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The automotive industry is pursuing significant cost competitive efforts to reduce vehicle weight while maintaining or improving durability and impact performance. One such effort for the body shell structure is the utilization of advanced and ultra high strength steels (AHSS and UHSS) using the existing automotive manufacturing infrastructure. Common AHSS and UHSS steels include Dual Phase (DP), Transformation Induced Plasticity (TRIP), Partial Martensitic (PM) and others. The use of these multiphase high strength steels for impact dependent components has resulted in the need for further material characterization in order to better predict impact performance and guide new material development. This paper addresses the material properties and microstructural influences on impact behavior of advanced and ultra high strength steels through the use of laboratory tests and component level testing.

More than 200 tensile-shear resistance spot welded specimens were produced and tested to analyze the effect of spot weld spacing, weld size, sheet thickness, and adhesive on the ultimate strength of joints made from a mild hot dip galvannealed steel and an unexposed quality hot dip galvannealed 590 MPa minimum tensile strength dual phase steel (DP590). The geometric layout parameters were analyzed by a design of experiment (DOE) approach. The analysis showed that weld size is a primary factor affecting the strength of the joints for a given material. It was also determined that structural adhesive created a large relative strengthening for joints made from the mild steel. Interactions of the geometrical factors are also presented.

The National Renewable Energy Laboratory (NREL) collaborated with Millennium Cell and DaimlerChrysler to study heat and water management in a sodium borohydride (NaBH4) storage/processor used to supply hydrogen to a fuel cell in an automotive application. Knowledge of heat and water flows in this system is necessary to maximize the storage concentration of NaBH4, which increases vehicle range. This work helps evaluate the NaBH4 system's potential to meet the FreedomCAR program technical target of 6 wt% hydrogen for hydrogen storage technologies. This paper also illustrates the advantages of integrating the NaBH4 hydrogen processor with the fuel cell.

Automakers in the United States have started using bag mini-diluters (BMD) for developing, testing and certifying vehicles, to meet PZEV and SULEV regulation requirements. The BMD system which is a new technology developed by AIGER, is being used as an alternative to the traditional CFV/CVS system for accurate ultra low-level emission measurement. BMD system has shown to have considerable advantage over CFV/CVS system, especially at ULEV/SULEV emission levels. This paper details modifications and diagnostic checks conducted with the existing BMD system at the DaimlerChrysler Tech Center emissions facility, Auburn Hills, Michigan. This paper also discusses possible scenarios where the BMD system at DaimlerChrysler could give erroneous results due to system setup, optimization issues and equipment limitations.

The future of diesel-engine-powered passenger cars and light-duty vehicles in the United States depends on their ability to meet Federal Tier 2 and California LEV2 tailpipe emission standards. The experimental purpose of this work was to examine the potential role of fuels; specifically, to determine the sensitivity of engine-out NOx and particulate matter (PM) to gross changes in fuel formulation. The fuels studied were a market-average California baseline fuel and three advanced low sulfur fuels (<2 ppm). The advanced fuels were a low-sulfur-highly-hydrocracked diesel (LSHC), a neat (100%) Fischer-Tropsch (FT100) and 15% DMM (dimethoxy methane) blended into LSHC (DMM15). The fuels were tested on modern, turbocharged, common-rail, direct-injection diesel engines at DaimlerChrysler, Ford and General Motors. The engines were tested at five speed/load conditions with injection timing set to minimize fuel consumption.

Today the worldwide convergence towards stricter fuel consumption and emission regulations is pushing carmakers and suppliers into new fields of innovation. Valeo Engine Cooling, VEC, is contributing towards these goals by applying its thermal management system expertise in order to reduce fuel consumption and emissions by using an advanced engine cooling system that incorporated variable speed PWM fans, an electric water pump and an electric water control valve. The paper discusses the benefits in terms of engine cooling, fuel economy and emissions over the FTP drive cycle. The paper gives some examples of advanced engine cooling strategies based on a virtual, predictive metal temperature sensor that is used to actuate the electrical water pump at the desired flow rate. The electrical balance between the 42V pump and fans has also been optimized to reduce the vehicle electrical power consumption and to keep the coolant temperature close to 110°C.

