bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inelastic Stress-Strain Predictions for Multiaxial Fatigue Damage Evaluation
Authors: Tipton SM , Bannantine JA 
Published: March 2009

The inelastic stress-strain response of a material subjected to complex loading must be known or estimated in order to predict the fatigue life of a component using many current multiaxial fatigue damage models. This paper presents stress-strain predictions obtained using two incremental plasticity algorithms for several nonproportional loading paths.
The two algorithms both employ von Mises yield surfaces with kinematic hardening. However, one algorithm translates a single yield surface within a stationary limit surface using the hardening rules specified by Mróz and invokes a radial return for neutral loading. The other algorithm translates multiple yield surfaces (or a field of plastic moduli) according to a modified Mróz hardening rule proposed by Garud with no neutral loading provision. The algorithms are used to predict stress histories that are compared with measured responses from strain-controlled tests on normalized 1045 thin-walled tubes. A variety of nonproportional load paths were investigated. In general, relatively good agreement between predicted and measured stress-strain response for the two algorithms was observed for application to multiaxial fatigue evaluation. Strengths and weaknesses of each model are discussed.
Mixed Mode Fatigue Crack Growth Behavior in a High-Strength Steel
Authors: Link RE 
Published: March 2009

Most of the currently available methods for predicting fatigue crack growth in structures do not consider effects due to mixed-mode loading. This is partly due to the limited information available concerning the fatigue crack growth under mixed mode loading. Previous investigations of mixed mode effects on fatigue crack growth have shown that under combined opening and in-plane shear loading, the cracks turn abruptly so that the in-plane shear mode is eliminated [1–3]. Very little data are generated before the crack curvature eliminates the mixed mode loading. The changing orientation of the crack during the test makes analysis of the problem difficult and may cloud the intrinsic fatigue crack growth rate behavior under mixed mode loading. Situations can exist in engineering structures in which cracks may grow in a self-similar manner even under the influence of mixed mode loading. Examples of such situations are radial cracks in bearing races [4] and transverse cracks in rotating shafts under shear and bending loads. The cracks may not change orientation because the in-plane shear component is fully reversed. It is necessary to understand the effects of mixed mode loading on fatigue crack growth in order to properly predict the behavior of these components.
This paper presents the results of an investigation to measure the fatigue crack growth rate of a high-strength steel under various ratios of mixed mode loading while maintaining self-similar crack growth. A primary objective of this investigation was to generate data for relatively large amounts of crack growth under a wide range of mixed mode ratios. Several models for predicting the mixed mode fatigue crack growth rate from opening mode data are evaluated based on the data generated in this investigation.
Crack Curvature in Thin Cylinder Failure
Authors: Fyfe IM , Guo ZH , Guo ZK 
Published: March 2009

An investigation was conducted on the role played by different factors on the directional stability of cracks in pressurized thin-walled cylinders under fatigue loading conditions. In addition to internal cyclic pressure, the test system was designed to allow axial loads to be applied independently. Fractional factorial design techniques were used to determine the interaction between a number of different parameters which could possibly control the crack path direction.
This statistical analysis shows the importance of the key experimental parameters and the interaction of these parameters on the crack path. It also serves to show that, although crack length and pressure control the bulge characteristics, a symmetric bulge in itself only plays a part in determining the stability of the crack path but not the direction. Another aspect of the study was examining the possible mechanisms which control the direction taken by an inherently unstable crack and the effect these mechanisms could have on the KII/KI ratio associated with the theoretical models of crack growth direction.
Notch Root Inelastic Strain Estimates Using GLOSS Analysis
Authors: Seshadri R , Kizhatil RK 
Published: March 2009

Inelastic strains in notched mechanical components and structures can be predicted with reasonable accuracy using the generalized local stress strain (GLOSS) method of analysis. The GLOSS diagram is essentially a normalized stress-strain plot of a “local” region that is subjected to greater inelastic strains as compared to the “remaining” region. Inelastic response of the local region due to plasticity and creep is simulated by artificially lowering the stiffness of the nominally inelastic region. Thus, inelastic strains at the root of a notch can be estimated on the basis of two linear elastic finite element analyses per point on the load-notch strain curve.
The theory underlying GLOSS analysis essentially relates the inelastic multiaxial stress redistribution in the local region to the uniaxial stress relaxation process. The varying degrees of interaction between the local and remaining regions, which are characterized by the “constraint parameter,” enable the determination of inelastic strains when used in conjunction with the cyclic stress strain curve.
The GLOSS method of analysis can be used to estimate inelastic effects for realistic notch geometries and component loadings. The method can be applied in a routine manner to a range of inelastic zone sizes. The incorporation of an Irwin's type of correction to the plastic zone enables reasonably accurate determination of the inelastic notch strains for the purpose of low-cycle-fatigue evaluations. The GLOSS method is applied in this paper to several geometric configurations of practical interest.
The Development of Bearing Steels for Long Life Rolling Bearings Under Clean Lubrication and Contaminated Lubrication
Authors: Furumura K , Murakami Y , Abe T 
Published: March 2009

