bluuebunny/crossref_metadata_2025 huggingface dataset:
OSHA's Wipe Sampling Policies and Procedures
Authors: Robbins MC
Published: March 2009

Chapter VI of the OSHA Industrial Hygiene Field Operations Manual (4 June 1979) describes the Occupational Safety and Health Administration's (OSHA's) policy and procedures for “documentation of the presence of a toxic material(s) in significant amounts.” The instructions tell the OSHA industrial hygienists to apply wipe sampling procedures to support general duty clause [5(a)(1)] citations for poor work practices. The entire procedure described is not based on sound professional judgment concerning airborne exposures or even potential ingestion of a contaminant. This paper reviews OSHA wipe sampling policies and raises questions about the lack of precise definitions for “presence,” “significant amounts,” and “risk establishment” of toxic materials found on workplace surfaces or protective equipment.
Effect of Aging on Bulk Formability of Aluminum Alloys
Authors: Ertürk T , Kazazoğlu E
Published: March 2009

Forming limit lines (FLL) developed for the analysis of workability in bulk deformation processes have been used to evaluate the bulk formability of 2014, 2024, and 7075 aluminum alloys as a function of aging. Using the height (intercept) of FLL's as a workability index allowed bulk formability to be expressed quantitatively. In the three alloys studied, workability was poorest in the naturally aged condition. The workability index increased as the alloys were aged artificially; greatest workability was obtained in the highly overaged condition for all alloys.

It was concluded that the low workability obtained in the naturally aged and peak-aged conditions resulted from localized shear failure. Tension test results on the 2014 alloy showed that shear localization was prevented in the overaged condition, leading to higher workability. Scanning electron microscope fractographs of fracture surfaces of upset cylinders in all conditions revealed dimples representative of microvoid coalescence. Vertical and 45-deg cracks, however, differed in fracture mode; the former showed features of fibrous tearing, while the latter exhibited shear failure characteristics.
Formability Tests Contrasting Ferrous Materials and 2036-T4 Aluminum
Authors: Newby JR
Published: March 2009

The concept that reduced weight will result in energy (fuel) savings has led to trial usage of aluminum for hoods and rear deck lid parts of automobiles. Conventional low-carbon steel sheets are being replaced by aluminum alloys, including 2036-T4, in selected applications.

Evaluative tests were used to explain performance differences among three samples of 1 mm-(0.040-in.)-thick sheets of 2036-T4 in forming a deck lid in a cooperative program among various testing laboratories.

As an extension of this program, comparative testing was done on low carbon steel sheet samples of types including rimmed and aluminum killed steels using the same techniques as with aluminum. The results show contrasts between values such as yield strengths that are similar in level for steel and aluminum, and elongations that are different. Other test values contribute information relative to formability and form a basis for comparisons of properties among competing materials, such as the plastic strain ratio and strain hardening capacity for deep drawing and stretch forming deformation modes.
Effects of Strain-Hardening Representation in Sheet Metal Forming Calculations of 2036-T4 Aluminum
Authors: Wang NM , Wenner ML
Published: March 2009

This paper describes numerical results from finite element modeling of several standard sheet metal forming tests of 2036-T4 aluminum, using two hardening representations, namely, the conventional power law model and a saturation stress model. Both hardening models are acceptable based on their fit to uniaxial tensile data for strains up to 0.18, but their behaviors at the large strain values typical in sheet metal forming are quite different. The forming tests calculated in this paper are: (a) a uniaxial tension test, (b) the hydraulic bulge test, (c) hemispherical punch stretching, and (d) cup drawing with a hemispherical headed punch. The results obtained from the two hardening models differ substantially, indicating that an accurate description of material hardening behavior is important for the numerical modeling of sheet metal forming operations. Comparison of the calculated results with existing experimental data in the uniaxial tension test suggests that the saturation stress model is currently a better choice for representing 2036-T4 aluminum.
Fittability Analysis in Press Forming of Large-Sized Autobody Panels
Authors: Ishigaki H
Published: March 2009

The formability of steel sheets in the press forming of large-sized autobody panels is strongly governed not only by the fracture but also by such surface deformation defects as minute unevenness, body wrinkle, and insufficient shape fixation. The strain analysis over the entire surface of autobody outer panels for more than ten years has suggested the importance of the fitting behavior of a sheet on the punch surface during the punch stroke, which is governed by the geometry of the panel and the die face, press operating conditions, and sheet mechanical properties, for the successful removal of surface deformation defects. The fittability of steel sheets is analyzed by using a fitting behavior diagram in which the height of a wavy wrinkle is plotted against the distance of the punch travel for various panel profiles, and is described in relation to sheet mechanical properties such as the yield point and the strain-hardening coefficient in the range of a small strain.
Material Flow and Defect Formation in Forging an Airfoil Shape from Metal-Matrix Composites
Authors: Ertürk T , Kuhn HA
Published: March 2009

Four types of defects that occur in the forging of a 2024 aluminum-alloy matrix reinforced with 25 volume percent stainless steel wires are characterized, and forming limit criteria for the prediction and prevention of the two major types are established. These criteria, presenting allowable stress states during deformation processing, are combined with an analysis of flow of metal in the forging process to provide design guidelines for the forging of an airfoil shape from rectangular preforms.

