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This paper evaluates several durability tire models using Virtual Tire Testing (VTT) strategy. VTT conducts tire testing (simulation) using LS–DYNA based on a Virtual Tire which is built by 3–D finite element mesh. VTT is repeatable and could do special tire tests which can't be done using normal tire testing bench. A brief review is given on durability tire models and several typical tire models are selected for this study. All the necessary parameters for establishing the analytical tire models are extracted from the Virtual Tire. Quarter vehicle model is used to simulate the vehicle vertical vibration. The comments of those analytical tire models are given based on their performance vs. VTT.

Carbon black has contributed a series of important performance enhancements to tires, ranging from increased wet and dry traction to decreased rolling resistance. This paper briefly discusses the roles that carbon black plays in tire manufacturing, then moves broadly through a decade-by-decade list of key technical milestones for carbon-black formulation and applications. The paper ends with a discussion of 2 new technologies for tire fillers: carbon-silica dual-phase, fillers for rubber, and chemically modified carbon blacks, a promising breakthrough that confers controlled reactivity to carbon-black filler. Overall, the paper demonstrates that carbon black has played a leading role in enhancing tire life and performance.

This paper describes the design development of a new steel wheel which utilizes spokes to provide either weight or strength benefits over a conventional dish center wheel. The spokes are designed to be deep along the axis of the wheel and thin in the plan view of the wheel to provide improved strength and fatigue resistance. This unique patented approach uses spoke pairs to help achieve those advantages. Wheel designs utilizing this type of spoke are analyzed using classical methods as well as the finite element method. Results of the traditional analyses are presented in the form of maximum apparent stress calculations for wheels of various sizes. Corresponding finite element results are presented in the form of stress distributions plotted on solid model representations of wheels with magnitudes and locations of stresses shown.

One of the objectives of laboratory measurements of tire rolling resistance is to compare tires. This requires that a common basis be established for this comparison. For tests performed per the current standard, SAE J1269, rolling resistance measured at a standard load/pressure condition, at 80 kph, is used for this purpose. However, a similar specification should not be used for rolling resistance measured as per the new standard under development, SAE J2452, because the data are collected at multiple speeds for each load/pressure condition. This paper explores alternatives, defines new parameters and proposes a new methodology for comparing tires using data generated as per J2452. The new parameters are MERF (Mean Equivalent Rolling Force) and SMERF (Standard Mean Equivalent Rolling Force). The mathematical derivation of these terms is presented and their use illustrated using laboratory rolling resistance data generated as per J2452.

The complex design and loading conditions of the wheel-hub assembly and decisive safety demands make it necessary to proof the wheel fasteners under reliable, service-like testing conditions. In this paper main parameters, the function and fatigue life of wheel fasteners and consequences for testing are described and discussed. The test procedure is based on the Biaxial Wheel Test Method, whereby the existing load program »Eurocycle« was extended by additional braking and torsional force sequences. The test requirement and some typical test results are presented.

The model of tire cornering properties with experimental modal parameters is proposed. By lateral modal parameters tire side force and self-aligning torque under different operating conditions are calculated and the trends of the calculated results qualitatively correspond with the experimental results of the references. Non-dimensional calculated results are compared with that of some empirical and semi-empirical models. Calculated side force, self-aligning torque and cornering stiffness under different loads can be easily fitted by widely used Magic Formula model and good results are achieved. The tire properties under different operating conditions can be calculated easily and the labored experimental works which is necessary by other methods of tire modeling can be released. Some tire basic properties, such as tire side deformation and distribution of side force, can be calculated while it can not be done by other methods.

Usually, wheels dimension are based on fatigue or impact loading and thus lead to one steel grade and one thickness. The use of tailored Laser blanks permits wheel weight to be reduced considerably. Rims can be divided into different areas subject to different in-service stresses. The new rim blank is composed of two or more strips of different steels and thickness', welded together and formed conventionally. Discs can be divided into concentric laser welded elements which correspond to the iso-risk fatigue zones. Prototypes have been tested successfully. Weight savings of up to 40 % have been achieved.

