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Fast-running metamodels (surrogates or response surfaces) that approximate multivariate input/output relationships of time-consuming CAE simulations facilitate effective design trade-offs and optimizations in the vehicle development process. While the cross-validated nonparametric metamodeling methods are capable of capturing the highly nonlinear input/output relationships, it is crucial to ensure the adequacy of the metamodel error estimates. Moreover, in order to circumvent the so-called curse-of-dimensionality in constructing any nonlinear multivariate metamodels from a realistic number of expensive simulations, it is necessary to reliably eliminate insignificant inputs and consequently reduce the metamodel prediction error by focusing on major contributors. This paper presents a robust data-adaptive nonparametric metamodeling procedure that combines a convergent variable screening process with a robust 2-level error assessment strategy to achieve better metamodel accuracy.

Deionized (DI) water is being used for humidification and cooling on some fuel cell designs. This highly purified water is corrosive, yet the high purity is required to maintain the function and durability of the fuel cell. A study of the deionized water system was undertaken to determine the effect of various materials on water quality, and also to determine the effect of deionized water on each material. The test setup was designed to circulate fluid from a reservoir, similar to an actual application. The fluid temperature, pressure, and flow rate were controlled. The resistivity of the water was observed and recorded. Pre- and post-testing of the water and the materials was performed. The goal is to achieve system cleanliness and durability similar to a stainless steel system using lighter, less expensive materials. This paper describes the test setup, test procedures, and the overall results for the eight materials tested.

Reductions of hardware costs as well as implementations of new innovative functions are the main drivers of today's automotive electronics. Indeed more and more resources are spent on adapting existing solutions to different environments. At the same time, due to the increasing number of networked components, a level of complexity has been reached which is difficult to handle using traditional development processes. The automotive industry addresses this problem through a paradigm shift from a hardware-, component-driven to a requirement- and function-driven development process, and a stringent standardization of infrastructure elements. One central standardization initiative is the AUTomotive Open System ARchitecture (AUTOSAR). AUTOSAR was founded in 2003 by major OEMs and Tier1 suppliers and now includes a large number of automotive, electronics, semiconductor, hard- and software companies.

In the North American automotive market, cylinder deactivation by means of engine valve deactivation is becoming a significant enabler in reducing the Brake Specific Fuel Consumption (BSFC) of large displacement engines. This allows for the continued market competitiveness of large displacement spark ignition (SI) engines that provide exceptional performance with reduced fuel consumption. As an alternative to a major engine redesign, the Active Fuel Management™ (AFM™) system is a lower cost and effective technology that provides improved fuel economy during part-load conditions. Cylinder deactivation is made possible by utilizing innovative new base engine hardware in conjunction with an advanced control system. In the GM 3.9L V-6 Over Head Valve (OHV) engine, the standard hydraulic roller lifters on the engine's right bank are replaced with deactivating hydraulic roller lifters and a manifold assembly of oil control solenoids.

The increasing demand for energy savings in cars of high production volume, especially those classified as emerging market vehicles, has led the automotive industry to focus on several strategies to achieve higher efficiency levels from their systems and components. One of the most diffuse initiatives is reducing weight through the application of the so-called light alloys. An engine cylinder block can contribute nearly two percent of the vehicle's total mass. Special attention and soon repercussion are given when someone decides to apply a light alloy such as the aluminum to this component. Nonetheless, it is known that peculiarities in terms of physical, chemical and mechanical properties, due to the material nature, associated with regional market characteristics make the initial feasibility analysis study definitely one of the most important stages for the material choice decision.

Hyper-elastic seals are extensively used in automotive applications for sealing various joints in assembly. They are also used in sealing battery packs. They are used in various sizes and shapes. Most of the gaskets used are solid gaskets. Hollow gaskets are also being used. Hollow gaskets typically have a fluid like air trapped inside. Analyzing these hollow gaskets also requires involving the physics of the fluid inside. The trapped fluid affects the performance of the gasket like contact pressure and width. Objective of this study is to analyze the hollow gasket performance including the effect of air trapped inside. The effect of air on performance of the hollow seal is also studied. Fluid Cavity capability in ABAQUS was selected after literature study to simulate the effect of trapped fluid (Air) on seal performance.

Currently, the dominant technology used in the manufacture of mass-market automobile structures is sheet-metal stamping because of its suitability for producing accurate, strong, durable components in large quantities [1]. While cost-effective and fast for high-volume applications, the cost of manufacturing stamping dies is difficult to profitably amortize over a low-volume product in any but the most high-priced vehicle segments. This study examines the application of automated fabrication technologies as an alternative to stamping for the production of low-volume body structure components, including the impacts on both design and performance.