The design guidelines developed, based on the forming limit criteria and metal flow analysis, demonstrate a systematic approach to the design of processes for forging complex shapes from metal-matrix composites. Utilizing this approach, process parameters (preform geometry, die configuration, friction) can be evaluated in the development of processes for forging sound, complex shapes from composite materials.
Formability and Application of New Hot-Rolled High-Strength Sheet Steels
Authors: Aoki I , Horita T , Herai T
Published: March 2009

Several types of hot-rolled dual-phase sheet steels prepared by simple temperature control in hot strip mill or by heat treatment on a continuous annealing line have been compared in this investigation with conventional microalloyed steels through various forming tests. Thickness of these steels ranges from 1.8 to 2.5 mm and yield strength from 300 to 520 MPa. Forming tests employed include stretching, drawing, flange stretching or hole expansion, and simulative model forming of automotive parts such as rear axle housing and spring support, and the behavior of these sheets is discussed in detail.
Recent Results Concerning Properties of High-Performance Cast Martensitic Stainless Steels: The 17Cr-4Ni Low-Carbon Steels
Authors: Pichard C , Nectoux G
Published: March 2009

Between 13 percent chromium cast martensitic steels, austenitic steels, and precipitation hardening 17-4 steels (17-4-PH steels), a new range of stainless steels has been developed over the past few years. These are cast martensitic steels with 16 to 17 percent chromium, 4 to 5 percent nickel, and low carbon.

In this paper are pointed out the basic characteristics of this class of steels, that is, foundry properties, chemical and mechanical properties, weldability, resistance to corrosion and corrosion fatigue, and susceptibility to hydrogen embrittlement. These are the results of some 20 years of industrial experience and of recently acquired laboratory data.

In the different fields involved, these 17-4 and 17-4 molybdenum steels have exhibited better properties than 13 percent chromium steels and in some cases properties quite similar to those of austenitic steels.

These steels are very widely used in cast parts, and particularly in hydraulic turbines and gas compressors, but they are also frequently used in wrought products, generally in the form of plates.
Weldability Testing of Cast Corrosion-Resistant and Heat-Resistant Steels
Authors: Cieslak MJ , Savage WF
Published: March 2009

A program to establish baseline hot-cracking sensitivities of cast corrosion-resistant and heat-resistant alloys was initiated. The Varestraint Test was used to investigate primarily the metallurgical variables associated with hot cracking in autogenous weldments of alloys CF8M and HK-40. Hot cracking in alloy HK is associated with the formation of a carbide-austenite lamellar eutectic. Hot cracking in alloy CF8M is a function of the primary solidification mode. Heats which by virtue of their composition solidify as primary austenite are more hot-crack sensitive than heats which solidify as primary δ-ferrite.
Metallurgical Characteristics of a Large Hydraulic Runner Casting of Type 13Cr-Ni Stainless Steel
Authors: Iwabuchi Y , Sawada S
Published: March 2009

Increasing the size of type 13 Cr-Ni martensitic stainless steel castings with complicated cross sections results in difficulty in obtaining a uniform temperature distribution during thermal treatment, which in turn leads to a critical condition for cracking, in addition to deterioration of impact properties due to slow cooling. Chromium carbides (Cr23C6) precipitated by slow cooling through the austenite region at prior austenite or δ-ferrite grain boundaries cause an adverse effect on toughness, giving mosaic-like intergranular failure. Reducing silicon and carbon, along with the addition of molybdenum, improves toughness as the result of suppressing the Cr23C6 precipitate. Toughness degradation due to slow cooling from the tempering temperature was considered to be associated with the decomposition of interlath-retained austenite and the solubility change of carbon. Lowering the silicon content and the addition of molybdenum lessen the toughness deterioration.
High-Strength Cast Stainless Steels with Enhanced Corrosion Resistance
Authors: Crawford JD , Rohrig K , Bechet S
Published: March 2009

CA6NM was a major step in the development of high-strength cast stainless steels. For severe service environments, even better mechanical and corrosion properties may be needed. To meet the requirements imposed by these environments, a group of steels containing nominally 12 to 17 percent chromium, 4 to 6 percent nickel, 0 to 2 percent molybdenum, and 0 to 2.6 percent copper has been developed and commercially produced. Heat treatment, mechanical properties, microstructures, weldability, and corrosion resistance of the alloys are described.
Iosipescu Shear Properties of SMC Composite Materials
Authors: Adams DF , Walrath DE
Published: March 2009

A shear test method introduced to ASTM in 1967 by Nicolae Iosipescu of Rumania for testing metals has been adapted by the University of Wyoming for testing many types of composite materials. These have included 3-D carbon-carbon, unidirectional glass/epoxy and graphite/epoxy, and five different types of sheet molding compounds (SMC). These SMC materials, all incorporating a polyester matrix, include random orientation chopped glass fiber composites (SMC-R25, SMC-R50, SMC-R65), unidirectional glass fiber plies combined with random, chopped fibers (SMC-C20/R30), and ±7½-deg angle-ply continuous glass fiber plies combined with random, chopped fibers (XMC-3). These various types of SMC materials are of particular interest in automotive applications at the present time.

