bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low-Cycle Fatigue Analysis of Notched Members
Authors: Zhang D , Sandor BI 
Published: February 2009

AbstractLow-cycle fatigue crack initiation and propagation lives of notched members are investigated. By relating Nci(ΔJ/ψρ)β = Cn to the Coffin-Manson equation and correlating to test results, β and Cn are found to be functions of several parameters: cyclic stress-strain constants, geometry of notch (depth and curvature), and stress ratio. (ΔJ/σ′y) is chosen as a parameter for crack propagation in notched members. Fatigue crack initiation and propagation tests were conducted on notched plate specimens of different notch radii and stress ratios. Crack initiation life, crack propagation life, and total fatigue life are compared with the calculations. There are good correlations between the test results and the calculations.
Chevron-Notched Specimens for Fracture Toughness Measurements Independent of R-Curve Effects
Authors: Barker LM 
Published: February 2009

Abstract
A relatively new plane-strain fracture toughness test method based on chevron-notched test specimens has created a keen interest in comparing toughness measurements by the new method against measurements by the conventional method (ASTM E 399). Tests of various aluminum alloys by the two methods have shown a divergence in test results at the higher toughness levels. The rising R-curve effect in tough aluminums has been cited as one of the factors contributing to the observed discrepancy. This paper shows why the chevron-notched test results are independent of rising R-curve effects, whereas ASTM E 399 tests often are not. The E 399 test dependence on the rising R-curve constitutes a specimen size effect, and this dependence is partly responsible for the divergence between chevron-notched and E 399 tests of tougher aluminums. The chevron-notched method produces the toughness values which would be obtained from E 399 measurements if sufficiently large E 399 specimens could be tested.
Effect of Strain Rate and Temperature on the Mechanical Anisotropy of Recrystallized Zircaloy TREX (Tube Reduced Extrusion)
Authors: Hussien SA , Murty KL 
Published: February 2009

Abstract
Tube Reduced Extrusion (TREX) is an intermediate product in the production of Zircaloy canning tubes for nuclear reactors. This paper studies the mechanical anisotropy, which has a direct relation to the formability of recrystallized Zircaloy-2 TREX. The yield stresses, as well as the anisotropy parameters (R and P) in the modified Hills equation, are evaluated using impression testing as a function of test temperatures and strain rates. The impression test offers a rather direct way for evaluating R and P through the uniaxial yield stresses along the three orthogonal directions. The anisotropy of the yield stress is evident at low test temperatures and decreases at high temperatures. The anisotropy parameter R is insensitive to test temperature (room temperature to 623 K) and strain rate (10−2 to 10−3s−1) and has a value close to unity. The P parameter decreases with increasing test temperature, approaching unity at 623 K.
There is a general trend for the anisotropy parameters to approach unity (the isotropic case) with increasing test temperature. This may be due to the activation of secondary slip systems. The linear relationship between compression and impression stresses, established at different test temperatures, is insensitive to the test temperatures within our range; it is in good agreement with the literature.
Evaluation of Performance of Three Slip Resistance Testers
Authors: Kulakowski BT , Buczek FL , Cavanagh PR , Pradhan P 
Published: February 2009

Abstract
Injuries and deaths from falls due to slipping on walking surfaces have been recognized as a major accident problem in many countries. The safety of walking depends primarily on the surface slip resistance, which is defined as the ratio of (a) the minimum shear force necessary to initiate slipping of a body over the surface to (b) the body's normal force. Several kinds of devices are currently in use to measure slip resistance. In this paper three slip resistance measuring devices are evaluated: the National Bureau of Standards-Brungraber Tester, the Horizontal Pull Slipmeter, and the Pennsylvania Transportation Institute Drag Sled Tester. The testing program consisted of two phases. In the first phase each tester was used to measure the slip resistance of selected surfaces representing a wide range of frictional characteristics of typical indoor and outdoor surfaces. All tested materials were in actual use on walking surfaces. In the mechanical tests the testers were evaluated with respect to their applicability, precision, repeatability, and sensitivity to the operator's measuring technique. The correlation was determined between the results produced by the testers on the same surfaces.
In the second phase of the testing program a series of experiments was conducted with human subjects walking over surfaces having relatively low slip resistance. The objective was to determine whether people will slip more often on surfaces which are measured as having lower slip resistance. In general, the agreement between the results of slip resistance measurements and the results of the biomechanical tests was high. It was observed, however, that the process of slipping involves a considerable randomness.
A Comparison of Test Methods for Shear Properties of the Cores of Sandwich Constructions
Authors: O'Connor DJ 
Published: February 2009

