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There are very few people in the industrial world that have driven vehicles who do not know the advantages of Power Steering. As a matter of fact, a relatively high percentage of on-highway vehicles are now power steered. There is even a much larger percentage of all off-highway vehicles that are also power steered. Many of these off-highway vehicles are primarily designed with power steering with no alternate. This presentation will be centered around off-highway steering needs which encompass Agricultural, Industrial, Construction, and other special purpose vehicles.

An approximate theoretical analysis of loading in a simple planetary gear system is presented for both the case where one central gear is not centered and the case where both central gears are centered. Numerical examples are used to compare the two types of arrangement, and to demonstrate the amount of load unbalance which may occur in practice. A possible method of improving load sharing is suggested.

A special fixture and test procedure is described which measures gear tooth bending stress in high contact ratio truck transmission spur gearing. A mathematical model which includes the effects of involute profile modifications, spacing variations, crown, and lead variations is described and its results are compared to the test measurements. Finite element analysis verification and disadvantages are described. Truck transmission dynamic measurement results of gear bending stress and torque split between the two twin countershafts are reported. Conclusions include that the mathematical model bending stress results compare favorably to test measurements and the twin countershafts have nearly equal torque load and small dynamic load variations with speed.

The recent introduction of closed loop electro-pneumatic servo systems for load simulation fills a gap between the performance limitations of open loop systems, and the higher cost of closed loop hydraulic systems. Closed loop pneumatic systems have been successfully employed in a number of load simulation applications.

Road load data is an essential input to evaluate vehicle durability and strength performances. Typically, load case of pothole impact constitutes the major part in the development of structural durability. Meanwhile, misuse conditions like driving over a curb are also indispensable scenarios to complement impact strength of vehicle structures. This paper presents a methodology of establishing Multi-body Dynamics (MBD) full vehicle model in Adams/Car to acquire the road load data for use in durability and strength analysis. Furthermore, load level between durability and misuse conditions of the same Impact road was also investigated to explore the impact due to different driving maneuvers.

A fundamental problem in soil-vehicle mechanics is the ability to predict accurately the load-sinkage characteristics of simple flat plates in homogeneous soils. This paper attempts to develop a more general theory of plate sinkage which will be applicable to a wide variety of soils, sinkages, plate sizes, and plate shapes. In a study to determine the strength characteristics of soils, many carefully performed tests must be conducted to eliminate the effects of the natural variability of the soil which can easily mask out the parameters being measured.

The level at which forces are transmitted from the striking vehicle in side impacts may influence the response of the struck car in several different ways. A better contact between the front bumper of the striking and the sill area of the struck car has been considered to be desirable in this respect. In side impacts, the most frequent direction of the impact is from 3 and 9 o'clock, while the direction of the forces is usually from 2 and 10 o'clock due to the velocity of the struck car. A European car and the EEVC moving deformable barrier have, therefore, been used in a crabbed mode to study the problem of load transfer at different levels above the ground. Volvo and Saab cars were used as targets in 55 km/h side impact with an APROD-81 side impact dummy placed on the struck side in the front seat. The results indicate that a difference in the level at which the loads were applied could influence the deformations, the kinematics of the struck cars, and the loading of the occupant.

This paper illustrates that the shoulder complex of the Hybrid III allows a load transfer from the upper extremities that can be associated with an increase of the thoracic spine acceleration. The force transferred by the Hybrid III shoulder and clavicle joints is a result of both inertial forces and contact forces acting on upper extremities. Its possible effect on the 3ms chest injury parameter raises some concerns. First, the Hybrid III shoulder joint compliance has been questioned by other publications. Second, there appears to be no documentation in the literature that supports a relationship between shoulder joint load and chest injury risk in humans. Lastly, kinematics of the upper extremities can vary from test to test, especially between different test facilities, which could contribute to variation of chest response. In this paper, original experimental and simulation data are used to explore this topic.

Friction between the piston and cylinder accounts for large amount of the friction losses in an internal combustion (IC) engine. Therefore, any effort to minimize such a friction will also result in higher efficiency, lower fuel consumption and reduced emissions. Plasma electrolytic oxidation (PEO) coating is considered as a hard ceramic coating which can provide a dimpled surface for oil retention to bear the wear and reduce the friction from sliding piston rings. In this work, a high speed pin-on-disc tribometer was used to generate the boundary, mixed and hydrodynamic lubrication regimes. Five different lubricating oils and two different loads were applied to do the tribotests and the COFs of a PEO coating were studied. The results show that the PEO coating indeed had a lower COF in a lower viscosity lubricating oil, and a smaller load was beneficial to form the mixed and hydrodynamic lubricating regimes earlier.

Finite Element modeling and analysis techniques can effectively support design and testing of complex mechanical components. This paper discusses how Finite Element modeling was utilized in the design and evaluation of a cup carrier for a new concept wheel bearing. Also discussed are field and laboratory tests conducted to check the validity of the Finite Element approach.

Compression ignition engines are widely used in the cargo and passenger transport sectors, this is due to their high energy efficiency and can operate with renewable fuels. The search for increased efficiency in internal combustion engines and reduced emissions are increasingly stringent, so to meet regulatory emission standards, new technologies are being studied and developed to reduce emissions generated by engines, in the case of diesel engines compression ignition, studies of techniques to reduce NOx and soot have been carried out. One of the techniques studied is the application of the DFI - Ducted Fuel Injection concept, which makes the fuel spray pass through a small cylindrical duct installed upstream of the injection orifice of the injector nozzle, thus improving the air/fuel, making it more homogeneous and allowing a more complete combustion. This work addresses a study of this application of DFI with different compression ratios.

