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Cyclic oligomers of butylene terephthalate (CBT™)† represent a new chemical route to semi-crystalline thermoplastic polybutylene terephthalate (PBT). The oligomers of interest melt completely at about 150°C to produce a low viscosity fluid that is ideal for wetting and dispersing fibrous fillers and reinforcements thereby enabling the development of composites that were previously not possible when working with high viscosity commercial PBT. Introduction of catalyst to undiluted molten cyclic oligomer leads to rapid ring opening polymerization and the formation of high molecular weight thermoplastic PBT without the generation of volatile organic compounds. The polymer resulting from this polymerization will be hereby referred to as pCBT. Treatment of cyclic oligomers in this fashion results in pCBT thermoplastic resin with a high melting point (230°C) and physical performance similar to that of other commercially available PBT resins.

The main purpose of this study is the development of an innovative methodology for Heat Exchangers (HE) design to replace the conventional design procedures. The new procedure is based on the definition of a software package managed by modeFRONTIER, a multi-objective optimization software produced by ESTECO, able to create HE virtual models by targeting several objectives, like HE performance, optimal use of material, HE minimal weight and size and optimal manufacturability. The proposed methodology consists first in the definition of a workflow for the automatic CFD simulation of a parametric model of a periodic HE cellular element.

The coupling is an integral part of the Cummins CELECT electronically controlled injector. Excessive wear was observed on early designs of the coupling and coupling bore. The coupling wear was caused by a high stress concentration and excessive side loading of the coupling as it slid against the coupling bore. The zero wear theory was used to develop a coupling design where the maximum wear depth does not exceed half the peak to peak surface finish (zero wear) over the life of the engine. The side load exerted on the coupling was compared with the calculated contact pressure for zero wear. The undesirable effects of a square edge stress concentration are discussed in the zero wear model. The physical effects of the sharp edge and chamfered coupling edge are reported, but not analyzed in this paper. Three different coupling designs were investigated by applying the zero wear concept.

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The hazardous bulk chemical liquid cargo transportation is usually made through highways, using special automotive devices, named semitrailer tank, a kind of mobile tank specially developed to perform this task, manufactured with many types of steel, selected according to the chemical characteristics of the product to be transported. Equipment sizing is made based on specific standards which include specified formulas, loading, and safety factors representing the design criteria of this type of device. Despite of the detailed design criteria for semitrailer tank, it has been observed failure of some pieces of equipment during operation, in a shorter effective life than that one considered in the design phase itself. Considering a detailed study of the stress distribution in this type of equipment, this paper shows a verification of the possibility of yielding failure in the semitrailer tank structure.

Instantaneous combine grain yield monitors need to provide reliable yield measurements since yield as a function of location is key information needed to manage fields by management zones. A scale and a yield monitor measured the same stream of grain and provided similar results when compared to each other. Data from either device may be misinterpreted if care in calibration and operation is not taken. Careful operators who pay attention to calibration, maintenance, and manufacturer's instructions will be required.

Yield potential was predicted and mapped for three corn fields in Central Illinois, using digital aerial color infrared images. Three methods, namely statistical (regression) modeling, genetic algorithm optimization and artificial neural networks, were used for developing yield models. Two image resolutions of 3 and 6 m/pixel were used for modeling. All the models were trained using July 31 image and tested using images from July 2 and August 31, all from 1998. Among the three models, artificial neural networks gave best performance, with a prediction error less than 30%. The statistical model resulted in prediction errors in the range of 23 to 54%. The lower resolution images resulted in better prediction accuracy compared to resolutions higher than or equal to the yield resolution. Images after pollination resulted in better accuracy compared to images before pollination.

In this paper, a gain-scheduling optimal control approach is proposed to enhance yaw stability of articulated commercial vehicles through active braking of the proper wheel(s). For this purpose, an optimal feedback control is used to design a family of yaw moment controllers considering a broad range of vehicle velocities. The yaw moment controller is designed such that the instantaneous tractor yaw rate and articulation angle responses are forced to track the target values at each specific vehicle velocity. A gain scheduling mechanism is subsequently constructed via interpolations among the controllers. Furthermore, yaw moments derived from the proposed controller are realized by braking torque distribution among the appropriate wheels. The effectiveness of the proposed yaw stability control scheme is evaluated through software-in-the-loop (SIL) co-simulations involving Matlab/Simulink and TruckSim under lane change maneuvers.

Tractor semi-trailer stability during emergency braking and steering maneuvers has been an issue that was improved through implementation of Anti-lock Braking Systems (ABS). Although some improvements have been achieved, the need for new control methodologies is evident from the number of accidents reported by NHTSA involving tractor semi-trailers. In this paper, a new control algorithm has been developed for improving the tractor semi-trailer stability through utilization of yaw moment, i.e., tire differential braking strategy. This new, multifaceted, adaptive control algorithm which allows the estimation of the unknown vehicle parameters through use of the adaptation laws is based on the Lyapunov Direct Method. A tractor semi-trailer model with four degrees of freedom was used to develop the control algorithm and the adaptation laws. The controller was implemented on a 2-axle tractor 1-axle van trailer in TruckSim 7©.