Manual transmissions for passenger cars are facing pressures due to rapid growth of automatic transmissions, which already represents more than 60% of Brazil market, and from higher torque demand due to strict emission legislation, which turbo engines had presented great contribution to it. To solve this contradictory issue, gears with higher strength and lower cost have been studied to replacement Nickel by Niobium in the steels. Furthermore, this technology could be applied to solve the issues with electrified vehicle, where high torque, speed and lifetime are demanded pursued for gears. This study aimed to build prototypes and compare the S-N curves, fracture analysis, microstructure for three kinds of steels (QS4321 with Ni, QS1916 FG without Ni & with Nb and QS 1916 without Ni and Nb) in the condition carburized, hardened and tempered with and without shot peening.

This paper describes the design and development of the rear compartment structure of the sixth generation Corvette, C6, which starts in the 2005 model year. The improved design integrates the rear compartment packaging to address issues seen on fifth generation Corvette, C5. The molded composite fiberglass reinforced, tub and surround panels are similar to the C5. These large panels are modified to fit the new styling theme of the C6, while also addressing the packaging requirements of the updated underbody structure and exhaust system. New composite side support brackets and cross car reinforcement combine to address several desired improvements. These side support brackets are designed to package the rear audio speakers, electrical modules, wiring and cable routing while also addressing build variation and localized stiffness improvement. The side brackets support the surround panel increasing the manufacturing control of the surround panel.

Fatigue is one of the most common failure mechanism in engineering structures. The statistical nature of fatigue life and the stress gradient are the two challenges among many while designing any component or structure for fatigue. Fatigue lives of the identical components exhibit the considerable variation under the same loading and operating conditions due to the difference in the material micro-structures and other uncontrolled parameters. Stress concentration at the notch causes stress gradient and therefore, applying the plane specimen results for actual engineering components with notches does not give quantitatively reliable results if the stress gradient effects are not considered. The objective of the work presented here was to carry out the fatigue tests of un-notched, U and V-notch specimens which were die cast using aluminum alloy (A380) and to obtain fatigue life using a variable critical distance method which considers the stress gradient due to the notch geometry.

Forming Limit Curves (FLCs) were developed for the 5083 aluminum alloy at conditions simulating high temperature processes such as superplastic and quick plastic forming. Sheet samples were formed at 450 °C and at a constant strain rate of 5x10-3 s-1, by free bulging into a set of elliptical die inserts with different aspect ratios. Friction-independent formability diagrams, which distinguish between the safe and unsafe deformation zones, were constructed. Although the formability diagrams were confined to the biaxial strain region (right side quadrant of an FLD), the elliptical die insert methodology provides formability maps under conditions where traditional mechanical stretching techniques are limited.

The paper describes the challenges and results achieved in developing a new high-speed Diesel combustion system capable of exceeding the imaginative threshold of 100 kW/l. High-performance, state-of-art prototype components from automotive diesel technology were provided in order to set-up a single-cylinder research engine demonstrator. Key design parameters were identified in terms boost, engine speed, fuel injection pressure and injector nozzle flow rates. In this regard, an advanced piezo injection system capable of 3000 bar of maximum injection pressure was selected, coupled to a robust base engine featuring ω-shaped combustion bowl and low swirl intake ports. The matching among the above-described elements has been thoroughly examined and experimentally parameterized.

The need for improved axle NVH integration has increased significantly in recent years with industry trends toward full-time and automatic four wheel drive (4wd) systems. Along with seamless 4wd operation, quiet performance has become a universal expectation. Axle gear-mesh noise can be transmitted to the vehicle passenger compartment through airborne paths (not discussed in this paper) and structure-borne paths (the focus of this paper.) A variety of mounting configurations are used in an attempt to provide improved axle isolation and reduce structure-borne transmission of gear-mesh noise. The configuration discussed in this paper is a 4-point vertical mount design for an Independent Front Drive Axle (IFDA). A significant benefit of this configuration is improved isolation in the range of drive torques where axle-related NVH issues typically exist.

A computational and experimental study was performed to characterize the flow within a gasoline injector and the ensuing sprays. The computations included the effects of turbulence, cavitation, flash-boiling, compressibility, and the presence of non-condensible gases. The flow domain corresponded to the Engine Combustion Network's Spray G, an eight-hole counterbore injector operating in a variety of conditions. First, a rate tube method was used to measure the rate of injection, which was then used to define inlet boundary conditions for simulation. Correspondingly, injection under submerged conditions was simulated for direct comparison with experimental measurements of discharge coefficient. Next, the internal flow and external spray into pressurized nitrogen were simulated under the base spray G conditions. Finally, injection under flashing conditions was simulated, where the ambient pressure was below the vapor pressure of the fuel.

