bluuebunny/crossref_metadata_2025 huggingface dataset:
Systems for Laboratory Automation
Authors: Wonsiewicz BC , Storm AR , Sieber JD
Published: March 2009

The use of computers to control experiments, acquire and analyze data, and maintain permanent test records has advanced significantly in recent years. This paper outlines two methods which have been used in automating materials testing. One consists of a stand-alone machine controlling testing or processing, another consists of a network of microcomputers each of which controls one or more experiments and is connected to a larger central processor. The latter approach is shown to be particularly attractive when more than a few experiments are automated.

Regardless of the configuration, automation is facilitated by: standardized hardware and interfaces, high-level programming languages, modularized software, and the presence of good tools for building programs, maintaining data archives, and analyzing or plotting results.
Materials Testing in an Automated Laboratory
Authors: Key PL , Sieber JD , Storm AR , Wonsiewicz BC
Published: March 2009

The application of a laboratory automation system to materials testing is described from the point of view of the user of the system rather than the designer. Both the hardware and software steps necessary for interfacing a laboratory instrument to the system are described. Application of these steps is illustrated with several examples including closed loop control of a servohydraulic mechanical testing machine and data acquisition from a magnetic hysteresigraph.
Design, Implementation, and Control of a Computerized Tension Testing Station
Authors: Emery RR
Published: March 2009

This paper is based on the author's recent experience with the development of computer software for a dual unit tensile acceptance test station controlled by two minicomputers in a graphite production facility. Specific examples from that experience are used as illustrations in a more general discussion. Major items that must be considered in the design, development, and implementation of a real-time software system are control, operator, and equipment interfaces, data acquisition and analysis, and software verification and change control.

In addition to actual movement of the test machine crosshead, control aspects include consideration of methods to determine the condition of the machine by way of calibration and load rate checks, and control of the specimen testing sequence. Operator and machine interfaces should be designed in such a way that the operator does not feel impeded in the performance of his work by the computer. Control panels should indicate the progress of the computer during testing so that the operator does not panic during computer delays.

The software must be designed to have a high probability of acquiring all of the digitized stress-strain points without placing a disproportionate load on the computing system. Data analysis programs should be designed to compute values for comparison with acceptance specifications and to assist in analyzing unusual data. Orderly verification of the software by an outside person provides added insurance that the final system will perform the activities specified in the original program specifications. Any changes to verified software should be fully documented, authorized, and, if required, reverified before implementation.

This paper describes how the general requirements outlined above were implemented in a production testing system.
Computerized Methods for JIc Determination Using Unloading Compliance Techniques
Authors: Clarke GA , Brown GM
Published: March 2009

A computerized test system used for the determination of the ductile fracture toughness value JIc is described. The system is comprised of a Westinghouse 2500 computer coupled to a servohydraulic test machine by a 12-bit data acquisition system. A considerable savings in time has been realized in the data reduction and plotting of the data using this system.

The possible bounds on the accuracy of the overall testing system is discussed along with the effects on the calculated JIc value due to these inaccuracies. Examples of test data on ASTM Quenched and Tempered Vacuum-Treated Carbon and Alloy Steel Forgings for Pressure Vessels (A 508-77) and HY-130 high-strength structural steel is shown along with graphic plots of the JIc results.

It is expected that a fully computer controlled test will result from this initial test program.
Automated Determination of Impact Absorbed Energy with a Velocity Detection System
Authors: Wogulis SG , Ireland DR
Published: March 2009

An automatic method for determining specimen absorbed energy in drop weight impact tests is presented. The method has distinct time and materials savings advantages for the ASTM Test for Dynamic Tear Energy of Metallic Materials (E 604-77) and is also applicable for use with pendulum impact machines. The times for interruption of a precise light beam, by a flag of known width, are measured at impact and after completion of the specimen fracture. A microprocessor device computes the hammer velocities and the change in kinetic energy, which is equated to that absorbed by the specimen. The three computed values are instantaneously presented on digital displays. Operational features of the device, computational methods, accuracy and limitations of the method, and comparative results with two other methods are presented.
Computer Assisted Impact Testing
Authors: Interrante CG , Low SR
Published: March 2009

A data acquisition system is described for use in instrumented tests of Charpy impact specimens, both standard and precracked types. The load signal from strain gages in an instrumented striker is amplified and stored in a digital oscilloscope where it is analyzed by the operator. A laboratory calculator is used to assist the operator in the conduct of the test, to store the raw data and other pertinent data taken by the operator, to integrate this data, and to compute parameters needed to determine various alternative measures of fracture toughness. The software described is designed to assist the operator in the conduct of standard and precracked Charpy tests, and much of it is readily adaptable to tests of other types of specimens. Raw data of load versus time are analyzed using values obtained from the operator's interpretation of the raw data. The calculator then operates on the data to compute various results, such as energy to maximum load, total energy absorbed, etc. A magnetic tape is used to store the raw data, test variables, and various other information, such as computed results and operator selected points of load on the load-time record. To assist the operator in the interpretation of the data and in the selection of test conditions for a series of tests, two other peripherals are used. A plotter furnishes a record of test response as a function of test temperature, and a printer provides a detailed record, for each test, of the information stored on the tape.
An Assessment of Thermal Insulation Materials for Building Applications
Authors: Tye RP , Ashare E , Guyer EC , Sharon AC
Published: March 2009