Adding oxygenates to diesel fuel has shown the potential for reducing particulate (PM) emissions in the exhaust. The objective of this study was to select the most promising oxygenate compounds as blending components in diesel fuel for advanced engine testing. A fuel matrix was designed to consider the effect of molecular structure and boiling point on the ability of oxygenates to reduce engine-out exhaust emissions from a modern diesel engine. Nine test fuels including a low-sulfur (∼1 ppm), low-aromatic hydrocracked base fuel and 8 oxygenate-base fuel blends were utilized. All oxygenated fuels were formulated to contain 7% wt. of oxygen. A DaimlerChrysler OM611 CIDI engine for light-duty vehicles was controlled with a SwRI Rapid Prototyping Electronic Control System. The base fuel was evaluated in four speed-load modes and oxygenated blends only in one mode. Each operating mode and fuel combination was run in triplicate.

The overall program objectives were three fold: assess the benefits and limitations of oxygenated diesel fuels on engine performance and emissions identify oxygenates most suitable for potential use in future diesel formulations based on physico-chemical properties (e.g. flash point), toxicity, biodegradability and estimated cost of production perform limited emissions and performance testing of the oxygenated diesel blends select at least two oxygenated compounds for advanced engine testing In Part 1 of this program which is described in this paper, an extensive literature review was conducted to identify potential oxygenates for blending into diesel fuels. As many as 71 oxygenates were identified for the initial screening process. Based on a set of physical and chemical properties, a screening methodology was developed to select the 8 oxygenates that will be eligible for engine testing.

Most driver information systems offered in automobiles today display vehicle speed, fluid levels, fluid temperatures, and some basic diagnostic information (warnings, panel lamps). Optional driver information systems add to this list by offering fuel economy information, compass heading, outside temperature and other comfort and convenience related items. Very few provide information in regards to the real performance of the vehicle, its motion in 3-dimensional space, or the driver’s skill and performance. Making this information available to the driver can enhance the “fun-to-drive” aspects of driving.

The Auto/Steel Partnership Corrosion Project Team has completed a perforation corrosion test program consisting of on-vehicle field exposures and various accelerated tests. Steel sheet products with eight combinations of metallic and organic coatings were tested, utilizing a simple crevice coupon design. On-vehicle exposures were conducted in St. John's and Detroit for up to seven years to establish a real-world performance standard. Identical test specimens were exposed to the various accelerated tests, and the results were compared to the real-world standard. This report documents the results of these tests, and compares the accelerated test results (including SAE J2334, GM9540P, Ford APGE, CCT-I, ASTM B117, South Florida Modified Volvo, and Kure Beach (25-meter) exposures) to the on-vehicle tests. The results are compared in terms of five criteria: extent of corrosion, rank order of material performance, degree of correlation, acceleration factor, and control of test environment.

This paper presents an energy relationship between vehicle impact pulses and restraint systems and applies the relationship to formulations of response factors for linear and nonlinear restraints. It also applies the relationship to derive optimal impact pulses that minimize occupant response for linear and nonlinear restraints. The relationship offers a new viewpoint to impact pulse optimization and simplifies the process mathematically. In addition, the effects of different vehicle impact pulses on the occupant responses with nonlinear restraints are studied. Finally, concepts of equivalent pulses and equal intensity pulses are presented for nonlinear restraints.

As the volume and complexity of electronics increases in automobiles, so does the complexity of the electromagnetic relationship between systems. The reliability and functionality of electronic systems in automobiles can be affected by noise sources such as direct current (DC) motors. A typical automobile has 25 to 100+ DC motors performing different tasks. This paper investigates the noise environment due to DC motors found in automobiles and the requirements that automobile manufacturers impose to suppress RF electromagnetic noise and conducted transients.

Significant efforts are underway in the automotive industry to reduce vehicle weight while maintaining performance and cost competitiveness. One such effort is the use of advanced high strength steels (AHSS) as the primary body materials method to meet weight targets using the existing automotive manufacturing infrastructure. Issues related to the stamping of AHSS are well known, and significant hurdles still exist for successful implementation. Due to material strength and mechanical behavior, springback is a major hurdle in forming AHSS. While working to form AHSS parts and reduce springback, press shops have encountered a new fracture type. The term shear fracture or local elongation has been loosely used to specify these fractures, which occur at part radii under low strains in multiphase AHSS. These fractures cause design limitations and manufacturing uncertainty.