Dual-brick catalyst systems containing Pd-only catalysts followed by Pt/Rh three-way catalysts (TWCs) provide an effective strategy for managing Pt, Pd and Rh precious metal inventories while achieving LEV/ULEV emission standards. Engine aged dual-brick converters containing front Pd catalysts followed by rear Pd/Rh or Pt/Rh TWCs demonstrated LEV emission levels in an underfloor location on a TLEV calibrated 3.8L vehicle, and achieved ULEV emissions with air addition. Using identical advanced washcoat formulations stabilized with ceria-zirconia promoters, single-brick Pt/Rh TWCs demonstrated equivalent performance to Pd/Rh TWCs after thermally severe aging, and dual-brick [Pd + Pt/Rh] systems also had equivalent performance to [Pd + Pd/Rh] catalyst systems. While a Pd-only system also achieved 100K mi equivalent LEV emissions, both dual-brick options lowered emissions further using substantially lower loadings and more balanced precious metal usage.

Controlled drift into terrain (CDIT) causes most wheel balance weight failures. Faulty installation causes only a small fraction. Prevent CDIT failures by installing wheel weights on the insides of wheels, at least on the front wheel on the side opposite the driver. The field data are: balance weights collected during two years from the streets of three zip codes vehicle registrations in those zip codes The balance weights were the clip-on, not the stick-on, type. The field failure rate per vehicle per year is 0.0044.

As U.S. and European regulation of automotive emissions is getting more stringent, great interest is growing around new solutions for future emission standards. Pollutant reduction can be achieved improving both engine out emission and aftertreatment system efficiency. Engine out emission can be reduced improving combustion process especially during warm-up, friction and the engine management system. In any case engine out emission reduction involves engine sophistication increasing costs, which must be accurately evaluated, especially for small displacement large mass production engine. Since, as it is well known, 80 - 90 per cent of HC and CO emissions are produced during the first 100s of NEDC cycle, great improvement could be achieved reducing the catalyst light-off time. Different configurations of exhaust gas after treatment system have been tested to improve conversion efficiency during warm-up phases.

ZLEV was accomplished by applying the Three-Stage Emission Management System, utilizing ultra-precise combustion and exhaust gas conversion control technology, and dividing the operation into three-stages of just after engine start, the warm-up stage, and normal running. These individual component technologies include improving engine combustion (high swirl combustion by variable valve timing and lift) and performing fuel control optimization during engine startup to reduce unburned HC emission, quick catalyst activation (engine control and catalyst improvements), HC adsorption of a hybrid catalyst (catalyst improvement and desorption conversion control), and high precision air-fuel ratio feed back control (catalyst condition predictive control, and others).

In this paper a computational model developed with the objective of simulating the thermal behaviour of the passengers' compartment of vehicles is presented. The model is based on the space-integral energy balance equations for the air inside the compartment and for the main vehicle bodies and surfaces. It can solve two kinds of problems. In the first one, calculates the heat stress that the air conditioning or heating system must equilibrate, in order to satisfy predefined permanent regimen project specifications. In the second one, once imposed a particular air conditioning system and given the ambient conditions, it computes the different temperatures and heat fluxes either in transient or steady regimens. The validation of this model was done with a railway car, in a summer situation, when it was immobilized and running. The model reproduced well the experimentally determined temperature and heat fluxes evolutions.

A computer controlled system capable of intercepting and performing closed-loop control of a vehicle subsystem during targeted modes of operation was developed. The system has been given the acronym ERIC, for Emissions Reduction Intercept and Control system. This study was prompted by the need for the ability to modify engine controls through targeted modes of operation, without altering the majority of engine operation, to assist in the integration of exhaust aftertreatment and engine systems. The general concept and approach for applying the ERIC method, and application of the system to perform targeted, mode-activated EGR control intercept on a 1997 Ford Crown Victoria, are described in this paper. Data are presented that demonstrate how the problem mode was identified, targeted, mapped, and modified. FTP-75 test data are presented to show the impact of this particular application.

