Criteria

Text:
Topic:
Display:

Results

Viewing 271 to 300 of 39463
1989-09-01
Technical Paper
892041
L. S. Socha, J. P. Day, E. H. Barnett
This study investigated the performance of various designs of ceramic monolithic catalyst supports for automotive emissions control. A test was conducted to examine the relationship of monolith volume, precious metal loading, cell density, and monolith frontal area on FTP emissions. The conclusion is that higher volume and/or higher cell density monoliths will yield improved catalytic performance using equal or less total precious metal per converter.
1989-09-01
Technical Paper
892373
Terry Scharton, Dennis Kern, Gloria Badilla
The advent of lightweight fairings for new spacecraft and the increased thrust of new launch vehicles have intensified the need for better techniques for predicting and for reducing the low frequency noise environment of spacecraft at lift-off. This paper presents a VAPEPS (VibroAcoustic Payload Environment Prediction System) parametrical analysis of the noise reduction of spacecraft fairings and explores a novel technique for increasing the low frequency noise reduction of lightweight fairings by approximately 10 dB.
1989-09-01
Technical Paper
892378
J. D. Gibbons, F. J. Marples
Several aircraft accidents in the past few years which have been attributed to corrosion and fatigue, have added to the concern on ageing aircraft, and understandably resulted in questions also being directed towards engines. The ageing process does have an effect on engines, but unlike airframes, engines have always been subjected to periodic disassembly, inspection, and rework/repair/replacement, either on a whole engine or modular basis. All the available evidence shows that the total control process results in a satisfactory situation, with no indication of lowering reliability or safety as the fleet ages. This paper looks at the various fleet statistics, and then reviews the design procedures which produce engines with inherent integrity into old age, and the in-service procedures which confirm and preserve it. Characteristics of some of the major components are discussed, and some further points are suggested in which engines differ from airframes.
1989-09-01
Technical Paper
892339
S. K. Clark, R. N. Dodge
A method is presented for calculating the stress-strain relations in a muiti-layer composite made up of materials whose individual stress-strain characteristics are non-linear and possibly different. The method is applied to the case of asymmetric tubes in tension, and comparisons with experimentally measured data are given.
1989-09-01
Technical Paper
892335
William W. Macy, Mark A. Shea, Rigoberto Perez, Robert E. Newcomer
An improved high-strength, high-toughness steel has been developed which shows considerable promise for landing gear applications. Previous materials provided high strength or high toughness, but not both. The improved material is a modified chemistry of AF1410 steel with increased carbon and an altered heat treat process. Tensile ultimate strengths (Ftu) of over 260 ksi (1.79 GPa) have been achieved while maintaining plane strain fracture toughness (Klc) in excess of 100 ksh/inch (110 MPa√m). In addition, the material has low sensitivity to environmental factors such as hydrogen embrittlement and stress corrosion cracking.
1989-09-01
Technical Paper
892337
William W. Macy, Mark A. Shea, David L. Morris
Design and fabrication of a titanium matrix composite (TMC) F-15 nose landing gear (NLG) outer cylinder is discussed. Results of a field experience survey examining landing gear (LG) operations are also discussed. Weight, supportabilty and cost benefits are summarized for this component and projected for production applications of the material.
1989-09-01
Technical Paper
892347
Pamela A. Davis, Sandy M. Stubbs, William A. Vogler
Tests of the Space Shuttle Orbiter nose-gear tire have been completed at NASA Langley's Aircraft Landing Dynamics Facility. The purpose of these tests was to determine the cornering and wear characteristics of the Space Shuttle Orbiter nose-gear tire under realistic operating conditions. The tire was tested on a simulated Kennedy Space Center runway surface at speeds from 100 to 180 kts. The results of these tests defined the cornering characteristics which included side forces and associated side force friction coefficient over a range of yaw angles from 0° to 12°. Wear characteristics were defined by tire tread and cord wear over a yaw angle range of 0° to 4° under dry and wet runway conditions. Wear characteristics were also defined for a 15 kt crosswind landing with two blown right main-gear tires and nose-gear steering engaged.
