bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of Constitutive Behavior of Sheet Metals Subjected to Dynamic Bulge Loading
Authors: Liu L. , Petrinic N. , Elliot B. , Ruiz C. 
Published: March 2009

Abstract
A newly developed method has been employed to quantify the mechanical behavior of sheet metals (both isotropic and orthotropic) subjected to dynamic bulge loading at strain rates of up to 400 s−1. Using newly developed dynamic bulge testing equipment with stereoscopic imaging, the exact shape of the bulging dome has been obtained and represented using high order polynomials before further constitutive analysis. The bulge profile functions discerned have been used to calculate the actual radius of curvature at the pole, thus replacing the spherical shape generally assumed in traditional bulge test analysis. Furthermore, the calculation of the thickness of the bulge has been improved by employing “dome volume” approaches. Effective strain and stress at the dome’s pole have been calculated considering both isotropic and orthotropic materials. The effect of gage length on the obtained values of strain and stress has been assessed.
A Method for Evaluating Fretting Wear Scars in Thin Steel Roping Wires Based on Confocal Imaging Profilometry
Authors: Urchegui M. A. , Tato W. , Gómez X. 
Published: March 2009

Abstract
Fretting is considered one of the most important degradation phenomena inside steel wire ropes. This phenomenon causes the formation of wear scars on individual wires, which will decrease the cross-sectional area of the rope. Hence, also the fatigue life of the rope will be reduced. The aim of this work is to describe a method for characterizing wear scars in thin steel roping wires using confocal imaging profilometry. This objective is a challenge because not only the scars are formed on curved surfaces (cylinders), but the cylinders can present helical or double-helical shape induced during the manufacturing process of the ropes. Therefore, different surface morphology measurement techniques are briefly described. A methodology to measure wear scars in steel roping wires is then presented: a confocal imaging profiler was employed and algorithms were developed to treat the data points provided by the confocal profiler and calculate the characterization parameters. In this way, the quantitative assessment of wear scars in thin steel wires can be performed.
The Development of ASTM D 4772: The Water Flow Test Method
Authors: Cary Richard T. 
Published: March 2009

Abstract
ASTM D 4772, “Standard Test Method for Surface Water Absorption of Terry Fabrics (Water Flow),” is a nondestructive test method for determining the effectiveness of terry fabrics and terry fabric products to remove water from various surfaces. Based on the water flow apparatus invented by employees of the former J. P. Stevens and Company, ASTM D 4772 was developed by the ASTM D 13.59 Task Group for the absorbency of woven fabrics. ASTM D 4772 was developed for use in ASTM D 5433 “Standard Performance Specification for Towel Products for Institutional and Household Use.” The single-material single-operator precision and the single-laboratory predictive validity of ASTM D 4772 were found to be good. However, the single-material interlaboratory precision of ASTM D 4772 was found to be poor.
Influence of Selected Mix Design Factors on the Thermal Behavior of Lightweight Aggregate Asphalt Mixes
Authors: Khan Ashfaq , Mrawira Donath 
Published: March 2009

Abstract
Lightweight aggregate (LWA) asphalt mix has been found to have lower thermal conductivity and thermal diffusivity compared to a conventional asphalt mix. Given these beneficial thermal properties, a LWA-asphalt mix can reduce frost penetration into the underlying pavement layers. It is therefore postulated that the LWA-asphalt mix can reduce damage associated with frost heave. This paper investigates the effects of binder grade and coarse aggregate content on the thermal properties of LWA-asphalt mixes. The effects of three asphalt binder grades (PG58-28, PG64-28, and PG70-28) and three aggregate gradations were investigated. The thermal conductivity was found to vary from 0.77 to 0.87 W/m°K for the LWA-asphalt mixes having bulk density in the range of 1585–1653 kg/m3 and air voids 3.5–4.5 %. Thermal diffusivity was determined to vary from 2.1 × 10−7 m2/s to 2.6 × 10−7 m2/s and a standard deviation of 0.18 × 10−7 m2/s. Specific heat capacity was found to be in the range of 1990 J/kg⋅°K to 2360 J/kg⋅°K, with a standard deviation of 130 J/kg⋅°K. Coefficients of variation for thermal conductivity, thermal diffusivity, and specific heat capacity were found to be 3.2, 6.1, and 7.6 %, respectively. These results show that the three thermal response variables vary in a very narrow range. It is concluded that the beneficial thermal properties of LWA-asphalt mixes appear to be insensitive to variation in asphalt binder grade and aggregate gradation.
Dynamic Testing of Materials with the Rotating Disk Indirect Bar-Bar Tensile Impact Apparatus
Authors: Xia Y , Wang Y 
Published: March 2009