A comprehensive assessment has been made of thermal insulation materials currently available for use in the building envelope. Information was obtained from four major sources: 1. manufacturers' literature, 2. open literature, 3. results of questionnaires, and 4. knowledgable experts in the field.

Information on a particular generic material or product was reviewed in relation to the major factors that influence thermal and physical performance, fire characteristics, and chemical properties. Areas in which insufficient information is available are identified.

The assessed information is reported as a series of data sheets such that the reported values for generic materials are consistent with present basic principles and this can be accepted as a reliable guide for current use. The assessment provides an authoritative collection of state-of-the-art information for government policymakers, regulatory bodies, manufacturers, installers, users, and consumers. Recommendations are made for further work on the development of properties of thermal insulation materials and on test methods for determining these properties.
Some Performance Aspects of Glass Fiber Insulation on the Outside of Basement Walls
Authors: Bomberg M
Published: March 2009

This paper reviews the technical aspects of one particular insulation system concept where a rigid fibrous insulation is placed outside the basement wall and thus contributes to both thermal and moisture control of the building structure. The following properties of mineral fiberboards are discussed: drainage characteristics of the material and water retention after the drainage process, thermal resisitance, compressive strength, and elastic and irreversible deformations. All these properties are affected by the aging process of the material. Effects of various aging conditions simulated in the laboratory are compared with deterioration of the material exposed for 5 or 6 years in soils and on an experimental roof deck. Findings of Scandinavian and Canadian research are presented.
The Energy-Efficient Residence: Research Results
Authors: Johnson RJ , Lee OG
Published: March 2009

The paper discusses the results of a Housing and Urban Development-sponsored research project in which the potential for saving energy in a typical model of a best-selling new home using practical, off-the-shelf energy-conserving products and techniques was investigated. An Energy-Efficient Residence (EER) was designed and built with only slight modification in the exterior appearance (in conformance with the contract) of the Conventional Comparison Home (CCH) selected for this research.

The paper describes the detailed energy-conserving techniques used in both the EER and CCH homes; the change in cost for the energy conserving techniques, as measured on-the-site with industrial engineering methods for both the labor and materials used in the EER and the CCH; the calculated heating and cooling loads at design conditions along with projected annual energy consumption in both homes; the economic and technical basis for selection of the energy-conserving techniques used in the EER; the results of thermographic surveys; general occupancy observations; and measurements related to comfort performance, including air, surface, and mean radiant temperatures and relative humidity. In addition, the actual measured energy consumption for three heating months and three cooling months while both homes, which are located adjacent to each other, are occupied by similar families is presented and analyzed. The results include data on energy used for space heating, heating equipment blowers, water heating, all individual major appliances, and lighting and miscellaneous uses. The dramatic reduction of energy use in the EER compared with that in the CCH is presented along with a comparison of actual to projected energy consumption for both homes. The design- and equipment-related consequences of these differences are also presented.
Influence of Insulation Deficiencies on Heat Loss in Walls and Ceilings
Authors: Vinieratos ER , Verschoor JD
Published: March 2009

The Navy is aggressively analyzing and implementing means for conserving energy in all of its operations. There is particular interest in improved thermal insulation for new and existing Navy buildings, especially in family housing. More attention is being given to previously unconsidered factors; one of these is the effect of common insulation installation practices on heat loss.

Several problems are created with the use of each type of insulation: some have to do with the type of insulation used, and others with common installation practices. These include uninsulated areas (void areas or gaps) in the insulation as installed. This may be aggravated, for example, by foam shrinkage, or by manual compression or careless cutting of batts around electrical boxes or pipes.

A common assumption within the construction industry has been that a 10 percent void area in insulation would result in a 10 percent increase in heat loss (that is, added heat loss would be proportional to void area). Recent test results indicate that the heat loss due to such insulation deficiencies is much more serious than has been assumed.

This paper addresses the effects of these insulation deficiencies on the thermal performance of wall and ceiling sections, and methods for detection and correction of deficiencies during building construction and in existing structures.
Interpretation of Building Thermograms
Authors: Stainton WD
Published: March 2009

The thermographic inspection of buildings is normally carried out to characterize the thermal performance of the cladding, to identify and characterize thermal anomalies, or to characterize the surface temperature uniformity.