1989-12-01
Technical Paper
892582
R. Guarienti, J. Stropki
The Research Department of the State Farm Insurance Companies, in response to the increasing demands of consumers, state legislators, and individual policyholders, has implemented several research programs to evaluate the production and performance quality of the aftermarket (AM) and original equipment (OEM) automotive replacement fenders. Collectively, the evaluations have been based on visual assessments of the corrosion resistance of coated fender components. Corrosion resistance was determined by analyzing the degree of red rust attack. In May, 1986, State Farm did contract out, to Battelle, a study of the corrosion resistance of 54 primed and/or topcoated replacement fenders (AM and OEM) after a 500-hr exposure to the ASTM B117-85 salt fog environment. The results of visual and microscopic (optical and SEM/EDX) examinations confirmed that the inherent corrosion resistance of topcoated AM replacement components was nearly equivalent to that of the OEM replacement components.
1989-12-01
Technical Paper
892583
Timothy K. Christman, John T. Stropki, Clifford K. Schoff
Laboratory salt fog tests on E-coated steel often show greater creep from scribed marks when the underlying steel is galvanized than when it is not, while the scab test produces the more realistically greater corrosion on nongalvanized steel. To explain these observations, the corrosion mechanisms, kinetics, and products of both procedures were carefully examined using specimen weight loss, alternating current impedance techniques, and X-ray diffraction analysis. The laboratory tests showed that the salt fog exposure on zinc produced poorly protective oxide and chloride films with linear corrosion kinetics, while the scab test resulted in a more protective carbonate film with parabolic kinetics. Thus, the scab test compares more favorably with natural outdoor exposures of zinc, which generally produce carbonate films. The same tests on steel produced the opposite results, with protective films favored by the salt fog and nonprotective layers by the scab test.
1989-12-01
Technical Paper
892580
Yoichi Ito, Yasuhiko Miyoshi
For the accumulation of knowledge of perforation corrosion, three doors of three field vehicles made with one-side galvanized steel on the inside of the outer panels were investigated with some microscopic and analytical methods after 8 or 10 years’ field running in the snow-belt areas of North America. For these doors, perforations were found within the lapped part of the door hems. Outer panel perforation began as zinc layer corrosion of the inside surface of the outer panel at the lapped part and/or as “bent part” corrosion of the outer panel at the door hem. The inside of the outer panel lightly corroded at the open part in spite of the lack of primer on the inside surfaces of the outer and inner panels. The corrosion behavior of a lapped panel specimen test was studied and compared with that of investigated door hem corrosion. In the case of these doors, the test provided a result having a fairly good agreement with the field vehicle doors’ behavior.
1989-12-01
Technical Paper
892581
Lawrence L. Franks
Eleven coated steels and cold rolled steel were painted with three automotive paint systems and subjected to a variety of corrosion test environments. The results of highly accelerated tests correlated poorly with the results of atmospheric and on-vehicle tests. The results of one accelerated atmospheric exposure (“Volvo” test) agreed with those of the longer-term tests. In a comparison of materials, it was found that all zinc-coated steels performed better than cold rolled steel, and that heavier zinc coatings provided longer-term protection than lighter zinc coatings.
1989-12-01
Technical Paper
892578
Arthur W. Bryant, Lynne M. Thompson, William C. Oldenberg, Glen Hook, Justin Schroeder
In 1985, the Body Division of the Automotive Corrosion and Prevention Committee of SAE (ACAP) concluded that an automotive body corrosion survey for public consumption was needed. The committee proceeded to develop a survey methodology and conducted surveys in the Detroit area every second year starting in 1985. The survey is a closed car parking lot survey of nineteen panels or partial panels checking for perforations, blisters and surface rust. Similar surveys have and will continue to be conducted at biyearly intervals for comparison purposes to track the results of industry wide corrosion protection “improvements”. This is a report of the results of the first three surveys. THE ACAP COMMITTEE BODY DIVISION has now completed the third in its series of biyearly surveys. It is now possible to see some very clear results of industry actions and some indication of future performance.