This paper investigates the yaw dynamic behaviour of a seven axle tractor semitrailer combination vehicle developed by VRDE (Vehicle Research & Development). The semitrailer has four steerable axles which follow command steering law i.e. all axles of semitrailer are steered in a particular relation with articulation of tractor. A 4 dof (degree of freedom) linear yaw plane model was developed for this combination vehicle. Yaw response characteristics such as lateral acceleration, yaw rate and articulation angle for step and sine steer is obtained from this model. Effects of speed on the above parameters are also studied to the same steering inputs. Lateral tyre forces due to semitrailer steering at various speeds are estimated to understand its distribution on each axle. Steady state yaw rate and articulation angle gain are obtained to predict the understeer / oversteer behaviour of combination vehicle.

It is the goal of this paper, to discuss the impact of electronics on modern day commercial vehicles an buses. Seen from the position of advanced engineering of an European commercial vehicle manufacturer, the emphasis will be placed on the mechanical-electronical system itself, rather than the electronics themselves. User friendly, logic protected systems will minimize operator unfamiliarity and misapplication and will offer not only component control, but shortly the integration of all of these subsystems in the total vehicle control. Total vehicle control will be the ultimate result, when the driver, the truck and the environment are brought together. Such vehicles will be more responsive, safer and easier to drive than today's commercial vehicles and buses and offer a cost effective utilization of these new technologies to the customer.

The quality and availability of distillate fuels in the coming decades has become an increasing concern to the U.S. Navy. In response, the Energy Research and Development Office of the David Taylor Naval Ship Research and Development Center (DTNSRDC) has conducted a worldwide survey of commercial marine fuels. An effort was made to obtain 50 commercial marine fuel samples from various suppliers worldwide. The purpose of the survey was to assess the current quality of available fuels by analytically characterizing each of the fuel samples obtained. This assessment consisted of the measurement of more than 44 fuel properties. This paper contains a summary of the analytical results which were obtained. In addition, the current analytical results are compared with refinery specifications, with the current Navy specification, and with the results of a similar survey conducted in 1983. Finally, the resulting conclusions and recommendations are presented.

United States construction equipment manufacturers are subject to a maze of product-oriented regulations in marketing their U.S.-built products in foreign countries. These same obstacles face their foreign-built products. In the past, these foreign regulations were more apt to be trade barriers to protect domestic markets than bonafide regulations to protect the users. These trade barriers are gradually being lifted because manufacturers in virtually all countries have now expanded beyond their domestic markets. Thus, the same manufacturers that formerly encouraged trade barriers must now cope with them. This expansion of markets now encourages the elimination of trade barriers and the harmonization of regulations. For the future, regulations will be retained and expanded. They will, however, be harmonized with international voluntary standards rather than having different regulations for each country.

This paper will discuss Concurrent Engineering as an emerging product development methodology. Specific emphasis will be placed on some of the key tools and considerations necessary for the success of Concurrent Engineering. In particular, the paper will discuss strategic product planning driven by customer requirements and how the product development effort will support the strategic product plan.

The idea of a world truck is a fascinating challenge - whereas cars are purchased more or less as seen; truck purchasers demand more individual configurations. In national and global terms, that means a highly complex truck market. Historically, a few European and North American manufacturers produced almost all the trucks for the world market. That changed through the 60's and 70's, with more local assembly plants around the world and increasing worldwide manufacturing capabilities. Concurrently, international component design standards have made some progress towards compatibility. Much greater co-operation is needed, however, before a genuinely international set of standards can be applied. As the task assigned to trucks is the same worldwide, namely to transport goods from A to B; it should be desirable and possible to work towards a greater commonality of vehicle - to ultimately achieve a world truck. The only unknown is the time scale.

All around the world, steps are being taken to improve the quality of our environment. Prominent among these are the definition, implementation, and attainment of increasingly stringent emissions regulations for all types of engines, including off-highway diesels. These rigorous regulations have driven use of technologies like after-treatment, advanced air systems, and advanced fuel systems. Fuel dispensed off-highway is routinely and significantly dirtier than fuel from on-highway outlets. Furthermore, fuels used in developing countries can be up to 30 times dirtier than the average fuels in North America. Poor fuel cleanliness, coupled with the higher pressures and performance demands of modern fuel systems, create life challenges greater than encountered with cleaner fuels. This can result in costly disruption of operations, loss of productivity, and customer dissatisfaction in the off-highway market.

Standardization and “Zero-Defects” are buzz-words among today's truck manufacturers. Electrical components is an area where these words must become reality. Components costing less than 1% of the final truck price should not cause problems for the end user or the manufacturer. The way to insure this is communication and design. Design out problems with new components.

Work solenoids are widely used in household appliances. The environment and design of this type application does not lead to solenoids for the earthmoving industry. This paper presents the environmental effects to be considered when designing a solenoid for the earthmoving industry. It further explains the need for, and type of, test necessary to validate the design. Finally a review of production quality procedures, necessary to insure reliable production parts is discussed.

With COSMOsim, OTSL is looking to better virtually recreate diverse driving conditions to enable safe and accurate verifications at a point when autonomous driving continues to move toward practical use around the world.