THE choice of a suitable lubricant for a given mechanism involves a study of the relation between the various factors of design, operation and lubricant characteristics. One of the most important phases of the extreme-pressure-lubricant problem is the development of laboratory apparatus and test methods for the determination of the characteristics of a lubricant that are significant measures of its service performance. During the last year the U. S. Bureau of Standards has undertaken a comprehensive study of the problem of extreme-pressure lubricants in cooperation with the S.A.E. Lubricants Research Subcommittee. Since the primary requisite for an extreme-pressure lubricant is that “it lubricate under high load,” it was decided that a start on this program be made with an investigation of the load-carrying capacity. The preliminary tests are described, the effect of speed and temperature is considered, and the apparatus and procedure are explained.

When a stationary automobile is on a horizontal road, the car and its suspension linkages are in static equilibrium under the actions of gravity loading, road reactions, and internal spring forces. When this same system is acted on by steady cornering and/or axial acceleration loads, in addition to gravity loading, the equilibrium configuration of the suspension will be changed substantially from its gravity-load-only condition, affecting the driving characteristics of the automobile. This paper presents a general computer-based method for determining displacement relations and equilibrium configurations of mechanisms which are restrained by springs and subjected to steady external loading. The method is illustrated by its application to several suspension systems of varying complexity.

This paper investigates the role that load-limiters play with respect to the performance of occupant protection systems, with focus on performance in frontal crashes. Modern occupant protection systems consist of not just the seat belt, but also airbags, interior vehicle surfaces and vehicle structure. Modern seat belts very often incorporate load-limiters as well as pretensioners. Published research has established that load-limiters and pretensioners increase the effectiveness of occupant protection systems. Some have argued that load-limiters with higher deployment thresholds are always better than load-limiters with lower deployment thresholds. Through testing, modeling and analysis, we have investigated this hypothesis, and in this paper we present test and modeling data as well as a discussion to this data and engineering mechanics to explain why this hypothesis is incorrect.

Load-sensitive hydraulic control systems have demonstrated new potential high efficiency levels. Mobile equipment designs which widely utilize open and closed center circuits are being adapted to total centralized load-responsive stand-by systems to curtail fuel consumption and operating costs. This paper outlines previous art in steering systems and highlights the design concepts required to adapt the steering function to load sensitive variable flow-pressure circuitry. Since the steering function power demands are normally low for corrective maneuvers, it is ideally suited to the environment of a central load-sensitive system. The general concept of a load-sensing steering valve and its relative design role to the other system components will be developed, emphasizing standard meter-in load-sensing technology. The possible new “feathered” and “absolute” type systems are introduced.

Electronic Control Units (ECUs) are typically programmed using external programming devices - frequently called Diagnostic Testers. We propose a system and software architecture that requires no Diagnostic Tester for ECU (re)programming. ECU (re)programming is instead managed by an on-board software component, the Flashware-Reprogramming-Controller. It can reside in any ECU that has sufficient memory and processing power as well as good connectivity to internal networks and external sources from which to receive the software to be installed. Appropriate choices could be modern telematic devices. A second co-located on-board software component - the Installation-Configuration-Controller - is used to supervise the installation of new software releases and to validate their integrity after installation. The proposed architecture can be used for software download into ECUs in development, end-of-line production and after sales.

In this paper, the microstructure-based finite element modeling method is used in investigating the loading path dependence of formability of transformation induced plasticity (TRIP) steels. For this purpose, the effects of different loading path on the forming limit diagrams (FLD) of TRIP steels are qualitatively examined using the representative volume element (RVE) of a commercial TRIP800 steel. First, the modeling method was introduced, where a combined isotropic/kinematic hardening rule is adopted for the constituent phases in order to correctly describe the cyclic deformation behaviors of TRIP steels during the forming process with combined loading paths which may include the unloading between the two consecutive loadings. Material parameters for the constituent phases remained the same as those in the authors' previous study [ 1 ] except for some adjustments for the martensite phase due to the introduction of the new combined hardening rule.

Accurate knowledge of diesel particulate filter (DPF) particulate matter (PM) loading is critical for robust and efficient operation of the combined engine-exhaust aftertreatment system. Furthermore, upcoming on-board diagnostics regulations require on-board technologies to evaluate the status of the DPF. This work describes the application of radio frequency (RF) - based sensing techniques to accurately measure DPF particulate matter levels. A 1.9L GM turbo diesel engine and a DPF with an RF-sensor were studied. Direct comparisons between the RF measurement and conventional pressure-based methods were made. Further analysis of the particulate matter loading rates was obtained with a mass-based total PM emission measurement instrument (TEOM) and DPF gravimetric measurements.

This paper focuses on dynamic analysis and frame optimization of a FSAE racing car frame. Firstly, a Multi-Body Dynamic (MBD) model of the racing car is established using ADAMS/Car. The forces and torques of the mechanical joints between the frame and suspensions are calculated in various extreme working conditions. Secondly, the strength, stiffness and free vibration modes of the frame are analyzed using Finite Element Analysis (FEA). The extracted forces and torques in the first step are used as boundary conditions in FEA. The FEA results suggest that the size of the frame may be not reasonable. Thirdly, the size of the frame is optimized to achieve minimized weight. Meanwhile the strength and stiffness of the frame are constrained. The optimization results reveal that the optimization methodology is powerful in lightweight design of the frame.