1989-12-01
Technical Paper
892570
Frits Blekkenhorst, Evert Nagel Soepenberg
In the framework of an extensive test program established by the Automotive Applications Committee of the American Iron and Steel Institute, Hoogovens took part with its newly developed accelerated cyclic corrosion test. Objective of this program is to develop a reliable laboratory accelerated test for cosmetic corrosion resistance in order to obtain a realistic ranking of automotive steel sheet products. A number of standard treated steel sheet products were tested in the new cyclic test including cold-rolled steel, hot-dip galvanised steel and electroplated zinc and zinc-nickel. Also included was a second phosphate system for cold-rolled steel and hot-dip galvanised steel. Results of the test are given in terms of paint creep from the scribe and blistering along the scribe. It is concluded that the new test discriminates well between relatively “good” and “bad” materials. It appears that precoating is not always beneficial in lowering undercutting.
1989-12-01
Technical Paper
892568
Kenji Miki, Masatoshi Iwai, Hirohiko Sakai, Shingo Nomura
In order to simulate the perforation corrosion of an automobile, hem model samples made of various kinds of coated steel sheets were set inside of the door outer panel and the door was exposed in the open air with once a week 5% salt spraying. After two years, the model samples were disassembled for investigation. Perforation corrosion occurred most severely just above the lapped portion of outer and inner specimens. Red rust samples taken from the hem model and from a field vehicle run in Detroit did not show clear pearks of spectra by X-ray diffraction analysis, whearas the one formed by a conventional cyclic corrosion test showed peaks of Fe3O4. These facts indicate that this new test well simulates the corrosion environment of an actual automobile hem portion. Corrosion resistance of many kinds of coated steel sheets was studied by this new test method. Perforation depth became smaller as a coating weight of pure zinc electroplated steel sheet increased.
1989-12-01
Technical Paper
892569
H. E. Townsend
A Task Force on Corrosion has been established by the Automotive Applications Committee of the American Iron and Steel Institute. The Task Force is composed of technical representatives from the North American sheet steel producers and experts from the major automakers and pretreatment suppliers, and it works closely with related committees of SAE and ASTM. The goal of the Task Force is to develop a laboratory accelerated test for cosmetic corrosion resistance that will provide a reliable ranking of automotive sheet steel products. Work to date has included reviewing available information on cyclic testing, designing new test cycles, identifying suitable test materials and procedures, and conducting tests at commercial laboratories. During 1988, four different cyclic tests were conducted on ten sheet steels coated with a full automotive paint system. The results of these tests are presented and discussed.
1989-12-01
Technical Paper
892575
Charles P. Bauer, S. S. Beicos, John J. Kmetz, Leonard S. Cech
Results obtained by a round robin test on seam penetration and protection against corrosion by three different test methods and six varied rust preventative products are presented. The methods were chosen as current practices of industry while the rustproofing materials were typical commercially available items. This Study was conducted under the auspices of the SAE Automotive Corrosion and Prevention Committee, Division 5 in order to determine the feasibility of using hem flange methods for ranking rustproofing coatings by accelerated laboratory means. The purpose was to investigate repeatability of the test methods and was performed by four independent laboratories. Test data indicated said methods had poor correlation between repetitions and sites for evaluating seam penetraton and corrosion protection. Since ranking of coatings changed with hem flange geometry, no one method could be used to differentiate between test coatings.
1989-12-01
Technical Paper
892579
William Oldenburg, Terry Dorsett, Thomas Masterson
The mini-door design was evaluated as a way to minimize typical testing shortcomings. Due to size and configuration, many types of materials can be realistically tested under similar conditions (processing and testing) in a shorter time span and at lesser cost, compared to using full-size door panels or vehicles. The mini-door configuration was evaluated by Proving Ground road and laboratory tests. The matrix results include a “statistical rank ordering/grouping” of the materials from several tests, along with correlation to other road and laboratory tests. The use of the mini-door as a material development and testing tool dramatically reduces typical testing shortcomings (i.e., time, correlation, cost, statistical validity, test sample size restrictions, etc.).
1989-12-01
Technical Paper
892571
Martin L. Stephens
This paper describes the activities of the SAE Automotive Corrosion and Prevention (ACAP) Committee, Division 3 (Environmental Mechanisms) in the evaluation of cosmetic corrosion test methods. Various methods for testing painted sheet steel are described and data from some of the tests are presented. Test methods being evaluated include automotive proving grounds, accelerated outdoor exposure, laboratory cyclic, and laboratory environmental. The test materials are various pre-coated and bare automotive sheet steels, pre-treated and painted with an automotive coating system. As this is an interim report, only partial data are presented.