Nearly ten years have passed since the LF-RH-CC process was adopted in the production of bearing steels. This process has become a common system for steelmakers, regardless of using EFs or BOFs as melting furnaces. The current cleanliness level of bearing steels shows a remarkable improvement when compared to that of ten years ago. The oxygen content in most steels has reached the high level of cleanliness of less than 10 ppm throughout the world. The bearing life in laboratory tests has been extended by several times in the last ten years.
However, in the fields of engineering and technology of bearing production and applications, it is still a matter of primary concern how to settle the problems of inside and outside debris— that is, how to grasp quantitatively and control accurately nonmetallic inclusions in steels and how to deal with outside debris that penetrates into the bearings exposed to application environments. This paper presents the latest results of studies relating to these timely problems.
Bearing Material/Treatment Developments at the SKF Engineering and Research Centre
Authors: Beswick J , Voskamp A , v. d. Sanden J , Verburgh M , Horton S 
Published: March 2009

The Engineering and Research Centre of the SKF Group (SKF ERC) is involved in the development and evaluation of materials for bearings.
Physical metallurgy activities include advanced electron microscopy studies, in particular, relating microstructures to bearing functional properties. The microstructure is affected to a great extent by the composition, prior processing, and applied heat treatment and some of these relationships are described in the paper.
Fatigue investigations involve the definition of the fatigue process in bearing materials. The major discoveries on fatigue processes in steels, in recent years, have been made by the use of X-ray diffraction techniques. By the application of a “pole figure” measurement program it has been quantitatively established that significant texture develops during contact fatigue, resulting in the characteristic contact fatigue spall shapes related to the application conditions.
Ceramic powder processes are of interest for bearing products and silicon nitride has the best combination of mechanical and physical properties of the current engineering ceramics. At SKF ERC the necessary specifications and quality assurance procedures have been developed in order to select and approve specific types and grades of material for ceramic bearing manufacture.
Bearings are sometimes used in situations that are incompatible with the properties of the commonly used bearing steel grades. In such cases, coating processes may be used to tailor the surface properties of bearing components to specific application conditions. The development or evaluation, or both, of such processes takes place at SKF ERC which is equipped with various surface treatment facilities and test equipment for such coatings. Examples of coated bearing products are described in the paper.
Advances in the Production of Bearing Steels by Modern Secondary Metallurgy and Continuous Casting
Authors: Kremer K-J , Jung H-P , Peschke G , Rakoski F 
Published: March 2009

Advanced production routes for billets, bars, and wire-rods for bearing application are discussed. The influence of modern secondary metallurgy, continuous casting, heating, rolling and heat-treatment on the critical product properties, especially non-metallic inclusions and microstructure, is presented.
Never-ending process improvement is the key to ensuring high consistency, reliability, and profitability.
Oxygen Compatibility of Metals and Alloys
Authors: Lowrie R 
Published: March 2009

The oxygen compatibility of metals and alloys is highly important because they constitute the major part of most oxygen systems. The recent development of semi-standard tests for metal specimens has greatly increased our understanding of the ignitability and combustibility of commonly used metals and alloys. The results of such testing are summarized and discussed for the major alloy groups.
The need for interaction among material choice, component and system design, and operational procedures to arrive at the most economical safe solution is stressed. Some possible ways for producing metals or alloys with decreased combustibility in oxygen are suggested.
Insidious Iatrogenic Oxygen-Enriched Atmospheres as a Cause of Surgical Fires
Authors: de Richemond AL , Bruley ME 
Published: March 2009

During many surgeries, the risks of fire exist because heat sources (e.g., electrosurgical probes, lasers) are used close to fuels (e.g., tracheal tubes, body hair, surgical drapes) in oxygen-enriched atmospheres (OEA). When the OEA is recognized as a hazard, precautions are taken to reduce the risk, e.g., minimizing oxygen concentration prior to use of electrosurgery.
However, some actions of the surgical team can lead to one of two types of OEAs that are not readily recognized by, or apparent to, the surgical team as a hazard. One type involves entering a body cavity that contains an OEA, during tracheostomy for example.The other type has an OEA developing around the surgical site as can happen when a misplaced or leaking breathing circuit is under the surgical drapes. With regrettable frequency in these cases, a surgical fire results.
This paper discusses several cases of fire during surgery that involved insidious oxygen-enriched atmospheres. Recommendations to prevent and to deal with such fires are also presented.
Promoted Ignition-Combustion behavior of Carbon Steel in Oxygen Gas Mixtures
Authors: Mcllroy K , Million J , Zawierucha R 
Published: March 2009