The paper discusses the requirements of each of these three objectives of a thermographic building survey. It stresses the importance of estimating the overall thermal performance as a prerequisite to examining the anomalies and the nonuniformities and gives the development and application of the dimensionless parameter, the “temperature index” or “TI.”

Typical thermograms of single family dwellings are analyzed.
Evaluation of ASTM C 201 Apparatus for Measuring the Thermal Conductance of Ceramic Fiber Insulation
Authors: Chaille CE , Wahle HW
Published: March 2009

The ASTM C 201 apparatus is being evaluated to determine its suitability for measuring the thermal conductance of ceramic fiber insulation. This work is being done in support of a proposed new ASTM test method. A two-dimensional thermal model of the ASTM C 201 apparatus was developed using a finite-difference conduction program. The errors in measured thermal conductance due to lateral heat flow were predicted for several test parameters. Results of laboratory experiments are also presented for the following investigations: hot- and cold-face temperature uniformity, calorimeter surface emittance, and calorimeter heat flow measurements. Comparisons are also made between thermal conductance data obtained from an actual furnace installation and data obtained on the C 201 apparatus. The results indicate that the ASTM C 201 apparatus yields satisfactory data for designing furnaces and predicting heat loss and cold-surface temperature on furnaces.
A Method for Determining the Thermal Resistances of Experimental Flat Roof Systems Using Heat Flow Meters
Authors: Hedlin CP , Orr HW , Tao SS
Published: March 2009

Experimental flat roof systems were studied at an outdoor test facility. Heat flow rates and temperatures were measured with heat flow meters and thermocouples, and the values were recorded on magnetic tape at fixed intervals. The results were averaged over 24-h periods. Thermal resistances of systems and individual components were found using average net heat flow rates and temperature differences. Two analytical methods were used. In the first, the ratio of heat flow to temperature difference was calculated. This method was unreliable at low heat rates due to a bias in the results. In the second method, the slope of heat flow versus temperature difference was used as the basis for calculation. Thermal resistances of several pieces of insulation found by this method were compared with results obtained using laboratory equipment. The differences ranged from about 0.5 to 5 percent.
Discussion on Experiments to Separate the “Effect of Thickness” from Systematic Equipment Errors in Thermal Transmission Measurements
Authors: Pelanne CM
Published: March 2009

The radiation-related “effect of thickness” in nonhomogeneous insulations can be readily confused with equipment-related effects resulting from increases in the thickness of the measurement. The relatively unexplored effect-of-thickness phenomenon and the requirements imposed by the ASTM Tests for Steady-State Thermal Transmission Properties by Means of the Guarded Hot Plate and Heat Flow Meter (C 177–76 and C 518–76, respectively) have prompted the rapid development of equipment to measure insulations at full-use thickness.

This paper discusses the problems which arise from attempts to accurately measure insulations at full thickness, a relatively unknown area of measurement, and suggests a method for the separation of the actual effect-of-thickness phenomenon from the errors induced by the equipment.
Insulation for Cryogenic Service
Authors: Cunningham CR , Roni JP , Oliver LT
Published: March 2009

The General Electric (GE) Co., Thermal Systems Programs, in Tacoma, Wash., has developed a medium-density rigid structural polyurethane foam insulation material to withstand thermal stresses imposed by temperatures down to absolute zero 0 K (−460°F). Structural test results according to ASTM standards are presented for tensile, compressive, and shear strength and moduli. Other structural properties presented are Poisson's ratio and creep characteristics. Thermal test results according to ASTM standards are presented for thermal conductivity and expansion/contraction. Foam thermal/structural performance at cryogenic temperatures as low as LN2 (liquid nitrogen) and LH2 (liquid hydrogen) conditions, 77 K (−320°F) and 22 K (−420°F), respectively, are also related. Applications for liquefied natural gas (LNG) ships and LH2 fueled subsonic transport aircraft are discussed. In part, a lot of technical information presented herein was used to obtain conceptual approval complete from the U.S. Coast Guard for the insulation of LNG ships utilizing GE cryogenic polyurethane foam.
Thermal Transfer Calculation Methods for Insulated Underground Piping Systems and Comparisons of Results
Authors: Barton RN
Published: March 2009

Heat-transfer calculation methods for underground piping systems differ from those for aboveground systems because of the earth envelope and its moisture content, and the thermal effect of each pipe on adjacent pipes through the earth heat sink. The calculation methods are not well known and are scattered through the literature, usually with a minimum of theory and detail. This paper reviews the choice of ground thermal conductivities and temperatures so important to accurate results. It also gives simple, once-through analytical methods for one-pipe and two-pipe systems along with basics for a currently used iterative computer program for systems of two pipes or more. The paper does not cover theory or derivations, but lists references for this information.

