bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Complete Plane-Stress Yield Loci of Zircaloy Tubing
Authors: Dressler G , Drefahl K , Matucha K-H , Wincierz P
Published: March 2009

The elastic and plastic anisotropy of commercially fabricated Zircaloy-4 cladding tubes has been determined for all four quadrants of the yield locus. The plane-stress yield locus has shown a significant asymmetry with regard to stresses created by internal or external pressurization, respectively. Knoop hardness tests are not suited for a description of the yield behavior of Zircaloy tubes. The anisotropy of the elastic properties has been evaluated as a function of the biaxial stress state. A proposed calculation model based on an extension of the general Hooke's law is suited to predict the elastic properties of textured Zircaloy tubes for biaxial stresses at room temperature, showing that the compliance constants determined for pure zirconium single crystals are also applicable for Zircaloy. The known temperature dependence of the compliance constants described less satisfactorily the elastic data measured at 400°C.
Effect of Thermomechanical Processing and Heat Treatment on the Properties of Zr-3Nb-1Sn Strip and Tubing
Authors: Curtis RE , Dressler G
Published: March 2009

The property response of Zr-3Nb-1Sn (weight percent) strip and tubing to variations in thermomechanical processing and heat treatment has been evaluated under commercial production conditions. When aged below the eutectoid temperature, that is, below 1100°F (593°C), cold-worked Zr-3Nb-1Sn strip and tubing were found to have out-of-reactor steam corrosion properties similar to the Zircaloys, while exhibiting superior tensile, creep, and formability characteristics. Creep was at least 20 times slower in Zr-3Nb-1Sn strip than in Zircaloy strip. Aging at 800°F (427°C) maximized creep strength by precipitating fine ω particles in the βZr phase when β was present in the form of a network surrounding individual αZr platelets, that is, a Widmanstatten morphology. The Widmanstatten morphology was developed by either high temperature rolling or solution treatment. Increasing aging temperature and reducing cooling rate increased precipitate size and caused the β phase to agglomerate. These changes improved ductility and formability but decreased strength and corrosion resistance. However, increasing annealing time at 1050°F (566°C) markedly improved corrosion properties. Good corrosion resistance in Zr-3Nb-1Sn is associated with a minimum volume fraction of β, enrichment of β in niobium, a small β-grain size, and a uniform distribution of the β phase. The welding characteristics of Zr-3Nb-1Sn were found to be similar to Zr-2.5Nb. In both alloys, post-weld heat treatment was effective in improving corrosion resistance and weld ductility while maintaining strength above base metal levels.
Thermomechanical Control of Texture and Tensile Properties of Zircaloy-4 Plate
Authors: Dahl JM , McKenzie RW , Schemel JH
Published: March 2009

The effects of controlling crystallographic texture, using a series of pseudoisothermal or falling temperature rolling schedules, on 315°C tensile properties of annealed 6.3-mm-thick Zircaloy-4 plate are discussed. Quantitative relationships between some tensile properties in both the longitudinal and the transverse directions and orientation parameters are reported. The 315°C elongation and reduction in area, in both directions, qualitatively follow the same type of second order relationship. The texture itself appears to depend on the average rolling temperature within three specific temperature ranges, probably as a consequence of changes in deformation mechanisms or changes in rolling stresses with changes in temperature. At temperatures near, but above the α/α + β transus, the basal poles are nearly coincident with the transverse direction; at temperatures between the recrystallization temperature and the α/α + β transus temperature, the basal poles approach the plate-normal direction; and at temperatures below the recrystallization temperature, the basal poles assume the usual cold-rolling orientation of 30 to 40 deg from the normal in the transverse plane.
Pilger Tooling Design for Texture Control
Authors: Schemel JH , McKenzie RW
Published: March 2009

It has been shown earlier that the crystallographic texture of a Zircaloy tube is determined by the ratio of wall reduction to diameter reduction during tube fabrication. The use of this ratio as applied mathematically to the starting tube size and the final tube size does not take into account the complex nature of the tapers in the tube reducing tooling. Instantaneous values of the reduction ratio along the tube transition are shown to vary widely in tools of conventional design. A tooling design scheme that holds the reduction or strain ratio constant is developed by mathematical integration of the basic premise.

Data showing the results of various reductions made holding the reduction ratio constant are shown. These tests indicate that the texture rotation is not a linear function of the reduction ratio, and there is a strong indication that the strain field is not homogeneous in thick-walled tubes.
Use of Ion Bombardment to Study Irradiation Damage in Zirconium Alloys
Authors: Adamson RB , Bell WL , Lee D
Published: March 2009

Zircaloy-2 having several different microstructures, textures, and compositions has been bombarded with either 5 MeV or 46.5 MeV nickel ions at 300 to 600°C to achieve doses ranging from 0.65 to 87.0 displacements per atom (dpa). Similar material was reactor-irradiated near 320°C to neutron fluences between 0.8 and 3.2dpa. Transmission electron microscopy methods were used to identify and compare the nature of the defect structure produced by the ions and neutrons.

