bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Precision Testing of a Standard Test Method for Screening Fuels in Soils
Authors: Sorini SS , Schabron JF 
Published: February 2009

Abstract
The ASTM Standard Test Method for Screening Fuels in Soils (D-5831-95), uses low-toxicity chemicals and can be used to screen organic-rich soils. It is also fast, easy, and inexpessive to perform. This screening method calls for extracting a sample of soil with isopropyl alcohol following treatment with calcium oxide. The resulting extract is filtered, and the ultraviolet absorbance of the extract is measured at 254 nm.
A collaborative study was conducted to determine the reproducibility (between participants) and repeatability (within participant) precision of the method when it is applied to a sand and an organic soil spiked with various concentrations of diesel fuel. The data generated in this study are specific to the test materials used. However, these data provide information on the variability that can be expected when the screening method is used by one or more users. Information obtained from the collaborative study will help potential users assess the usefulness of the screening method for their proposed applications.
Shear Lap-Joint Testing with Rubber Substrate
Authors: Chang DJ , Hanna WD 
Published: February 2009

Abstract
A test method has been developed and demonstrated for the determination of shear strength in a lap joint with rubber-like material as a substrate. A testing fixture used a stiffened aluminum substrate with a load-transferring lip, combined with a clamp, that restrained the lateral movement of the rubber. This fixture successfully produced shear-type failures on two back-to-back single lap-joint specimens. The design of the fixture was based on the near-incompressible nature of the rubber materials. The experimental part of the task included two phases: a pathfinder test series; and the actual data generation test series. The former phase involved testing concept development, test fixture design and modification, optimization of test specimen configuration, and failure mode demonstration. This phase was conducted using specimens fabricated in-house by the Mechanics and Materials Technology Center at The Aerospace Corporation. In the second phase, actual shear failure data were generated using specimens that were machined from panels fabricated by the vendor, Elkton Division, Tactical Operations of the Thiokol Corporation.
Linear elastic finite element analyses were performed to assist in the optimization of test parameters. The results identified optimal dimensions for lap-joint length, transverse groove width, and bracket lip width for the specimen and fixture configuration. Sixteen tests were done on specimens machined from vendor-supplied carbon phenolic/Epon EA 934 NA/ethylene propylene diene monomer (EPDM) panels. The average failure stresses were 4.46, 3.39, and 3.32 MPa (0.56, 0.43, and 0.42 ksi) for the 7.62, 10.16, and 12.70-mm (0.3, 0.4, and 0.5 in.) long lap-joints. Some of the failures were initiated inside the adhesive whereas other failures occurred between the adhesive and the substrate.
This test method should be considered as a viable technique in determining shear strength of bond line with rubber-like material as a substrate. More refinement, however, is needed before an optimal test fixture design can be reached.
Strain-Controlled Cumulative Fatigue with Mean Strains and High-Cycle and Low-Cycle Interaction
Authors: Gong Y , Norton MP 
Published: February 2009

Abstract
This work reports on baseline fatigue and cumulative fangue damage results of mild steel under cyclic strain control All cumulative damage tests were conducted with a step loading in a decreasing order, from a high strain amplitude of 0.4 or 0.3% to a lower one of 0.2%. Different mean strain values of −0.2, 0, and 0.2% were applied in each strain amplitude level. Seven combinations of strain amplitude and mean strain were investigated. It was observed that cyclic softening in the second level was significantly stabilized by the presence of the first level, which accounts for approximately 20% of the total fatigue life. Mean stress relaxation in the second level depended upon the loading in the first level and was similar to that for single-level loading under certain strain amplitudes and mean strains. The damage summations in terms of cycle ratio (Miner's damage sum), both with and without mean strain correction, were calculated and discussed. For all of the cases investigated, the average damage summations were found to be in the range of 0.94 to 1.28. The degree of approximation and the deviation of each individual test from unity depends on whether mean strain correction was made. The competing effects of mean stresses induced and plastic deformation tended to overshadow the more classical loading sequence effects in terms of the damage summation. Fatigue damage accumulation has also been analyzed using Continuum Damage Mechanics modeling. The sources of the deviation of damage summation from unity and the nonlinear accumulation of damage are discussed.
Determination of Ductile-Brittle Transition Temperature (DBTT) in Dynamic Small Punch Test
Authors: Joo Y-H , Hashida T , Takahashi H 
Published: February 2009

Abstract
A dynamic small punch test technique is demonstrated for measuring the ductile-brittle transition temperature (DBTT) of aged Cr-Mo-V turbine rotor steels. Based on fracture energy measurements and fracture surface observations it is shown that the dynamic small punch test specimens exhibit a clear ductile-brittle transition behavior. The DBTT can be determined reliably by statistically analyzing the scatter in the fracture energy data and by defining the fracture appearance transition temperature. The measured values of DBTT are compared with those obtained from Charpy impact tests.
Finite Element Method (FEM) Analysis of Elastic-Linear-Hardening Materials and Comparison with Measurements on Commercial Materials
Authors: Murakami Y , Yuan LP 
Published: February 2009

Abstract
The Brinell hardness HB (kgf/mm2) of elastic-linear-hardening materials with various yield stresses σY (MPa) and hardening moduli H (MPa) is analyzed by a finite element method (FEM). The well known empirical formula for the ratio of tensile strength σB to HB, σB/HB ⋟ 3.5, does not hold for materals having a large relative strain hardening modulus H/σY, where H is defined by dσ/dε in the σ-ε curve. It is shown that the dimensionless stress-strain curves (σ/σY vs. ε) of elastic-linear-hardening materials and those of various commercial materials give the crucial measurement in determining the value of σB/HB. The ratio of σB/HB remains in the range of 3.2 to 3.8 if the relative strain hardening modulus H/σY at large strains is less than ∼2.5. Correlations between the stress-strain curve and indentation shape, plastic zone size, and residual stresses are also investigated.
Analysis of Gas-Fired Ceramic Radiant Tubes During Transient Heating: Part II—Thermoelastic Stress Analysis
Authors: Segall AE , Hellmann JR 
Published: February 2009

Abstract
Transient radial and axial temperature distributions based on measured external surface temperatures and finite-element calculations were used with temperature dependent elastic material properties to determine the thermoelastic stresses experienced by reaction-bonded and sintered-alpha silicon-carbide open ended radiant tubes during gas-combustion beating. The resulting stresses exhibited a dependence on the radial temperature difference and the curvature of the axial temperature distribution. A failure rate analysis using a two-parameter Weibull formulation with a polyaxial stress approximation, the calculated surface and volume principal stresses, and temperature-dependent surface and volume Weibull strength data indicated low failure rates and the viability of both materials for the transient heating conditions studied.
Hydrochlorofluorocarbon (HCFC) Blowing Agents for Foam Insulation of Launch Vehicle Cryogenic Propellant Tanks
Authors: Strauss EL , Bzik JW 
Published: February 2009

Abstract
Two polyurethane spray-on foam insulations (SOFI) were evaluated with five hydrochlorofluorocarbon (HCFC) blowing agents each (HCFC-141b, HCFC-123, and three blends). Foams were evaluated by measuring bond and flatwise tension strengths at four temperatures, compression at ambient temperature, and substrate strain compatibility at liquid helium temperature. Additionally, foams were characterized for density, closed-cell content, oxygen index, and ablation under radiant heating. Compression strengths of RDB-1-152 (polyether polyol) exceeded those of SS-1825 SOFI (polyester polyether, blend). Highest compression and tensile strengths were for foams sprayed with HCFC-141b and strengths decreased with increasing HCFC-123 content in the blowing agent. No foam failures occurred adhesively at the aluminum substrate, but a high incidence of premature failures occurred in the knitline between successive spray layers. Process optimization studies will be conducted with the two best SOFI systems, RDB-1-152/HCFC-141b and RDB-1-152/30% HCFC-123: 70% HCFC-141b.
Experimental Evaluation of a Laboratory Twin-Probe Nuclear Gage for Specimen Density Measurement
Authors: Fwa TF , Tan SA 
Published: February 2009

Abstract
This paper describes a series of tests conducted to establish the operating requirements of a laboratory twin-probe nuclear gage for density measurement of cylindrical specimens of homogeneous materials. The nuclear device is an adaptation of a direct transmission field gage for laboratory density measurement. It is shown in this evaluation program that three forms of analysis are required for the setting up of such an apparatus: calibration analysis, precision evaluation, and accuracy assessment. Three specimen diameters (75, 100, and 150 mm), three materials with densities from 0.8 to 2.7 g/cm3, and nuclear gage source-to-detector spacings ranging from 250 to 450 mm were included in the evaluation program.
It was found that density calibration based on radiation attenuation theory is valid, and that a diameter-count rate relationship can be established experimentally so that only a single set of density calibration using one specimen diameter is needed for routine testing. In the accuracy assessment, it was found that there exists a narrow range of source-to-detector spacings for unbiased density estimation. A spacing of 280 mm is recommended for the device studied. At this spacing, the density measurement precision at 95% confidence level, using four 1-min counts per test, is found to vary from 0.010 g/cm3 for 150-mm-diameter specimens to 0.017 g/cm3 for 75-mm-diameter specimens.
Introduction to Symposium on Radiation Shielding for the 21st Century
Authors: Volkman DE 
Published: February 2009

Abstract
The Symposium on Radiation Shielding for the 21st Century was held in Atlantic City, New Jersey, on 24 June 1991. The event was sponsored by ASTM Committee C-9 on Concrete and Concrete Aggregates and hosted by ASTM subcommittee C09.08.02 on Concrete for Radiation Shielding.
Comparison of Fine Particle Colemanite and Boron Frit in Concrete for Time-Strength Relationship
Authors: Volkman DE , Bussolini PL 
Published: February 2009

AbstractThe element boron, when added to concrete, has proved effective in shielding neutron particles by absorbing the neutron and emitting a low-energy gamma ray. The various boron additives used with concrete can severely retard the set time and strength gain. An advantage to using small particle size boron is that the smaller grain size provides better boron disbursement within the concrete matrix to absorb neutrons. However, boron additives of powder consistency are usually not used due to the greater potential of forming chemical solutions that act as a retarder in the concrete.Research has shown that the amount of boron additives in concrete can be reduced significantly if fine grain particles can be successfully incorporated into the concrete matrix. The purpose of this study is to compare strength gain characteristics of concrete mixes containing various quantities of fine grain boron additive. The boron additive colemanite, a natural mineral, is compared with two brands of manufactured aggregate, boron frit. Concrete test cylinders are molded for testing the compressive strength of the mix after 4, 7, 28, and 56 days. Tested are five different quantities of colemanite as well as five comparable amounts of boron frit for each brand of the material. The test values are compared with a control concrete specimen containing no boron additive. Results of this study can be used to optimize the cost and effectiveness of boron additives in radiation shielding concrete.
An Apparatus for Biaxial Strength Testing of Standard Tensile Specimens
Authors: Mazachek KD , Faddis TN 
Published: February 2009

Abstract
A novel, low cost testing apparatus has been designed for the application of biaxial stress on standard tensile spectmens. The apparatus independently applies compressive loading perpendicular to a tensile load. The compressive load is transferred through a compression pad, applying hydrostatic pressure to the test section.
The experimental results of tests conducted on 6061-T6 aluminum have been analyzed and compared using the von Mises failure criterion. The results indicate that using this test apparatus with a polytetrafluoroethylene (PTFE) compression pad produces biaxial failures consistent with the failure envelope defined by the von Mises failure criterion.
Compression Testing of Lumber: A Comparison of Methods
Authors: Green DW , Evans JW 
Published: February 2009

Abstract
A study was conducted to compare compression strength values obtained using short segments cut from full-length lumber and tested in accordance with ASTM D 4761-87 with those values obtained using full-leagth specimens and tested in accordance with ASTM D 198-84. Tests were conducted on Southern Pine lumber conditioned to a target moisture content of 9%. To obtaim a short-segment compression strength estimate within a factor of about 1.05 of those obtained by testing full-length (3-m [10-ft]) specimens, it is necessary to select two of the apparent worst strength-reducing defects in the full-length specimen using ASTM D 245-84 sorting criteria.
Field Evaluation of Pavement Instrumentation Methods
Authors: Tabatabaee N , Al-Qadi IL , Sebaaly PE 
Published: February 2009

Abstract
Full-scale testing was conducted to compare the performance of different in situ instrumentations used in flexible pavement, including strain gages, pressure cells, geophones, and single-layer deflectometers. Two test sections were instrumented: one thin section (15.2 cm [6 in. thick]) and one thick section (25.4 cm [10 in. thick]). Each section is 15.2 m (50 ft) long. The testing variables included pavement structure, load, tire pressures, and speed. The criteria for evaluation of performance of the instruments included survivability, repeatability, reliability, the effect of test variables, ease of installation, and data processing. The measured response under different conditions was compared with the calculated response using a multi-layered elastic model. Falling weight deflectometer (FWD) testing was used to quantify the in situ material properties needed for the computer model.
Ultrasonic Technique for Residual Stress Measurement in Ductile Iron Continuous Cast Round Bars
Authors: Srinivasan MN , Chundu SN , Bray DE , Alagarsamy A 
Published: February 2009

Abstract
An ultrasonic technique using critically refracted longitudinal (LOR) waves was used to determine the residual stresses in ductile iron bars in the as-cast, annealed, normalized as well as quenched and tempered states. The results conform to expected trends based on differential cooling rate and phase transformation effects.
Notch Dimensions for Three-Point Bend Fracture Specimens Based on Compliance Analyses
Authors: Baratta FI , Underwood JH 
Published: February 2009

Abstract
Load-line compliance was calculated for various three-point bend specimens containing finite width notches and cutouts, using methods of engineering strength of materials and elastic superposition. Comparison of compliance results for notched specimens with results for the ideal zero width crack was used to propose two basic notch configurations for fracture testing. A relatively wide notch that could be produced by conventional manufacturing methods resulted in load-line compliance values 10% or more above those of the ideal crack case. A narrow notch that could be produced by electric-discharge machining resulted in compliance values much closer to those of the ideal crack case.
Superposition Theory Applied to Nail/Glue Joints in Wood: Part I—Strength Behavior
Authors: Pellicane PJ 
Published: February 2009

Abstract
A model was developed based on concepts involving superposition of nail and glue joint strength to predict the ultimate load of nail/glue joints in wood subjected to lateral loading. Four combinations of two wood species (lodgepole pine and hard maple) and two nail sizes (6d and 8d) were examined. One brand of commercially-available elastomeric construction adhesive was used. A total of 169 nail, glue, and nail/glue joints were tested to ultimate load. Theoretical predictions based on nail and glue joint strength were compared with experimental data from nail/glue joint tests. The results showed that mean joint strength was predicted to within 9% for three of the four combinations of nail size and wood species studied. Statistical analyses revealed that for these three data sets, mean experimental and theoretical values were indistinguishable at the 0.01 level. In addition, the presence of glue in a nailed joint accounted for a substantial increase in strength over joints without glue.
Crack Initiation and Total Fatigue Life of a Carbon Steel in Vacuum and Air
Authors: Kujawski D , Ellyin F 
Published: February 2009

AbstractFully-reversed strain-controlled test results of a carbon steel (ASTM A 516 Gr. 70) in an ambient atmosphere and in a vacuum of 0.1 mPa are compared. Vacuum data may be viewed as representing a “pure” (mechanical) fatigue damage. In the case of an air environment, the rate of fatigue damage accumulation increases due to the environmental contribution.The test results are described in terms of the crack initiation and total lives. The crack initiation data are fairly well-correlated with the plastic strain energy per cycle. The significance of the environment condition on the life prediction procedures is discussed.
The Shear Stress-Strain Curve Determination from Torsion Test in the Large Strain Range
Authors: Wu HC , Xu Z , Wang PT 
Published: February 2009