Comparisons of the results of each method on specific problems indicate reasonable results of analytical methods under many conditions, but also show that the computerized iterative results are always best.
V378A Polyimide Resin—A New Composite Matrix for the 1980's
Authors: McKague L
Published: March 2009

During 1979, General Dynamics conducted an extensive screening program to evaluate new graphite composite materials. V378A, a new modified bismaleimide resin developed by U.S. Polymeric, has met the predetermined screening criteria for harsh aircraft environments [recurrent service to 177°C (350°F) following prolonged exposure to 75 percent mean relative humidity]. During the screening procedure, environmental, mechanical, and processing requirements were examined.

In this report, these criteria, in addition to the V378A results, are reviewed and compared with results for 5208 resin, a widely used epoxy resin. The comparison shows that V378A resin represents an important advancement in composite properties and processibility with widespread application in the manufacture of composite materials.
Dynamic Tests of Graphite/Epoxy Composites in Hygrothermal Environments
Authors: Rehfield LW , Briley RP , Putter S
Published: March 2009

The objective of this research is to experimentally determine the effects of hostile, hygrothermal environments on the dynamic behavior of graphite/epoxy composites.

This objective has been accomplished by performing flexural vibration tests on Narmco 5208/T300 beam specimens of four distinct layups. Dynamic behavior in the dry, room temperature state is contrasted with five other environmental states, including moisture saturation and temperatures up to 93°C (200°F). The properties determined are fundamental natural frequency and damping. The former can be directly related to an effective dynamic modulus in flexure. These properties reflect the consequences of plasticization of the epoxy matrix material in hygrothermal environments. The experimental results indicate that matrix controlled modes of response are the most affected. Generally damping increases and stiffness decreases with increasing hygrothermal conditioning. For most applications, stiffness reductions are the dominant concern; the experimentally determined dynamic reductions are consistent with known static ones.
Wear Testing of Abrasion-Resistant Coated Plastics
Authors: Haluska LA
Published: March 2009

State-of-the-art standards currently used to evaluate the comparative wear performance of plastics with abrasion-resistant coatings—such as tests that quantify rubbing and impact abrasion—are surveyed along with other recent developments in test methods. In addition, tests that determine the wear resistance of abrasion-resistant coated plastics after exposure to environmental effects are explored. Wear testing is also covered as it relates to different applications for abrasion-resistant coated plastics.
Solid Particle Erosion of Coatings on Transparent Polycarbonate and Reinforced Composites
Authors: Zahavi J , Schmitt GF
Published: March 2009

Solid particle erosion of transparent hard coatings on polycarbonate and elastomeric and hard polyurethane and fluorocarbon coatings on glass-reinforced epoxy and quartz-reinforced polyimide laminates has been investigated at 35 to 42 m/s with 210 to 297 μm natural sand by using a sand blast nozzle apparatus. Erosion was determined as a function of impact angle, total weight of impacted sand, and velocity of impact. Characterization of eroded specimens included weight loss. Talysurf profilometry, scanning electron microscopy, and transmittance measurements (for the polycarbonate materials).

The hard transparent coating (Du Pont's Abcite) on the polycarbonate exhibited maximum erosive weight loss at lower angles (30 deg) with brittle cracking and subsequent adhesion loss of the coating; the cracking was also observed in the substrate itself. The average surface roughness of the coated and uncoated polycarbonate increased with increasing weight of sand impacted, but was reduced at the higher (60, 75, and 90 deg) compared with the lower impact angles. Measurement of transmittance loss showed more reductions on coated and uncoated polycarbonate at 30 deg than 90 deg at low velocity and low sand weight impinged, but showed the opposite effect at higher velocity/sand weight conditions.

Erosion of the reinforced composite materials was typically brittle in nature with a maximum weight loss at 75 deg. When they were coated with the elastomeric polyurethane or fluorocarbon, the maximum erosion occurred at 15 to 30 deg impact angles with minimum weight loss at 45 deg or above (in these exposure conditions). By contrast the hard MIL-C-83286 polyurethane paint on these composites exhibited continuously decreasing weight loss from 30 to 90 deg under these conditions. The primary mode of failure was tearing or chunking of the coating with microscopic cracking and adhesion loss; this was aggravated at the lower angles where the angularity of the impacting particles interacted with the surface to gouge out pieces of coating. Maximum surface roughness was measured at 30 deg, and surface roughness corresponded closely to erosive weight loss. This surface roughness did not change appreciably as a function of amount of sand impacted. The surface roughness of the hard polyurethane coatings was twice that of the elastomeric coatings.
Assessment of the Wear of Composite Coatings in Reciprocating Line Contact Conditions
Authors: Lancaster JK
Published: March 2009