For doses below 10 dpa (8 × 1021 neutrons (n)/cm2 (E> 1 MeV)) and temperatures below 400°C, the predominant defects formed by nickel ion bombardment are black spots and loops on the order of 100 Å (10 nm) diameter. For these conditions the damage appears to be similar in most ways to that produced by neutron irradiation. An exception is that a diffraction contrast effect termed “corduroy” is consistently observed after neutron irradiation but generally not after ion bombardment. At temperatures above 400°C, the residual microstructure appears to depend on the rate of displacement damage. For doses above about 10 dpa and irradiation temperatures between 400 to 500°C, bombardment with 5 MeV nickel ions produces a striking alignment of defects on {0002} planes. At 600°C, no residual irradiation damage was observed. For all conditions where damage was present, some of the defects had Burgers vectors with a component parallel to the C-axis. Possible implications of the various observations are discussed.
In—Reactor Stress Relaxation of Zirconium Alloys
Authors: Causey AR
Published: March 2009

In-reactor stress-relaxation tests were done on zirconium alloys with different compositions, grain sizes, heat-tratments, cold-work, and specimen stress directions at 568 ± 5 K in a fast neutron flux (E > 1 MeV) of 2.0 × 1017 neutrons (n)/m2s, for up to 8200 h with initial stresses up to 300 MPa. The relaxation behavior can be represented by σ/σo = D exp (-Kt) where σ/σo is the ratio of the unrelaxed stress at time t to the initial stress, D is a constant which approximates the stress ratio after a rapid initial drop, and K is a relaxation rate constant.

The effects of the metallurgical variables on the in-reactor stress relaxation of zirconium alloys is small. Variations in composition and heat-treatments change the relaxation rate constant by factors of 2 to 4, while variations due to cold-work and working direction change the constant by factors of up to 2. Stress-relieving (or aging) following cold-work decreases the initial stress drop.
Strength and Ductility of Neutron Irradiated and Textured Zircaloy-2
Authors: Rieger GF , Lee D
Published: March 2009

The roles of stress state and crystallographic texture on plastic flow fracture and fracture behavior were examined for Zircaloy-2 sheet specimens irradiated to fluences of 0.7 to 1.9 × 1021 neutrons/cm2 (E > 1 MeV) at 327°C. The extent of strengthening achieved by texture was determined by comparing the level of flow strength obtained under the plane strain loading condition to that of simple uniaxial tension, all at the test temperature of 250°C. It was demonstrated that the relative aspects of texture strengthening were retained in the post-irradiation tests; that is, the material with the peak basal pole density parallel to the sheet normal evidenced less ductility than that with the peak basal pole density inclined at 30 deg to the sheet normal. Supporting evidence is presented in terms of the changes in flow stress and ductility with texture and by the magnitude of R, the ratio of the transverse plastic strains. Plane strain loading increased the flow stress by 66 percent in the material having the peak basal pole density parallel to the sheet normal, but did not change the flow stress for material with the peak pole density inclined > 60 deg to the sheet normal. Texture strengthening persisted to the maximum fluence tested, suggesting a strong texture effect on the mechanical behavior of irradiated materials. The overall level of strain at fracture was substantially reduced by irradiation. The deformation and fracture modes were also strongly affected by texture as well as by the loading methods. The irradiated Zircaloy sheet with the peak basal pole density in the normal direction tended to deform by means of sharply defined deformation bands; intersection of these bands also leads to initiation of fracture. In the other materials (peak basal pole densities inclined to the normal by angles > 30 deg) the deformation bands tended to be more diffuse.
Irradiation Damage Recovery in Some Zirconium Alloys
Authors: Carpenter GJC , Watters JF
Published: March 2009

The recovery of irradiation damage in a number of zirconium alloys has been studied by means of hardness measurements. The experiments were designed to examine the effect of different solutes (copper, aluminum, titanium, niobium, molybdenum) and metallurgical condition on the stability of irradiation-induced defect clusters.

Sheet specimens have been irradiated at 50°C to a fast neutron fluence of 5.5 × 1019 neutrons (n)/cm2 and the hardness changes studies during isochronal annealing. The specimens were heat treated prior to irradiation as follows: (a) well annealed, to approach the equilibrium structure and (b) β-quenched. Most of the annealed alloys recovered in one stage over a temperature range of about 100°C within the range 300 to 460°C.

The behavior of the β-quenched specimens was more complicated due to the simultaneous annealing of the martensitic substructure and solute precipitation. The presence of a high supersaturation of niobium or molybdenum resulted in large hardness increments as a result of irradiation. This is believed to result from precipitation of the solute on a fine scale or to the formation of solute/radiation damage complexes.