A life cycle inventory (LCI) study evaluates the environmental performance of the ULSAB-AVC (UltraLight Steel Auto Body - Advanced Vehicle Concepts) vehicle product system. The LCI quantifies the inputs and outputs of each life cycle stage of the ULSAB-AVC PNGV-gas engine vehicle (998 kg) over the 193,000 km service lifetime of the vehicle. The use phase of the ULSAB-AVC PNGV-diesel engine variant (1031 kg) is also quantified. The data categories measured for each life cycle phase include resource and energy consumption, air and water pollutant emissions, and solid waste production. The ULSAB-AVC LCI study is based on the methods, model and data from the 1999 study by the United States Automotive Materials Partnership (USAMP), a consortium within the United States Council for Automotive Research. This model was modified to represent the ULSAB-AVC PNGV-gas engine vehicle for each life cycle phase as well as the use phase of the PNGV-diesel engine variant.

The need for fuel economy gains is crucial in todays automotive market. There is also growing interest and knowledge of greenhouse gases and their effect on the environment. Paulstra's magnesium powertrain brackets were a solution that was presented not just to reduce the weight of the engine mounting system (which was already under its weight target before magnesium introduction), but in response of the OEM's desire to further reduce the weight of the vehicle for CAFE and weight class impact. This new engine mounting system has three powertrain mount brackets that are high-pressure die cast AZ91D magnesium alloy. This paper will show that these brackets to have a dramatic weight reduction compared to the standard aluminum die-cast material that they replaced. This paper describes the process of approval: concept and material sign-off by the OEM, FEA for strength and modal performance, corrosion, and the final product.

To cope with the increasing number of advanced features (e.g., smart-phone integration and side-blind zone alert.) being deployed in vehicles, automotive manufacturers are designing flexible hardware architectures which can accommodate increasing feature content with as fewer as possible hardware changes so as to keep future costs down. In this paper, we propose a formal and quantitative definition of flexibility, a related methodology and a tool flow aimed at maximizing the flexibility of an automotive hardware architecture with respect to the features that are of greater importance to the designer. We define flexibility as the ability of an architecture to accommodate future changes in features with no changes in hardware (no addition/replacement of processors, buses, or memories). We utilize an optimization framework based on mixed integer linear programming (MILP) which computes the flexibility of the architecture while guaranteeing performance and safety requirements.

In order to increase the efficiency of automotive turbochargers at low speed without compromising the performance at maximum boost conditions, variable geometry compressor (VGC) systems, based on either variable inlet guide vanes or variable geometry diffusers, have been recently considered as a future design option for automotive turbochargers. This work presents a modeling, analysis and optimization study for a Diesel engine equipped with a variable geometry compressor that help understand the potentials of such technology and develop control algorithms for the VGC systems,. A cycle-averaged engine system model, validated on experimental data, is used to predict the most important variables characterizing the intake and exhaust systems (i.e., mass flow rates, pressures, temperatures) and engine performance (i.e., torque, BMEP, volumetric efficiency), in steady-state and transient conditions.

Historically, vehicle brake feel has usually been evaluated in a subjective manner. If an objective measure was used, it was pedal force versus the deceleration rate of the vehicle. Stopping distance is almost always used to characterize vehicle braking performance by the automotive press. This represents limit braking performance, but ignores braking performance under normal driving conditions experienced by customers most of the time. Evaluation of pedal feel by the press is generally limited to subjective adjectives such as “mushy”, “positive”, and “responsive”. A method will be presented, which is being used by General Motors, to translate customer brake feel expectations into objective performance metrics. These metrics are correlated to actual subjective ratings and are used to set objective, measurable requirements for performance.

Planetary gear set is one of the most commonly used gear systems in automotive industry as they cater to high power density requirements. A simple planetary gear set consists of a sun gear, ring gear, planets and carrier which houses planet gears. Efficiency of a transmission is dependent upon performance of gear sets involved in power transfer to a great extent. Structural rigidity of a planetary carrier is critical in a planetary gear set as its deflection may alter the load distribution of gears in mesh causing durability and noise issues. Limited studies exist based on geometrical parameters of a carrier which would help a designer in selecting the dimensions at an early stage. In this study, an end to end automated FEA process based on DOE and optimization in Isight is developed. The method incorporates a workflow allowing for an update of carrier geometry, FE model setup, analysis job submission and post-processing of results.