Promoted ignition-combustion is a term which has been used to describe a situation where a substance with poor oxygen compatibility ignites and supports the combustion of a more resistant material. Previous papers on the subject in recent years have reported on the investigation of this phenomenon as it related to carbon steel, stainless steels and a number of engineering alloys. However, the bulk of these investigations have involved relatively high pressures.
Carbon steel is a common alloy used in the construction of equipment used in industrial gas applications. Yet, promoted ignition-combustion test data on carbon steel samples showing the effects of variables such as test pressure, oxygen purity, temperatures, section size, promoter types, etc. on promoted ignition-combustion behavior are scarce; particularly, at low pressures.
In this investigation, the promoted-ignition combustion behavior of carbon steel was studied in oxygen-nitrogen gas mixtures over the pressure range of 0.118 MPa to 0.446 MPa with oxygen purities ranging from 70% to 99.7%. Comparative tests were made using 3.175 mm and 6.35 mm diameter rods at pressures up to 0.273 MPa. Over the pressure and purity ranges tested, there was little difference due to size effects. Carbon steel burns occurred at pressures as low as 0.118 MPa with oxygen purities of 95% and above, in the promoted ignition-combustion tests.
Pressurized Flammability Limits of selected Sintered Filter Materials in High-Pressure Gaseous Oxygen
Authors: Schadler JL , Stoltzfus JM 
Published: March 2009

Previous promoted combustion tests have demonstrated that the threshold pressure (the minimum oxygen pressure required to self-sustain combustion) of various engineering alloys is dependent on the configuration of the sample. Monel 400, when configured as a 3.2-mm (0.13-in.) -diameter rod, has a threshold pressu re 500 times greater than when configured as a 60 × 60 wire mesh constructed of 0.19-mm (0.0075-in.) -diameter wire. Sintered filter elements, often used in oxygen systems, have finely divided construction (a high surface to volume ratio) similar to a wire mesh configuration. This similarity raises the question whether the threshold pressure data for the 3.2-mm (0.13-in.) -diameter rod, the wire mesh, or neither should be used for various alloys configured as sintered filter elements.
This study was conducted on three engineering alloys configured similar to sintered filter elements. Monel 400 powder, 316L stainless steel (SS316L) powder, and three types of tin-bronze powder were sintered into rods ranging in diameter from 3.2 to 6.3 mm (0.13 to .25 in.), with pore sizes representative of 3- to 150-μm-rated filters. Each sample was mounted vertically in a 12.4 liter (757 in.3) vessel and ignited at the bottom using an aluminum-palladium igniter wire. For each sample a threshold pressure was determined.
The test results indicated that the sintered Monel 400 and the sintered SS316L have threshold pressures closer to the wire mesh than 3.2-mm (0.13-in.) -diameter solid rods. As tested, the Monel had a threshold pressure of 0.69 MPa (100 psig) and the SS316L had a threshold pressure of White Sands Test Facility ambient, 82 kPa (12 psia). Except for two grades of A type sintered tin-bronze, all the sintered tinbronzes had threshold pressures above 68.9 MPa (10000 psig). Grade 153A and grade 103A had threshold pressures of 68.9 MPa (10000 psig) and 37.9 MPa (5500 psig), respectively. The results indicate that P or HP types of sintered tin-bronze filter elements are preferred for use in oxygen systems.
Modeling of Al And Mg Igniters Used in the Promoted Combustion of Metals and Alloys in High Pressure Oxygen
Authors: Steinberg TA , Wilson DB , Benz FJ 
Published: March 2009

NASA determines flammability of metal and alloy samples in high pressure oxygen by Test 17 of NHB 8060.1C. An aluminum or magnesium promoter, releasing at least 3.0 kJ, is used as the sample ignition source. This ignition system is modelled using lumped-parameter mathematical equations and solved using the MATLAB computer code. Model parameters were obtained from the combustion of Al and Mg promoters on copper rods in the standard flammability instrument system. The copper rod is non-flammable under test conditions, that is, pure oxygen pressures of 3.44, 6.89, 20.7, 34.4 and 68.9 MPa. At test conditions, both aluminum and magnesium alloyed with the copper rod and burned in liquid phase reactions. The following heterogenous kinetic reaction rate functions were obtained: for Al: RAl=0.102Po21.+0.186Po2,g/m2s for Mg: RMg=0.067Po21.+0.146Po2,g/m2s.
The model is validated by comparing ‘time-to-ignition’ values for iron samples with measured experimental time-to-ignition for this material. Model predictions are between −5 to +28% of measured values. This work also provides ‘burn-rates’ for bulk aluminum and magnesium as functions of oxygen pressure.
Compatibility of Aluminum Packing with Oxygen Environments under Simulated Operating Conditions
Authors: Zawierucha R , Million JF , Cooper SL , McIlroy K , Martin JR 
Published: March 2009

