bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
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.
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.
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.
End-Result Specifications—A Contractor's Viewpoint
Authors: Jones WH , Scherocman JA 
Published: March 2009

Method-type specifications penalize a competent asphalt paving contractor by requiring the contractor to use prescribed equipment, materials, and methods to construct a particular pavement. End-result specifications, on the other hand, allow the contractor to use his available resources to accomplish the required end product in the manner of his own preference.
The Indiana State Highway Commission let to contract a paving project under end-result specifications. This contract, awarded to Magaw Construction, accepted the asphalt content, aggregate gradation, and pavement surface smoothness on the basis of statistical-type specifications. The quality control exercised by the contractor was excellent, with the penalties assessed being equal to only 1.24 percent of the value of the paving work.
A lack of knowledge by state personnel of the significance of end-result specifications and differences in sampling and testing techniques have, in the past, caused the assessment of many of the penalty points. The differences in the results obtained could be reduced on future projects, however, through the use of a certified asphalt technician approach to end-result specifications.
Prediction Capability and Improvements of the Numerical Notch Analysis for Fatigue Loaded Aircraft and Automotive Components
Authors: Nowack H , Hanschmann D , Foth J , Lütjering G , Jacoby G 
Published: March 2009

Because they combine minimum experimental expenses with a maximum flexibility regarding their application areas and objectives, numerical notch analysis methods have attained special importance among the presently available crack initiation life prediction methods.
The first part of this study gives the results of an evaluation program in which the prediction capability of the numerical notch analysis concept using the Neuber approach for the consideration of the notches was investigated. The loading histories considered are standard flight loading histories (TWIST and FALSTAFF), automotive histories, and simple, systematically varied loading histories. The test specimens were center notched and angle type, and the materials were high-strength aluminum alloys, Ti6-4, and others. The test results showed satisfactory predictions in many cases; however, unacceptable deviations occurred, especially under long-term random loading, after high peak loads, and under a high amount of compressive loads.
The second part of this study investigates the reasons for the deviations in the predictions. The main reasons are (1) inadequate consideration of the sequence effects on the damage accumulation, and (2) differences in the stress states and crack initiation processes at the stress raisers of the notched specimens and at the unnotched specimens.
A new damage evaluation procedure is proposed that is based on these test results. A more adequate definition of the crack initiation stage is attempted and a consideration of short cracks is provided.