bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Determination of the Thickness Effect in Glass Fiber Building Insulation
Authors: Hollingsworth M 
Published: March 2009

Thermal insulations which permit significant heat transfer by radiation show an increase in thermal conductivity (or decrease in R-value per unit thickness) as thickness is increased. This thickness effect, for a common type of glass fiber building insulation, was determined in a large heat flow meter apparatus by comparing the R-value of a stack of pieces with the sum of the R-values of the separate pieces. Contrary to widespread belief, this effect, for a change from 38 to 152 mm (1.5 to 6.0 in.) was found to be only in the range of 1.5 to 3 percent. This percentage change will depend upon the thickness used as basis for comparison; for example, if at 152 mm (6.0 in.) the change from 38 mm (1.5 in.) were 2.5 percent, the change from 25 mm (1.0 in.) would be estimated to be about 4 percent.
At greater thicknesses, even after an extensive test program using an apparatus that is exceptionally well guarded and exceeds ASTM requirements, uncertainties exist which point to the need for more strict ASTM requirements and for even larger equipment. However, the high cost, greatly increased test times, and currently unproven accuracy of thick measurements may limit the use of extremely large equipment.
Various other data relating to these tests and to verification of the test equipment are also reported.
Field Measurements of Heat Flow Through a Roof with Saturated Thermal Insulation and Covered with Black and White Granules
Authors: Shuman EC 
Published: March 2009

In the past, thermal effects of moisture and deteriorating effects of moisture on constructions were considered separately rather than as total potential problems that arise from interactions dictated by the laws of physical performance. This paper contributes thermal data on two large industrial buildings; on one the roof insulation had become flooded, on the other the insulation was essentially dry. Also presented are brief examples of adverse effects of moisture in walls and floors. To present only data on excessive heat flow from moisture without also indicating how common problems induced by moisture may arise would not be helpful to those not familiar with the laws of physical performance. Without such associated information, little will be accomplished in overcoming moisture problems through preventive design, construction, and maintenance.
Three times as much heat flowed through the roof with flooded insulation as through the roof on which the insulation remained dry. This ratio of three was also found in the same location when the wet insulation was replaced with dry. During hot days, 35°C (95°F), the reduced peak heat flow from wet to dry insulation to maintain 24°C (75°F) indoors was equivalent to 40 W/m2 [12.8 Btu/(ft2·h)] or about one ton of refrigeration per 92 m2 (1000 ft2).
Roofing granules that reflect sun heat were found to reduce heat-transfer rate into the building, but the indications were that reliable reflectance data on materials being considered for such use are necessary, because light color to the eyes does not necessarily indicate effective reflectance of solar heat.
Wet-Sand Rubber-Wheel Abrasion Test for Thin Coatings
Authors: Saltzman GA 
Published: March 2009

One category of machines for determining the low-stress abrasion resistance of materials uses a rubber wheel rotating in a water-sand slurry and rubbing against a stationary specimen. Using the Wet-Sand Rubber-Wheel Abrasion Test Method being developed by the SAE produces a wear scar on the order of 0.25 mm deep in normalized 1090 steel at HRC 30, and so may be unsuitable for testing thin coatings and surface treated materials. This was confirmed in testing boride coatings on steel, the coatings being penetrated prior to completion of the test.
Modified practices were investigated in order to determine procedures more suitable for wet-sand rubber-wheel testing of coatings. Tests were conducted using the SAE Practice, with three rubber wheels of varying rubber hardness but with reduced numbers of revolutions per wheel, and using single rubber wheels and repeated increments of varying numbers of wheel revolutions. The criterion for acceptance of a modified practice was the correlation of weight loss (wear) ratios obtained for selected materials with those obtained using the SAE Practice. Results are discussed in terms of this correlation, and selected modified practices were evaluated for three highly varied coating types; electroplated chromium, a boride diffusion coating, and plasma-sprayed alumina, all on plain carbon steels.
Methods of Evaluating Materials for Icebreaker Hull Coatings
Authors: Calabrese SJ , Murray SF 
Published: March 2009