Aerospace dry-bearing materials commonly consist of a plastics-composite coating, typically 200 to 400 μm in thickness, adhesively bonded to a metal substrate. These materials are intended for use at high loads and low speeds, and assessments of their performance in full-scale bearing tests are expensive and time-consuming. This paper describes an accelerated test procedure for determining the wear behavior of such coatings, in which a small coated strip is loaded in nominal line contact against a rotating metal ring. The advantages and limitations of the method are discussed and examples given relating to (1) comparative screening of commercially available bearing liners, (2) effects of coating structure and composition on wear, (3) importance of the adhesive bond between the coating and its substrate, and (4) assessment of which particular parameters, amongst the many known to influence sliding behavior, are most important to the wear of these coatings. One problem identified by the work is the need for more information on the mechanical properties of thin composite coatings.
Wear Characteristics of Industrial Platings
Authors: Budinski KG
Published: March 2009

Electroplates and chemical conversion coatings are frequently employed to alter the tribonetic characteristics of surfaces; there are, however, no standard test methods for comparing these coatings. In this study, widely used metal-to-metal and abrasive wear testing techniques were modified to rank the wear characteristics of commonly used industrial electroplates and similar treatments. The main problem encountered with these “standard” tests was comparing thick platings with those that can only be produced by normal techniques in thicknesses less than about 5 μm. The testing problems and test rigs are described, and test results are presented to serve as an aid in selection of platings for solving wear problems in machine components.
Effect of Processing Variables on the Mechanical and Thermal Properties of Sheet Molding Compound
Authors: Tung RW
Published: March 2009

The increasing usage of sheet molding compound (SMC) materials in the automotive industry for weight reduction motivated this study on the effect of processing on SMC properties. The processing variables investigated were cure time, mold temperature, and mold pressure. A total of 15 different molding conditions were used to produce flat SMC panels from a laboratory mold. Tensile, flexural, and impact properties and heat deflection temperatures of these sample panels were measured. It was found that while the processing variables studied have little effect on the mechanical properties, they have a more severe effect on the thermal property.
Vibration Characteristics of Automotive Composite Materials
Authors: Gibson RF , Yau A , Riegner DA
Published: March 2009

This paper describes measurements of dynamic stiffness and internal damping (that is, the complex moduli) of automotive fiber-reinforced plastics over the frequency range 10 to 1000 Hz at maximum strain amplitudes up to 0.0017. Three types of chopped E-glass fiber-reinforced polyester composites and two types of hybrid chopped/continuous fiber-reinforced polyester composites are tested, along with neat resin samples. Complex moduli are measured by using a forced flexural vibration technique. Materials having the greatest stiffness are generally found to have the lowest damping, and vice versa. The complex moduli of all materials are found to be essentially independent of frequency and amplitude within the ranges investigated. Damping in the composites is at least one order of magnitude greater than the damping in an aluminum calibration specimen.
Evaluation of Fretting Corrosion by Means of a New Device for the Control of Oscillation Amplitude
Authors: Budinski KG
Published: March 2009

Many studies of fretting corrosion and wear are conducted on production machinery or on fatigue testing devices. Such devices often rely on elastic strains in loaded members as the source of the fretting motion. This makes measurement and control of slip amplitude and frequency and of normal force difficult. Assessment of the damage is also often difficult.

This paper discusses problems in studying fretting phenomena and describes the use of a slider-crank tester that allows control of most fretting variables, including slip amplitude. Fretting resistance test data are presented on a variety of coatings and metal couples. Recommendations are made on the use of various metal couples and selected surface treatments.
Fretting of Electrical Contacts
Authors: Antler M
Published: March 2009

Fretting can cause the contact resistance of electrical components to become unstable. Fretting originates in vibration, mechanical shock, thermal fluctuations, and magnetic forces to which conductors are subjected. Gold is a preferred contact material because it is inert and therefore has a contact resistance which remains nearly constant during fretting. However, insulating oxide films appear at the interface of base metal contacts and gold-coated base metal contacts when the gold wears out. Platinum group metal contacts catalyze the formation of frictional polymers from organic materials, such as air pollutants, in their vicinity. Thus, fretting corrosion and friction polymerization can increase contact resistance and thereby cause electrical failure.

This paper describes a new research apparatus for studying the fretting of electrical contacts, in which a stepping motor causes small oscillatory movements of a slide table. One specimen is mounted on the table, and the stationary contact is loaded against it in the force range of 5 to 500 g. Contact resistance is determined at 1.6-μm intervals along the wear track by a data acquisition system computer. Examples of the use of this equipment to model fretting of electrical contacts are given.
Heat Exchanger Tube Fretting Wear: Correlation of Tube Motion and Wear
Authors: Ko PL , Tromp JH , Weckwerth MK
Published: March 2009

A typical steam generator in a nuclear power station consists of about 4000 tubes which form the boundary separating the light water in the secondary circuit from the primary circuit water. The integrity and the life expectancy of these tubes are therefore of prime concern to the designers.