Abstract
An experimental method is proposed to investigate the tensile behavior of materials at high strain rates by using a developed split Hopkinson tension bar, rotating disk indirect bar-bar tensile impact apparatus. The mechanically-filtered input tensile pulse is generated by incorporating a prefixed metal bar connected between the impact block and the input bar. The pulse amplitude is controlled by the diameter of the prefixed metal bar. The pulse duration is determined by the length of the prefixed metal bar and the velocity of the impact hammer. Dynamic properties of metallic and nonmetallic materials are presented as examples by using this developed rotating disk indirect bar-bar tensile impact apparatus.
Radiation Effects on the Metallurgical Fracture Parameters and Fracture Toughness of Pressure Vessel Steels
Authors: Wullaert RA , Ireland DR , Tetelman AS 
Published: March 2009

The effect of radiation on tensile properties, notch bend properties, and fracture toughness was determined on A212B steel from the Pathfinder reactor surveillance program and on A533B steel from the U.S. AEC Heavy Section Technology program. Impact tests were performed on an instrumented Charpy machine which provided load-deflection data in addition to energy absorption data. Valid fracture toughness values were obtained from precracked Charpy specimens.
The results of the notch bend tests on the irradiated steels indicated that the radiation induced increase in the ductile-brittle transition temperature was mainly due to the large radiation induced increase in the friction stress. Radiation reduced the strain rate sensitivity of the yield stress but did not change the temperature dependence of the yield stress. The microscopic cleavage strength was essentially unaffected by irradiation. The relationships between the metallurgical fracture parameters (Cottrell-Petch) and the ductile-brittle transition temperature (DBTT) and fracture toughness (KIc) were established. These relationships were used to predict the radiation induced change in fracture toughness (both DBTT and (KIc) from a knowledge of the effect of radiation on metallurgical fracture parameters.
The Effect of Neutron Irradiation on the Mechanical Properties of Zirconium Alloy Fuel Cladding in Uniaxial and Biaxial Tests
Authors: Hardy DG 
Published: March 2009

Short-time axial tension, transverse ring tension, and biaxial closed end burst tests were conducted on sections of fuel cladding from 17 different batches and heat treatments of Zircaloy 2, Zircaloy 4, and Zr-2.5Cb alloy. Specimens were irradiated at 2 to 3×1020 n/cm2, E &gt; × MeV, at temperatures of 125 to 250 C and tested at temperatures of 20 and 300 C.
The level of residual cold work was found to have the greatest effect on the mechanical properties of the Zircaloys prior to irradiation, and, although irradiation altered the general level of each property, the effect of cold work was preserved after irradiation for all properties except the uniform elongation. Very low values of uniform elongation (&lt; 1 percent) were obtained in the burst test after irradiation at all levels of cold work. In the instances where the texture and grain size influenced the properties, the effect was also preserved after irradiation. For the Zircaloys, the increment in the strength properties due to irradiation was constant at this fluence, independent of cold work, texture, and grain size. The decrements in the uniform and total elongations due to irradiation decreased with increasing cold work. The irradiation hardening of the Zr-2.5Cb alloy was greater than that experienced by the Zircaloys.
Beta heat-treated Zircaloy had higher strength and lower ductility than alpha annealed material in the tension test. Grain size was found to have a much more significant effect on the strength and ductility in the burst and ring tests than in the axial tension test.
Metallurgical Properties of Cold-Worked Zircaloy 2 Pressure Tubes Irradiated Under CANDU-PHW Power Reactor Conditions
Authors: Langford WJ 
Published: March 2009

