretical results. The calibration constants can be used for the determination of residual stresses in structural components by the hole drilling technique.
Effect of Axial Compression
Authors: Javorik LJ
Published: February 2009

The beneficial effects of work hardening have been long known to, and appreciated by, the steel industry and have been accepted as a step in the same direction as heat treatment. Because of the obvious difficulty with buckling, however, so far only the tension mode and the transverse compression mode have been commonly used (e.g., pipe expanders for tension, and cold-rolling, cold-drawing for transverse compression).

Treatment stresses in the tension method are restricted to stresses less than the ultimate strength of the material. Compression loads can be many times that of the ultimate tensile strength of the material.
Predicting the Durability of Bricks
Authors: Winslow DN , Kilgour CL , Crooks RW
Published: February 2009

The pore size distributions of approximately 80 bricks removed from walls of existing buildings were measured using mercury intrusion. These distributions were used to calculate a Durability Factor using the method of Maage. This Durability Factor was then correlated with the observed performance of the bricks on the buildings. It was found that all bricks with a Durability Factor greater than 70 exhibited no freeze/thaw durability problems. Further, with very few exceptions, all bricks with a Durability Factor less than 70 were suffering freeze/thaw failures. This technique is more accurate and faster for selecting potentially durable bricks than the current use of absorption measurements.
Evolution of the Internal Quality Audit at Ford Motor Company's Central Laboratory
Authors: Terjimanian A , Kelly CJ
Published: February 2009

This paper discusses the evolution of an internal laboratory quality audit which takes into account the needs and expectations of the laboratory customers, the laboratory management, and the laboratory employees. This audit has been in operation for over 15 years and its development and early years were reported at an ASTM Symposium in 1981. Since then a number of changes have been implemented to improve the effectiveness of the audit.

This paper describes the creation of the auditor position with organizational independence. Developments in the Quality Audit Manual, the Laboratory Report Format Procedure and other audit standards are also reported. The paper discusses the advantages and disadvantages of using a classification system to rank discrepancies identified by the audit process.

Because the underlying purpose of an internal quality audit is to improve laboratory report quality, the major beneficial role is as a learning tool. As originally structured the audit was conducted with complete anonymity of the laboratory employee. Unfortunately this anonymity constrained the reporting procedure and inhibited the universal implementation of corrective actions.

After several years with no improvement in the discrepancy rate, a process change was desired. Coinciding with this need, process improvement methodology based on Deming's Plan-Do-Check-Act cycle [1] was used to develop an improved process. An audit improvement team proposed and conducted a pilot audit procedure that audited reports monthly for the natural work groups with open discrepancy reporting at work group meetings. Based on the successful pilot, management approval was obtained to implement the revised procedure and improvements in laboratory report quality as assessed by the internal laboratory quality audit are observed.
Eliminating Wasteful “Cut and Try” Procedures in Gas Chromatography Method Development Using Computer Modeling
Authors: Annino R , Villalobos R
Published: February 2009

Computer programs that accurately predict the performance of one's chromatograph considerably shorten the interval between an analysis request and the final report by eliminating laboratory time spent in “cut and try” attempts at finding the right column and analysis conditions. Examples are presented of a program used to quickly design the optimum column or columns and conditions for multiple application scenarios.
Determination of the Geometric Profile and Stress/Strain State in the Necked Region During Inelastic Deformation at Elevated Temperatures Using a Non-Contact Measurement Technique
Authors: Gaudig W , Bothe K , Bhaduri AK , Maile K
Published: February 2009

An improved testing methodology for determining the geometric profile and true stress/true strain at elevated temperatures through continuous monitoring of the specimen profile in the necked region using a video camera is demonstrated through a slow creep tensile test. The results show that the video camera is an appropriate tool for accurately monitoring specimen necking at elevated temperatures, and that the true stress and strain can be adequately determined from the specimen profile. Based on this test methodology, true strain rate-controlled creep testing can be carried out. This is essential for determining the true material parameters required for establishing appropriate constitutive equations for realistic finite element modeling.
Time-Dependent Bending Properties of Lumber
Authors: Kliger IR , Pellicane PJ
Published: February 2009

Research related to structural stressed-skin panels (SSP) and their component parts has been ongoing at Chalmers University of Technology. In recent years, attention has been focused on SSP with lumber webs and sheet metal and chipboard panels as tension and compression flanges, respectively. In this study, certain mechanical and rheological properties of structural lumber were evaluated as part of a larger project designed to predict the long-term behavior of SSP under load.