The Iosipescu test method and associated specimen configuration are briefly described, then detailed experimental results are presented for the five SMC materials described above, including both shear strength and stiffness data. It is demonstrated that the Iosipescu method is capable of testing composites in any one of the six shear loading modes. Short beam shear strengths for these same SMC materials were also determined, for comparison, demonstrating limitations of the short beam test for testing SMC materials, due to the predominance of bending rather than shear failure modes. Literature values of two-rail and three-rail shear tests of SMC materials are also compared with the Iosipescu shear data.
Mechanical Characteristics of T300-6K/V378A Graphite/Polyimide
Authors: McKague L , Reynolds JD , Fruit J
Published: March 2009

Mechanical characteristics of T300-6K/V378A, a new graphite-fiber-reinforced modified bismaleimide, have been determined. Tests were conducted on batches of material incorporating normal changes in resin and fiber constituent lots. Both fiber-dominated and resin-dominated properties were determined for dry and moisture-conditioned specimens. Investigations included 0-deg and 90-deg flex and tension tests, 0-deg compression, ±45 tension, and bolt-bearing properties. These typical properties show that this graphite/polyimide composite is structurally equivalent to graphite/epoxy for room-temperature dry conditions. However, humidity-conditioned graphite/polyimide has much better mechanical properties than graphite/epoxy at temperatures of 129°C (265°F) or above.

A review of these properties and a comparison with typical properties of graphite/epoxy are presented. The methods of testing are also reviewed, with particular attention to methods of environmental conditioning and testing of moisture-saturated specimens. For elevated temperature properties, these testing procedures involved use of special setups and apparatus to achieve rapid heating of the test section of each specimen. These procedures were required to ensure that the mechanical test specimens did not dry out prior to completion of the test.
Matrix Cracking in Short Fiber Reinforced Composites under Static and Fatigue Loading
Authors: Mandell JF , Lee BL
Published: March 2009

Matrix crack initiation and accumulation have been characterized in SMC R25 and R50 and injection-molded reinforced thermoplastics under static and fatigue loading. The following topics are presented and discussed: (1) crack initiation S-N curves of composites, (2) crack density measurements for composites during fatigue and at failure, and (3) acoustic emission response of the matrices and composites during static loading. The effects of matrix toughening by rubber modification are described for SMC R25. The nature of damage initiation, development, and interaction with fibers is described for the various materials.
History-Dependent Thermomechanical Properties of Graphite/Aluminum Unidirectional Composites
Authors: Min BK , Crossman FW
Published: March 2009

A high-modulus graphite(VS0054)/aluminum(6061) unidirectional composite was tested to characterize its thermomechanical properties as influenced by the thermomechanical history. The experiments included (1) tension tests at four different temperatures under monotonically increasing load followed by unloading; (2) measurement of the cyclic thermal expansion in the longitudinal and transverse directions, conducted on annealed and T-6 heat-treated composite specimens; and (3) tests on the thermal expansion behavior of specimens simultaneously held at a constant transverse tensile stress during the thermal cycling. The tension test results show that the yield strength of the composite is greatly influenced by the residual stress, which may vary with the thermomechanical loading history. During thermal cycling the aluminum matrix of the annealed specimen undergoes elastic and plastic deformation owing to the thermal mismatch between the matrix and the fiber. This results in a characteristic cyclic nonlinear response during thermal cycling, as observed by the cyclic thermal expansion measurement.

In order to interpret these results, an engineering material model (MET*MAT) was developed to characterize the salient features of this deformation. The model considers the aluminum as an elastic-perfectly plastic material with temperature-dependent yield and thermal expansion properties. The model permitted calculation of the internal (residual) stresses during the thermal and mechanical loading. The observed behavior was correlated to the predictions made by the model within an acceptable accuracy.
Testing of Buried Fiberglass-Reinforced Plastic Pipes
Authors: Galili N , Shmulevich I
Published: March 2009

The design of buried fiberglass-reinforced plastic (FRP) pipe for cooling systems of power plants was tested experimentally. The tests were conducted in a soil-box, with a pipe specimen of 903 mm internal diameter and 9.92 mm wall thickness. The backfill material was poorly graded sand at three different densities. Radial deflections, hoop strains, and soil pressure distribution around the pipe were measured during backfilling and after over-pressures of up to ten times the design load (200 kN/m2) were applied. The test results were used to evaluate load concentration factors, circumferential bending moments, and total pipe deflections.

