Search Results

A comprehensive selection of automotive sheet steels were exposed in an outdoor scab corrosion test to provide a base-line of cosmetic corrosion performance. Eighteen different coated sheet steels along with CRS as a control were processed using two commercially available zinc phosphate chemistries. The phosphating was done using both immersion and spray phosphate processes in a laboratory and an automotive assembly plant. Scribe creepage results are reported for 5 years outdoor scab exposure. Comparisons of the scribe creepage behavior of CRS, zinc, and zinc alloy coatings and the effect of the phosphate treatment are provided. An estimate of 10 years field performance is made.

Roll bars are currently a primary source of operator protection for recreational vehicles, for certain lawn and garden tractors and for small agricultural tractors. In this paper we describe a family of nonlinear models to predict the large deflection response of a roll bar due to yielding of the material. This yielding permits the structure to absorb energy. The stress-strain relationship employs a power law model. Subsequent calculation of the complementary energy stored in the structure and application of Castigliano's second theorem yield the deflection at the point of loading. To demonstrate the feasibility of this energy method in the simulation of testing of roll bars, we present numerical results for the side, vertical, and fore-aft loading cases. Results include the load-deflection response for each load case as well as the strain energy stored in the roll bar as it deforms.

There is currently no widely accepted accelerated test used by the automotive industry to evaluate perforation (inside-out) corrosion. Historically, automotive companies have used Proving Ground evaluations of full vehicles to assess perforation corrosion. Such tests are expensive, do not lend themselves to comparative testing of a large matrix of materials or processes, and are not available to supplier companies. The Perforation Subcommittee of SAE ACAP Division 3 has initiated a project to obtain perforation corrosion data from on-vehicle exposures that will lead to the development of appropriate laboratory perforation corrosion tests. The first phase is the development of a test specimen and methods to evaluate corrosion on this specimen. The proposed specimen is a two-panel assembly having an un-painted test area separated by a gap distance of .25 mm.

This paper describes the design analysis required for either the rise or return phase of a cam with a radial roller follower, consisting of four circular arcs. The motivations for using the four circular arcs are discussed, and the analysis is formulated. Appropriate computer solution techniques are indicated, and typical results are shown.

ROPS-TEST is a newly developed, interactive, graphics program that may be used to simulate testing of roll bars. Cross-sections that it currently supports include solid rectangular, rectangular tubing, and circular tubing. ROPS-TEST can be used to simulate testing for crush, rear and side loading. Output from ROPS-TEST includes load-deflection and strain energy-deflection plots. ROPS-TEST does not replace actual testing of prototype roll bars. Rather it serves as a design tool to select the best design options for a particular application prior to actual testing of the prototype roll bars.

Thickly coated hot-dip tin sheet was evaluated in fuel immersion, exterior corrosion, and weldability tests to determine its viability for methanol fuel tank applications. Performance in solutions of pure gasoline and low percentage methanol blends at ambient temperature and 60°C was excellent for hot-dip tin coated steels. However, in high-temperature testing in high methanol fuel blends, hot-dip tin sheet experienced some coating etching that was likely related to the added contaminants of formic acid and chlorides. Regarding exterior atmospheric corrosion protection, tin coatings are not sacrificial to exposed sheet steel, and therefore, tin coated sheet could be expected to provide exterior corrosion protection similar to terne coated sheet at similar coating weights. Tin coatings may require a primer coating for added exterior corrosion protection in fuel tank applications.

In order to clarify the effect of design and materials of the hem as well as the climatic factors on perforation corrosion of the automobile doors, field car and laboratory investigation has been carried out Field car investigation revealed that corrosion of the hem can be minimized by using two side galvanized steel plus adhesives. The ratio of wet/dry environment was evaluated in laboratory on hemmed sample, and it was found that the design of the hem in conjunction with the various wet/dry ratio affected the corrosion rate differently.

Wind powered water pumping systems are an attractive alternative for developing countries, as well as for applications in remote areas. Although many existing systems offer good performance, not all are well adapted to developing countries. A pumping system such as a Savonius rotor attached to a reciprocal pump is an appropriate solution because of its simple construction, ease of maintenance and low technology requirement. Usually, the design of such systems is based on the proper selection of wind turbines and pumps for the local conditions. Maximum power conversion efficiency is achieved when the proper combination of wind turbine rotational velocity and water pump outflow is satisfied. Unfortunately, this situation occurs at one, and only one combination of these conditions. It was therefore required to investigate a mechanism that will vary the load on the rotor as wind speed increases, thus maintaining the wind turbine at an optimal system rotational speed.

A diaphragm-type, strain-gage, surface-slope sensor has been designed for off-road vehicles. The sensor is capable of continuously measuring surface slopes in longitudinal and lateral directions simultaneously. Instrumentation amplifiers with low-pass filters were used for signal processing. Laboratory tests showed that the sensor had satisfactory sensitivity, linearity, and dynamic characteristics. Potential applications of the slope sensor include studies of vehicle mobility, stability, tractive performance, and safety.

A variable stroke mechanism was developed to optimize the efficiency of wind powered water pumping systems, by widening the range of efficient operation. The mechanism maintains the system near optimum operating efficiency by varying the stroke of a reciprocating pump to regulate the load on the turbine as the wind speed changes. Computer program was developed to optimize the design, and a prototype of the optimized device was constructed and tested. There were small differences between experimental and theoretical results obtained from the computer optimization program. Variation of the stroke length was observed over typical rotational speed ranges, generally from 150 to 275 RPM. Small differences between theoretical and experimental results can be related to friction forces as well as to the mass distribution of certain members, which were not taken into account in the computer program.