The performance of cold-worked Zircaloy 2 reactor pressure tubes has been assessed by destructive tests of tubes irradiated under CANDU-PHW power reactor conditions of temperature (240 to 280 C), stress (10,500 to 17,200 psi), and neutron irradiation. Reactor service increases biaxial burst strength, accompanied by a change in deformation mode that leads to reduced ductility after irradiation. Crack tolerance of the tubing is virtually unaffected by reactor service, and the critical crack length exceeds 3 in. (75 mm) at 16,000 psi (11.3 kg/mm2) hoop stress and 300 C.
Uniaxial tension tests indicate that operating stress reduces the transverse tensile strength of unirradiated tubing. Irradiation strengthening appears to be direction dependent, suggesting a possible influence of operating stress on the distribution of irradiation damage. Transmission electron microscopy shows the damage to be in the form of discrete dislocation loops.
Oxidation rate in water is enhanced by neutron irradiation but is acceptably low, as is hydrogen/deuterium pickup. Diameter measurements support the evidence from in-pile creep investigations that creep rate partly depends on fast neutron flux.
Effect of Fast Neutron Irradiation on the Creep Rupture Properties of Type 304 Stainless Steel at 600 C
Authors: Bloom EE , Stiegler J 
Published: March 2009

The creep rupture properties of Type 304 stainless steel have been determined at 600 C after irradiation at temperatures in the range from 370 to 600 C to fast neutron fluences of 1×1021 to 6.7×1022 n/cm2, E &gt;0.1 MeV. The microstructures were characterized by electron microscopy. Irradiation at 370 to 470 C caused a decrease in ductility and rupture life which became larger with increasing fast neutron fluence. The irradiated specimens fractured along the grain boundaries with no evidence of deformation within the matrix. A specimen irradiated at 410 C to 6.7×1022 n/cm2 ruptured in 0.5 h with 0.1 percent elongation, as compared to a rupture life of 185 h and elongation of 19.7 percent for the unirradiated material tested at the same stress. Specimens irradiated at 600 C to fluences from 2.5 to 3.5 ×1022 n/cm2 exhibited decreased ductilities and creep rates and essentially the same rupture lives as unirradiated specimens.
The increased tendency for grain boundary fracture, and thus reduced ductility and rupture life, appears to result from the effects of the irradiation produced voids and dislocations upon deformation processes, which effects would be inoperative in an unirradiated specimen. The voids and dislocations prevent dislocation motion within the matrix. Regions along grain boundaries are denuded of these defects and grain boundary sliding occurs, leading to stress concentrations and the initiation of grain boundary cracks. The presence of helium at the boundaries may increase the rate of crack propagation.
Influence of Neutron Irradiation on the Creep Rupture Properties of a 16Cr-13Ni Steel
Authors: Ehrlich K , Böhm H , Wassilew C 
Published: March 2009

The influence of neutron irradiation (up to 1.1 x1022 n/cm2, E&gt;0.1 MeV) on the creep rupture properties of a Cb stabilized 16Cr-13Ni steel was studied in this paper. Different heat treatments and cold work conditions and several irradiation temperatures were investigated.
Low-temperature irradiation causes an increase in time to rupture at 650 and 750 C, whereas creep rate is reduced by more than a factor of ten. The creep ductility decreased to less than 1 percent. High-temperature irradiation does not cause a substantial change in rupture time at 650 C for the aged condition and the 50 percent cold work and 50 percent cold work+1 h 850 C conditions.
The rupture life of specimens which were cold-worked 10 percent is strongly decreased by irradiation. Only slight changes in creep rate could be observed after high-temperature irradiation. Electron microscopy investigations indicate that the increase in rupture life and reduction in creep rate after low-temperature irradiation is due to a large number of dislocation loops. In the specimens irradiated at 650 C and above only He bubbles could be detected.
Correlation Between the Mechanical Properties and Microstructure of Irradiated Iron and Low-Carbon Steel
Authors: Stefanović VM , Milašin NLj 
Published: March 2009

The radiation hardening of iron and low-carbon steel was studied on the basis of transmission electron microscopy and tension test data. No visible defects were observed in the iron specimens after irradiation to 3.5×1019 n/cm2, E&gt;1 MeV, at 35 C, as well as after postirradiation annealing at 150 C. Marked microstructural changes occurred in steel irradiated to 2.5×1018 n/cm2 both at 320 C and 450 C. In the former case a 5.1×109 cm-2 increase in dislocation density was found, while in the latter the presence of small dislocation loops of average diameter 200 Å and density 2.4×1014 cm-3 was observed.
The approximative theoretical values of yield stress increment were calculated using the models for hardening by small dislocation loops and by a dislocation forest and were compared with the experimental values of the yield stress increment. A satisfactory agreement was obtained.
Environmentally Controlled Cavitation Test (Improvements in a Cavitating Film Erosion Test)
Authors: Hobbs JM , Rachman D 
Published: March 2009