Abstract
ASTM C 273 and BS 4370 single block tests for shear properties of sandwich cores are critically examined. A previous appraisal using finite element modelling is highlighted and extended to include the effects of stress concentrations. Overall performance is assessed by selected laboratory programs and comparisons with panel test and flexural test methods. The ASTM method is shown to give accurate results generally. Modifications are required to the BS 4370 method. Problem areas with regard to theoretical stress concentrations in both methods are identified in relation to the test for shear strength.
Dynamic Reconciliation Algorithm Used on a High-Purity Propylene System
Authors: Bozenhardt H 
Published: February 2009

Abstract
One of the most pervasive and chronic problems in the processing industries is the control of unit operations with substantial dead-time. Dead-time can be the result of large multi-staged or interunit operations. This paper deals with a process that contains both types of dead-time.
All too often dead-time and intertower controllability are problems handled (actually mishandled) by building “safety margins” into targets and allowing the unit's operations to cycle as long as all cycles are within an “acceptable” zone. This paper attacks the dead-time problem with simple, yet effective, methods and demonstrates substantial economic savings. This paper is intended for process control engineers and those in operations management.
Fatigue Performance of AISI 1140 Modified Steel
Authors: Hertzberg RW , Vecchio KS , Schmidt FE 
Published: February 2009

Abstract
A study of the fatigue behavior of modified AISI 1140 resulfurized steel containing manganese (1.05 to 1.25%) and sulfur (0.16 to 0.23%) was conducted at room temperature under load-controlled conditions. Monotonic and cyclic mechanical tests were conducted with samples possessing a “C” shaped ring configuration; a finite element analysis was used to establish the stress levels appropriate to the “C”-ring specimen. Quantitative S-N and Goodman (1) diagrams were determined, based on cyclic stresses representing different fractions of the ultimate strength of the material. A toughening mechanism is postulated that accounts for the interaction between the advancing crack front and the duplex microstructure which includes finely oriented manganese sulfide (MnS) stringers encapsulated in the ferrite phase.
Fractography of AISI 1140 Modified Steel under Static and Cyclic Loading Conditions
Authors: Vecchio KS , Hertzberg RW , Schmidt FE 
Published: February 2009

Abstract
The fracture behavior of modified AISI 1140 resulfurized steel containing manganese (1.05 to 1.25%) and sulfur (0.16 to 0.23%) has been studied under controlled fast fracture and fatigue fracture conditions. “C”-shaped ring samples were machined from tubes hammer forged at 700°C by the GFM process (Gesellschaft für Fertigungstechnik und Maschinenbau [AG] manufactured in Steyr, Austria) so as to develop a highly fibered (axial) microstructure. The microstructure of the material was evaluated and compared with the fracture surface morphology as a function of loading history. It was determined that the MnS inclusion stringers were encapsulated within the ferrite phase and that static fracture progressed along the stringer-ferrite interface. Conversely, fatigue cracks as evidenced by the presence of fatigue striations propagated mainly within the ferrite phase.
Applicability of the Southwell Plot to Shear Deformable Columns
Authors: Koh CG , Kelly JM 
Published: February 2009