In this study, several test series were conducted to evaluate short- and long-term properties of European redwood (called Scotch pine in North America) (Pinus sylvestris). From 22 pieces of lumber measuring 25 by 125 by 4000 mm, specimens were cut for use in several test series to determine solid wood properties. Wood modulus of elasticity (MOE), accounting for the shear effects, was evaluated from initial deflections of long-term tests. Mean MOE values of about 14 500 MPa were obtained.

Four series of long-term tests were conducted under different combinations of stress level and distribution, as well as loading history. The results suggested that the magnitude of relative creep was greatest under lower stress levels. Different stress distribution (resulting from center- and third-point loading) proved to have little effect on creep behavior. Two mathematical models, i.e., power functions (Clouser function without exponential terms and power function with exponential terms) [1] were evaluated as predictors of the deformation-time relationship for lumber under constant loading. Differences in accuracy of predicting creep behavior between the two models studied were very modest.
A Critical Evaluation of the Performance of Optical Fiber Sensors for Monitoring Dynamic Strains
Authors: Singh RP , Shukla A
Published: February 2009

An experimental study is conducted to evaluate the applicability of optical fiber sensors in measuring strains under dynamic loading conditions. Both phase modulated and intensity modulated sensors are studied. The experiments are performed to characterize the high strain rate response of these sensors and test their ability to measure changes in dynamic strain resulting from one-dimensional stress wave propagation. The stress waves are generated using both compressive and tensile gas gun setups. Then, optical fiber sensors are employed to monitor the stress wave pulse as it propagates down the bar. The output from the optical fiber sensors is compared to strain gages mounted at the same location. The results demonstrate that only localized optical fiber sensors that are bonded over the entire sensing region can be used for monitoring dynamic strain fields.
Structure and Property Evaluation of Large-Diameter Spray-Formed Superalloy Piping
Authors: Moran AL , Rebis RE
Published: February 2009

A comparative testing evaluation program was conducted to assess the mechanical properties, metallurgical characteristics and fabricability of spray-formed Alloy 625 tubes and subsequently processed piping. Spray-formed preforms were deposited and reduced via pilger rolling or roll extrusion to produce thin-walled piping in diameters of 10.2, 20.3, and 35.6 cm (4, 8, and 14 in. nominal pipe size). Evaluations based on chemical analysis, strength, ductility, hardness, impact toughness, fatigue properties, weldability, and corrosion resistance demonstrated that spray-formed piping appears to be a viable substitute for conventionally produced Alloy 625 piping and that a minimal amount of cold working is required on the as-deposited tubular preforms in order for them to meet the specification requirements for naval applications.
Bias Testing: Myths, Misconceptions, and Mistakes
Authors: Gould G
Published: February 2009

The art and science of testing sampling systems for bias has been controversial from its beginnings, some 35 years ago. Since then it has evolved as a discipline of increasingly broad scope and complexity. Currently under consideration as a standard practice, it involves univariate, multivariate, parametric, and nonparametric statistical treatments, static and dynamic operating modes, single and two-stage tests, and matched samples consisting of single increments, sublots, and lots. Testing for bias has been encumbered with an ever-expanding set of myths, misconceptions, and mistakes. The author explores the most common and grievous among them using graphics to help the reader visualize the issues.
Determination of Thermal Properties of Pavement Materials and Unbound Aggregates by Transient Heat Conduction
Authors: Tan S-A , Fwa T-F , Chuai C-T , Low B-H
Published: February 2009

A laboratory procedure for determining the thermal conductivity (k) and diffusivity (α) of pavement materials and unbounded aggregate beds by means of a transient heat conduction experiment is described. It is first established that the plane-wall theory of heat conduction can be applied to a finite-slab problem provided that the thickness-to-width ratio is kept within 0.2. The procedure is to obtain the k and α values that would match the theoretical temperature-time history response with the measured response. An analytical curve-fitting technique is used to match the inflection points of the measured to the theoretical temperature-√t curves. The heat experiment is conducted in a controlled convection oven with parallel air flow at constant velocity over a horizontal test specimen bed. This allows for the testing of unbounded aggregate beds made into a slab by placement of aggregates in an insulated polystyrene box that fits into the base of the oven. The test method is first validated by comparing steady-state heat conduction results with the transient test predictions of k for a solid acrylic slab, two bituminous slabs, and four concrete slabs, with good agreement in the values of k determined by both methods. For the unbounded aggregates, it is observed that there is trend of decreasing values of k and α, with increase in particle size. Also, wet aggregates exhibit higher thermal conductive properties than dry aggregate beds. The test method will be useful for obtaining thermal properties of pavement materials to allow for thermal analysis in pavement layers subjected to solar heating.
Eddy Current Decay Resistivity Measurements Using a Digital Voltmeter
Authors: Hua CY , McDonald LC , Hartwig KT
Published: February 2009

