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After several alternative procedures were investigated for preparing chromium-plated zinc die castings for painting, one procedure proved best for contaminated chromium surfaces. This procedure included six steps: (1) alkaline spray cleaning, (2) electrolytic alkaline cleaning, (3) rinsing with high-purity water with a specific resistance of 500,000-700,000 ohm-cm, (4) immersing in chromic acid solution (0.05 oz/gal) at 150 F for 2 minutes, or treating cathodically in 0.7 oz/gal of sodium dichromate with a current density of 0.05 amp/sq ft for 30-60 sec, (5) rinsing with high-purity water, (6) forced-air drying with filtered air at 15 psi. Good adherence was obtained by following these procedures and painting with a single coat of acrylic or alkyd-resin paint. Other preparation procedures resulted in inferior paint adherence.

In recent years alternative automobile power technologies have received increased attention from OEM's, special interest groups, and the public. Plausible power technologies now include internal combustion engines, batteries, fuel cells, and a variety of hybrid technologies. The merits of each of these technologies as a means to move personal and fleet transportation into the next century have been highly debated. One technology that has emerged as a viable alternative to the internal combustion engine is the fuel cell. Considering arguments on all sides of the debate, the authors describe the results of a systematic, focused examination of the sustainability of fuel cells for transportation and discuss strategies for sustainable technology design. Sustainable technologies are those that contribute to preserving or improving societal quality, the environment, and the economy for future generations.

Transient heat transfer effects in heat storage devices are examined. Material and design parameters are developed which lead to almost full utilization of the heat capacity of the storage device during cyclic operation. Particular emphasis is placed on the problems associated with high-temperature storage applications. Detailed analyses are carried out for three storage element configurations, namely: flat plates heated on two sides, hollow cylinders heated internally, and solid cylinders heated externally. In general, it is found that storage utilization depends on material properties, fluid properties, geometry, heat transfer coefficient, and cycle time in a unique manner. Pumping power requirements are also evaluated as functions of above quantities.

This paper presents a numerical analysis of the effect of weld induced residual stress on the fatigue behavior of a T-joint. The thick-section T-joint contained 18 individual weld passes and was subjected to fully-reversed, zero-maximum, and zero-minimum fatigue cycling. The effect of the residual stress was demonstrated by comparing the result with and without residual stress. It was concluded that the local fatigue parameters (mean stress, alternating stress, and stress ratio) at the suspected crack initiation site were changed significantly by the residual stresses when the applied stress were other than fully reversed. In addition, the effect of the stress concentration at the weld was more significant that the effect of the residual stress for the applied fatigue loads levels that were considered. The analysis method presented can be used to assess weldment design and process variables.

In the new design, the electrode employs composite electrode face construction with dissimilar materials. A cylindrical insert located in the electrode face center is made of low thermal and electrical conductivity material, such as stainless steel, and an annular outer sleeve is made of stainless steel and located at periphery of the electrode. Base material of the electrode is still made of copper alloys. With this electrode design, the electrical-thermal-mechanical conditions can be improved by confining the current flow path to reduce current level required for the weld nugget formation, and optimizing electrode pressure distribution, and minimizing electrode face heating and plastic deformation.

Currently the U. S. Department of Defense (DoD) exclusively uses potassium acetate (KAc)-based runway deicing fluids (RDFs) to deice and anti-ice military runways and taxiways. Commercial airports predominantly use KAc, but some also use RDFs composed of KAc plus propylene glycol (PG) or urea plus PG. Conventional RDFs have environmental concerns due to toxicity as well as material compatibility problems such as corrosion of aircraft carbon brake-pad components, cadmium-plated landing gear, and airfield lighting fixtures. Under the Strategic Environmental Research and Development Program (SERDP), Battelle tested a series of patented - bio-based RDFs to address these issues. Tests showed that the Battelle RDFs met the mandatory Aerospace Material Specification (AMS) 1435 requirements. These new RDFs have reduced ecotoxicity compared to currently used RDFs and are compliant with all other environmental requirements.