The results of the study showed that strains and deflections of the FRP pipe are primarily controlled by the type of backfill and its density. When properly installed, the deflections and the bending moments of the tested pipe were substantially lower than those calculated by conventional design methods, leaving a higher safety factor to assure long-term durability of the FRP pipe. The results also suggest that simple deflection tests made during construction may provide a complementary inspection method to ensure proper installation of the pipe.
Reaction Injection Molding Urethanes—Detroit and Beyond
Authors: Lewis GD
Published: March 2009

Reaction injection molding (RIM) of microcellular urethane elastomers has in a few years become an accepted technology for the production of elastomeric fascias and bumper covers for a variety of automobiles. This technology is now being extended to additional applications, both in automotive and nonautomotive uses. This wide variety of new applications is discussed along with the factors which have caused RIMs rapid growth.
Reaction Injection Molding Urethanes: Heat Sag Characteristics
Authors: Rice DM , Dominguez RJG , Lloyd RF
Published: March 2009

The heat sag test is used by many end users in their specifications for reaction injection molding (RIM) methane materials. The test is evaluated for low-modulus fascia RIM materials and the high mod RIM material presently being studied for exterior body panel applications. A number of variables which can influence the heat sag test are examined and their relative effect discussed.
A Comparison of Dynamically Determined Shear Modulus with Statically Determined Flexural Modulus for Reaction Injection Molding Urethanes
Authors: Meyer LW
Published: March 2009

Dynamic mechanical spectroscopy continues to emerge as an effective laboratory instrument to analytically examine and characterize the molecular structure of polymers. Its value to the applications designer or engineer, however, has been rather limited. What it provides best, shear modulus, is not what they need or want which is flexural modulus. This paper compares dynamically determined shear modulus G with statically determined flexural modulus E and equates the two moduli through known theoretical equations. From the data generated, the value of Poisson's ratio was determined to be 0.28. The study is based on the evaluations of four distinct reaction injection molding (RIM) urethane systems.
Critical Failure Modes in Cracked Mechanically Fastened Stiffened Panels
Authors: Gunther CK , Wozumi JT
Published: March 2009

Conventional residual strength analysis of complex panels is founded on the principles of linear elastic fracture mechanics. Rigorous application of linear analysis techniques combined with failure criteria of ultimate stress capability and critical stress intensity factor results in the conclusion that there exist three potential panel failure modes: (1) skin failure, (2) stringer failures, and (3) fastener failure. Such analysis is in good agreement with test observations for cases involving limited damage. However, for cases where extensive damage exists in the skin element, one or two bay skin crack, linear elastic considerations can result in erroneous conclusions of failure mode and residual strength capability. Elasto-plastic finite-element analysis was conducted; this accounted for the plastic deformation capability of all elements. Crack configurations studied include unstiffened sheet, stringer stiffened sheet with all stringers intact and with center stringer broken. Effects of variations in material, stiffening ratio, and fastener flexibility on failure modes of stiffened panels were investigated. The results show that in all cases skin failure is always the critical failure mode.
Durability and Damage Tolerance Behavior of Adhesively Bonded Primary Structure
Authors: Potter DL
Published: March 2009

The Primary Adhesively Bonded Structure Technology (PABST) program was a U.S. Air Force sponsored program started in Feb. 1975 for the purpose of validating the use of adhesive bonding to join primary aircraft fuselage structural members. This paper will report on the analysis and component testing performed during the design development phase of the program, and the successful full-scale fuselage durability and damage tolerance test that was performed to four design lives. The goal of the program was to provide a savings of 20 percent on the acquisition and maintenance cost relative to mechanically fastened primary structure. Such effects as manufacturing quality, environment exposure, and a unique design criterion for bonded structure have significant impact on analysis methods. The initial development test program and results led to new testing techniques required for bonded joints to gain early design information. This is shown to be especially true for pressurized structure due to the unique behavior of metal crack propagation in this type structure. The full-scale fuselage test results and analysis correlation will be discussed as will the expanded purpose of the damage tolerance phase of this test and resulting demonstrations of crack containment within a stiffened skin panel under full cabin pressure.
Fatigue and Fracture Tolerance Evaluation of Tall Loran Tower Eyebolts
Authors: Rice RC , Smith CE
Published: March 2009

Laboratory and analytical fatigue studies were undertaken to assess the criticality of flaws found within several 63.5-mm-diameter communication tower eyebolts. Fatigue-fracture mechanics analyses provided fatigue life predictions which compared closely with subsequent fatigue experiments on the eyebolts subjected to particular load histories. Results of the study provided the basis for continued usage of many of the used eyebolts and gave specific guidelines on flaw size/location/criticality that were important in setting nondestructive inspection intervals and sensitivity limits.
Fracture Tolerance Analysis of the Solid Rocket Booster Servo-Actuator for the Space Shuttle
Authors: Smith SH , Ghadiali ND , Zahoor A , Wilson MR
Published: March 2009