Abstract
This paper examines the applicability of the Southwell method to predict the buckling load of columns where the shear deformation cannot be neglected. It is shown by mode superposition that the convergence of the series solution to the buckling mode is slow, since there are two critical loads of the same order associated with the first mode shape for rotation of the cross section. More important, the Southwell plot is not linear even when only one mode shape (corresponding to the lowest critical load in compression) is considered. An example of numerical simulation demonstrates that linearly fitting the Southwell plot can lead to significant errors in the prediction of the buckling load. The accuracy of buckling load determined by the Southwell method for typical elastomeric isolation bearings is also discussed.
The Concept of Filament Strength and the Weibull Modulus
Authors: van der Zwaag S 
Published: February 2009

Abstract
The strength of high-performance filaments is a complex parameter which can not be fully described with a single value. The Weibull model is used to describe the intrinsic statistical nature of the fracture strength. Possibilities and limitations of the Weibull model are illustrated. The relationship between material properties and the parameters in the Weibull model is discussed.
An Encapsulation Technique for Conducting Mechanical Properties Tests of Metallic Specimens in a Controlled Environment without a Retort
Authors: Kschinka BA , Marriott DL , Stubbins JF , Vassos N 
Published: February 2009

Abstract
A novel technique to encapsulate metallic mechanical properties test specimens in a controlled atmosphere has been developed that eliminates the need for cumbersome retort systems. The procedure consists of brazing stainless steel flexible bellows tubing on a test specimen in such a manner that the tubing acts as a miniature retort around the gage section of the specimen. While convenient, this method demands a special correlation relating strain in the gage section to displacement between the specimen shoulders in order to conduct displacement-controlled fatigue tests. Results of such tests using vacuum encapsulated specimens were generally excellent and agreed reasonably well with data from related studies, supporting the validity of both the encapsulation technique and the subsequent correlation.
Rotation Corrections in Three-Point Single Edge Notch Bend Specimens
Authors: Perez Ipiña JE , Santarelli EL 
Published: February 2009

Abstract
In elastic-plastic fracture toughness tests of three-point single edge notch bend (3P-SENB) specimens, very ductile materials suffer significant distortions from their initial geometrical configuration, producing large rotation angles of the arms and causing the rollers to move out and detach themselves. These effects should be taken into account when the Unloading Compliance Method is employed to obtain the slow stable crack growth, because the equations are calculated for the initial condition of null rotation angles.
Experimental measurements of the span change for 3P-SENB specimens with different rotation angles and under several conditions were obtained. The results were compared with other authors' results and with those corresponding to CT specimens. Expressions for the corrected values of span and compliance were deduced, and the errors for not using the corrections were estimated. Conditions that give minimal errors were also documented.
A Method to Obtain Ideal Fatigue Crack Propagation for Steels
Authors: Masuda H , Matsuoka S 
Published: February 2009

Abstract
To predict fatigue crack growth rates under variable loading conditions, a new fatigue test method was developed. Fatigue crack propagation properties were studied for HT80, SM50B, and SUS304 steels. Test results showed that the acceleration of the crack propagation rate occurred at low ΔK regions when the intermittent compressive overload was applied. The maximum acceleration of crack propagation was dependent on both the frequency and amplitude, of the overload. When the compressive overload is frequently applied, the crack propagation rate becomes proportional to the second power of ΔK.
These accelerations of the crack propagation rate under compressive overloading conditions were discussed with respect to the deformation mode at the crack tip.
Flow of Semi-Solid Foods over Inclined Packaging Surfaces as an Index of Traction
Authors: Lai CC 
Published: February 2009

Abstract
A modified tilted plane procedure was evaluated for characterizing the traction property of fluid or semi-solid foods in contact with packaging surfaces. The method was shown to be a useful technique as demonstrated by studying the flow of tomato sauce, salad dressing, and mustard paste over five commonly used polymeric packaging film surfaces.
Establishing Criteria for a Computerized Vision Inspection of Holes Drilled in Carbon Fiber Composites
Authors: Hough CL , Lednicky TE , Griswold N 
Published: February 2009