Transmission electron microscopy under kinematical conditions revealed the presence of “black spot” images, 30 to 70Å (3 to 7 nm) in diameter in a concentration of ∼5 × 1016/cm3 The smallest images could not be clearly distinguished owing to the presence of a thin oxide film on the surfaces of thin foil specimens. Some possible implications of these results to the problem of in-reactor creep are discussed.
Corrosion and Hydriding Performance of Zircaloy Tubing After Extended Exposure in the Shippingport Pressurized Water Reactor
Authors: Hillner E
Published: March 2009

Three original blanket fuel bundles from the Zircaloy-2 clad pressurized water reactor (PWR) at the Shippingport Atomic Power Station were discharged after continuous exposure for the entire first core, consisting of one original seed and three seed refuelings, and for the first seed life of the second core. Detailed visual examinations of these components after ∼4100 calendar days of operation (41 000 EFPH) revealed only the anticipated uniform gray-tan (post-transition) corrosion products with no evidence of a gross Zircaloy corrosion acceleration; all corrosion films were found to be tightly adherent to the underlying cladding.

An extensive destructive evaluation of two fuel rods from each of the three fuel bundles produced greater oxide film thicknesses (7 to 12 μm or 0.28 to 0.47 mils) than the values predicted from the time-temperature history of the components (3 to 5 μm or 0.12 to 0.20 mils); an average corrosion acceleration factor of 2.4 can be calculated from the data. In slightly different terms, the observed corrosion acceleration was equivalent to raising the average surface temperature by ∼40°F. The accelerated corrosion attack was accompanied by a considerably lower total hydrogen pickup than that calculated from the observed film thicknesses. This combination Of an irradiation-induced corrosion acceleration and a less-than-predicted hydrogen absorption is suggestive of operation in an oxygenated environment although the Shippingport PWR coolant is maintained at a hydrogen concentration in the range 10 to 60 c3 H2/kg H2O.
Study of Zirconium Alloy Corrosion Parameters in the Advanced Test Reactor
Authors: Johnson AB , LeSurf JE , Proebstle RA
Published: March 2009

The influence of nuclear radiation on zirconium alloy corrosion was studied in the North (1D) loop of the Advanced Test Reactor (ATR). The loop was new and therefore was free of fissionable contamination. The principal corrosion parameters were: alloy composition (Zircaloy-2, Zircaloy-4, Zr-2.5Nb, and crystal bar zirconium); flux level (unirradiated, 6 × 1012 to 1.7 × 1014 neutrons (n)/cm2 s > 1 MeV); metallurgical condition (Zircaloy-4 and Zr-2.5Nb in two conditions); oxygen concentration (0.6 ppm O2 and < 0.05 ppm O2); and surface pretreatment (as-etched, thin prefilms, and thick prefilms). Maximum exposures were 61.6d (oxygenated) and 102.1 d (deoxygenated) at 280°C, 2000 psig, in pH 10 LiOH.

In the oxygenated test, corrosion rates were substantially accelerated at high-flux locations. At the low-flux location, corrosion rates were unaffected or slightly accelerated on Zircaloy-2 and -4, substantially accelerated on zirconium, and slightly reduced on Zr-2.5Nb. Thick prefilms tended to suppress accelerated corrosion in the oxygenated system. In the deoxygenated test, corrosion rates were substantially accelerated for zirconium, but were only slightly above unirradiated values for the other materials.

The results from the ATR loop paralleled previous results from the ETR G-7 loop, indicating that dissolved oxygen, rather than fissionable contamination, was the principal cause of accelerated corrosion in both systems.

The Zr-2.5Nb alloy (quenched, cold-worked, aged) had the lowest weight gains and hydrogen absorption in both oxygenated and deoxygenated tests, but showed some pustule formation in the oxygenated test.

Zircaloy-2 coupons which had oxidized rapidly to 120 to 160 mg/dm2 (2.0 to 2.6 mg/dm2d) in the oxygenated system were transferred to the deoxygenated system. After transfer the corrosion rates decreased to 0.5 to 0.6 mg/dm2d. Inspection of coupons under polarized light revealed evidence of oxide porosity on coupons undergoing accelerated corrosion.
A New Technique for Determining the Deformation and Frictional Characteristics of In Situ Rock
Authors: Pratt HR , Black AD , Brown WS , Brace WF
Published: March 2009

We describe a new technique for measuring the deformation and load bearing capability of large intact and jointed in situ rock specimens under applied uniaxial stress. The specimen configuration is an equilateral triangular prism of constant cross section with one end still connected to the rock mass. The free end of the specimen is loaded by a triangular flat-jack package. Displacements are monitored along and across joints; strains are measured on the surface of the specimen.

Forty-six tests have been performed at five sites on solid and jointed specimens over a range of effective diameters from 6 to 50 in.; on surfaces with orientation ranging from horizontal to nearly vertical; and on a wide variety of rock types including granites, sandstones, amphibolites, and chloritic schists. The technique has been used to measure the effect of specimen size on the strength of intact rock and frictional characteristics such as maximum and residual shear stress, normal and shear stiffness, and friction angle on natural joints with surface areas up to 750 square inches.
Reliability of Dilatometer Tests in the Determination of the Modulus of Deformation of a Jointed Rock Mass
Authors: Singh B
Published: March 2009