The choice of suitable bench tests to evaluate the wear of materials must be prefaced by careful consideration of the various modes of wear that may be encountered in the actual application. For example, sliding tests at constant loads and velocities can provide useful information on wear rates and frictional behavior for mechanisms that operate under similar conditions. If the application also involves impact loading and abrasion, however, the wear data obtained from the simple sliding tests may be very misleading. It is essential to select test conditions that realistically simulate the operating conditions.
This article describes the types of bench tests that were used to screen candidate materials for use as coatings on icebreaker hulls. Such coatings are subjected to high impact loads and severe two-body abrasion. Good correlation was found between the results of the bench tests and full-scale tests on actual icebreakers.
Influence of Residual Stress on the Predicted Fatigue Life of Weldments
Authors: Lawrence FV , Burk JD , Yung J-Y 
Published: March 2009

A model was developed that predicts the influence of residual stress and stress ratio on the total fatigue life of a weld. The total fatigue life of a weld was considered to be composed of both crack initiation and crack propagation. Weld toe residual stresses were considered to influence the crack initiation life but not the crack propagation life.
The crack initiation life was estimated using cumulative damage concepts. Actual weld material properties (weld metal and heat-affected zone) were considered in the initiation life estimation. Neuber's rule was used to determine the local cyclic stress-strain behavior at the weld toe, and the fatigue notch factor was evaluated by using Peterson's equation. Residual stresses were introduced into the analysis as a simulated pre-stressing of the weld. Cyclic relaxation of the mean stress established during the set-up cycle was modeled by a power function and allowed relaxation to be considered in the life estimates.
Fatigue tests of steel weldments and aluminum butt welds having tensile and compressive residual stresses were conducted to verify the analytically predicted total fatigue life predictions. Agreement between analytical predictions and experimental results was quite good.
Effect of Surface Residual Stresses on the Fretting Fatigue of a 4130 Steel
Authors: Kudva SM , Duquette DJ 
Published: March 2009

Fretting fatigue is defined as the fatigue of a material caused by the presence of a rubbing contact with a relative displacement of less than 100 micrometres. The presence of fretting results in a lowering of the fatigue life of the material. The relative displacement, also known as the slip amplitude, has a considerable effect on the life of the specimens that were investigated. Different surface microstructures were studied in order to investigate the effect of slip amplitude on the fatigue life. These treatments, namely carburization and decarburization, also induced surface residual stresses which were instrumental in causing the changes that were observed in the fatigue life.
Effects of residual stress on fretting fatigue were studied using three kinds of heat-treated specimens of a medium carbon steel. Two sets of experimental specimens were respectively decarburized and carburized to induce residual stresses on the surface. A set of control specimens of tempered martensite was used to compare results. All three structures showed a minimum in life versus the slip amplitude; the carburized specimens exhibited longer lives in general and the opposite was true for the decarburized specimens. In all cases, transverse cracks initiated on the surface, at the interface between the contacting and free surfaces, and propagated inwards, perpendicular to the loading axis. An attempt is made to explain the observed phenomena using residual stress arguments.
Creep and Cyclic Tension Behavior of a Type 316 Stainless Steel at Room Temperature
Authors: Nomine AM , Dubois D , Miannay D , Balladon P , Heritier J 
Published: March 2009