The results of an evaluation of the fracture tolerance of three components of the thrust vector control servo-actuator for the solid rocket booster of the space shuttle are described. These components were considered as being potentially fracture critical and therefore having the potential to fall short of a desired service life of 80 missions (that is, a service life factor of 4.0 on a basic service life of 20 missions). Detailed stress analysis of the rod end, cylinder, and feedback link components was accomplished by three-dimensional finite-element stress analysis methods. A dynamic structural model of the feedback system was used to determine the dynamic inertia loads and reactions to apply to the finite-element model of the feedback link. Twenty mission stress spectra consisting of lift-off, boost, re-entry, and water impact mission segments were developed for each component based on dynamic loadings. Experimental fracture response data da/dN, KIc, and Kc were used for the structural alloys of the actuator components. These alloys were Inconel 718, 17-4 PH (H1025), 6061-T651, 2024-T851 (T351), and A286. Linear fatigue crack growth life and residual strength analyses were performed on the component critical locations using the Forman da/dN equation and CRACKS III computer code. Most components were determined to have the potential of reaching a service life of 80 missions or service life factor of 4.0.
Time-Independent and Time-Dependent Deformation of Metals
Authors: Alden TH
Published: March 2009

In most contemporary theories the deformation of metals is treated as a time-dependent or viscous process. A quasi time-independent character is sometimes introduced by means of an athermal back “stress” from long-range obstacles, but only at T = 0 K or in other limited temperature ranges is the deformation predicted to show time-independent behavior. Several experimental results, mainly on pure face-centered-cubic metals, are in disagreement with this theoretical approach. The most important results are that (1) time-independent strain (loading strain) has been measured on sudden increase of stress during creep deformation, even for very small stress increments; and (2) the strain rate ratio measured in a load relaxation experiment, R = ˙εr/˙εℓ, is consistently less than unity and increases toward unity as the stress approaches saturation. These results are reviewed and new data from load relaxation on lead and the superplastic Pb-Sn eutectic are presented. It is the author's conclusion from these data that time-independent deformation may be more important than is normally acknowledged. Thus, in future efforts at modeling plasticity, the possibility of a dual time-dependent, time-independent nature ought to be considered.
An Evaluation of Deformation Models for Grain Boundary Sliding
Authors: Langdon TG , Vastava RB
Published: March 2009

Grain boundary sliding is an important deformation process during high-temperature creep. Sliding often makes a significant contribution to the total creep strain of the specimen and, in addition, the sliding process is important in the nucleation, growth, and subsequent linkage of intergranular cavities.

The various theoretical deformation models for grain boundary sliding are reviewed, and it is shown that they fall into two groups depending on whether they relate to intrinsic sliding or to sliding with an associated accommodation process. Published experimental data on grain boundary sliding are tabulated for a number of different metals for comparison with the theoretical models, and the data are supplemented with recent results obtained on aluminum. It is demonstrated that all the available models lead to predictions which are inconsistent with one or more of the trends observed experimentally.
A Study of Alabama Black-Belt Soils
Authors: Rosser GK , Moore RK
Published: March 2009

The adverse physical and engineering behavior of the montmorillonitic soil of calcareous origin of the Alabama “Black-Belt” or “Black Prairie” region has been recognized for over 100 years. However, limited basic data have been developed that characterize these soils and define their behavior when treated with high-calcium lime. The purpose of this study was to determine basic variation of soil characteristics and the influence of sampling location on lime reactivity. Lime reactivity as defined by Thompson is the increase in unconfined compressive strength by comparison of untreated and lime-treated (6 percent lime content calculated by dry weight of soil solids) soil specimens having been cured for 48 h at 49°C (120°F) in a sealed condition. Harvard miniature compaction was utilized.

Basic physicochemical and clay mineralogy data are presented to demonstrate the variation inherent in the 11 soil series. Compaction statistics associated with Harvard miniature compaction are presented.

Eleven soil series (Boswell, Demopolis, Eutaw, Houston, Kipling, Leeper, Oktibbeha, Sumter, Susquehanna, Vaiden, and Wilcox) were sampled at three different locations to determine the effect of sampling location on laboratory lime reactivity. Sampling location significantly affected Eutaw, Kipling, Oktibbeha, Susquehanna, Vaiden, and Wilcox at an alpha level of 5 percent.
Automotive Coolants in Europe: Technical Requirements and Testing
Authors: Berchtold P
Published: March 2009

The paper attempts to give an overall view of the very complex antifreeze situation existing in Europe today. It is written with the hope of creating a better understanding of the actual realistic requirements that have to be set for modern coolants. It is further hoped that it may help to pave the way for a standardization of coolant test methods.
Static Vehicle Corrosion Test Method and Its Significance in Engine Coolant Evaluations for Aluminum Heat Exchangers
Authors: Park KH
Published: March 2009

A method for testing engine coolants using static vehicles is described. Tests were conducted with engines idling at the speed equivalent to 97 kph (60 mph) with an operating cycle of 16 h on and 8 h off for 161 000 simulated service kilometres (100 000 miles). The initial antifreeze coolant concentration was 45 percent with ASTM corrosive water for approximately 8000 simulated kilometres (5000 miles) in order to duplicate the original coolant fill condition at the vehicle assembly plant and allow sufficient period for film forming inhibitors to react with the internal multimetal surfaces. The initial coolant concentration was then cut in half to simulate a depleted coolant condition and accelerate the corrosion activity in the engine cooling system.