Early attempts to produce cavitation erosion on a stationary specimen close to a vibrating probe showed promise as a means of testing weak materials and coatings. However, the geometry affected the damage rate, the condition of the cavitating liquid was not accurately known, and the temperature in the cavitation zone rose appreciably. An improved version of this test has been devised at the University of Strathclyde, Glasgow, and subsequently further developed at the National Engineering Laboratory, East Kilbride.
The specimen is mounted a small distance from the vibrating probe, and liquid is fed continuously through a central hole in the stationary specimen. With water the temperature rise could be kept easily below 2 C. In oil, although the temperature rise was considerably higher (10 C) it was under complete control and depended mainly on the flow rate and specimen separation.
The erosion pattern obtained on the stationary specimen was well distributed and fairly uniform. The rate of erosion reach an early maximum value and then decreased with time. It decreased as the separation was increased. Optimum test conditions were obtained with 0.5 mm (0.020 in.) separation from a 20 kHz vibrator having a peak-to-peak amplitude of 50μm (0.002 in.). The specimen and vibrating probe were both 16 mm (5/8 in.) diameter. Effects of probe amplitude, test liquid flow rate, temperature, and static pressure were examined.
This technique has been used with considerable success for the evaluation of white-metal layers in lubricating oils, fiber-reinforced epoxy resins in water, and a range of typical engineering alloys.
Cavitation Damage Mechanism and Its Correlation to Physical Properties of Material
Authors: Hirotsu M 
Published: March 2009

Several test surface configurations were proposed by which better reproducibilities of experimental results were achieved. There were no mechanical difficulties in machining and polishing test specimens.
Cavitation phenomena on the surface of a specimen were photographed with a special camera arrangement at adequate intervals within a cycle. These phenomena have been classified into three processes: generating, growing, and collasping. Each regime was studied closely by the aid of photographs.
Long exposure time tests, with the use of the proposed test specimens, showed mean depth penetration rate (MDPR) curves somewhat different from those previously reported. They reached the maximum MDPR in a relatively short time and decreased.
Observations of the damaged surfaces were made by means of an optical roughness meter and an ordinary microscope. The curves of maximum pit depth versus time showed a close relation to the MDPR curves.
To find a correlation between damage and physical properties of material, maximum MDPR and ultimate resilience (UR) were employed. In a very rough approximation, the correlation was (maxMDPR×area)×(UR)≑constant
The advantage of taking the maximum MDPR as a reference value was shown clearly in the results of stationary test specimen experiments. Within the limits of uniform damage patterns, the following simple relation was found. maxMDPR≑Ke-βx where x is a separation distance and β is a constant having no relation with the nature of material tested. It is assumed that K is the most characteristic value of maximum MDPR, since it is a hypothetical value when there is no vibratory motion to induce cavitation.
Erosion Rate-Velocity Dependence for Materials at Supersonic Speeds
Authors: Schmitt GF 
Published: March 2009

A comprehensive investigation of plastic, elastomeric, ceramic, glass, metallic, and composite materials for short exposure time—rain erosion resistance at velocities of Mach 1.5, 2.0, 2.5, 3.0, and 4.0 has been accomplished.
Wedge-shaped holders capable of exposing multiple materials specimens at five different impact angles were designed, fabricated, calibrated, and successfully employed for 65 supersonic firings on the rocket sled track at Holloman Air Force Base, N. Mex.
Droplet breakup effects on the wedge because of shock-wave-droplet interactions have been analyzed and found to influence a portion of the data. Quantitative data in the form of weight loss per unit area and mean depth of penetration rate (MDPR) were determined for the various materials, and an equation for relating the erosion rate (MDPR) with the normal component of the velocity (V sinθ) was developed as follows: MDPRsinθ=K(Vsinθ)α Values of K and α have been determined for all of the materials.
The relationship of erosion rate-velocity dependence for numerous materials at powers of five or greater for the velocity exponent has been confirmed at velocities up to three times as great as previously conducted.
The values for the velocity exponent (α) have been determined as 6 to 10 for bulk ceramics, 5 to 7 for bulk plastics and fiber-reinforced plastic composites, 6 to 8 for glasses, and 7 for aluminum indicating a very strong erosion rate-velocity dependence at speeds up to Mach 4.0.
Rain and Sand Erosion, Phenomena of Material Destruction Caused by Repeated Loads
Authors: Hoff G , Herbert W , Rieger H 
Published: March 2009