The available results from radial jacking and dilatometer tests are inadequate for the proper assessment and comparison of the reliability of these test procedures. In order to arrive at a rational evaluation of such tests, a computer program was devised to simulate a jointed rock mass, and sets of test data were then developed by performing (that is, mathematically simulating) a series of dilatometer tests at various locations within the rock mass. The computations indicate that dilatometer tests may provide a more reliable estimate of the mass modulus at a much lower cost than two or three radial jacking tests, provided that the orientation of both tests are the same. Curves are presented to facilitate estimation of the minimum number of tests required, in terms of average joint frequency and modulus reduction factor (MRF). Further, it is shown that the discrepancy between small and large scale tests may be due largely to the difference in orientation between tests and improper statistical inference there-from.
Laboratory Calibration and Field Performance of Inclinometers
Authors: Butler DK
Published: March 2009

The state of the art in the use of inclinometers in engineering is reviewed briefly. Use of inclinometers in structures such as earth and rockfill dams, embankments, piles, behind retaining walls, etc., can be instrumental in detecting conditions leading to both short-term catastrophic failure and long-term progressive failure.

The types of inclinometer systems in general use are discussed. Field data acquisition procedures are described as well as necessary considerations in the interpretation of the data. Among the considerations are instrument drift, calibration, cross-sensitivity, and casing spiral. A laboratory device is described which is capable of checking the calibration of inclinometers, the effect of drift on instrument output, and the effect of cross sensitivity on measured angles. Results of the laboratory evaluation of two inclinometer systems are presented.
Site Engineering Indexing of Rock
Authors: Aufmuth RE
Published: March 2009

An “Engineering Index” has been developed, (Aufmuth, 1972) for use at field sites, by means of which the pertinent characteristics of the intact and in situ rock mass may be presented in a brief, clear, and relevant manner. The Engineering Index consists of two parts; a lithologic and an engineering description. The latter is determined accurately from field index tests which have been directly correlated to laboratory investigational procedures.

The Engineering Index allows for the rapid and economical determination of the engineering properties of rock materials under field conditions and facilitates the acquisition of design data and experience translation from site to site.
Overview of the Role of Geologic Investigation and Rock Property Determination in Fragmentation Field Testing
Authors: Steckley RC , Podnieks ER , Chamberlain PG , Pugliese JM
Published: March 2009

This paper presents an overview of a systematic approach for the evaluation of the geology and rock properties of field sites used for fragmentation tests. Comprehensive flow diagrams illustrate the steps involved in selecting sites for field tests, and in evaluating the results of field rock fragmentation tests. These steps consist of regional test site selection, field site selection, geologic and fabric investigations, pre-test rock property determinations, fragmentation tests, post-test geologic and fabric investigations, and post-test rock property determinations. A systematic approach, such as this one, is necessary if major rock excavation problems are to be solved.
Optimization of the Design and Use of a Triaxial Strain Cell for Stress Determination
Authors: Gray WM , Toews NA
Published: March 2009

A mathematical model is given for stress determination in inhomogeneous rock with special reference to a triaxial strain cell. The practical effects of variations in the form and the positioning of the straingage rosettes is considered. Four-element rosettes are shown to provide an estimate of the basic measurement variance that, although sensitive to small scale inhomogeneities, is insensitive to anisotropy of the rock. The application of this estimate to an analysis of variance of the data is outlined. A cell incorporating three four-element strain-gage rosettes spaced circumferentially in the borehole at 120-deg spacing is shown to be highly efficient in providing estimates of the stress components with relatively low variances. In addition, the covariances are very low, and this lessens the complexity of expressing and understanding the complete error pattern.
Exfoliation Corrosion Testing of 7075 and 7178 Aluminum Alloys—Interim Report on Atmospheric Exposure Tests
Authors: Sprolws DO , Summerson TJ , Loftin FE
Published: March 2009

Atmospheric exposures of 18 to 39 months have been completed at seacoast and inland industrial locations to determine the resistance to exfoliation corrosion of specially heat-treated test panels of high-strength aluminum alloys. Two seacoast locations, one at Point Judith, Rhode Island, and another at Daytona Beach, Florida, were selected, together with an industrial location near Chicago, Illinois, to represent the relatively severe atmospheric conditions to which aluminum alloy aircraft structures are subjected in service. The purpose of these tests was to demonstrate the relationship of the performances in the accelerated exfoliation corrosion tests previously evaluated by this task group with those in relatively aggressive natural environments.

The exfoliation performance is being evaluated on test panels heat treated to produce three different metallurgical structures that would be expected to provide a high, low, and medium resistance to exfoliation of both a 7075 alloy extrusion and a 7178 alloy rolled plate. Results obtained thus far are gratifying in that the atmospheric exposures are ranking the test materials in the same relative order as the new ASTM Standard Method of Test for Exfoliation Corrosion Susceptibility in 7XXX Series Copper Containing Aluminum Alloys (G 34-72, EXCO test). That is, the materials that showed either a high or a low resistance to exfoliation in the EXCO test also showed the same performance in the seacoast atmosphere, and that which showed an intermediate resistance in the EXCO test showed more spotty and a slower rate of exfoliation in the atmospheric exposures.