Using neural networks, an algorithm has been developed to steer a wheel loader vehicle. Mathematical functions have been used in the past in an attempt to model a human in their operation of many types of vehicles. Since such functions can typically only be derived for situations in which the problem domain is thoroughly understood, research continues in an effort to develop a complete “operator model”. Neural Network algorithms were utilized in an attempt to determine the feasibility of accurately modeling the operator of a wheel loader construction vehicle. These algorithms were also used to determine how the control of different vehicle functions might be automated on a wheel loader.

This paper reviews current changes in seedbed preparation, planting and cultivation toward reduced input where crops are planted without prior seedbed preparation, i.e. no-till. Herbicides are usually used to control weeds and post-planting cultivation may be eliminated. Financial, labor and machine input data are compared for several systems. Also additional factors which help explain increased use of no-till are discussed. These include timeliness (freedom from narrow windows of time) environmental and other factors. The potential impact of these recent trends on the design of propulsion systems used in agriculture, including tractors, self propelled combines and sprayers is discussed.

In order to use computer to carry out quick, accurate and economic design of product shape and colour, a package of AUTOLISP programs was developed which can be run under AUTOCAD main environment. Due to the limitation of AUTOCAD 11.0 and 12.0 in 3-D design of complex curved surface, the 3-D design functions were enhanced in the following aspects: (1) 3-D line JOIN and BREAK commands were developed to join and break 3-D polylines. SPIRAL command was designed to create 3-D cone or cylindrical spiral line. In addition, EFTURN and MEFTURN commands were developed to change the vertex sequence of polyline totally or midway. (2) 3-D elements and characters Existing subroutines were revised to directly generate Box, Cone, Pyramid, Dome or Dish, Torus, Sphere and Wedge ready for solid modeling. Furthermore, CONVEX, HOLE and TUBE commands were developed to generate different kinds of convex, hole and tube respectively.

Mechanical Design Synthesis (MDS) is an evolutionary step in design methodology. It combines several past steps such as Design by Analysis, Finite Element Analysis, Dynamic Mechanism Modeling, Thermal Analysis, Parametric Sensitivity, and Shape Optimization techniques under one software design environment. MDS can benefit every phase of the product development and delivery process and all members of the extended design team. A definition of MDS and a differentiation of MDS versus traditional methods are followed by a case study where MDS was used to trim 25% of the cost from a proposed design. The redesign project, which started with a nearly clean sheet of paper, was completed in 20% of the calendar time with a fourth as many people involved as in the first design attempt.

Hydrocarbon composition of fuel affects the deposit composition, its capacity to heat up the hot spots, and propensity of the fuel to preignition. Presently, fluidized catalytically cracked streams forms a large fraction of total gasoline pool in India and gasolines contain up to 50% olefins. About 60% of total gasoline in the country is consumed by the two wheeled vehicles powered mostly by 2-stroke engines. Preignition tendency of fuels with varying content of olefinic hydrocarbons was studied on a 2-stroke engine, during a 50 hour test. Preignition was indicated by sudden increase in combustion chamber surface temperature. Results showed a marked increase in preignition as the olefin content of gasoline increased above 20% by volume.

This paper describes the test of a direct injection diesel engine, operating electronically controlled diesel fuel unit injectors with variable injection timing. Diesel fuel injection was electronically controlled to retard or advance initiation of the injection event. Advancing or retarding injection timing of a direct injection diesel engine has a significant effect upon performance and emissions. Injection timing was varied to determine effects on exhaust emissions, performance, and fuel efficiency.

This paper deals with a research project concerning an effective utilization of exhaust gas heat. Exhaust gas from a exhaust gas-separate type two-stroke cycle engine containing a high concentration of unburned gas was temporarily stored in a floating-bell type tank as an form of heat energy conservation, while in the previous report [1]* exhaust heat was recovered with continuous operation. A Stirling engine with a hot-water supply system was then used to oxidize or burn again the exhaust gas in a catalyzer and an after-burner unit in order to recover the unspent heat energy from the exhaust gas. A three-way catalyzer was employed to remove pollutants both from the combustion gas in this process and the high-concentration burned gas from the two-stroke cycle engine. The results of the research in the present paper are intended as a follow-up of the previous report [1] to clarify a method for the more effective use of exhaust gas heat.

This paper details the investigation of the properties of inlet gases and shows how they affect the flow patterns immediately in front of the catalyst and the subsequent loss of efficiency. A thorough analysis of the flow distribution at the inlet of the catalyst enabled the effective catalyst diameter to be calculated. Subsequent calculations were then carried out to determine the loss of catalyst function through flow maldistribution. Experimental work involved flowing engine proportioned amounts of air through canisters of a fixed geometric profile containing a catalyst. Inlet cones of angles 10°, 15° and 45° were flowed to estimate the effect of the cone design on the velocity distributions at the face of the catalyst. Simple geometric profiles were investigated to allow a thorough understanding of the mechanism of flow to be comprehended and its affect on catalyst conversion to be analysed.

A 500 cc single cylinder two-stroke engine employing cross scavenging and direct air-assisted gasoline injection is described. Preliminary engine test results are presented for 3000 rpm full load and 1600 rpm part load operating conditions. The effects of fuel injection timing on full and part load brake specific fuel consumption and exhaust emissions are examined.