A digital voltmeter is shown to successfully capture the voltage decay signal during eddy current decay (ECD) measurements at cryogenic temperatures on low-resistivity specimens. The use of a voltmeter simplifies ECD measurements, typically made using a digital oscilloscope. An added benefit of using a voltmeter is that under certain circumstances, measurement precision exceeds that which is normally obtained with a preamplifier-digital oscilloscope combination. Results indicate that the best combination of instruments for capturing extremely weak signals (i.e., those with long exponential time constants) is a preamplifier-voltmeter configuration. Results of a comparative study using a preamplifier-digital oscilloscope configuration, a digital voltmeter alone and a preamplifier-digital voltmeter arrangement are presented and discussed.
Hot Plane Strain Compression Testing of Aluminum Alloys
Authors: Shi H , McLaren AJ , Sellars CM , Shahani R , Bolingbroke R
Published: February 2009

Plane strain compression is a versatile laboratory testing method for simulating industrial hot working operations such as plate and strip rolling. The deformation can be closely controlled to the required conditions of temperature and strain rate, and high strains can be achieved without instability. However, for accurate determination of flow stress, care must be taken with experimental procedure and the interpretation of the measured force-displacement data.

This paper reports the results of work carried out in three laboratories on samples of the same cast of Al-1% Mn alloy. In particular, the effects of spread and friction are analyzed as a function of initial specimen geometry. When consistent procedures are used it is shown that excellent reproducibility of flow stress data is obtained between laboratories. In deriving constitutive relationships, the importance of considering the effects of lubricant films, of deformational heating, and of heat transfer are clearly demonstrated.
High ResolutionR-Curve Characterization of the Fracture Toughness of Thin Sheet Aluminum Alloys
Authors: Haynes MJ , Gangloff RP
Published: February 2009

The plane-strain initiation fracture toughness and plane-stress stable crack growth resistance were determined with a single small compact tension (C(T)) specimen for each of three precipitation hardened aluminum alloy sheets (AA2024-T3, AA2519-T87 (+Mg+Ag), and AA2650-T6). Crack length was monitored precisely with direct current potential difference (DCPD) measurements, and specimen plasticity was accounted for with the J-integral. The DCPD technique resolves a small amount of crack-tip process-zone damage (≈20 µm) that constitutes crack initiation under plane-strain constraint. Two measures of initiation toughness are calculated: the elastic-plastic fracture toughness detected by DCPD (JICi, KJICi) and the toughness based on ASTM Standard E 813 () and the toughness based on ASTM Standard E 813 (JIC, KJIC). High resolution of fracture initiation is necessary to obtain a lower bound initiation toughness,). High resolution of fracture initiation is necessary to obtain a lower bound initiation toughness, KJICi, because plane-strain constraint is present ahead of the fatigue precrack but is rapidly lost with crack extension in thin sheet. KJIC overestimates toughness due to constraint loss coupled with the offset blunting line definition of fracture initiation. The J-integral/DCPD method provides a reproducible measure of the plane-stress linear-elastic resistance curve (KJ − Δa) that compares reasonably to R-curves determined for large middle-cracked tension specimens. The small specimen method is effective for studies pertaining to alloy development, environmental effects, and fracture mechanisms.
Development and Evaluation of a Method to Measure Traction on Turfgrass Surfaces
Authors: McNitt AS , Middour RO , Waddington DV
Published: February 2009

Traction, as it relates to field quality, involves the athlete, studded footwear, and the turf. Traction involves two types of forces: those acting in a vertical manner that compress the turf and those that act horizontally and produce a shearing or tearing effect on the turf. The objectives of this research were to develop and evaluate an apparatus to measure the horizontal forces associated with traction, compare this apparatus with other devices routinely used to quantify traction, and examine how different turfgrass stand characteristics combine to influence traction.

