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In order to resist impact loadings that usually occurs in an off-road circuit an integrated approach of mechanical design is developed to obtain an optimized vehicle suspension. Efforts were made to model a front suspension, type double A of an off-road vehicle Mini-Baja. The focus was stressed in the transmissibility of mechanical forces through front suspension. A simple analytic model was done to esteem the reactions generated at points of linkage of suspension and structure of Mini-Baja, during a transient impact load. Numerical simulation softwares were also used to visualize dynamic behavior of different front suspension configurations. Finally experimental test was done with data acquisition system, with the use of load cells, to generate a reference data to compare analytic and numerical models.

The growing competition of the automotive market makes more and more necessary the reduction of development time and consequently, the increase of the capacity to quickly respond to the launching of the competitors. One of the most costly phases on the vehicle development process is the field durability test, both in function of the number of prototypes employed and the time needed to its execution. More and more diffused, the fatigue life prediction methods have played an important part in the durability analysis via CAE. Nevertheless, in order they can be reliable and really being able to reduce the development time and cost, they need to be provided with load cases that can accurately represent the field durability tests. This work presents a CAE approach used for light trucks in order to get a reasonable understanding of component durability behavior due to payload increase. In general, road load data is not available for a new payload condition.

The New Kubota Grand L30 Series Compact Tractors are powerful, user-friendly compact tractors that have advanced functions to provide the maximum performance. Many new features such as IntelliPanel enable users to obtain high workability, comfort, and operability. IntelliPanel is an advanced function that displays information on a liquid crystal display to help users' with operation and maintenance. An electronically controlled multi-gear GST (Glide Shift Transmission) enables users to choose gears for 12 travel speeds using one lever, during travel without operating a clutch. An ECU (Electric Control Unit) controls solenoid valves and a proportional reducing valve to allow for smooth gear changes.

The paper attempts to determine which traction model best fits with experimental data for a romanian lugged tractor tire. Different models for predicting net traction and traction efficiency for off-road conditions were considered. These models assume different tire-ground pressure distributions (constant, parabolic) over the undertread area and different contact patch length calculations. Experiments were conducted and the results were compared to the theoretical data. Two of the models are the best fit with the experimental data; both models assumed a parabolic pressure distribution over the undertread.

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.

Current trends in vehicle development, including both automotive and commercial vehicles, are characterized by short model life cycles, reduced development time, concurrent design and manufacturing development, reduced design changes, and reduced total cost. All of these are driven by customer demand of higher load capacity, reduced weight, extended durability and warranty requirement, better NVH performance and reduced cost. These trends have resulted in increased usage of computational simulation tools in design, manufacturing, and testing, i.e. virtual testing or virtual prototyping. This paper summarizes our work in virtual testing, i.e. fatigue life simulations using computational fracture mechanics for commercial vehicle axle gearing development. First, fatigue life simulation results by using computational fracture mechanics CRACKS software were verified by comparing with gear teeth bending fatigue test data and three point bending fatigue test data.

This paper discusses dry stopping performance comparisons of various foundation brake systems on Class-8 truck tractors (having a GVWR greater than 33,000 lbs.). For these studies, four configurations of foundation brakes were fitted to two modern 6x4 conventional truck tractors without modification to the control, application, or ABS systems. Foundation brakes compared include standard S-cam drum brakes on all six positions, high-output S-cam drum and then air disc brakes on the steer axles, and air disc brakes on all six brake positions. Discussions include analyses of stopping distance from 60 mph (96.6 kph) for all test conditions. The truck tractors were tested in two weight configurations, LLVW (i.e., bobtail) and GVWR (50,000 lbs. total axle weight, using an unbraked control semitrailer).