Abstract
Two basically different carbide bit designs, a dagger bit and a standard twist drill, were tested extensively in graphite/epoxy composite material. A commercially available computer vision system was utilized to evaluate hole quality as the bits wore for fraying, delamination, and hole tolerance. Methods and procedures for establishing acceptance criteria using the vision system are given. Based on manual acceptance criteria, vision system criteria were established for fraying and suggested for entrance delamination.
Fatigue Life Prediction in Flexural Bending of Hollow Cross-Sectional Bars from Axial Fatigue Information
Authors: Muralidharan U 
Published: February 2009

Abstract
Bending fatigue results in the low cyclic life range often differ from those of axial fatigue due to the plastic flow, which alters the linear stress-strain relation normally used to determine the nominal stresses. An approach was presented and an equation derived in earlier work to take into account the plastic flow in calculating nominal bending stress based on actual surface stress for solid rectangular and circular cross-sectional bars. The flexural bending fatigue life prediction of bars with hollow cross sections is addressed in this paper. An equation is derived for calculating the nominal bending stress versus life curve for hollow cross sections that depends directly on the functions derived for the solid section of the same geometry, and k, the ratio of inner to outer dimensions. The nominal bending stress versus life curves are shown for the case of hollow circular sections for six typical materials for various k values.
Chimney Venting Performance Study
Authors: Timusk J , Seskus AL , Selby KA , Rinella J 
Published: February 2009

Abstract
An investigation was undertaken to determine the levels of house depressurization against which naturally vented gas-fired furnaces and domestic water heaters can establish and maintain safe venting of combustion products. Also investigated were the maximum depressurizations of buildings which could be achieved by the installed fans and fireplaces. A test procedure was developed whereby venting failure can be artificially induced by depressurizing the house with a large fan. Results show that it is highly improbable that the maximum depressurizations found in houses by operating all the fans and the fireplaces at the same time will cause the chimney to vent improperly even in conditions under which venting failure would be most likely to occur (cool temperatures, low wind, cold chimney, large number of exhaust fans, weak venting furnace/chimney combination, relatively tight house).
A Microcomputer-Aided Four-Point Bend Test System for Determining Uniaxial Stress-Strain Curves
Authors: Yokoyama T 
Published: February 2009

Abstract
A microcomputer-aided four-point bend test system has been developed for determining the tensile and compressive stress-strain curves, as well as elastic constants, for a material from a single bend test. A special four-point bend fixture has been designed and constructed to minimize loading errors which may occur in the tests. Microcomputer software has been developed for processing the large amount of data obtained from each bend test. Two kinds of cast iron (ASTM A48 and A536), which exhibit different stress-strain characteristics in tension and compression, have been tested to examine the validity of the test system for a limited range of strain. It has been shown that the stress-strain relations derived from the bend tests are in good agreement with those obtained directly from the uniaxial tension and compression tests for strains less than about 5%. The advantages and limitations of the bend tests are also discussed.
J1c Measurements on Single Subsized Specimens of Ferritic Alloys
Authors: Huang F-H 
Published: February 2009

AbstractFracture toughness tests on subsized, circular, compact tension specimens of ferritic alloys were performed at temperatures ranging from −192 to 427°C. Test results for 9Cr-1Mo show that the electropotential single specimen method agrees well with the multiple specimen method in determining the upper shelf J1c. The ductile-brittle transition temperature and lower shelf toughness of HT-9, tested at loading rates of 2.1 × 10−5 and 3.2 × 10−2 m/s. were also determined using the J-integral approach. The size criteria for valid J1c values, for a wide range of test temperatures, were satisfied by the subsized specimen used in this work.
Stress Intensity Factors for Notched Configurations
Authors: Baratta FI 
Published: February 2009

AbstractA method is presented for approximating stress intensity factors for notched-configurations without cracks. It is expected that estimates obtained from such analyses, which are outlined in the text and detailed in the Appendix, should be useful in estimating the failure load in a notched structure behaving in an idealized elastic manner. Additionally, this approach will allow an estimate of the magnitude of load required to precrack fracture toughness specimens having crack starter notches.Several notch geometries and loadings are investigated, such as a V-notch, to first illustrate the method of analysis and compare results with those in the literature and to also establish merit and accuracy limits of the method. Two additional cases are then solved, both for finite width tensile sheets, one having symmetric U-notches and the other employing a central slot with finite radii at each end. Both cases are reduced to their end limit: a U-notch in a sheet of semi-infinite width and a circular hole in an infinitely wide sheet. The resulting approximations agree well with limited available data.Finally, to aid the experimentalist who either uses the compliance approach or a photoelastic analysis to obtain stress intensity factors, the question of how deep or how long a side-edge U-notch or a central slot compared to its radius should be to simulate a crack, is provided.
Effect of Misalignment on the Time to Rupture
Authors: Schmieder AK 
Published: February 2009

Abstract
The materials tested were a low-alloy steel in three conditions of heat treatment and a high-alloy steel in two conditions of heat treatment. The heat treatments were chosen to provide specimens with various notch strength ratios. Notch rupture tests of these five materials were made with various degrees of misalignment. When heat treated to attain the highest notch strength ratio, the low-alloy steel showed no significant change in time to rupture for the range of misalignment tested. The corresponding high-alloy steel specimens showed approximately 3% reduction in time to rupture for each 1% increase in bending strain. For the high-alloy steel, the amount of reduction in time to rupture appears to be almost independent of the notch strength ratio. In contrast, the low-alloy steel showed a reduction in time to rupture of approximately one half that of the high-alloy steel at a notch strength value near unity and almost twice that of the high-alloy steel at the lowest notch strength ratio tested.
Correction of the Results of Standard Fire Resistance Tests
Authors: Harmathy TZ 
Published: February 2009

Abstract
The ASTM Method for Fire Tests of Building Construction and Materials (E 119) empirical formula for correcting the results of fire resistance tests is examined in the light of the normalized heat load concept. The formula, on the whole, does not contradict theoretical conclusions, but its accuracy is questionable. Under practical conditions the corrections is not expected to amount to more than a few minutes.
Poisson's Ratio As Determined for Elastic and Plastic Deformation and for Monotonic and Cyclic Loading—Part I: Critical Review
Authors: Rahka K , Laird C 
Published: February 2009

AbstractPoisson's ratio is defined strictly on the assumption that the material is homogeneous. In applications of Poisson's ratio to mechanical problems, this assumption can be overlooked. To check whether the assumption applies to monotonic and cyclic loading, we review measurements of Poisson's ratio, or rather the ratio of diametral strain to axial strain. Such measurements are quite rare for cyclic deformation. However, they show that the ratio of diametral strain to axial strain can differ from values expected on the basis of traditional values of Poisson's ratio for elastic and plastic deformation. The technical consequences of this difference are indicated.
R-Curve Round-Robin Program for ASTM Recommended Practice for R-Curve Determination (E 561)
Authors: Pearson HS , McCabe DE 
Published: February 2009

Abstract
A round-robin program sponsored by ASTM Task Group E24.01.02 on Crack Growth Resistance Curves was conducted to establish guidelines on variability for a Precision and Accuracy statement for ASTM Recommended Practice for R-Curve Determination (E 561). Two high strength aluminum alloys were tested by seven participants using the compact configuration specimen. The results of these tests are summarized herein, and a Precision and Accuracy section given along with variability at four levels of effective crack growth.
Determination of Calibration Constants for Hole Drilling Technique Using Special Strain Gage Rosette
Authors: Jayarama Rao G , Ravi Sankar K , Narayanan R 
Published: February 2009

Abstract
Experimental evaluation of calibration constants using a specially designed indigenous strain gage rosette is presented. Performance of this indigenous rosette is compared with an imported rosette and theoretical results. The calibration constants can be used for the determination of residual stresses in structural components by the hole drilling technique.