An apparatus, termed PENNFOOT, was developed and field tested. PENNFOOT consists of a framework that supports a leg and foot assembly that can be used to measure both rotational and linear traction using different footwear under various loading weights. When we compared PENNFOOT to other traction measuring devices, the force values we obtained from different grass species and varying cutting heights provided low correlation values.

Experiments were conducted to determine the effect of turfgrass and soil conditions on traction of turf areas. Tall fescue and Kentucky bluegrass provided the highest traction values whereas perennial ryegrass and creeping red fescue provided the lowest. Higher linear traction values occurred with lower cutting heights.

Although more work is needed on the turf and soil characteristics that influence traction, the PENNFOOT with its versatility seems appropriate for traction evaluation.
International Symposium on Slip Resistance: The Interface of Man, Footwear, and Walking Surfaces
Authors: Sacher A , Ownes JM
Published: February 2009

The final four papers of this issue were presented at the International Symposium on Slip Resistance: The Interaction of Man, Footwear, and Walking Surfaces, which was covered in part in the November 1996 issue of this journal. Held 30–31 October 1995 at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD, the symposium was sponsored by Committee D 21 on Polishes and Subcommittee D 21.06 on Slip Resistance. This symposium represents the culmination of research initiated in the 1950s to determine the coefficient of friction of polished walkway surfaces. Extensive laboratory and field studies of methods and apparatus led to the development of the ASTM Test Method for Static Coefficient of Friction of Polish-Coated Floor Surfaces as Measured by the James Machine.
Comparison of Walkway Safety Tribometers: Part Two
Authors: Marpet MI , Fleischer DH
Published: February 2009

Fall accidents generate large injury, morbidity, and mortality costs. Many falls are caused by pedestrian slips, which are in turn a result of one or a combination of factors: pedestrian, walkway surface, footwear, or environmental.

It is important to be able to quantify and characterize the slipperiness of walkways and shoe bottoms, both separately and in combination. There presently exist on the market many tribometers (walkway-friction measuring instruments); different tribometers do not necessarily give the same results under identical conditions.

In the summer of 1991, ASTM Committee F-13 on Safety and Traction for Footwear organized a workshop at Bucknell University, Lewisburg, PA to compare nine tribometers against each other and against a force plate, which measures ground-reaction forces.

Briefly, we found that different tribometers gave different results. An earlier paper contained results of data aggregated by tribometer. It appeared that the differences were at least in part a result of the fact that the tribometers measured different types (mechanisms or models) of friction. The force plate “saw” and mimicked whatever the tribometer “saw.” Thus, if the tribometer's design made it incapable of seeing the correct frictional mechanism vis à vis pedestrian-generated friction, the force plate saw the same incorrect model. This paper summarizes the procedures used and continues the analysis of the workshop data, aggregating it by test condition.
The Effect of Footwear Midsole Hardness and Thickness on Proprioception and Stability in Older Men
Authors: Waked E , Robbins S , McClaran J
Published: February 2009

Support surface interface (footwear, flooring systems, etc), thickness, and hardness strongly influence stability in men of all ages. We hypothesize interfaces influence stability through their effect on proprioception. We tested this by means of an experiment based on a randomized, cross-over, and controlled comparison design. Footwear midsole hardness and thickness were independent variables. Dependent variables were foot position and perception of foot position, measured concurrently. Thirteen subjects were a random sample of healthy older men (mean age 72 years, sd ± 4.50). They were tested barefoot using six support surface interfaces consisting of shoes that were identical, except for midsole hardness and thickness, that spanned the respective ranges in current footwear. Measures were balance failure frequency defined as falls per 100 m of beam walking, rearfoot angle measured via an optical position measurement system, perceived maximum supination estimated by subjects via a ratio scale when walking, and foot position error, defined as rearfoot angle minus perceived maximum supination. The results demonstrated: (1) foot position awareness was positively related to stability; (2) foot position error was negatively related to support surface interface thickness; (3) foot position error was positively related to support surface interface hardness; and (4) foot position error correlated best with maximum supination. We conclude that instability induced by support surface interfaces is caused by its effect on foot position awareness. Thin hard-soled shoes provide superior stability for older men. Most currently available footwear provides poor stability because soles are too soft and thick. Since suboptimal support surface interfaces are encountered by everyone daily, they represent substantial safety hazards. Likewise, improving this situation through setting stability safety standards is a promising means of improving public safety. At the very least, the public must be informed about products imparting suboptimal stability so that they can anticipate potential problems and compensate for them without falling.
A Methodology for the Fire Resistance Testing of Structural Components at Reduced Scale
Authors: O'Connor DJ , Morris B , Silcock GWH
Published: February 2009