One of the several tube failure mechanisms, which include corrosion and fatigue, is fretting wear due to flow-induced tube vibrations. The tube-tube support clearance needed for design considerations allows periodic separation and impacting between the tube and the tube support hole and hence ready removal of loose wear particles by the fluid flow. It has been found that the combined rubbing and impacting motion, together with the periodic separation of contacting surfaces, all contribute to an accelerated wear process.

A tube-fretting test apparatus has been developed to study the effect on tube wear of various parameters, such as tube-tube support interaction, materials, temperature, and clearance. Tests have been conducted in water at room temperature and at steam-generator operating temperature (265°C). Recently the authors have looked into the more fundamental aspect of tube fretting wear mechanisms. Some of the worn surfaces were further studied by a surface analyzer interfaced with a computer and by a scanning electron microscope. The results from these analyses were correlated to other tube fretting parameters, namely, tube motion, clearance, and impact forces at the support. We have found that the effects of these parameters on wear are interrelated. The understanding of these interrelated effects is of great importance in predicting long-term tube wear. This paper will describe our fretting test facilities and present the results from recent studies on wear correlations.
Fretting-Resistant Ion-Plated Coatings
Authors: El-Sherbiny MG , Salem FB
Published: March 2009

This paper presents experimental results on fretting testing of various surface coatings, with particular reference to ion-plated films. A special test setup is described, and some peculiar testing conditions are discussed. The results indicate that ion-plated films are superior to vacuum-deposited, gas-deposited, and sputtered-surface coatings. The effectiveness in alleviating fretting of four ion-plated soft metallic films—namely, lead, indium, tin, and silver—is evaluated. Lead showed the best fretting resistance at small slip amplitudes, while tin showed a good resistance at high slip amplitudes. Ion-plated titanium carbide films were also examined. The wear-resistant hard carbides showed outstanding fretting resistance.
Polymeric and Composite Materials for Use in Systems Utilizing Hot, Flowing Geothermal Brine III
Authors: Lorensen LE , Walkup CM , Pruneda CO
Published: March 2009

This paper documents recent progress in our continuing program aimed at finding optimum polymeric materials for use in geothermal plants. Coatings and bulk specimens of high-performance polymers and composites were exposed to brine in the laboratory and in the field. Several levels of temperature and flow conditions were employed. Physical changes, scaling tendencies, and changes in surface characteristics resulting from exposure were studied by techniques including optical and scanning electron microscopy, energy-dispersive spectroscopy, and contact-angle measurements. Certain fluorocarbon and hydrocarbon polymers continue to respond favorably to the severe geothermal environment. Surface roughness, either present originally or developed during exposure, appears to be an important factor in promoting scaling and scale adhesion.
Concrete Polymer Materials as Alternative Materials of Construction for Geothermal Applications—Field Test Evaluations
Authors: Fontana JJ , Zeldin AN
Published: March 2009

A serious problem in the development of geothermal energy is the availability of durable and economical materials of construction for handling hot brine and steam. Hot brine and other aerated geothermal fluids are highly corrosive, and they attack most conventional materials of construction. The Brookhaven National Laboratory, Upton, N.Y., has been investigating the use of concrete polymer materials as alternative materials of construction for geothermal processes. To date, successful field tests have been demonstrated at the Geysers, Calif., the U.S. Bureau of Mines Corrosion Facility, Niland, Calif., and the Department of Energy Geothermal Facility at East Mesa, Calif. This report is a survey of field and laboratory evaluations of concrete polymer materials that have been shown to be durable and economical as alternative materials of construction.
Organosiloxane Polymer Concrete for Geothermal Environments
Authors: Zeldin AN , Kukacka LE , Fontana JJ , Carciello NR
Published: March 2009

The feasibility of using the products of free-radical copolymerization of modified organosiloxane in the formation of a thermally stable and chemically resistant polymer concrete for use in geothermal environments has been demonstrated. Specimens have been produced by using mixtures of organosiloxane containing pendant vinyl groups and styrene or different silicone fluids as a comonomer in conjunction with a free-radical initiator and several aggregate materials. The use of these monomers in conjunction with materials such as silicon dioxide (SiO2) and portland cement to form polymer concrete results in composites with high compressive strength (80 to 100 MPa) and thermal and hydrolytic stability. The results from studies to determine the effect of variables, such as sand particle size, type of cement, and sand/cement ratio, are discussed.
Chemical Logging of Geothermal Wells
Authors: McAtee RE , Allen CA , Lewis LC
Published: March 2009

Chemical logging was developed to permit identification of zones bearing geothermal water during drilling of geothermal wells. This technique consists of collection of circulation fluid samples at specified periods determined by drill-bit depth. These samples are analyzed for bicarbonate (HCO3−), Cl−, F−, Ca++, and silicon dioxide (SiO2). The results are plotted as a function of depth, and the resulting log indicates the presence of water-bearing structures. It was discovered that the ratio of Ca++ and HCO3− concentrations is a temperature indicator. It was also found that chemical composition changes precede structural changes. This report describes chemical logging of three wells at the Raft River geothermal site, Idaho.
Human Evaluations of Warning Odorants in Propane
Authors: Brinkman DW , Goetzinger JW , Cotton FO , Whisman ML
Published: March 2009

