bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Chevron-Notched Specimen Types for Fracture Toughness Testing of Aluminum
Authors: Morrison J , Gough JP , KarisAllen KJ 
Published: February 2009

Abstract
There is increasing interest in the use of chevron-notched specimens for the measurement of plane-strain fracture toughness. Attention has been focussed on the short rod/bar specimens, for which several different geometries have been proposed. This paper describes a series of tests on 6061-T651 aluminum alloy aimed at providing a comparison of five short rod/bar specimen types with three different thicknesses. Also included are data from standard compact-tension specimens.
Effects of Small Surface Cracks on Ductility Loss in Low Cycle Fatigue of 70/30 Brass
Authors: Murakami Y , Makabe C , Nisitani H 
Published: February 2009

Abstract
The loss of fracture ductility after strain cycling in low cycle fatigue tests is not due to so-called weakening or losing of the strength quality caused by irreversible slips in crystals but rather is attributable to the existence of small surface cracks. The degree of loss of fracture ductility depends on the crack length ℓ. If ℓ is larger than the critical length ℓc, the fatigue crack causes macroscopic shear fracture in the tensile test after strain cycling. On the other hand, if ℓ &lt; ℓc the fracture surface becomes the so-called cup-and-cone type. For 70/30 brass, ℓc ≅ 400 µm.
Fatigue Crack Propagation Threshold
Authors: Marci G , Castro DE , Bachmann V 
Published: February 2009

Abstract
Service-type fatigue loading conditions are critically analyzed with respect to their relevance for a fatigue crack growth threshold. It was found that a threshold should be experimentally determined as a function of the monotonic-plastic zone size (i.e., as a function of Kmax). For each Kmax the cyclic-plastic zone size depends on the applied ΔK and threshold testing should cover the range ΔK ≈ ΔKth and ΔK (R = 0) for tension fatigue. For a given plastic zone, Kmax and ΔK fixed, the threshold ΔKth could occur anywhere between Kmax and Kmin. This study presents experimental procedures and furnishes results for Inconel 617 and a Ti-6A1-4V alloy which allow one to analyze the influence of the three parameters cited above. It demonstrates the following:
• The threshold decreases “linearly” with increasing monotonic-plastic zone size; this confirms existing data.
• The cyclic-plastic zone has minimal influence on the fatigue threshold with Ti-6A1-4V, while this influence is substantial in the case of Inconel 617.
• A shift of threshold between Kmax and Kmin does not alter the magnitude of the threshold.
A Model to Predict the Sources and Magnitude of Scatter in Toughness Data in the Transition Region
Authors: Anderson TL , Stienstra D 
Published: February 2009

AbstractScatter in cleavage fracture toughness data is analyzed with a statistical model. This model indicates that when a material fails by weakest-link cleavage under J-controlled conditions, the corresponding fracture toughness data will follow a two-parameter Weibull distribution with a characteristic slope. This slope is 2.0 for critical J-integral and crack tip opening displacement (CTOD) data, and 4.0 for critical stress intensity values. Published experimental data for a wide range of materials verify these slopes.The discovery of an invariant Weibull slope that is the same for all materials has important practical implications. For example, it is now possible to predict the relative magnitude of toughness scatter prior to testing. It is also possible to extract useful information from small data sets. The authors demonstrate these applications with sample calculations. A number of additional analyses are presented, including evaluations of the effects of thickness and local brittle zones on toughness. Also, a methodology is presented which allows one to predict fracture toughness distributions when specimens belonging to multiple populations are tested. This latter analysis can be used to assess the effect of experimental error.The analyses in this article are not valid when cleavage fracture is preceded by large-scale plasticity or stable crack growth. In such cases, the crack tip stresses are lower than predicted by J-integral theory. This causes the Weibull slope to decrease from its theoretical value. Current research is aimed at predicting fracture toughness distributions for large-scale yielding conditions.
Linear-Elastic Fracture of High-Nitrogen Austenitic Stainless Steels at Liquid Helium Temperature
Authors: Tobler RL , Reed RP , Purtscher PT 
Published: February 2009