The behavior of a Type 316 L austenitic stainless steel subject to creep and cyclic tension under imposed load is examined at room temperature. Tests are carried out on the material in both the annealed and work-hardened state; in the latter case the influence of an initial hardening by cyclic tension on the subsequent creep behavior, together with the influence of creep hardening on the subsequent cyclic tension behavior, are determined. All tests are conducted with stresses from half the 0.2 percent yield stress up to a stress leading to an initial plastic strain of about 10 percent.
We demonstrate the existence of a (critical) stress limit for creep and a stress limit for (cyclic) accommodation. The creep strain, for a given time interval, increases with the applied stress and, in general, the material continues to creep after 10 000 h. The plastic elongation, between the 1st and the 1000th cycle, that occurs during cyclic tension tests on the annealed materials goes through a maximum when plotted as a function of the maximum applied stress. The creep strain obtained after prior cyclic tension (1000 cycles at the same maximum stress level) has the same stress dependence as the plastic strain that occurs between the 1st and the 1000th cycle, and exhibits a maximum. A creep pre-strain before the cyclic tension tests considerably decreases the elongation measured during cycling.
Behavior in Fatigue-Relaxation of a High-Creep Resistant Type 316L Stainless Steel
Authors: Mottot M , Pétrequin P , Amzallag C , Rabbe P , Grattier J , Masson S 
Published: March 2009

In order to predict long-term behavior of a high-creep resistant low-carbon Type 316L stainless steel under low-cycle fatigue with long hold times, a series of tests of fatigue relaxation was undertaken at 550, 600, 650, and 700°C for medium strain ranges (Δεt = 0.7, 1.2, and 1.6 percent). Hold times up to 5 h were introduced at the maximum tensile strain. It has been shown that a reduction of fatigue life occurred, generally associated with intergranular cracking when hold times increased. A maximal effect was observed at 600°C.
Different methods for extrapolating results for very long hold times, such as those encountered on fast breeder reactor components (∼1000 h) were proposed. These methods were based on a time-temperature equivalence comparable to those used for extrapolating creep rupture data. A correlation between reduction of fatigue life with the amount of stress relaxation during hold times was also used. Predictions by these methods are compared with ASME N47 fatigue design curves.
Low-Cycle Fatigue Behavior of Thick High-Strength Steel Plates for Pressure Vessels
Authors: D'Haeyer R , Simon P 
Published: March 2009

In this study of low-cycle fatigue, the following steels were evaluated: (1) two reference steels used in pressure vessel construction, A 543, Grade B (200 mm thickness) and St 52-3 (50 mm thickness); these steels were also studied after heat treatments simulating heat-affected zones of weldments with heat inputs ranging from 10 to 150 kJ/cm; (2) one structural steel, St E47 (50 mm thickness), after either normalization or quench-tempering treatment in order to compare two characteristic values of the yield strength/ultimate tensile strength ratio; and (3) fifteen experimental steels (28 mm thickness) in a thermal condition simulating the water quenching at the core of a plate 200 mm thick, this quenching being followed by a tempering.
Smooth and notched specimens were fatigue tested at 20 and 350°C under completely reversed tension-compression. The imposed diametral strain range was controlled to a constant value throughout each test.
Results were compared with ASME design curves and showed sufficient performances in all cases, so that the choice of the steel may be based upon another use property or economical argument. Nevertheless, differences between steel fatigue properties were studied by statistical methods as a function either of the tensile properties or of the chemical composition in the case of quenched and tempered steels. Concerning these last correlations, the influence of chromium at 350°C was particularly noted.
Meeting Construction Aggregate Fracture Requirements with Natural Product-Sized Material
Authors: Polhemus BH 
Published: March 2009