Human awareness of several odorants at varying concentrations were monitored within different environments. The effects of distractions, unfamiliarity with the test environment, and previous training were found to be significant. Efforts were directed at determining not only the odorant levels that can be detected, but also the levels that will be detected.
Effects of Exposure and Context on Hedonics of Olfactory-Taste Mixtures
Authors: Murphy C
Published: March 2009

Twelve subjects judged the pleasantness of five concentrations of the tastant sodium chloride, five concentrations of the odorant citral, and of all 25 possible mixtures of these, prepared in aqueous solution and presented in the mouth. Subjects judged the set of stimuli twice in a 1-h session and twice again in a second session approximately two weeks later. The single massed exposure produced an immediate effect, that is, pleasantness judgments were significantly more negative on the second presentation. Pleasantness also shifted as a result of spaced exposure, namely, after the two week interval the same stimuli were judged as significantly less negative than on previous exposure. Ten of the original subjects were retested in a second experiment a year later. Pleasantness judgments had shifted back to initial levels. Finally, in a third experiment manipulating the context in which the citral stimulus was presented significantly altered both the degree of pleasantness and the shape of the hedonic function.
Effects of Context and Interstimulus Procedures in Judgments of Saltiness and Pleasantness
Authors: Riskey DR
Published: March 2009

Saltiness and pleasantness of soups were judged in four contexts defined by the relative frequency of stimuli high and low in sodium chloride (NaCl) concentration. Context affected judgments of saltiness such that a given stimulus was judged saltier when presented in a distribution including many low concentrations, less salty when higher concentrations were more frequent. Ratings of pleasantness were also affected by context; concentrations judged intermediate in saltiness tended to be rated maximally pleasant. In a second experiment, rate and method of stimulus presentation were manipulated to assess the possible role of sensory adaptation in the observed contextual effects. Although different presentation procedures had significant effects on judgments of saltiness, these effects had no impact on the size of the observed contextual effects.
Standards for Residual Stress Measurement
Authors: Mordfin L
Published: March 2009

It has been long appreciated that residual stresses can exert significant influences on fatigue and fracture behavior, but only recently have analytical models been developed which enable the influences to be quantified. These new capabilities have fostered increased demands for residual stress measurements and these, in turn, have revealed that the reliability and the reproducibility of such measurements are often less than adequate. The need for standards for residual stress measurements is now recognized as being urgent. Few standards presently exist, and they do not provide the required levels of measurement reproducibility.

Several organizations are attempting to respond to this critical need. This paper is a status report on the growing national effort to develop voluntary consensus standards to enhance the reproducibility of residual stress measurements. This effort has achieved noteworthy progress in only a few years, but it has also become evident that further progress will be increasingly more difficult because our understanding of some residual stress phenomena is limited. There is need for a national research effort to parallel and to support the standardization effort.
Stress Intensity Factors, Crack Profiles, and Fatigue Crack Growth Rates in Residual Stress Fields
Authors: Parker AP
Published: March 2009

A linear elastic fracture mechanics approach to crack growth rate prediction implies the need to calculate accurate, effective stress intensity (K) factors, and hence effective R-values, (Kmin/Kmax), for components containing residual stress. To this end the weight function and associated superposition techniques are described, with emphasis on stress intensity and crack shape prediction for residual stress problems. Stress intensity factors are presented for various geometries with residual stress fields. The nonlinear, crack surface ‘overlapping’ effect is noted, and the case of cracks emanating from notches in residual stress fields is shown to be an associated problem.

The application of such results in crack growth rate prediction is addressed. The characteristic crack growth rate features of several different loading systems are predicted, and shown to agree with available experimental data. Finally, the qualitative changes in the form of standard S-N curves for welded details are predicted, and shown to conform with limited available S-N curve experimental data.
Influence of Tensile Residual Stresses on the Fatigue Behavior of Welded Joints in Steel
Authors: Maddox SJ
Published: March 2009

Fatigue tests were carried out on fillet welded joints in four steels, with yield strengths ranging from 332 to 727 N/mm2, under various applied load ratios. Some specimens were stress-relieved but most were spot-heated to ensure that high tensile residual stresses, as would be present in as-welded joints in real structures, were present in the specimens. The aim was to investigate the effect of tensile residual stresses on the fatigue behavior of fillet welded joints under different load ratios and the relevance of the tensile strength of the steel, particularly in relation to the magnitude of residual stresses developed.