Abstract
Four commercial Fe-Cr-Ni-Mn austenitic stainless steels containing 0.14, 0.26, 0.28, and 0.37 wt% N were fractured in liquid helium at 4 K, and measurements of the linear-elastic plane-strain stress-intensity factor, KIc, were made. Interstitial nitrogen significantly strengthens these steels at low temperatures so that brittle fractures occur under plane strain conditions at 4 K despite moderate ductility in uniaxial tension. The brittle fracture mechanism at 4 K involves a form of cleavage or slip-band cracking as evidenced by the formation of transgranular facets on {111} planes.
Creep Rupture Behavior of Precorroded Carbon Steel
Authors: Ragab AR , Alawi H , Sorein K 
Published: February 2009

Abstract
Creep rupture tests have been conducted on specimens of AISI 1018 low carbon steel pre-exposed to various environments: polluted seawater, natural seawater, industrial seashore tide, drinking tap water, and industrial air. Exposure to increasingly corrosive environments before creep testing results in decreasing creep strength by appreciable amounts. With suitable extrapolation procedures, creep rupture test data may be cautiously used to generate design creep curves involving service temperature, stress, and life for precorroded steel. Further experiments are needed to investigate the combined effect of corrosion and creep on rupture life over a wider range of environmental test parameters.
Specimen Geometry Effects on the Strength of Unidirectional Resin-Matrix Composites
Authors: Loveless HS 
Published: February 2009

Abstract
This paper describes some of the problems encountered in determining the tensile and flexural strengths of uniaxially aligned glass fiber-resin composites by conventional methods, and suggests alternative procedures for overcoming them. Special emphasis is placed on the effects of test specimen geometry with respect to these properties and equations are developed for the stress-strain properties of half-round, pultruded rods subjected to ordinary bending, assuming elastic behavior.
In addition, measurements carried out on flat, unidirectional moldings are described, which show a linear relationship between the tensile and flexural strengths of these composite materials.
Interlaboratory Evaluation of KIscc and da/dt Determination Procedures for High-Strength Steels
Authors: Wei RP , Novak SR 
Published: February 2009

Abstract
This report is prepared on behalf of ASTM Joint Task Group E24.04.02/G01.06.04 on Test Methods for Measurement of KIscc and SCC Growth Rate. It summarizes and provides an assessment of the results from an interlaboratory program to evaluate the procedures, based on linear fracture mechanics, for determining the threshold stress intensity factor for stress corrosion cracking (KIscc) of high-strength steels and the crack growth rates (da/dt). Problem areas and additional work are identified.
Effects of Temperature on the Fracture Toughness of Carburizing Steels for High-Temperature Applications
Authors: Cutler RA , Leslie WC 
Published: February 2009

Abstract
The fracture toughness of steels with good retention of hardness at elevated temperatures (CarTech EX00053, Timken CBS 600 and 1000M, and Vasco X-2M) was compared with that of conventional carburizing steels (EX55, AISI 4820, 8620, and 9315). The short-rod method was used to determine short rod/short bar fracture toughness KIcSR between 22 and 400°C. Wide variations in fracture toughness were observed over this temperature range. The toughness of EX00053 and CBS 1000M increased sharply between 22 and 100°C with the former having the highest toughness of any of the steels studied.
Review of the Effects of Fatigue Cracking Loads on Plane Strain Fracture Toughness
Authors: Towers OL 
Published: February 2009

AbstractPlane strain fracture toughness for Mode I loading KIc testing standards impose restrictions on the loads used to prepare the fatigue cracks because experiments have shown that if the loads are too high the resulting toughness measurement might be unconservative. Data displaying the effects of fatigue cracking load level on KQ measurements (“candidate” KIc values) have been reviewed and compared to restrictions imposed by two relevant standards on fatigue cracking load level and on the R ratio (KFmin/KFmax). For the majority of the materials studied these restrictions are sufficiently stringent, but for some materials that display a particular tendency to cyclically soften it may be necessary to increase their severity to the maximum value of stress intensity factor in fatigue KFmax ≯ 0.5 KQ. The basis of the restrictions on R ratio of the two standards is unknown, but relaxation of the limit (≯ 0.1) is difficult to recommend because of lack of relevant data.
Cyclic Stress-Strain and Fatigue Properties of Sheet Steel as Affected by Load Spectra
Authors: Martin JF 
Published: February 2009