This technical paper continues a sequence of previous SAE Technical Papers that document progress of wheel bearing adjustment on tractor/trailer combination vehicles. In an earlier SAE paper, 2000-01-3496, misinformation provided was recognized. This material is reviewed following the conclusion of this technical paper and corrections are offered. However, of primary importance, disclosure will be made of new developments accomplished in wheel bearing preload adjustment procedures since December 2000. The intent of this paper is to advise the means by which selected amounts of preload can be introduced into trailer wheel assemblies. These are identified as axle nut adjustable systems that are serviceable by mechanics in commercial carrier fleet operations. No commentary will be presented relative to the permanent type of wheel bearing adjustment systems that are factory installed and are unable to be adjusted while in service.

This paper discusses wet stopping performance and stability comparisons of various foundation brake systems on Class-8 truck tractors (having a GVWR greater than 33,000 lbs.). For these studies, four configurations of foundation brakes were fitted to two modern 6×4 conventional truck tractors without modification to the control, application, or ABS systems. The foundation brakes compared include standard S-cam drum brakes on all six positions, two hybrid configurations (high-output S-cam drum and then air disc brakes on the steer axles), and air disc brakes on all six brake positions. The truck tractors were tested in two weight configurations, LLVW and GVWR using an unbraked control semitrailer. Analytical analyses of wet brake-in-curve testing indicate that the hybrid brake systems (employing higher-torque brakes on the steer axle only) might degrade brake-incurve performance. This disadvantage appeared to exist for both load conditions.

A target-setting procedure for the design of the suspension system of a tractor-semi-trailer combination is described in this paper. This procedure is based on computer modeling and simulation of the complete vehicle system, as well as the modeling and simulation of suspension subsystems. The procedure relies heavily on computer-aided engineering software which provides the capability for automating the modeling and simulation of various suspension configurations, designing the screening test matrix, generating the response surface associated with each vehicle performance metric, and performing the multi-objective optimization with deterministic and stochastic constraints. The key to the success of this procedure is having a vehicle model wherein the inputs to the model are the attributes of the suspension subsystem, which in turn, become the design targets during the design of the suspension subsystem.

The accurate prediction of commercial-vehicle ride and handling performance with computer simulation tools is dependent on the level of correlation between the computer model and experimental data. Correlating vehicle attributes to physical test data is often challenging due to the large number of degrees of freedom - and, correspondingly, the large number of tunable parameters - typically required to accurately model vehicle behavior. A high level of interaction between input parameters and vehicle attributes further complicates the task. As a result, this type of correlation is a multi-objective optimization exercise in which the judicious planning of supporting test activity is critical to achieving the right level of model accuracy with an acceptable amount of resource investment. This paper discusses the methodology implemented in the validation of a tractor-semitrailer ADAMS model for both ride and handling simulations and presents the results obtained.

In the past decades, the diesel engines are considered as the major power source, not only because of their high thermal efficiency, high torque output, and easy maintenance; but also due to the improved exhaust emissions reduction technology. In order to increase the thermal efficiency, the low heat rejection ceramic coating engine is one of the possible solutions for future engine manufacturing. Due to the thermal insulating effects of the ceramic material (low thermal conductivity), the cylinder charge and engine components' temperatures are substantially increased. However, the thermal impact problem and the possible high friction characteristics of the new coating material can be deadly to the engine's lifetime. Various non-ceramic and ceramic materials are tested in this research to decide their thermal insulating effects on the engine performance and their downside on the friction and thermal impact problems.

The paper gives an overview of the partially extremely complex problem when looking into commonalities and differences of the three main application areas of engines and powertrains - automotive, agricultural tractors, and industrial engines, the last being predominantly but not exclusively focused on construction equipment. The modern “platform” approach has been used in the automotive world to a large extent and the learned experiences may be of interest for the agricultural tractors and/or the construction equipment manufacturers. On the other hand the truck engine engineers and manufacturers will learn more about the special requirements of the tractor and the industrial engines fields, and thus influence concepts and development procedures and also the production of the automotive engines which in many cases serve as the basis for derivate engines.