The full scale fire resistance test forms the basis of acceptance of structural integrity in fire. However, such tests are too expensive to provide more than a limited amount of test data of parametric significance as a means of fully exploring a width of structural responses, required for research purposes as underpinning to the formulation of design guidance.

In this paper a methodology for the fire testing of reduced-scale structural models, previously outlined in other fire engineering journals, is presented for dissemination to the wider testing community. The principles of scale modeling applied to general structural testing and the specific requirements for scaled thermal modeling are detailed. Their application to the formulation of a new model fire curve for reduced-scale modeling is defined. An initial normalized temperature distribution condition in a test specimen requires the imposition of an inverse scale incident heat flux rule and a scale squared time scale rule. The increased flux requirement can be accommodated by an enhanced temperature axis formulated by consideration of convective and radiative surface heat transfer processes. An alternative suggestion to control model test furnaces by heat flux instrumentation is also postulated.

Finally, experiences with the application of the methodology to some wide-ranging research studies on brickwork compartment walls, reinforced concrete floor slabs, and steel columns in standard fire tests are presented to illustrate different facets of the application of the methodology. Further applications to “natural” fire tests performed within the Cardington Frame program are also referenced.
Statistical Design of Experiments in Metal Cutting—Part One: Methodology
Authors: Astakhov VP , Osman MOM , Al-Ata M
Published: February 2009

A comprehensive analysis of the statistical design of experiments and its application in metal-cutting studies is carried out. This subject is treated in two parts. The main concern of Part 1 is the design methodology. The applied aspects of the design such as the basic requirements to the criterion of effectiveness, factors selection, and mathematical model formulation were considered. Special attention is paid to the pre-process decisions. A 23 factorial experiment, complete block was chosen as the basic type of the design of experiments in metal cutting. The basic properties of this type of design were considered. It is shown that the design of experiments requires that special attention be give to the accuracy of the experimentations.
Statistical Design of Experiments in Metal Cutting—Part Two: Applications
Authors: Astakhov VP , Osman MOM , Al-Ata M
Published: February 2009

In the first part of this paper, a comprehensive analysis of the statistical design of experiments was made, and a design methodology was presented. The applied aspects of the design, such as the basic requirements to the criterion of effectiveness, factor selection, and mathematical model formulation, were considered. A 23 factorial experiment was chosen as the basic type of the design of experiments in metal cutting. In this paper, the practical aspects of using the proposed methodology in metal cutting experiments are examined. BTA deep-hole drilling is studied, as an example, using the design of experiments. The influence of cutting speed, feed, and cutting fluid flow rate on the machined holes roughness and roundness is studied using a 23 factorial experiment, complete block. In order to study the tool life and the cutting forces, logarithmic coordinate transformations of the regression equation in Taylor form are proposed.
Computerized Chemical Structural Information (CSI) and Associated Data: A Study of Computerized CSI Pathways Used by Synthesis Chemists, and Recommendations for Guidelines
Authors: Gragg CE
Published: February 2009

Synthetic chemists are confronted with an array of computerized chemical structure drawing packages, chemical database packages, and chemical spreadsheets for organizing data. Software that is task-oriented has become available. Integration of two or more tasks in one software package is possible. For example, it is possible to draw a chemical structure suitable for inclusion in a printed document, and also use the same structure as an on-line search query. Pathways that are followed by synthetic chemists include the

• decision to make a chemical,

• submission of queries to chemical databases,

• selection of preparative methods,

• procurement of the starting materials,

• preparation of the sample itself,

• disposal of waste products,

• collection of data to support chemical structure assignment,

• registration of information about chemical samples into personal and shared databases,

• submission of samples of the chemical for appropriate testing,

• preparation of reports,

• submission of manuscripts to journals, and

• publication of chemical structural information and data associated with it in the primary literature.

These pathways will be discussed, with examples of software that may be suitable for each task. Guidelines will be recommended.