Commercially available antifreeze coolants have been evaluated using this test method in the recent production vehicles, equipped with prototype aluminum radiators. Data showing variations in coolant characteristics and the decay of certain inhibitor components as a function of the simulated vehicle mileage are presented. The reproducibility of data was also analyzed.

A conclusion is developed which suggests that the static vehicle corrosion test could provide an additional screening test method for the automotive engineers to evaluate corrosion protection and inhibitor stability of antifreeze coolants in conjunction with fleet and customer service testing.
Refinement of the Vibratory Cavitation Erosion Test for the Screening of Diesel Cooling System Corrosion Inhibitors
Authors: Hudgens RD , Carver DP , Hercamp RD , Lauterback J
Published: March 2009

A modification of the ASTM Vibratory Cavitation Erosion Test (G 32-77) is proposed for the evaluation of a cooling system corrosion inhibitor's ability to reduce the deterioration of the water-side of diesel engine cylinder liners. The procedure combines the effects of cavitation and corrosion, and, therefore, better simulates the pitting attack on cast iron cylinder liners. Results from the modified test correlate well with laboratory engine results and field experience. Further areas of investigation are suggested, although it is recommended that the general test procedure be considered for adoption as an ASTM test method for diesel engine coolant corrosion inhibitors.
Cavitation Corrosion
Authors: Oakes BD
Published: March 2009

Cavitation corrosion of wet-sleeve diesel engine cylinder liners has assumed increased importance in recent years due to design changes intended primarily to extract more power per unit of fuel consumed. As the piston moves up and down within the liner, the liner wall moves slightly to initiate the cavitation phenomenon. Vacuum cavities form next to the liner on the coolant side. As the liquid collapses to fill these cavities, damage is done with the end result as a line of pits on the coolant side of the liner wall. In this study, using a vibratory cavitation erosion test, at atmospheric and slightly elevated pressures, propylene glycol (PG) and methoxypropanol (MP) based coolants are shown to provide consistently more resistance to cavitation corrosion of cast iron than ethylene glycol (EG) based coolants. At slightly elevated pressures MP coolants may be superior to PG coolants.
Cooling Systems Corrosion in Relation to Design and Materials
Authors: Beynon E , Cooper NR , Hannigan HJ
Published: March 2009

Field experience revealing corrosion failures relating to engine cooling system design and material causes as well as coolant deficiencies are reviewed. Basic corrosion mechanisms are described and related to specific component failures. The role of ethylene glycol base inhibited coolants is discussed and the real world of consumer practices and service problems is described. Conclusions are developed which suggest viable approaches to further improvements in cooling system performance and reliability.
Testing of Solder for Corrosion by Engine Coolants
Authors: Beal RE
Published: March 2009

Two new specimens are introduced and evaluated for the study of soldered joints in engine coolant environments. A cup-shaped specimen has been designed that will provide visual appearance determination of the effect of solder joint processing and operation variables on the propensity toward the development of blooming corrosion on soldered radiator joints. A stressed soldered joint specimen assists in discrimination of solder and coolant variables on exposure in conformance to the ASTM Corrosion Test for Engine Coolants in Glassware (D 1384-70) test environment. These new specimens used in conjunction with ASTM D 1384 glassware test provide added information that is useful in evaluating solder alloy and coolant interactive effects in copper and brass radiator engine systems.
Impediments in the Characterization of Copper-Nickel-Tin Spinodal Alloys by Atomic Absorption Spectrometry
Authors: Kometani TY
Published: March 2009

The metallurgical properties of copper-nickel-tin (Cu-Ni-Sn) spinodal alloys are critically dependent on composition. One of the alloys of primary interest, Cu-15Ni-8Sn-0.25Nb, must be manufactured by suppliers to meet stringent Bell System specifications for nickel, 15 ± 0.5 percent, and tin, 8 ± 0.5 percent. Precision of analysis better than ±1 percent and absolute errors less than ±1 percent have been achieved by atomic absorption spectrometry (AAS). Problems such as limited sensitivity, matrix interferences, and instrument limitation have been resolved in order to obtain these results. A fuel-rich air-hydrogen flame was found to give the most stable and sensitive absorption measurement for tin at 224.6 nm. Significant interfering effects on tin absorption from acids and other metals in the low temperature flame were identified and corrected by proper addition of salts and acids to all solutions. Nickel was determined with an air-acetylene flame at the wavelength, 232.0 nm.

Measurements of absorbance by a rapid direct method were compared with a high precision method. Repeated determinations of both nickel and tin performed on a single sample solution showed that the high precision method was capable of 0.14 percent relative standard deviation (RSD) while the direct method gave 0.5 percent RSD.