Pure tone whine noises produced by transmission gear meshing can be a particular annoyance to vehicle occupants. In this case the gear meshing was exciting a resonance within the transaxle, resulting in an especially obtrusive pure tone noise within a narrow speed range. This report presents the identification of the resonating component and the development of a novel approach to eliminate the noise problem. Specifically a laminated steel (MPM) disk was fastened to the face of the gear to provide damping. Knowledge of the gear's mode of vibration was used to optimize the effectiveness of the damping treatment. This approach is proven to be effective via experimentally verified prototypes

The new generation of drive-by-wire systems currently under development has demanding requirements on the electronic architecture. Functions such as brake-by-wire or steer-by-wire require continued operation even in the presence of component failures. The electronic architecture must therefore provide fault-tolerance and real-time response. This in turn requires the operating system and the communication layer to be predictable, dependable and composable. It is well known that this properties are best supported by a time-triggered approach. A consortium consisting of German and French car manufacturers and suppliers, which aims at becoming a working group within the OSEK/VDX initiative, the OSEKtime consortium, is currently defining a specification for a time-triggered operating system and a fault-tolerant communication layer.1 The operating system and the communication layer are based on applicable interfaces of the OSEK/VDX standard.

Stochastic simulation is used to account for the uncertainties inherent to the system and enables the study of crash phenomenon. For analytical purposes, random variables such as material crash properties, angle of impact, human response and the like can be characterized using statistical models. The methodology outlined in this approach is based on using the information about the probability of random variables along with structural behavior in order to quantify the scatter in the structural response. Thus the analysis gives a more complete picture of the actual simulation. Practical examples for the use of this technique are demonstrated and an overview of this approach is presented.

Tests were conducted at independent laboratories on a patented ashless additive technology designed generically for Fuel Charter I, II and III diesel fuels as defined by, AAMA (American Automobile Manufacturers Association), ACEA (European Automobile Manufacturers Association), EMA (Engine Manufacturers Association) & JAMA (Japan Automobile Manufacturers Association). The instantaneous effect of these additives in 6 light and 2 heavy duty engines in reducing particle number and particle mass emissions were measured as were mileage accumulation effects. Emission tests confirmed PM reduction of up to 19 % from both light duty vehicles tested under ECE15+EUDC or MVEG cycles and heavy-duty engines tested under the R49 or FiGE cycle. The results also indicated that such reduction had negligible or possibly a beneficial effect on NOx emissions.

Deposits on engine parts, and in particular in combustion chambers of modern engines are causing increasing concern in the automobile industry. Highly sophisticated engine management systems make effects on emissions or performance obvious as outgassing of unburned hydrocarbons or variation of spark advance. Reduced mean heat flux away from the cylinder influences engine thermodynamics. Extreme deposits may cause noise increase by carbon rap. A special form of combustion chamber deposits, well known under the synonym spark plug fouling, is a carbon needle on spark plugs, which can cause the total damage of the catalysts (Japanese Industrial Standard D 1606: Adaptability Test Code of Spark Plug for Automobiles) The Co-ordinating European Council for the development of performance tests for transportation fuels, lubricants, and other fluids (CEC) started the development of a new performance test in 1994.

In a consortium of European industrial partners and research institutes, a combination of industrial development and scientific research was organised. The objective was to improve the catalytic NOx conversion for lean burn cars and heavy-duty trucks, taking into account boundary conditions for the fuel consumption. The project lasted for three years. During this period parallel research was conducted in research areas ranging from basic research based on a theoretical approach to full scale emission system development. NOx storage catalysts became a central part of the project. Catalysts were evaluated with respect to resistance towards sulphur poisoning. It was concluded that very low sulphur fuel is a necessity for efficient use of NOx trap technology. Additionally, attempts were made to develop methods for reactivating poisoned catalysts. Methods for short distance mixing were developed for the addition of reducing agent.

A comparative investigation of airbag and HANS driver safety systems was carried out (HANS, is a Registered Trademark in the U.S.A.). With both systems, head and neck loads were reduced from potentially fatal values to values well below the injury threshold. Both systems performed similarly in reducing the potential for driver injury. For this reason and given the high costs of development and testing, there is no justification for further development of airbags for racing.