1989-12-01
Technical Paper
892573
S. R. (Steve) Dunn
Internal corrosion in mufflers caused primarily by exhaust condensate, is known to have a major impact on their durability. UOP's novel technology for reducing the corrosiveness of exhaust system condensate employs a small amount of unique zeolite adsorbent which, when the car engine is shut down, adsorbs the water and acid precursors from the gas phase in the interior of the muffler before they can condense and attack the mufflers internal parts. Vehicles exhaust gas desorbs the water and acid precursors while the engine is in operation, preparing the adsorbent for the next engine shutdown. Data is presented from a series of 5 statistically designed vehicle fleet tests which demonstrate that the corrosion rates of actual muffler parts can be reduced by more than 65%, when zeolite adsorbents are inserted in the muffler.
1990-02-01
Technical Paper
900004
Seong K. Rhee, Michael G. Jacko, Peter H. S. Tsang
A brake system must provide high and stable friction, low wear and noise/vibration-free performance for the reasons of safety, comfort, and durability. These performance characteristics can be influenced by the friction film (glaze) formed on the sliding surfaces of the brake rotor and pads. This investigation was undertaken to study friction film formation and destruction between a semimetallic friction material formulation and a gray cast iron disc, and its influence on passenger car disc brake behavior. Brake rotor surface roughness, the ease or difficulty of friction film formation, its formation mechanism, its effect on friction and wear, and brake squeal/vibration mechanisms are discussed.
1990-02-01
Technical Paper
900009
Shunsaku Komatsu, Yoshinobu Kanoh, Hideharu Fukube, Hisashi Manda
This paper deals with the newly developed technique of the squeeze casting process by using a horizontal die casting machine. Mechanical properties of squeeze castings are superior to those of gravity die casting. The productivity is attainable as high as the pressure die casting by employing the horizontal type of die casting machine for the squeeze casting process. We found also that 0.4∼0.6% Mg addition to A356 alloy improved the squeeze casting performance and that it led to higher tensile strength. The process has been put into practical use to fabricate disc brake calipers, gear pump casings, brake pedals and so on commercially.
1990-02-01
Technical Paper
900025
Rudolf R. Maly, Rupert Klein, Norbert. Peters, Gerhard Kðnig
Engine knock causes severe damage to the surfaces of the combustion chamber in I.C. engines. Since the detailed damaging mechanisms are still unknown, we performed a theoretical and experimental study in order to identify potential erosion processes. To circumvent the considerable cyclic variations of combustion in I.C. engines the experiments use an optically accessible bomb. It is shaped to resemble a typical geometry which is known to be particularly susceptible for knock damage. In this way we establish well defined conditions for knock simulations. By means of very high speed Schlieren diagnostics we measure the propagation speeds of detonation waves in the duct and use the data to estimate the wall loading due to instantaneous pressure peaks and sudden large temperature increases. Qualitative agreement between numerical simulations and experimental observations is achieved in the calculations.
1989-11-01
Technical Paper
892498
J. Aurell, S. Edlund
The use of steered rear axles on heavy vehicles has increased. They occur both on trailing units and on trailers. The extent to which the dynamic stability is affected depends on the location of the steered axles and on the steering principle. The effect on the dynamic stability was investigated for different applications and steering principles. The analyses were performed with both linear and non-linear models and also with experimental methods.
1989-11-01
Technical Paper
892495
Clifford A. Schumacher
Abstract Several different piston engine components were fabricated and evaluated in engine survival tests to demonstrate the capability and flexibility of the proprietary LANXIDE™ ceramic and metal matrix composite technology for advanced engine applications. The demonstration components are ceramic matrix composites, containing either alumina or silicon carbide particulate fillers in an alumina matrix. The four demonstration components - cam follower, camshaft, valve seat insert, and exhaust port liners - were made to near net shape and characterized for mechanical and thermal properties. The valve seat insert was made in larger quantities to evaluate process reproducibility.