High surface area aluminum structured packings are possible components in cryogenic distillation columns used for air separation. Recently published literature has reported on the occurrence of strong energy releases involving aluminum structured packing which was subjected to flammability tests in the presence of liquid oxygen using strong thermite and magnesium promoters, under conditions which may not be typical of operating conditions in a cryogenic distillation column.
An experimental program was conducted to determine the compatibility of aluminum packing under test conditions which more closely simulated actual column operating conditions. The effects of various thermite, magnesium, hydrocarbon and metal promoters were evaluated in LOX/GOX environments with a nominal oxygen purity of 99.9% at pressures up to 0.17 MPa.
A major finding was that aluminum packing which was “irrigated” with LOX but not immersed in LOX did not experience severe energy releases in flammability tests up to a maximum pressure of 0.17 MPa at a nominal oxygen purity of 99.9 %. This simulated column operating conditions. Elimination of packing “irrigation” and immersion of the aluminum packing at one end in LOX resulted in a severe energy release in one test conducted at 0.16 MPa. The latter result verified recent literature reports but was not considered representative of packing operating conditions.
Of particular interest in this paper are details and schematics of a pressurized test vessel which was designed for the program. This test apparatus is capable of providing various combinations of packing immersion and irrigation, thereby simulating actual operating conditions.
The Behaviour of Oil Films on Structured Packing Under Cryogenic Conditions
Authors: Kirzinger A , Baur K , Lassmann E 
Published: March 2009

Today structured packing is commonly applied in cryogenic air separation plants. Packing is typically characterised by a high surface-to-volume-ratio. Due to the large surface of packing in comparison to common sieve trays — provided equal amounts of oil are attached to surfaces more organic material may be present within a low pressure column of an air separation plant. Since an enrichment of organic material in an air separation plant or in liquid oxygen is a principal hazard and a major accumulation of organic material magnifies this risk, experimental tests were conducted to determine whether chipping of oil at cryogenic temperatures is possible.
Tests are discussed where single sheets of a packing segment had been coated with an oil film of definite thickness. The oil coated sheets were rinsed by moving them up and down in liquid nitrogen or in liquid oxygen. After fixed time intervals the oil content of a single sheet was determined.
It was concluded that the original oil residue on the sheets up to 250 mg/m^ remained attached to the packing surface and no decrease of oil was found within the accuracy of the oil determination method.
A Critical Review of Flammability Data for Aluminum
Authors: Werley BL , Barthélémy H , Gates R , Slusser JW , Wilson KB , Zawierucha R 
Published: March 2009

Aluminum is one of the more thoroughly studied metals for flammability properties. Results with aluminum in both the laboratory and the field have been mixed and experimentalists have obtained significantly differing data through the years, partly due to differing goals for application of the data. The literature contains data from ignition testing, propagation testing and heat of combustion testing. Ignition testing includes: autoignition temperature, liquid oxygen mechanical impact, friction, shock wave, resonance, promoter influence, fresh-metal exposure, and particle impact. Propagation testing includes: promoted combustion, propagation velocity, flammability limits, and alternative oxidants. Theory has been developed, but has not allowed prediction of aluminum's performance in specific applications.
Data and theory from more than one hundred sources and previously unpublished results of the contributing author's companies spanning the last forty years are abstracted and commentary is offered on experimental design, results and application to current-day loss prevention design of aluminum/oxygen systems.
An Investigation of Laboratory Methods for Cleaning Typical Metallic Surfaces Using Aqueous Type Cleaning Agents
Authors: Mcllroy MS 
Published: March 2009

Presently, industry places heavy reliance on the use of chlorinated solvents to achieve acceptable levels of cleanliness for systems in oxygen service. The Montreal Protocol and other restrictions will prohibit the use of these types of solvents because of potential damage to the environment. This paper discusses some of the issues involved in assessing aqueous based cleaning agents. A gravimetric test procedure has been developed to have a standard method of comparing the ability of a cleaning agent to remove oil and grease contaminants from prepared metal coupons. Data is presented to demonstrate the results of the test procedure. The testing addresses the use of a soak method and ultrasonics. The effects of time and temperature are directly addressed. Other variables are discussed in general terms such as disposal and cost considerations.
Three contaminants were selected for evaluation: hydrocarbon oil, lithium grease, and Halocarbon grease. Some of these contaminants present potential hazards in oxygen systems. The test method allows a common method for evaluation of cleaning agents and verification of contaminant levels for oxygen systems. The test procedures can also be applied to general degreasing of metal components throughout industry.