Exfoliation of the most susceptible items initiated more rapidly (within five months) at the seacoast, but the exfoliation tended to be more uniform at the industrial site. Other factors such as the climatic conditions at the seacoast, location, and exposure position of the test panels are considered.
Ten-Year Seawater Tests on Aluminum
Authors: Ailor WH
Published: March 2009

Seven aluminum alloys and panels of high-purity aluminum were exposed for ten years in seawater at Wrightsville Beach, N. C. Replicate 4 by 12-in. panels of each material were exposed in half-tide immersion and full immersion. Removals in triplicate were made at the end of one-, two-, five-, and ten-year exposures.

Other than the 1199 aluminum (99.99 percent purity), seven aluminum-magnesium alloys (5000 series) were tested. Panels were degreased prior to exposure and were cleaned ultrasonically after exposure in a chromic-phosphoric acid solution. After depth of pitting was measured, tension specimens were cut from each panel, and the mechanical properties determined.

Panels were heavily fouled with barnacles and other marine growth for all exposure periods. The fouling had little apparent effect on the pitting depth of the aluminum in tidal immersion, but generated heavy etching on some alloys during the 5 to 10 year exposure interval.

Little change in tensile properties after ten years' exposure was noted for any of the test alloys. Tensile losses reported for several alloys after full immersion include: 5086-0 (3.7 percent), 5154-H38 (5.1 percent), and 5457-H34 (5.2 percent). The high-purity 1199 and alloys 5154-H38, 5456-0, and 5456-H321 showed losses of 16 to 27 percent in elongation while the change in elongation for the 5086-0 was a decrease of about 6 percent.

Confirming other work, we found the corrosion rates to be greater for the full seawater immersion than for the tidal immersion. The lowest ten-year corrosion rate in the half-tide location was 0.014 mpy (mils per year) and the 5456-0, and the highest rate for the aluminum-magnesium 5000 series was 0.051 mpy for the 5456-H321 alloy. In full-immersion tests, the lowest rate was 0.064. For comparison, the rates for the 1199 alloy were 0.036 mpy in tidal and 0.061 mpy in full immersion. Corrosion weight losses and depth of pitting had reduced rates of growth over the interval between five years and ten years. Maximum depth of pitting for an alloy was generally at least four times the magnitude of the average of the twenty deepest pits.

The deepest pit found for any alloy after ten years was 72.0 mils for 5456-H321 in half-tide immersion and 131.0 mils for the same alloy (0 temper) in full immersion. Least apparent pitting depths occurred on alloys 5154-H38, 5457-H34, 5086-0 and high-purity 1199 where heavy etching tended to hide pits on the ten-year full-immersion panels.
Corrosion Tests in the Gulf Floor
Authors: Di Gregorio JS , Fraser JP
Published: March 2009

Because of the importance of good corrosion control to the safe operation of offshore pipelines, a test program was started in 1966 to study the behavior of pipeline materials in and near the ocean bottom in waters of pipeline depth (50 to 500 ft). This program has included the study of the corrosion of pipeline steels in and near the ocean bottom, the cathodic protection required to control this corrosion, and the performance of coating, paint, and anode systems in and near bottom sediments of the Gulf of Mexico.

Results to date have shown that the corrosion of separate, buried steel panels and the cathodic protection current densities required to control this corrosion are less than in the ocean immediately above the mudline. The corrosion rate of unprotected steel panels exposed to seawater above the mud is as high as 11 mpy (mils per year) depending on the time and location of exposure. Unprotected panels below the mudline, however, corrode at rates of 1 to 3 mpy. Pitting corrosion of these panels is also more intense in the water above the mud than buried in the mud. The current density required to reduce the corrosion rate of these panels to less than 1 mpy is in excess of 3.2 mA/ft2 above the mudline; below the mudline a current density of 0.6 to 2.5 mA/ft2 is required to reduce the cor- rosion rate to the same level. The current density required to control corrosion decreases with increasing depth of burial below the mudline. The corrosion rates of electrically connected pipe lengths partially buried in the mud are inde- pendent of position relative to the mudline. A large amount of calcareous deposit was formed on zinc metal when it was made electrically negative for 10.5 months in seawater.
Evaluation of Paint Coatings Tested in the Deep Atlantic and Pacific Oceans
Authors: Rynewics JF
Published: March 2009

Seven different paint coating systems were tested on structural steels, high-strength stainless steels, and aluminum alloys. The Pacific specimens were placed on the bottom in 5900 ft of water for six months while the Atlantic specimens were on the bottom at 4050 ft for more than four years.

The epoxy paint system provided good to excellent corrosion protection at both test locations.

The inorganic zinc coating provided adequate protection to the steel specimens for six months in the Pacific Ocean, but would have to be at least 0.010 to 0.020 in. thick to be effective for up to one year.

The two stainless steels Almar 362 and Carpenter 455 were highly susceptible to crevice corrosion when not coated. Uncoated specimens suffered from crevice attack in the same manner as types 302, 303, and 304 stainless steel.