This paper addresses the modeling issues of resistance spot welds. The state of the art modeling techniques on weld process simulation, weld property prediction and weld engineering performance evaluation are presented. First, weld process simulation is performed using the incrementally coupled thermal-electrical-mechanical analyses. The resulted weld nugget size, weld residual stress and weld material property distributions are then used in determining the static performance of a single weld coupon. Comparisons with experimental measurements are presented as validations. Results generated from this single weld coupon is then used in the simulation of dynamic crush mechanism of a spot welded single hat section.

This paper discusses the general effects of the physical, technological, and economic environments of Southeast Asia on the design, operation, and maintenance of mechanical and electronic equipment. The need for better information on applicable environmental parameters, and the relationship of this problem to the pressing requirement for applying U.S. research, development, and engineering abilities to the problems of “remote area” countries, are emphasized.

THIS report of a survey of hydraulic packings, especially O-ring seals, covers friction studies, torsional strength tests, plasticizer development, a study of rubbers, molding technique, and spiral failure. The Institute is reported to be planning to conduct research work along the lines of cycling tests and studies of stress aging, compounding, and backup rings.

THIS PAPER describes an investigation into the use of radioactive cylinders in wear research. Battelle Institute and Fairbanks, Morse agree that the method has potential as a research tool. The effect on cylinder wear experienced with variables such as starting, idle or cold temperature operation, sudden load changes, speed, torque, and such, can be determined easily and relatively inexpensively. The authors describe the techniques and precautions taken during the testing. *

Increased research devoted to the foundry arts has resulted in a greater understanding of the factors essential in producing high quality castings. One outgrowth of these studies has been the development of premium quality aluminum castings. The procedures used for the production of premium quality castings are reviewed, and the improvements in properties that result from adequate attention to these procedures are described.

The cost of electroplating zinc die castings can be reduced by employing microcracked or microporous chromium in place of conventional chromium; the former is more effective in improving corrosion performance while conserving nickel. Exposure data are examined and specifications for nickel and chromium content are presented.

The procedure utilized during a research evaluation of the effect of agglomerates in heavy fuels is described, and a simple light microscopic method for the study of particle dispersion in heavy fuels is given. The effectiveness of commercial additives for the treatment of heavy fuels to initiate dispersion is outlined as well as the development of a fast and inexpensive filtration test for accurately measuring the effect of various additives on various heavy fuels. Finally, the basic development work and the results obtained using ultrasonic dispersion of agglomerates during an actual engine performance test with heavy residual fuel oil is presented.

The purpose of this paper* is to describe research toward the application of Bayesian statistical methods to the calculation of system reliability The motivation for the suggested procedures stems from (1) the fact that Bayesian methods provide for the formal inclusion of all relevant information in reliability calculations and (2) the suitability of Bayesian methods to problems in which the probability distributions of interest change over time. In this report, suggested procedures are given for obtaining component reliability u estimates based on system test outcomes. Three possible test outcomes are considered: (1) success, (2) failure caused by known components, and (3) failure caused by unknown components. Using this procedure, substitution of new components or modification of the configuration of the system does not invalidate the test data accumulated up to the time of the changes.

This study evaluated whether a driver's intention to comply with a stop sign, and/or negotiate a turn, or proceed on a straight path could be predicted through the identification of patterns in driver input to vehicle primary controls. Driver input to primary controls was assessed during intersection approach, according to type of intersection maneuver. Control input patterns, relative to intersection arrival, will be used to identify effective timing of driver alerts and warnings regarding potential hazards at an intersection. The results of this study will support the development of countermeasures to prevent or reduce the severity of intersection crashes.

An important emerging technical area is computer-based modeling of the various manufacturing processes that are used in many diverse industries. These models are used to optimize manufacturing techniques to reduce fabrication costs and improve the service performance. One manufacturing process important in steel fabrication is welding. It can be a useful tool to aid in reducing fabrication costs and service durability by optimizing the weld process and is the subject of this paper.