Abstract
Axial strain controlled fatigue tests were performed without buckling on thin 1.78-mm (0.070-in.) thick hourglass profile sheet steel specimens. Cyclic strain amplitudes up to ±0.015 were obtained. Material properties for cyclic 1stress-strain behavior varied considerably when obtained by using three different procedures. For fatigue resistance, an initial cyclic overstrain did not appreciably affect fatigue life; however, periodic cyclic overstraining did have a noticeable effect.
Fracture Mechanics Analysis of the Effects of Residual Stress on Fatigue Life
Authors: Throop JF 
Published: February 2009

Abstract
In this paper it is reemphasized that the effect of residual stress in fatigue is analogous to but not the same as the mean stress effect from applied loads. By including a residual stress term in the stress intensity factor range of the fatigue crack propagation rate equation, one is permitted to include the residual stress in calculations of fatigue life estimates. Using crack shape factors calculated for given aspect ratios of surface flaws and integrating the fatigue crack growth rate da/dN, one obtains an equation for the applied stress-cycles to failure S-N curve that includes the residual stress effect on fatigue performance. In this process of calculation that fact that compressive residual stress has a much stronger influence on fatigue life than tensile residual stress is revealed, mainly because the former decreases the stress intensity factor range and increases the critical crack size while the latter only decreases the critical crack size. A numerical solution of an example illustrates an application of these concepts.
Precision of Early Shrinkage Measurements
Authors: Kass JL , Campbell-Allen D 
Published: February 2009

Abstract
A method has been developed for the determination of early shrinkage measurements of higher accuracy than previously attained. Its basis has been a consideration of thermal effects previously disregarded. Experiments have been devised in which movements due to thermal effects and drying shrinkage can be analyzed separately. Thus early drying shrinkage values can be determined without thermal shrinkage interference.
Fatigue-Crack Growth in Type 304 Stainless Steel Weldments at Elevated Temperatures
Authors: James LA 
Published: February 2009

AbstractThe propagation of fatigue cracks in gas-tungsten-arc weldments of Type 304 stainless steel was studied at 75 (24) and 1000 F (538 C). It was found that the crack growth rate for cracks propagating normal to the direction of welding decreased as the crack approached the weld, and then increased as the crack grew through the weld and out the other side. It is postulated that this is due to the residual stresses produced during the welding process, and that metallurgical variations in the weldment play a minor role.
Cyclic Stress, Strain, and Energy Variations under Cumulative Damage Tests in Low-Cycle Fatigue
Authors: Bui-Quoc T 
Published: February 2009

AbstractCumulative fatigue damage tests have been carried out on two pressure vessel steels at room temperature with five increasing or decreasing levels of stresses or strains. Variations of stress, strain, and energy are discussed. In the low-cycle region, the behavior of the materials is relatively more stable under strain-controlled than under stress-controlled tests. The total plastic energy at failure is dependent upon the strain range and not upon the strain ratio. A relation is suggested for estimating the plastic energy required for fatigue failure under cumulative damage tests. On a basis of absorbed plastic energy, both materials investigated have the same fatigue resistance at about 10,000 cycles at failure.
Evaluation of Creep Rupture Behavior of 1Cr-1Mo-0.25V Steel with 0.04 wt% Sn
Authors: Bashu SA , Singh K , Chowdary KM 
Published: February 2009

Abstract
Results of creep rupture testing of a commercial quality 1Cr-1Mo-0.25V steel forging with 0.04 wt% Sn at 500, 550, and 600°C over a range of stresses for periods varying from about 4600 to 27 000 h have been reported. Rupture lives were found to be higher and rupture ductilities to be lower than data available in the literature for a similar steel. Auger electron spectroscopic analysis of specimens creep tested at 500 and 550°C for 25 692 h and 27 203 h, respectively, revealed no perceptible segregation of Sn to grain boundaries. Thus Sn (0.04 wt%) does not appear to be responsible for the lower rupture ductilities observed in this investigation. Selected area electron diffraction of carbides extracted by carbon extraction replicas from interrupted creep specimens, currently in progress, may possibly explain the observed anomalies in the creep behavior.
X-Ray Residual Stress Measurements in Notched Test Specimens
Authors: Dowling NE , Hendricks RW , Ranganathan K 
Published: February 2009