The cathodic protection achieved by the inorganic zinc coating on steel specimens indicates that cathodic protection is a practical method of corrosion control in the deep ocean.
Techniques for Characterizing Bituminous Materials Using a Versatile Triaxial Testing System
Authors: Terrel RL , Awad IS , Foss LR
Published: March 2009

This paper is part of an experimental investigation of the resilient properties and the stress-strain relationship of asphalt treated base material. It describes the triaxial testing system which was designed for this purpose and the different tests employed in the material stress-strain characterization.
Summary of Complex Modulus Laboratory Test Procedures and Results
Authors: Witczak MW , Root RE
Published: March 2009

The fundamental properties of an asphalt mixture are an important input to the new design procedures being developed. The complex modulus test, which measures both elastic and viscous material properties, is one of the several tests available for use with these procedures. In order to use these test results for design, it is necessary to assume that the mixture exhibits both linear and isotropic behavior. A review of current literature is presented which shows both assumptions valid for the elastic properties of an asphalt mixture under certain limiting conditions. The literature review is also used to provide background information for the development of a standard test method by defining the effect of test variables on complex modulus results.

The results of a study of complex modulus data from both cored specimens and laboratory molded specimens are used to determine testing variability associated with various testing strategies. The testing error for the elastic part of the complex modulus, as defined by the coefficient of variation is equal to 4 percent for cored specimens and 8 percent for laboratory molded specimens. The variation between specimens was 8 and 17 percent, respectively, for laboratory molded and field cored specimens. Based on these results, a testing strategy consisting of three specimens tested twice at each test condition for laboratory molded specimens, and six specimens tested once at each test condition for cored specimens is recommended.

The final section of the paper develops a method of predicting the elastic component of complex modulus. An equation is presented which can be used to predict this value from the results of the flexural fatigue tests.
Material Characterizations for Rational Pavement Design
Authors: Kenis WJ
Published: March 2009

This paper describes a basis framework which is composed of an assemblage of mathematical models to form a structural subsystem intended to be used in the structural analysis of flexible pavements. Emphasis is placed upon describing the newer type laboratory tests which provide the necessary inputs for the operation of the structural subsystem computer program package referred to in this paper as VESYS II. A method is presented whereby variations of the material properties which might be expected to occur in the field can be determined from the results of the laboratory tests. Several examples of computer output are given as well as those significant limitations which should be imposed on its use.
Analysis and Control of Inertial Effects During Instrumented Impact Testing
Authors: Saxton HJ , Ireland DR , Server WL
Published: March 2009

To improve the understanding of load-time traces observed during instrumented impact testing, analytical and experimental studies have been conducted to determine the effects of inertial loading. The first load discontinuity in a load-time profile has been found to result from the interaction of a rapidly decreasing inertial load developed by Charpy specimens as they accelerate from rest and the finite ability of the instrumented tup to react to very rapid load transients. A model is developed which quantitatively correlates initial portions of load-time profiles for A1203 and U-3/4Ti with rigid-body accelerations of these materials. In addition, the magnitude of the initial load discontinuity is related to the acoustic impedances of the tup and specimen and the initial impact velocity in agreement with theory drawn from elastic wave mechanics. Successful correlation of this theory for a large variety of materials has allowed a semi-empirical relation to be developed for the prediction of inertial loads. Control procedures are suggested to both identify and reduce the role of inertial loads in instrumented impact testing.
Nonstandard Test Techniques Utilizing the Instrumented Charpy and Izod Tests
Authors: Server WL , Ireland DR
Published: March 2009

The Charpy impact test is rapidly being upgraded to include instrumentation for revealing the load history of the specimen while it is being fractured in three-point bending. Unfortunately, similar interest in upgrading the Izod test (cantilever bending) has been notably lacking. The first part of this paper discusses the results of a recent study of techniques for instrumenting the Izod test. Results from both standard and nonstandard Izod specimen tests are compared with similar results from instrumented Charpy tests. Also included are the results of instrumented Izod tests of tubular specimens of aluminum, steel, and composite materials.

Instrumented low-blow testing and three-point bend testing of ring-shaped specimens are typical variations of the instrumented Charpy impact test. These two test techniques are also discussed in this paper. There is hope that these and other variations in test techniques will lead to new inexpensive methods of evaluating material and small structure behavior under adverse loading conditions.
Impact Testing of Carbon-Epoxy Composite Materials
Authors: Toland RH
Published: March 2009

Advanced fiber composite materials exhibit elastic properties and fracture mechanisms distinctive from metals. Consequently, the mechancis of impact resistance are also different for these materials. Carbon-epoxy and boron-epoxy composites can exhibit brittle modes of fracture. In studies to improve the impact resistance of carbon-epoxy materials, traditional impact tests provided very little understanding of the problems involved. However, instrumented Charpy-type tests provided considerable insight into the mechanisms associated with impact resistance. Load versus time response records can be partitioned into regions corresponding to events occuring sequentially in time. Energy absorbed by a composite specimen through the various fracture mechanisms is seen to be the distinguishing characteristic between composite systems. Two mechanisms to improve the carbon-epoxy system's impact resistance are shown to be the modification of the fiber-resin interfacial strength and hybridization with a second fiber of high strength and lower modulus.
Instrumented Impact Testing of Titanium Alloys
Authors: Ewing A , Raymond L
Published: March 2009

The dynamic fracture toughness was determined for two titanium alloys (Ti-6A1-4V and Ti-6A1-6V-2Sn) from different suppliers and in various heat-treated conditions. The strain-rate effect associated with the dynamic test is shown to increase the fracture toughness for all the alloys with the exception of mill-annealed and duplex-annealed Ti-6A1-6V-2Sn, where the fracture toughness was found to be independent of strain rate. Dial energy per unit specimen area (W/A)d for precracked Charpy specimens can be used to calculate KId as long as a relatively flat fracture appearance (small shear area) is obtained. Otherwise, when a large amount of shear is present, the energy to maximum load (W/A)m or Pmax from the load-time trace must be used to calculate KId.
Effect of Test System Response Time on Instrumented Charpy Impact Data
Authors: Hoover WR
Published: March 2009

The effect of response time on instrumented Charpy impact data obtained on unidirectional Borsic-aluminum composites has been examined. It has been shown that the use of filters to eliminate high-frequency noise in the load-time traces obtained can significantly increase the response time of the testing system and lead to grossly inaccurate data. The current results indicate that as the response time is increased, the load is attenuated, the time to fracture is increased, and the absorbed energy is unaffected. The attenuation characteristics of the testing system can be documented through the use of a sine wave generator. These characteristics can be used both as a guide to ensure the adequacy of the system response time for future testing and as a means of correcting attenuated data which were obtained on a testing system with excessive filtering (inadequate response times).
The Origin and Present Status of the IPTS-68
Authors: Preston-Thomas H
Published: March 2009

Those of you who are familiar with the early plans for this Symposium know that Cecil Barber was to have presented the opening address. My great regret at having to substitute for him, because of his death from a heart attack three months ago, is, I know, shared by his colleagues from many countries. These colleagues had, without deliberation but with near unanimity, regarded Barber as the dean of the temperature measurement field. This is not the occasion to describe his accomplishments, though this would be easy to do; I will, however, point out that it was a typical attribute of this unofficial position that Barber held that resulted in his being the automatic choice for chairman of the small group that, during 1967 and '68, had the task of converting a very rough and inadequate outline of a temperature scale into the current official scale—the International Practical Temperature Scale of 1968.
International Practical Temperature Scale of 1968
Authors: Benedict RP
Published: March 2009

Temperature is recognized today as one of the basic variables in science, yet even a cursory examination will indicate that a great deal of confusion exists as to what temperature means. Because the International Temperature Scale is undergoing a major revision at this time, it is appropriate that we revisit this subject, reexamine its foundations and proceed from this review with renewed confidence in our temperature measurements.
Applied Cavitation Erosion Testing
Authors: Tichler JW , de Gee AWJ , van Elst HC
Published: March 2009

When a material has to be applied on locations where cavitation is expected, the resistance against uniform material removal from the surface (Re) and the resistance against pit formation (rp) are of paramount importance.

Experiments with steels and copper-nickel alloys showed that for these materials Re is proportional to the true ultimate tensile strength (σB*) to the 2.3rd power. The tests with the steels were performed under different pressures and at different temperatures. It was found that variations in pressure and temperature did not affect the value of the power exponent. It was further shown that deformation can have a considerable and essentially unpredictable influence on the erosion resistance of materials with a relatively complicated structure. In particular grain boundary precipitation is important in this respect.

Experiments with nitriding steel, carburizing steel, maraging steel, and two cobalt alloys in different conditions of application showed that rp is determined primarily by the structure of the materials. In this case the product of Re and rp (that is, the time to pitting tp) was found to be particularly useful for screening purposes. In the mechanism of pit formation, surface fatigue as well as corrosion can play important roles.
Influence of Physical Properties of the Liquid on the Erosion of Solids
Authors: Rochester MC , Brunton JH
Published: March 2009

Results are presented for the erosion of nickel in a series of experiments involving ten different liquids chosen so that the effects of density, acoustic impedance, and viscosity could be investigated separately. The shape of the erosion curve was not greatly affected by changes in the physical properties of the liquid. The level of damage in all stages of erosion was strongly dependent on acoustic impedence and viscosity; changes in density affected only the later stages of erosion. When carbon tetrachloride was used as the eroding fluid it was found that the damage during the second stage of erosion was proportional to the fifth power of the impact velocity, a result similar to that reported for water.

Measurements of the impact pressure distribution under the surface of a 5.0-mm-diameter water drop at velocities up to 140 m/s are presented. The distribution was found to be symmetrical about the center of impact with a central maximum of 0.7 poCoV. The distribution along the central axis of the drop was also measured. No evidence of high pressures other than at the center of impact was found.
Studies on Cavitation Damages
Authors: Erdmann-Jesnitzer F , Louis H
Published: March 2009

Tests in a new chamber for flow cavitation led to damages which are characteristic of erosive destruction caused by imploding cavitation bubbles. To develop material of greater cavitation resistance, it is necessary to find out exactly the different stages of damage. To do this, we started to examine model materials in a special testing chamber.