A standard addition method was necessary to control the strong suppression and enhancement interferences by acids and cations on niobium absorptions. The presence of 3 percent iron was found to give a threefold enhancement of niobium absorption, allowing quantitative determinations down to 0.05 percent niobium.
Software for a General Purpose Materials Testing Computer System Using a Real-Time Multitasking Executive
Authors: Bushnell ML , Sisterson LK
Published: March 2009

The emergence of low cost microprocessor and minicomputer technology and the increasing functional density of integrated circuits has made it practical to apply advanced general purpose operating systems to small laboratory computing systems. The desirability of automating materials testing laboratories has increased because of the successes achieved in reducing man-hours per test, improving data accuracy, and program flexibility to handle complex tests. Instron has developed a system based on the software executive RSX-11M (trademark of Digital Equipment Corporation) which is capable of controlling many laboratory instruments, and can be built in a modular fashion, from a small dedicated system to a large distributed processing network. The system depends on microprocessor-controlled interface modules for efficient data acquisition and control. These interface modules are serviced by a flexible device driver, which forms an interface between the hardware and the application programming language, commonly FORTRAN IV, Interpretive BASIC, or Compiled BASIC. The use of the RSX-11M multitasking operating system means that many instruments can be serviced easily. Instruments such as servohydraulic testing instruments which have requirements of complex real-time control, substantial data reduction, and data reporting can be serviced by several tasks running at different priorities. Control tasks thus take precedence over data reduction tasks. A feature of the system in larger configurations is the use of distributed processing units (DPUs) as front-end concentrators performing detailed control of a small number of instruments. Several such DPUs may be connected to the central processor to form a star network. A great advantage of this system is the ease with which it can grow to meet the advancing needs of the laboratory.
Hardware for a General Purpose Materials Testing Computer System Using a Distributed Parallel Processing Architecture
Authors: Nisar R
Published: March 2009

Computer automation of materials testing is becoming increasingly common in research laboratories and industrial quality control facilities. Until recently, computer architectures of the single processor variety have dominated the industry and their cost has limited the automation of general laboratory instruments. With the emergence of low cost microprocessor technology, it is now practical to design systems with several interconnected processing elements performing independent tasks in parallel. this paper presents the design techniques and hardware aspects of a distributed processing computer system for the automation of materials testing instruments. The advantages accrued by the use of multiple processing elements are discussed. This approach relieves the central processor from a number of routine tasks, thereby allowing the computer to execute more powerful software. The design of an intelligent interprocessor communications module and its utilization in a distributed computer system is also described.
Comparison of Some Data Acquisition Systems
Authors: Link GL
Published: March 2009

Over the past five years, at least a half-dozen data acquisition systems have been installed in the author's working area. The hardware ranged from a maxicomputer to minicomputers to a calculator; the software ranged through BASIC, FORTRAN, and special languages; in environments ranging from no operating system to OS-8 and UNIX (UNIX is a trademark of Bell Laboratories). The degree of our involvement ranged from none (an original equipment manufacturer (OEM) turnkey system) to building the complete system from drivers on up.

This paper compares some of the systems and offers general remarks intended to assist the first-time user in selection of an automated data system.
A Computerized Data Acquisition System for High-Temperature, Pressurized-Water, Fatigue Test Facility
Authors: Cullen WH , Menke BH , Watson HE , Loss FJ
Published: March 2009

The hardware and software of a data acquisition system for a high-temperature, high-pressure water fatigue crack growth facility is described in this article. This system monitors crack lengths of 15 specimens, together with water pressures, temperatures, and water chemistry data such as dissolved oxygen content, pH, and specific conductance. The measurement strategy is defined by the cyclic count: each of the specimens has its unique measurement targets and measurement interval. The computer constantly compares the instantaneous accumulated count with the count targets of the 15 specimens and enters a data acquisition subprogram when any count target is reached. The methods of data acquisition, data reduction, file management, input/output and system status modification are described.
Settled Density of Wood Fiber (Cellulose Based) Loose-Fill Thermal Insulation Using the CS-204 Method
Authors: Derbyshire B
Published: March 2009

An evaluation has been made of the Custom Scientific Instruments Model CS-204 density method in comparison with the ASTM Test for Density of Fibrous Loose Fill Building Insulations (C 519-65), and the 28-day, drop-box, humidity-cycling method in Federal Specification “Insulation Thermal (Loose Fill for Pneumatic or Poured Application): Cellulosic or Wood Fiber” (HH-I-515d).

The evaluation was done on cellulosic materials where the installed density was measured on material removed from structures previously insulated for more than a two-year period, and on newly manufactured materials.

Reproducibility of CS-204 as a laboratory method was verified by a series of interlaboratory “round robins.” CS-204 has been found to be an accurate, rapid method for determining settled density of wood fiber (cellulosic based) loose-fill insulation.

The report discusses the research process, results, and application of the final method to the cellulosic loose-fill insulation industry.