Areas of the country which are not fortunate enough to have ample accessible supplies of good quarry stone rely on diminishing gravel deposits for the bulk of their construction aggregates. This paper intends to show how producers in those areas which have strict minimum fracture requirements for asphalt material can utilize a larger portion of the natural supplies.
Wear course asphalt specifications often require 80 to 100 percent of the particles in the asphalt mix which are retained on the #4 mesh to have at least one fractured face.
Field experience has shown consistently that centrifugal impact crushing of natural aggregates that are already within this size range achieves fracture counts of 80 to 95 percent, often in a single pass. The operator can then utilize this material and reduce or eliminate the need to separate, handle, and stockpile a waste material.
A centrifugal impactor can accomplish this because it does not depend on a “closed side setting” to achieve crushing as do compression units, so virtually every particle entering the machine has an equal chance of fracturing, even if it is already product size.
On the other hand, the vertical shaft impactor has the ability to minimize the loss to fines (minus #10 mesh) often a problem with conventional horizontal shaft impactors. This is a direct result of the crusher's geometrical design and its control of the trajectory of the rock. The design minimizes scuffing on the rock and incorporates no grinding path, consequently allowing the option of reducing production of fines.
The requirement for fractured faces on asphalt aggregate is an important parameter to assure proper interlocking of particles and stability of the resulting asphalt mix. But with the proper equipment the operator can meet this requirement, waste less material, and conserve more of the often scarce high-quality aggregates.
Stresses and Strains in Roofing Membrane Caused by Substrate Movements
Authors: Guay F , Persoz B 
Published: March 2009

A computer program permits the estimation of stresses and strains in multi-ply membranes. This program covers the case of membranes fully bonded on: (1) a concrete substrate: sudden opening of a crack and (2) thermal insulating materials in two different situations: (a) time-linear opening of the joint between two boards caused by the drying of the board and (b) time-sine opening of the joint due to dilatation and shrinkage of the boards (day/night cycles, sun/rain cycles).
The constituent materials of the roofing are considered as elastic (coated sheets) and viscous (adhesives). The computer program provides a better insight into the operation of multi-ply membranes. It describes also the influence of the properties and dimensions of the constituent materials on the stresses and strains in a membrane as a whole and in its constituents (coating and felt).
Bonding Ethylene Propylene Diene Monomer Roofing Membranes: The Theory and Practice of Adhering Vulcanized Ethylene Propylene Diene to Itself
Authors: Westley SA 
Published: March 2009

Single-ply roofing has now become a significant factor in today's industrial and commercial flat-roofing market. The single-ply roof made from ethylene propylene diene monomer (EPDM) rubber, while possessing outstanding sheet properties, does present opportunities to improve seam adhesion owing to the inert nature of the EPDM and the surface presented for on-site bonding.
The author examines the surface of several commercial EPDM sheets with the scanning electron microscope and finds an absolute requirement for cleaned surfaces for adhesion. Classical adhesion theory is used to suggest ways to improve or develop adhesive systems that would be more compatible with EPDM. Of all adhesive systems available, the neoprene-phenolic contact adhesive is the predominant class used on site.
Results from peel and shear testing of adhesive joints made from EPDM membranes with contact adhesive are revealed with and without a proprietary primer designed to bridge the polarity between rubber and adhesive. This primer is suggested for further study to improve adhesion on field applied lap seam joints.
Reference Toxicants in Quality Control of Aquatic Bioassays
Authors: Lee DR 
Published: March 2009

Use of a reference toxicant promises to improve the usefulness of toxicity tests. Criteria such as &lt;10 percent mortality during a pretest acclimation period indicate only that the test organisms can survive the holding facility. A more reliable and logical method is to use a reference toxicant to estimate the fitness of organisms. Coupled with other standard bioassay procedures, a reference toxicant enables interlaboratory and intralaboratory comparisons of toxicity information to be made. In the context of invertebrate toxicity tests, where the available space and numbers of organisms are not so limiting as in fish bioassays, routine testing of a reference toxicant, conducted in conjunction with routine bioassays, is a realistic expectation.
One problem with reference toxicant information is the question of what can be done when the test organisms are inexplicably abnormal in their resistance. A proposed solution is to use a “sensitivity factor” to adjust the LC50 values obtained with the abnormal test group.
Sodium pentachlorophenate is recommended as a reference toxicant. It has a convincing history of use in toxicity testing, it is fast acting and nonselective in its toxicity to both invertebrates and fish, and it is recognized as an environmental contaminant. Other potential reference toxicants are also considered.
Assessment of Fire Risk for Exterior Structural Members
Authors: Gewain RG 
Published: March 2009