Abstract
X-ray residual stress measurements were made in notched test specimens of 7475-T651 aluminum and annealed Ti-6Al-4V in a configuration designed to simulate fatigue testing in a tensile testing machine. An automated and portable X-ray stress analysis system with a position-sensitive proportional counter was used for making the measurements. Sources of error in the measurements resulted from counting statistics, grain size, and preferred orientation in the specimen, and the radius of curvature of the notch. The feasibility of in situ residual stress measurements during brief pauses in fatigue testing is demonstrated.
Strain-Hardening Characteristics of Aluminum-1050A, α-(70/30) Brass, and Austenitic Stainless Steel under Biaxial Loading
Authors: Makinde A , Ferron G 
Published: February 2009

Abstract
The biaxial strain-hardening behaviors of aluminum, α-brass, and austenitic stainless steel are characterized in plane and equibiaxial deformation paths using a novel low-cost biaxial device. These tests are complemented by conventional uniaxial tensile tests and by complex strain path studies consisting of uniaxial tension after biaxial pre-strain. The experimental results are analyzed and compared using two criteria of plasticity: von Mises and Hill. It is shown that different stress-strain curves obtained under different strain paths could not be correlated with the phenomenological yield criteria.
Evaluation Procedure for Low Cycle Fatigue Data
Authors: Foss SK 
Published: February 2009

Abstract
An evaluation procedure for low cycle fatigue data is described that uses engineering judgement as a primary evaluation tool, coupled with a computer and statistics. The procedure is suitable for micro or main-frame computers and can be used by technical personnel. Advantages of this procedure are speed, ease of use, and the ability to maintain automatically the integrity of all necessary equations and yield fatigue properties that can be employed in actual life predictions. The mathematical model used within the procedure is an extension of the S-log N curve and accounts for plastic strain which causes fatigue damage. This model, however, applies only to wrought metals, where internal defects do not govern fatigue life.
Effects of Testing Variables on Damping and Stiffness of Nailed Wood-to-Sheathing Joints
Authors: Polensek A 
Published: February 2009

Abstract
Specifications for experimental evaluation of nail-joint properties under dynamic and pseudodynamic loading are lacking. Because testing conditions affect joint properties, nailed joints between wood and plywood and between wood and gypsum wallboard were tested to determine the effect of the following factors on experimental damping and stiffness: specimen assembly technique, magnitude and rate of loading, and assumption of linear behavior in evaluating slip work. Nailing techniques controlled friction between contact surfaces, which in turn controlled damping and stiffness. Increasing loading rate increased damping and stiffness, but increasing load magnitude diminished both properties. Damping ratios were significantly lower when evaluation of equivalent viscous damping was based on linear, rather than nonlinear, behavior. Standard testing techniques are needed to achieve uniformity in dynamic testing of mechanically connected joints between structural wood materials.
Additives for Bitumen in Road Construction
Authors: Jain JP , Gupta AK , Khanna SK , Jain SS 
Published: February 2009

Abstract
In India most all-weather roads have bituminous surfaces. Properties of bitumen depend upon its source and manufacturing process. Bituminous surfaces sometimes fail prematurely, however, the most common causes are the effect of water and variation in temperature.
In this paper an attempt has been made to document the effects of some additives on conventional properties of bitumen. These properties are penetration value, softening point, ductility, and stripping value. The additives are derived from plants. Various tests have been conducted on a mixture of 80/100 grade bitumen and different types and percentages of additives.
A detailed investigation has been carried out on five additives which have been code-named A, G, S, T, and W. The test results indicate a definite trend in the variation of the conventional physical properties of bitumen for Additives A, G, and W and a spectrum of values with finite variation in the conventional properties for Additives S and T.
Comparison of Compliance Results for the Wedge-Loaded Compact Specimen
Authors: Underwood JH , Newman JC 
Published: February 2009

Abstract
Results of the ratio of stress intensity factor to crack-mouth displacement as a function of crack length are presented for the wedge-loaded compact specimen. Comparisons are made between experimental compliance results, numerical results from collocation methods, and deep-crack limit-solution results. Applications are for crack-arrest and stress-corrosion-cracking tests for metals and other materials under predominantly linear elastic conditions.
Fatigue Threshold Regime of a Low Alloy Ferritic Steel under Closure-Free Testing Conditions: Part II—Hysteresis in Near-Threshold Fatigue Crack Propagation: An Experimental Assessment
Authors: Vaidya WV 
Published: February 2009

Abstract
Near-threshold fatigue crack propagation behavior of a high strength steel was investigated in laboratory air under closurefrec testing conditions at R = 0.7 (= Rcff) and at two different K-gradients. Depending on the criterion assumed, the threshold value differed; the criterion of non-propagation gave a lower threshold value than that assumed by the propagation criterion. Nevertheless. the subsequent propagation following a load increase was discontinuous in both cases, and da/dN versus ΔK curves obtained on the some specimen during the K-decreasing and the K-increasing test were not necessarily identical in the threshold regime. This behavior, hysteresis, is analyzed mainly from the experimental viewpoint, and it is shown that hysteresis is not an artifact.
Fatigue Behavior of (BS 1470 N8-0) Aluminum Alloy and (BS 1501–510) Nickel Steel Double-Fillet and Tee-Butt Welds (Subject to Bending)
Authors: White GC 
Published: February 2009

Abstract
The shell to base welds of liquefied natural gas (LNG) tanks are normally double fillet welds, although in some tanks teebutt welds are used. The fatigue behavior of these welds has been examined by testing 134 full-size specimens. The testing examined the low cycle, high strain performance of the welds in air at +20°C and in liquid nitrogen at −196°C. The results from this work have shown that double fillet weld and tee-butt weld fatigue performance are comparable. The low temperature fatigue performance matched or exceeded that under equivalent ambient conditions. The shell to bottom welds used in British Gas LNG tanks have fatigue lives well in excess of that required for operational duty.
An Experimental Research Program on the Behavior of Stone Masonry Structures
Authors: Chiostrini S , Vignoli A 
Published: February 2009

Abstract
A program of experimental research on the seismic behavior of full-scale masonry specimens is discussed. The main part of this program was developed at the Department of Civil Engineering as part of the C.N.R.-G.N.D.T. (National Council of Researches, National Group for Earthquake Defense)-Subproject 2: Preveation of Building Damages-Working Group 2.2: Experimental Evaluation of the Seismic Behaviour of Structures coordinated research program.
The main objective of this project is to investigate the seismic behavior of commonly used stone masonry constructions in the Florence area. Laboratory and in situ tests were performed in order to assess the mechanical characteristics of stone masonry and its strength under shear forces. This paper presents the setup and results of laboratory diagonal tests of full-scale stone masonry specimens, in situ destructive shear tests, and in situ testing of masonry walls using the flat-jack technique.
Laboratory Study of Microtexture-Related Skid Resistance Characteristics of Concrete Pavement Materials
Authors: Fwa TF , Tan CC 
Published: February 2009

Abstract
This paper reports the results of a laboratory test program conducted to study the variations of microtexture-related skid resistance of concrete materials with moisture condition, measurement temperature, and surface polishing. The materials used for concrete pavement construction in Singapore were studied. Surface wetting was found to produce a surface-wet frictional resistance considerably lower than the initial surface-dry value. However, neither the surface-wet nor surface-dry measurement was affected by the degree of moisture saturation of the materials tested. Surface temperature had a strong influence on the results of surface-wet tests, but not the surface-dry tests. The temperature-dependent variations was highly correlated to either measurement temperature or viscosity of water, always showing a coefficient of correlation exceeding 0.94 in absolute value. Polishing had the effect of reducing both surface-wet and surface-dry resistance. However, cement mortar specimens were found to respond differently from granite and steel slag aggregates due to differences of their surface wear behaviors in the process of polishing.