This presentation is a synopsis of a two-year study on a settled-density test method for loose-fill wood fiber (cellulosic based) thermal insulation. The detailed work this paper is based upon is available at present from the author.
The Calibration of Heat Flow Meters
Authors: De Ponte F , Maccato W
Published: March 2009

The heat flow meter electromotive force is first expressed as a function of the heat flow meter thermal conductivity and its correlation with temperature and density, as a function of the thermoelectric voltage of the couples of junctions of the thermopile in the heat flow meter, and as a function of the modulus of elasticity of the material used to build the heat flow meter. This relationship can define a heat flow meter model useful for predicting the range of operating conditions.

The second step is to assume a model for the reference specimen used in the calibration, in order to set limits of thickness, thermal conductivity, temperature difference, and mean specimen test temperature, once the calibration accuracy is defined.

The last step is to compare the calibration of the heat flow meters, using a double-specimen reference sample in a heat flow meter apparatus with a single meter and a single specimen, two meters and a single specimen, or a single meter between two specimens.

The paper also gives an account of the speed and edge heat losses: moreover, the reader is cautioned against some possible errors in the use of the heat flow meters and in the interpretation of measured data.
Development of a Canadian Standard for Urea Formaldehyde Thermal Wall Insulation
Authors: Bowles AM , Shirtliffe CJ
Published: March 2009

A committee of manufacturers, applicators, users, and concerned interests was charged with writing a Canadian standard for urea formaldehyde (UF) foamed-in-place thermal insulation. The findings of this committee and of the research that it commissioned are presented herein.

The integrity of the material was found to be retained after several years' service, but installation techniques need drastic improvement. Available data suggested that the linear shrinkage of UF foam installed in wall cavities could be expected to stabilize at about 7 percent. The magnitude of the shrinkage, equivalent to 21 percent by volume, was estimated to reduce the effective thermal performance of the material to 60 percent of that which would have been realized had there been no shrinkage.
Research Needs in the Insulation Industry
Authors: Stenger LA
Published: March 2009

Research needs and existing programs supporting the role of insulation products in buildings are discussed from the component, envelope and total energy system viewpoint. Needs which dictate continued industry effort to develop knowledge of the thermal performance of individual building components (walls, attics, etc.) are outlined, and a specific research program in the area of attic thermal performance is described. Needs are also outlined for work to more adequately describe interaction effects which occur when components are combined into total envelopes. This theme is carried further to describe work needed to quantify the effects that heating, ventilating, and air-conditioning equipment, distribution equipment, and control devices have on energy consumption. Throughout, note is also taken of the desirability of coupled programs of experimental and analytical research aimed at developing experimentally validated mathematical models of components, total envelopes, and total building energy systems which can be used with confidence to generalize the experimental results.
Space Environmental Effects on Graphite/Epoxy Composites
Authors: Leung CL
Published: March 2009

In a study of T300/934 graphite/epoxy composite, which forms the composite skin of the space shuttle cargo bay doors, the following composite properties were investigated as a function of increasing gamma-radiation exposure dosages: directional moisture absorption/desorption kinetics, glass transition temperatures, interlaminar shear strength and damping peaks (tan δ). Irradiation conditions were: open to atmosphere and vacuum, ambient and high temperature (100°C).

Four dosage levels were investigated: 4 × 107, 8 × 107, 1.4 × 108, and 3.2 × 108 rads, the final dosage level being equivalent to a three-year orbit life. Directional moisture diffusion studies indicate anomalies in the three diffusing axes (translaminar, transfibrous, and interlaminar). Interlaminar shear strengths showed an initial increase, followed by a decrease, as the dosages increased. Although the glass transition temperatures remained essentially unchanged, the peak heights of the tan δ measurements also showed an initial increase, and then decreased as radiation dosages increased.
Environmental Exposure of Carbon/Epoxy Composite Material Systems
Authors: Givler RC , Gillespie JW , Pipes RB
Published: March 2009

The effect of potentially adverse environmental conditions on composite material systems is investigated. Hybrid glass-carbon/epoxy laminates were thermally cycled between −54 and +177°C, and residual compressive and flexural properties determined. Results indicate that extended thermal cycling had only negligible effect on laminate compressive or flexural strength. Observed cracks in the 90-deg and adjacent ±45-deg plies were observed and their existence predicted by laminate analysis, which showed thermal residual stresses to exceed the intrinsic material strength in those plies. Thermal fatigue loading increased crack density in the 90-deg and ±45-deg laminae eight-fold, subsequent to 1000 cycles.
Crack Propagation Modes in Injection Molded Fiber Reinforced Thermoplastics
Authors: Mandell JF , Huang DD , McGarry FJ
Published: March 2009

The modes of crack propagation are reported for injection molded short glass and carbon fiber reinforced thermoplastics. The matrices ranged from ductile to brittle, including Nylon 66, polycarbonate, polysulfone, poly(amide-imide), and polyphenylene sulfide; fiber contents were 30 or 40 percent by weight. The main crack is found to grow in a fiber avoidance mode, bypassing regions of agglomeration of locally aligned fibers. The local mode of crack tip advance varied with matrix ductility and bond strength. The fracture toughness and fatigue resistance of each material are related to the mode of crack growth.