The traditional fire exposure in fire tests used to evaluate the performance of construction materials is the standard time-temperature curve specified in ASTM Fire Tests of Building Construction and Materials (E 119-80). There is growing concern that the severity of a fire defined by ASTM Method E 119-80 may not be representative of most fires which occur in buildings such as offices, schools, hotels, apartments, and other similar occupancies. Extensive research on postflashover conditions in building compartments supports this concern. However, the heating conditions in ASTM Method E 119-80 are not appropriate for exterior structural members. Therefore, research described in this paper provides a simple method for describing fire exposure of structural members located outside the enclosing walls of buildings.
The following procedure establishes the intensity of the fire in the compartment under ventilation-controlled or free-burning conditions, the shape and size of the flame emerging from openings in exterior walls of the fire compartment, and the temperature of the flame, all of which are needed to calculate the heat transfer to structural members outlined by the American Iron and Steel Institute.
Capacity of Reinforced and Prestressed Concrete Pile Sections
Authors: Gamble WL 
Published: March 2009

Information needed to compute the nominal strengths of various pile cross sections that are subjected to combined compressive thrust and bending moments is presented, with examples of moment-thrust interaction diagrams for several typical kinds of pile sections.
The components of the factor of safety are examined, with particular emphasis on the reliable strength of the pile section. The use of a “strength reduction factor,” a multiplier that is less than 1.0, to establish a reliable or minimum expected failure load that is somewhat lower than the nominal failure load to be expected from an ideal member is discussed.
This strength reduction factor may vary with the number of piles in an individual footing and should be higher for piles that can be inspected than for those that cannot be inspected after completion. Precast piles and piles that are cast in permanent metal cylinders are examples of members that can be inspected to different extents, while piles cast-in-place in unlined holes or that have the liner pulled out of the hole after the concrete is cast are examples of members that cannot be easily inspected after construction.
Design of High-Performance Prestressed Concrete Piles for Dynamic Loading
Authors: Gerwick BC , Brauner HA 
Published: March 2009

Although prestressed concrete piling have given exemplary performance as foundation piling and there exists ample guidance as to their design, manufacture, and installation for such purposes, recent extensions of their application to more demanding situations requires a renewed look at the criteria for longitudinal prestress (precompression) and spiral confinement.
Problem areas include the occasional occurrence of transverse cracking under heavy driving into erratic soils, longitudinal cracking during and after installation, and the need for ductile response to imposed deformations due to earthquakes.
A more rational analysis is attempted to explain and quantify these phenomena and the stresses and strains developed. Recommendations are then made giving values of prestress and steel requirements that will enable these severe criteria to be met. Some of these recommendations are supported by tests that are as yet unreported elsewhere.
It is believed that these recommendations will enhance the capabilities of prestressed concrete piling and thus make practicable their extension to more demanding applications.
Effects of Moisture, Residual Thermal Curing Stresses, and Mechanical Load on the Damage Development in Quasi-Isotropic Laminates
Authors: Kriz RD , Stinchcomb WW 
Published: March 2009

This investigation demonstrates how moisture absorbed in [0/±45/90]s and [0/90/±45]s graphite epoxy laminates significantly alters the stress state and chronology of damage development along the laminate edge during static tension and tension-tension cyclic loading.
Emphasis is placed on using reasonable approximations for wet and dry elastic properties, including out-of-plane properties (v23 and G23), since these properties are required by finite element and shear lag models to predict the stress state at the laminate edge.
Moisture was observed to alter the dry edge stress state in the 90-deg plies of the [0/±45/90]s laminate such that delaminations occurred at a lower load and transverse cracks occurred at a higher load. A model was developed which predicted the differences in loads required to initiate damage in the 90-deg plies of the two laminates in the wet and dry conditions.
Although moisture can alter the chronology of damage development, the damage state in each laminate observed prior to fracture appeared to be independent of moisture content.