Abstract
A modified Nadai's method is proposed to determine the shear stress-strain curve by use of a solid circular cylinder subjected to torsional load. The modification is accomplished by taking into account the axial length change of the specimen. The method is extended to give the shear stresses in tubular specimens.
A series of experiments on annealed isotropic high purity cast aluminum material was conducted under the pure torsion condition. Torque-twist and axial elongation-twist curves were recorded. The shear stress-strain curves obtained from tubular specimens of various wall-thicknesses and solid circular cylindrical specimens are compared by using different methods of data analysis. It is found that the present method is the most appropriate one among all methods considered. It is suggested that long gage-sectioned, thick-walled tubular specimens be used to determine the shear stress-strain curve in the large strain range.
Comparison of the Fracture Behavior of Conventional Class U Railway Wheels and an Experimental Alloy Wheel
Authors: Bowles CQ , Roland JR 
Published: February 2009

Abstract
The fracture properties of high and low carbon Class U railway wheels were compared with an experimental low carbon alloy wheel using tensile, Charpy impact, and KIc tests on specimens cut from the circumferential and transverse directions of wheel rim. The experimental alloy design was based on results of dynamometer tests and service experience that suggested a decrease in carbon content increased fracture resistance. Additional chromium was added to the experimental alloy to maintain pearlitic microstructure, thereby maintaining wear resistance. The low carbon wheels were found to have the highest fracture toughness, which was attributed to a continuous network of grain boundary ferrite that inhibited crack growth across grains. However, impact toughness was not significantly higher. Toughness of the experimental alloy was found to be similar to the high carbon wheels. However, a limited number of toughness tests coupled with a number of nonvalid tests make toughness results tentative. It was believed that the addition of chromium to produce a nearly pearlitic structure also eliminated the continuous network of proeutectoid ferrite necessary for good toughness.
Residual Stresses and Fatigue Precracking Techniques for Weldment Fracture Toughness Specimens
Authors: Reemsnyder HS , Pisarski HG , Dawes MG 
Published: February 2009

Abstract
This article examines the ability of the local compression, stepwise high R-ratio, and reverse bend weldment fatigue precracking techniques to remove the residual stresses in the uncracked ligaments of as-welded fracture mechanics test specimens. The stepwise high R-ratio and reverse bend techniques appeared to have no significant influence on the residual stresses in the ligament. This was demonstrated by the occurrence of nonuniform fatigue cracks when these techniques were followed by the standard fatigue precracking procedures. Specimens given these treatments, and other specimens fatigue precracked using the standard procedures, showed evidence of crack closure and initial compliances that were lower than normal for these specimen geometries. In contrast, local compression reduced the residual stresses in the uncracked ligaments to low, uniform levels. This was indicated by acceptable fatigue precrack front-straightness and normal specimen compliance. Therefore, of the three precracking techniques investigated, only the local compression technique is recommended.
Fatigue Crack Initiation in Nonferrous Materials: A Model Assessment
Authors: Azimi HR , Miller GA 
Published: February 2009

AbstractElastic stress concentration (Ktd approach), fracture mechanics, and local strain approaches were evaluated for predicting fatigue crack initiation for a 2024-T3 aluminum alloy, commeretally pure copper. 70–30 brass, and Cu-Be alloy 25 Blunt (keyhole) and sharp (V-notched) compact tension specimens were subjected to cyclic loading in ambient laboratory air to produce crack initiation in the range 104 to 106 cycles.The results show that the best initiation model. Ktd approach is based on computed estimates of strain at some distance ahead the notch root. This distance was shown to be inversely related to the material's strength. This model properly described the influence of both material and geometry over the full range of initiation cycles. Ni. Local strain and fracture mechanics models were less sensitive and exhibited greater variability.