A rotating arm for maximum peripheral speeds of 1000 m/s has been developed at Dornier-System for testing the material behavior of multiple impact of solids. The test equipment will be discussed.
Fundamental tests concerning the relationship between fatigue behavior and erosion and cavitation strength for various materials have been performed in a rain erosion test rig M = 1.4 and on a magnetostrictive oscillator of 20 kHz. The influence of various treatments on the erosion resistance has been investigated on the stellites which are important for the construction of steam turbines.
By altering the test temperature of high polymers the dependence of erosion resistance to the relaxation characteristics has been determined.
To detect the influence of the altitude on the rain erosion of aircrafts, measurements have been performed to investigate the rain erosion as a function of the atmospheric pressure.
Effects of Mean Stress and Prestrain on Fatigue-Damage Summation
Authors: Topper TH , Sandor BI 
Published: March 2009

A cumulative damage procedure based on smooth-specimen tests of 2024-T4 aluminum alloy and aircraft quality SAE 4340 steel is formulated in which the effects of prestrain and mean stress on fatigue life are investigated separately. It is assumed that life reductions due to prestrain or mean stress at a given strain level may be separately incorporated into a simple cycle-ratio damage summation.
Small plastic prestrains are shown to cause considerable life reductions. Larger prestrains appear to have little additional adverse effect. It was found possible adequately to correlate results with and without mean stress by a parametric representation of mean stress and strain amplitude.
Analysis of arbitrary stress-strain sequences indicates that the proposed damage-summation procedure gives adequate life predictions. Cycle-ratio summations were close to unity for both stress-controlled and strain-controlled tests in which sequence, number of blocks, fraction of life at mean stress, and the life fraction at which plastic straining occurred were all varied.
Peak-Distribution Effects in Random-Load Fatigue
Authors: Broch JT 
Published: March 2009

This paper reports the effects of the stress-peak distribution upon the fatigue life of a certain type of test specimen excited to bending by Gaussian random vibrations. Approximately 200 specimens were tested using two different peak-distribution functions. The peak-distribution functions were produced by means of single- and two-degrees-of-freedom systems, respectively, excited by bands of random noise.
The root-mean-square (RMS) level of the strain and the average number of zero crossings were kept constant and equal in both tests. Statistical and physical interpretations of the test results are presented and discussed.
Effects of Block Size, Stress Level, and Loading Sequence on Fatigue Characteristics of Aluminum-Alloy Box Beams
Authors: Breyan W 
Published: March 2009

A fatigue investigation was performed for constant- and variable-load amplitudes using a box beam fabricated from 7075-T6 aluminum elements. This structure was tested as a simply supported beam under unidirectional bending. The primary objectives were to determine the relative cumulative fatigue damage resulting from the imposition of four flight-loads test spectra and to determine the effects of stress level, block size, and load sequence on life. A full factorial experiment with two replications was used to perform both fixed- and random-sequence tests for the parameters of load spectrum, static margin of safety, and block size.
The beam exhibited fatigue characteristics that correlated well with those of full-scale structures, the beam-fatigue lives appearing as the upper bound of the lives of full-scale structures. When subjected to fixed sequence loading, a significant increase in life was found for an 11 percent increase in static margin of safety and for increases in test-block size. These results were explained on the basis of the compressive residual stresses produced around the fastener holes. The results support the use of the smallest feasible block size for the fatigue tests of full-scale structures. Comparisons between fixed- and random-sequence experimental data showed that, in general, the smallest fixed-sequence block size most closely simulated random loading within a block and that the fatigue life under random loading was less than that for fixed-sequence loading.