In the case of soft aluminum, these damages, caused by single imploding bubbles, give an idea about the way of load that is the effect due to micro-liquid-jets which impact the specimen surface under special conditions. Typical stages of deformations, formation of cracks and fractures are described with regard to the structures of the model materials by scanning electron microscope.

To transfer the different stages of damages from one material to others of the same crystalline structure, changes at different stages caused by the different mechanical properties, for example, as in the case of copper, must be taken into consideration.
Influence of Velocity, Impingement Angle, Heating, and Aerodynamic Shock Layers on Erosion of Materials at Velocities of 5500 ft/s (1700 m/s)
Authors: Schmitt GF , Reinecke WG , Waldman GD
Published: March 2009

The dependence of materials erosion in rain at supersonic velocities up to 1700 m/s (5500 ft/s) has been determined as a function of velocity, impingement angle, and aerodynamic heating. The erosion rate of materials has been found to vary with the 4.5 to 6.5 power angle. Coupled heating and erosion effects are highly significant for polymeric composites. The effects of shock layer breakup, acceleration, deflection, and deformation of the droplets have been quantitatively assessed, and damage gradients in materials are shown to be a function of primarily droplet distortion and breakup resulting from drop traversal of the shock layer around the vehicle.
A New Method for Testing Brake Lining Materials
Authors: Begelinger A , de Gee AWJ
Published: March 2009

A new method for testing brake lining materials in the laboratory is described. This method is essentially isothermal by nature, thus avoiding the usual problems associated with differences between the heat-transfer characteristics of brake assemblies in road vehicles and those of laboratory test rigs. As an example of application of the method, friction-time-temperature curves of five different brake lining materials are presented and discussed in terms of time- and temperature-depending transformations in the composition of the lining materials.

The quality of the materials is described by the following properties: temperature range in which glazing effects occur; temperature range in which carbonization effects occur; steady-state value of the coefficient of friction; wear (decrease in thickness) of the lining; and sensitivity of the lining material to moisture.
Acoustic Emission During Phase Transformation in Steel
Authors: Speich GR , Schwoeble AJ
Published: March 2009

Acoustic emission was monitored during phase transformations that occur during cooling in a wide variety of steels. Acoustic emission was generated during the formation of martensite but not during the formation of ferrite, bainite, or pearlite. This observation is consistent with the rapid, diffusionless, shear-like nature of martensite formation and the slow, diffusion-controlled growth of ferrite, bainite, or pearlite. The martensite start temperatures, and the temperature range of martensite formation determined by acoustic emission were in good agreement with those determined by metallographic or dilatometric methods. The intensity of acoustic emission generated during martensite formation decreased markedly as the carbon content of the steel decreased, becoming nearly undetectable in a maraging steel. This decrease in intensity correlates with a morphological change from large plate-shaped martensite units to smaller lath-shaped martensite units as the carbon content of the steel is decreased.
Acceptance Testing Welded Ammunition Belt Links Using Acoustic Emission
Authors: Hutton PH
Published: March 2009

The objective of the work described in this paper was to provide a reliable method for 100 percent acceptance testing resistance welds used in the fabrication of 40-mm automatic weapon ammunition belt links. Links contain rounds of ammunition and are coupled together to form a belt which is automatically fed into the weapon. If one of the links in a belt fails, the immediate result is a jammed weapon. Four projection resistance welds (two on each side) are used to assemble the link, and weld quality can vary widely. Conventional nondestructive test techniques cannot distinguish a sound resistance weld from a weak one in the post-weld condition. This work has shown, however, that by applying a moderate proof load to the weld joint, weak welds can be detected by acoustic emission. The technique is being adapted to production application with an expected inspection rate of 1200 links per hour in its initial version. This work is representative of many applications of acoustic emission to measure component structural integrity that can be accomplished within existing state-of-the-art technology.
Metric Conversion in the United States—Coordinating the Change
Authors: O'Hagan ME
Published: March 2009

This article provides an introduction to the formation, purposes, policies, and progress of the American National Metric Council. Included are: an explanation of the structure and function of the various committees representing affected sectors of the American economy; discussion of ANMC's effective information program including publications, seminars, and an information center; and a section on the hard versus soft conversion issue.
The Fastener Success Story
Authors: Belford RB
Published: March 2009

The history of the ANSI-OMFS metric fastener committee is traced and its accomplishments during three years of research effort summarized. International negotiations to gain ISO acceptance of new technical advances are described.
The Livermore Plan: Managing Transition in a Multi-Discipline Research and Development Environment
Authors: Pearson JW
Published: March 2009

Our experience indicates the Livermore Plan can be used as a low-cost way to manage transition in a job shop, engineering, designing, and fabricating environment, with the caution that good communication is needed during start-up with both your own shops and with vendors. The principal benefit of the Livermore Plan is that it allows engineering and design to get out of inches and into metric with minimum transition time. It places the measurement system interface during transition within fabrication where experience indicates it can be managed without significant cost or production penalty.