In the present specimens, the residual stresses were no higher in the high-strength steels than the mild steels, with the result that the tensile strength of the steel had no effect on the fatigue strength of the joints in both the as-welded and the stress-relieved conditions. Furthermore, it was found that for the range of R-values used (R = −∞ (zero compression to R = 0.67) applied load ratio had little effect on the fatigue strength of the as-welded joints provided that “failure” under compressive loading was taken to be a crack length less than or equal to that at which the rate of crack growth began to decrease. Stress relief was only partially effective, with the result that applied compressive stresses were still damaging. Thus under partly compressive loading the fatigue strength of the joint increased but not greatly. However, stress relief had no effect on the fatigue strength of the joint when it was subjected to tension loading.
Influence of Compressive Residual Stress on the Crack-Opening Behavior of Part-Through Fatigue Cracks
Authors: Hack JE , Leverant GR
Published: March 2009

Direct observations of the surface crack opening displacement (SCOD) of surface and corner fatigue cracks were made on samples of Ti-6Al-4V under both cyclic and static loading conditions. The experiments were conducted in situ in a scanning electron microscope. Results show that surface residual stresses can significantly affect crack opening behavior—thus crack growth behavior—even when the crack has grown well beyond the zone of residual stress. An analytical approach was developed and used to predict SCOD for Mode I part-through cracks based on crack geometry and the boundary integral technique. Correlation with independent results for macrocracks and values for microcracks measured in this program are excellent for the case of zero residual stress. The analytical approach is currently being extended to more accurately account for the presence of residual stress gradients.
Effect of Residual Stress on Fatigue Fracture of Case-Hardened Steels—An Analytical Model
Authors: Kim C , Diesburg DE , Eldis GT
Published: March 2009

The influence of residual stress at and near the surface on fatigue life was modeled by utilizing linear elastic fracture mechanics to quantify the stress intensity change due to the residual stress. The initiation and the propagation stages of the fatigue cracking process were distinguished using the concept of the threshold stress intensity amplitude; with a constant load amplitude, the propagation stage commences from the crack length at which the maximum fatigue stress intensity is equal to the threshold value. The influence of residual stress is to increase or decrease the crack length which corresponds to the initiation stage, thereby controlling the fatigue crack initiation life.
Structural Property Comparison of Solid Concrete Block Paving
Authors: Schoenfeld GD
Published: March 2009

Concrete masonry pavers are tested to determine physical and inherent characteristics of a variety of specimens manufactured on different equipment. Freezing and thawing, tensile splitting, compressive strength, and absorption are compared in order to assess the potential of each property as a measure of field durability and quality control.
Compressive Strength of Grouted Hollow Brick Prisms
Authors: Brown RH , Whitlock AR
Published: March 2009

The effect of grout on compressive strength of hollow brick prisms was investigated experimentally and analytically. Grout was found to benefit compressive strength in the great majority of cases. Factors that improved prism compressive strength were high strength grout, high strength mortar, high tensile strength brick, and low brick coring percentage.
Water Permeance of Masonry: A Laboratory Study
Authors: Ribar JW
Published: March 2009

Sixty-four walls were built and tested in accordance with ASTM Test for Water Permeance of Masonry (E 514). All M, S, and N mortar combinations shown in the Proportion Specification of ASTM Specification for Mortar for Unit Masonry (C 270) were used, including prepackaged M and S mortars in combination with concrete and clay masonry units, each from a single source. Research was directed at establishing the effects on masonry wall water permeance of mortar water content, cementitious material content of mortar, masonry unit physical properties, the effect of storage (curing), and exposure condition (varying water quantity and pressure. Test results showed that (1) all mortar types are capable of satisfactory performance in a masonry wall; (2) properly designed masonry walls are capable of resisting water permeance when quality workmanship and materials are used; (3) there is a need for specific controls in the preparation of specimens to be subjected to this test method; and (4) there is a need for revisions to ASTM E 514 that will incorporate a more realistic approach to exposure conditions and specific requirements to differentiate among specimens being tested for workmanship or materials.
Adaptations and Additions to ASTM Test Method E 514 (Water Permeance of Masonry) for Field Conditions
Authors: Monk CB
Published: March 2009

The main proposed adaptation of ASTM Test for Water Permeance of Masonry (E 514) concerns the exploration of field conditions. Emphasis is placed primarily on the measurement of water passing into the exterior face of a masonry wall, rather than measurement of conditions from water passing through to the inside face. A tentative rating criterion for water penetrating the exterior face is suggested. This measurement is useful to evaluate the effectiveness of water-repellent treatments on the surface and to assess the water that stays in the wall, possibly never penetrating to the interior face.

The main proposed addition to ASTM E 514 is a calibrated nozzle technique used to test permeance at caulkings, flashings, expansion joints, gravel stops, etc., not easily tested by the enclosed chamber method of E 514. Such an auxiliary device can be calibrated and applied to simulate desired rainfall intensity and wind pressure.