A program to demonstrate the performance of advanced emission control systems in light of the California LEV II light-duty vehicle standards and the EPA's consideration of Tier II emission standards was conducted. Two passenger cars and one light-duty pick-up truck were selected for testing, modification, and emission system performance tuning. All vehicles were 1997 Federal Tier I compliant. The advanced emission control technologies evaluated in this program included advanced three-way catalysts, high cell density substrates, and advanced thermally insulated exhaust components. Using these engine-aged advanced emission control technologies and modified stock engine control strategies (control modifications were made using an ERIC computer intercept/control system), each of the three test vehicles demonstrated FTP emission levels below the proposed California LEV II 193,000 km (120,000 mile) ULEV levels.

For the BMW V8 engine, a new LEV/EU3 emission concept has been developed by improvements to the previous engine management and secondary air supply and a complete new exhaust system. Beside the emission limits, also high engine output targets and high operating reliability were targeted. In addition the new exhaust system had to meet low cost targets. Based on these requirements an exhaust concept with separate pre catalyst and main catalyst was chosen. To reduce the heat mass and to optimize the pressure drop, 4.3mil/400cpsi thin wall ceramic substrates were used for the pre and main catalyst.

A new converter concept is introduced, which utilizes the additional space in the inlet cone of the converter. An optimized design is obtained by the application of computational fluid dynamics (CFD) and flow distribution measurements, resulting in up to 20% improved flow distribution through the substrate. In addition, the volume of the converter can be increased by approximately 15% using the same space envelope. Durability tests of the converter system have been performed using a thermal cycling test on an engine test bench for 135 hours. No deterioration of the substrate or mounting system occurred. The emissions performance was evaluated on a stationary dynamometer. The impact of the flow distribution on the temperature field and the conversion behavior during light-off and steady state operation were investigated. Under the current testing conditions, no differences in light-off behavior were determined, despite significant differences in the temperature field.

The automotive industry and emission system suppliers invest considerable efforts for the improvement of the conversion efficiency of a catalytic converter, in order to lower vehicle emission. One of the methods to improve the catalyst conversion efficiency is to use a higher cell density brick with a thinner wall to increase its geometric surface area. However, there is a significant drawback for the system - higher pressure loss along the brick. Moreover, the mechanical strength and thermal degradation of the brick become major concerns. In this paper, the concept of a brick with radially variable cell density is introduced to possibly resolve several issues. A CFD study was conducted to verify benefits in both flow efficiency and pressure loss along the brick with several different flow rates.

Ultrasonic, capacitive, and infrared (IR) occupant position sensors were tested to determine their compatibility with crash test dummies. In this phase of testing, the sensors' responses to a Hybrid III 50th percentile male crash test dummy were compared to those of a human male of similar size. After the data were compared, crash test dummy modifications were developed so that sensor responses to the dummies more closely resembled their responses to humans. Ultrasonic sensors detected little difference between the dummy and the human. However, testing of capacitive and infrared sensors revealed differences in their responses to a crash test dummy and a human subject.

Fleet tests conducted on electrical vehicles around the world have very clearly shown that battery-powered cars may be regarded as zero-emission vehicles with respect to their local environments only. Emission measurements on vehicles powered by internal-combustion engines equipped with optimized exhaust-post-treatment systems have indicated the prospects the latter offer for cleaning up the environment, i.e., for yielding negative emissions, when run at their normal operating temperatures. Replacing electric cars with SULEV's is thus a matter currently under discussion. This paper will cover the functions of the various individual components of such post-treatment systems, and will show that optimizing the interactions among those components will improve their catalytic efficiencies.

The air bag has proven effective in reducing fatalities in frontal crashes with estimated decreases ranging from 11% to 30% depending on the size of the vehicle [IIHS-1995, Kahane-1996]. At the same time, some air bag designs have caused fatalities when front-seat passengers have been in close proximity to the deploying air bag [Kleinberger-1997]. The objective of this study was to develop an accurate and repeatable out-of-position test fixture to study the deployment of air bags into out-of-position occupants. Tests were performed with a 5th percentile female Hybrid III dummy and studied air bag loading on the thorax using draft ISO-2 out-of-position (OOP) occupant positioning. Two different interpretations of the ISO-2 positioning were used in this study. The first, termed Nominal ISO-2, placed the chin on the steering wheel with the spine parallel to the steering wheel.