FORD OTOSAN has developed a new heavy-duty diesel engine, ECOTORQ, for the new Ford Cargo Trucks whose production started in September 2003. The engine is 7.3 liters, 6-cylinder in-line, with common rail fuel injection system and overhead camshaft design having 4 valves per cylinder. The engine meets the Euro-III exhaust emissions limits, which were in effect when it was introduced, and the engine incorporates the potential to meet Euro-IV. Modern computation and simulation methods were used and extensive experimental studies were made during the design and development stages, which helped reach the targets of compactness, modular structure, low fuel consumption, low noise level and low emissions.

The validation of the wheel/hub assembly has been carried out in the Biaxial Wheel/Hub Test facility since the early ‘1980’s developed at Fraunhofer LBF. This test procedure became a standard at most of the European wheel and truck producers and was also introduced as SAE wheel standard J 2562, issued in 2003. For newly developed Super Single low profile tires 495/45R22.5, which will replace double rear tires on heavy trucks and buses, the corresponding steel and aluminum wheels had to be designed by the suppliers. Because of the lack of information about load data and load programs for testing, extensive research had to be undertaken. The load data had been measured in collaboration with DaimlerChrysler on a M.B. Actros on proving grounds and on the “Black Forest round track” in Germany. Based on the derived data a special “Eurocycle” load program has been developed for accelerated testing of the wheels in the Biaxial Wheel Test Rig.

A complete analytical design and analysis procedure of permanent magnet motors for ‘in-wheel’ traction application system is developed. Method to obtain minimum power requirement and optimal torque-speed profile to meet acceleration performance is explained. Analytical design procedure to optimize electric motor parameters, such as, back emf and torque constants, inductance and magnet thickness is developed that are based on the torque-speed requirement of the system. The optimization technique focuses on minimizing the power and volt-ampere rating of the entire electrical system. The design process is validated through experiment and field-testing. Although the paper is focused on electric bicycle system, the approach is also applicable to electric and hybrid electric vehicles.

Decreasing the propensity for rollover during steady state cornering of tractor semi-trailers is a key advantage to the trucking industry. This will be referred to as “increasing the lateral stability during steady state cornering” and may be accomplished by changes in design and loading variables which influence the behavior of a vehicle. To better understand the effects of such changes, a computer program was written to optimize certain design variables and thus maximize the lateral acceleration where an incipient loss of lateral stability occurs. The vehicle model used in the present investigation extends that developed by Law [1] and presented in Law and Janajreh [2]. The original model included the effects of tire flexibility, nonlinear roll-compliant suspensions, and fifth wheel lash. This model was modified to include (a) additional effects of displacement due to both lateral and vertical tire flexibility, and (b) provisions for determining “off-tracking”.

The ISO11783 (ISOBUS) standard for communication between tractors and farming implements provides significant opportunities to improve the service process for agricultural equipment. Existing approaches to diagnostics in the transportation industry include an array of different technologies. These existing technologies can be combined in new ways in the ISOBUS environment to provide new value. Of particular interest is a data-driven diagnostic test system that ensures implements produced by different manufacturers provide a consistent and compatible interface to generic diagnostic test systems. By sharing data and software components, such a system can produce significant gains in quality, efficiency and interoperability.

Powder Metallurgy (P/M) is an increasingly viable alternative for applications requiring high material performance. Continuous advances in alloy systems and processing techniques, combined with powder metallurgy's ability to produce complex net shapes, have made it possible for powder metallurgy to compete with other technologies in engine and transmission applications. This paper will focus on new alloy systems and advanced processing techniques. The properties achievable with currently available materials, such as chromium containing materials, combined with advanced processing techniques, such as warm compaction and surface densification, will be presented. Additionally, a case study where a warm compacted synchronizing latch cone in a heavy duty truck transmission was found to have equal or superior performance to precision forged and powder forged latch cones.

This paper describes a radical new approach to variable flow oil pump design, which addresses some concerns of earlier designs and also conventional fixed displacement pumps. Detailed here are the testing and results to date, the potential areas for the future work, together with the reduction in parasitic power loss and potential fuel consumption savings. Also discussed are the benefits that can be realised by using this product as a tool for radically changing current automotive lubrication systems.