1989-04-01
Technical Paper
890925
Dell F. Skluzak, Jerry T. Whicker
The use of polished aluminum fuselage skins has been a standard on U.S. commercial jet transport aircraft for decades. Increasingly stringent environmental regulations for paint stripping combined with fuel and maintenance savings allows consideration of flying polished non-painted aircraft. Boeing, McDonnell Douglas and Embraer currently manufacture commercial aircraft with polished alclad aluminum fuselages. Commercial airlines such as American Airlines, USAir, Eastern, Northwest and ASA fly non-painted fleets. These customers require the aircraft to be delivered with a polished appearance incorporating minimum fleet graphics. The manufacturing of polished aircraft requires unique production and handling procedures to fabricate all exterior panels with identical color match and reflectivity.
1989-04-01
Technical Paper
890926
Robert A. Pauli, Art M. Wittenberg
At the U.S. Department of Defense Tri-Service Advanced Coatings Removal Conference, Orlando, Florida, March 1-3, 1988, we presented information on Air Canada's interest in the development of a dust-free, automated, plastic media dry stripping system. This included a description of semi-automated equipment under development for this project based on Air Canada's stationary/simulator configuration experience. Phase I of their program was to build a prototype of the proposed robotic arm, and it's dust enclosure to: prove basic automation concepts; show reasonable paint removal rate from a curved surface; and, establish that process is dust-free and recovers media in a closed-cycle fashion. Phase I was successfully completed by the March 1988 date of the first paper, except for the determination of optimum blasting parameters.
1989-04-01
Technical Paper
890928
Joseph Kozol, Steven Thoman, Kenneth Clark
The Naval Air Development Center is conducting a program to characterize the effects of Plastic Media Blasting (PMB) as a coating removal process. The objective of this study was to determine the effects of PMB on the microstructure of graphite/epoxy (Gr/Ep) materials. In the first phase of the program, screening tests were performed to evaluate and optimize the critical operating parameters. For Phase II of the program, optimized parameters were chosen from the Phase I test results and the effects of four repeat paint and blast cycles were determined on graphite/epoxy panels. After four repeat blast cycles, several of the conditions caused minimal visible damage.
1989-04-01
Technical Paper
890929
Edward R. Novinski
Thermal sprayed abradable seal coatings are a specially designed class of materials used to reduce gas path clearance in gas turbine engines. These coatings directly translate to lower engine fuel consumption and higher performance and are employed in virtually every commercial and military jet aircraft in operation, Abradable coatings are characterized by a friable structure of carefully selected materials. These coatings are difficult to design since they must be readily abrad able and yet resist particle impact erosion from engine ingested abrasive dust at high gas velocities. Other important criteria are temperature stability, inertness, and consistency. This paper describes the classes of abradable seal materials; the characterization of thermal sprayed abradables; current coating materials temperature, erosion, and abradability performance; and current research in thermal sprayed abradable coating materials.
1989-04-01
Technical Paper
890914
Kenneth R. Newby, Allen R. Jones
Historically, hard chromium plating has been limited to the conventional 12-16% efficient chemistry developed by Fink and Eldridge in 1926 and to the mixed catalyst 20-25% efficient chemistry developed in the early 1950's. Recent discoveries have now led to a new non-fluoride high efficiency chromium chemistry which gives deposits with surprisingly consistent physical properties over a wide range of bath operating conditions. In this paper the microhardness and Falex sliding wear characteristics of the new chromium deposits will be compared with those for the conventional chemistry over a wide range of bath operating parameters which include composition, current density and temperature.
1989-04-01
Technical Paper
890917
Kenneth E. Abbott
Plastic Media Blasting (“PMB”) is a revolutionary method for the rapid and safe removal of primer, paint and even powder and other chemically resistant coatings from a vast range of products without the use of toxic chemicals or pneumatic blasting with hard abrasives. Although resembling sandblasting, PMB does not use the hard abrasives or high pressures of that process. Instead, PMB uses reusable-plastic particles which are applied at pressures of 20 to 40 psi. The unique abrasive blast media not only replaces potentially hazardous abrasives such as silica sand, but since it is reusable it also generates less overall waste material.
Viewing 271 to 300 of 39463

Filter

  • Range:
    to:
  • Year: