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To help address the issue of message authentication on the Controller Area Network (CAN) bus, researchers at Virginia Tech and Ford Motor Company have developed a proof-of-concept time-evolving watermark-based authentication mechanism that offers robust, cryptographically controlled confirmation of a CAN message's authenticity. This watermark is injected as a common-mode signal on both CAN-HI and CAN-LO bus voltages and has been proven using a low-cost software-defined radio (SDR) testbed. This paper extends prior analysis on the design and proof-of-concept to consider robustness testing over the range of voltages, both steady state drifts and transients, as are commonly witnessed within a vehicle. Overall performance results, along with a dynamic watermark amplitude control, validate the concept as being a practical near-term approach at improving authentication confidence of messages on the CAN bus.

Residual stresses in metals are caused by a number of processes such as inhomogeneous deformation, phase changes and temperature gradients. This investigation focuses on the residual stresses caused by plastic deformation of automotive metals. Such stresses are responsible for part springback and shape distortion in many manufacturing and assembly processes. Tensile residual stresses may lead to stress cracking and, in some alloys, to stress corrosion cracking which may ultimately lead to premature product failure. The residual stress potential of metals can be evaluated by using the Split Ring Test Method. The test can be used to evaluate the effect of materials on residual stresses in cup drawing. Drawn cups are used because they produce large amounts of residual stresses and, therefore, increase measurement accuracy and reduce experimental error. A closed form analytical solution is used to estimate residual stresses in split rings taken from sections cut from the drawn cups.

The use of lightweight materials to produce automotive glazing is being pursued by vehicle manufacturers in an effort to improve fuel economy. As glazing’s become thinner, reduced rigidity means that the critical flaw size needed to create fracture becomes much smaller due to increased strain under load or impact. This paper documents experiments focused on the impact performance of several alternative thin laminate constructions under consideration for windshield applications (including conventional annealed soda-lime glass as well as laminates utilizing chemically strengthened glass), for the purpose of identifying new and unique failure modes that result from thickness reduction. Regulatory impact tests and experiments that focused on functional performance of laminates were conducted. Given the increased sensitivity to flaw size for thin laminates, controlled surface damage was introduced to parts prior to conducting the functional performance tests.

Low frequency brake system noise has been a systemic and ongoing issue for several automakers. The noise is a combined effect of brake and suspension systems working with each other. The noise transmission path is also important. The latest warranty and quality indicators on this has resulted in high degree of dissatisfaction for several vehicles. The customer complaints have been for grind noise, grunt and groan. The team focused on a multi-level integrated approach for this problem. The first step was deep diving and dissecting the customer complaint data. The low frequency noise for grind and groan can be reduced to several contributors. One of the main issues was the movement of pads over the rotor fins resulting in dynamic groan type of noise. It was important to relate this to the customer complaint for grind. In association with that, the grind noise was also caused by in-stop grunt type of noise.

A study was conducted to understand the acoustic viability of using post consumer rebond seat foam materials in vehicles for floor carpet underlayment applications. These foam materials were obtained from two different sources: 1) polyurethane foam dismantled from seats of end of life vehicles (ELV or scrap vehicles), and 2) polyurethane foam recovered and cleaned from auto shredder residue (ASR) by the Argonne National Laboratories (ANL) using their cleaning method. The study was conducted using three North-American cars, each serving different market segments. Based on both laboratory and on-road tests conducted on each vehicle, the study concluded that the acoustical performance of the floor carpet underlayment part made of post consumer rebond foam is comparable to that of the current production part mostly made of shoddy materials.

As motor vehicle emissions have been reduced to meet requirements of the clean air acts, they have become low enough to be difficult to measure accurately. This is especially the case for hydrocarbons, because after warm-up, there are fewer hydrocarbons emitted from a modern vehicle's tailpipe than in the surrounding air. It is therefore important to correctly compensate for the ambient hydrocarbon levels of the air used to dilute the collected exhaust. In estimating the accuracy of the federally required testing procedures, previously published error analyses have examined the effects of random errors. This study examines the systematic errors inherent in the CVS (Constant Volume Sampling) technique specified in federal regulations, estimates their sizes, and proposes a method using proportional ambient sampling whereby they can be avoided.

The US Automotive Materials Partnership (USAMP) and the US Department of Energy launched the Magnesium Powertrain Cast Components Project in 2001 to determine the feasibility and desirability of producing a magnesium-intensive engine; a V6 engine with a magnesium block, bedplate, oil pan, and front cover. In 2003 the Project reached mid-point and accomplished a successful Decision Gate Review for entry into the second half (Phase II) of the Project. Three tasks, comprising Phase I were completed: (1) evaluation of the most promising low-cost, creep-resistant magnesium alloys, (2) design of the engine components using the properties of the optimized alloys and creation of cost model to assess the cost/benefit of the magnesium-intensive engine, and (3) identification and prioritization of scientific research areas deemed by the project team to be critical for the use of magnesium in powertrain applications.

One of the biggest challenges for the Product Development Engineers is to have a clear understanding of the Quality Principles and Disciplines they should follow while they are engineering. In general, the current Product Development System guides of the Automakers companies are mostly focused on provide guidance for the Engineers on the following areas: Design Efficiency; Design Rules for Product Robustness; Design Validation; Product Reliability; Testing Procedures. The introduction of a new/advanced technology system alone does not mean low incidence of customer complaints. The only way to get that is plan/execute Consumer Driven Design with excellence. Global Vehicles are more sensitive to Quality since they must satisfy diverse cultural customers without compromise reliability. When a new vehicle is being developed to be sold in many markets around the world - Global Product - this problem is even bigger. Different markets mean different customer expectations.

Given continued industry focus on reducing parasitic losses, the ability to accurately measure the magnitude of losses on all driveline components is required. A standardized test procedure enables manufacturers and suppliers to measure component losses consistently, in addition to offering a reliable process to assess enablers for efficiency improvements. This paper reviews the development of SAE draft standard J3218, which is a comprehensive test procedure to break-in and characterize the efficiency of beam axles. Focus areas of the study included ensuring the axle’s efficiency does not change as it is being characterized, building a detailed map of efficiency at a wide range of operating points, and minimizing test time. The resulting break-in procedure uses an asymptotic regression approach to predict fully broken in efficiency of the axle and determine how much the efficiency of the axle changes during the characterization phase.

In this paper, a three-dimensional (3D) microstructure-based finite element modeling method (i.e., extrinsic modeling method) is developed, which can be used in examining the effects of porosity on the ductility/fracture of Mg castings. For this purpose, AM60 Mg tensile samples were generated under high-pressure die-casting in a specially-designed mold. Before the tensile test, the samples were CT-scanned to obtain the pore distributions within the samples. 3D microstructure-based finite element models were then developed based on the obtained actual pore distributions of the gauge area. The input properties for the matrix material were determined by fitting the simulation result to the experimental result of a selected sample, and then used for all the other samples’ simulation. The results show that the ductility and fracture locations predicted from simulations agree well with the experimental results.

From the brake system point of view the world can be split into comfort and performance markets. This market split evolved historically and reflects local legal requirements, driving style and the customer expectations. Noise, cold judder and brake dust play the dominant role in the perception of the customer on the comfort market. The performance markets call for high friction level and good fade performance. Currently these customer needs can only be satisfied by usage of different pad materials: NAO and Semi Met materials for comfort markets and generally Low Met materials for performance markets. Due to the differences mentioned above, additional brake system development and testing is done (different testing locations for the same brake attribute). Harmonizing testing, usage of the same test location and same test method could save not only the human resources but also decrease the number of prototypes used in the development phases.

Since being commissioned in 2001, the aero-acoustic wind tunnel at DTF, Wind Tunnel 8 (WT8) has been used to conduct a wide variety of tests. In 2003 alone, over 5250 hours of aerodynamic and aero-acoustic testing were run on over 2000 test articles, including commercial cars, trucks and racing vehicles. Additionally, more unique test articles such as solar cars, motorcycles, Olympic sleds, and others have also been recently tested. The demand for WT8 is driven by the fact that it is among the quietest wind tunnels in the world and one of a very small number of facilities that combines aerodynamic, aero-acoustic, and climatic capabilities in one facility. To enhance WT8's ability to meet the ever-increasing demands of the testing community, and the Motorsports community specifically, an effort was recently initiated to optimize and document the repeatability of aerodynamic force measurements in this tunnel.

In order to quantify the dynamic restraint capability of a passenger airbag, a sub-system test method has been developed. The sub-system included a passenger airbag, an adjustable generic instrument panel (IP) and an adjustable windshield. The test was called the Passenger Air Bag Linear Impactor Test (PABLIT). This test method could be used for not only A to B comparisons, but also to evaluate the performance of any PAB module design in general, including performance variability of airbag systems. A variety of impactor, pendulum and drop tower test methods are currently used by inflatable restraint suppliers. PABLIT was aimed to standardize airbag testing and data analysis. Various production hardware designs were tested to investigate the characteristics of the sub-assemblies that provide restraint capability.

The International Lubricant Standardization and Approval Committee (ILSAC) ATF subcommittee members have compared the two oxidation bench test methods, Aluminum Beaker Oxidation Test (ABOT) and Indiana Stirring Oxidation Stability Test (ISOT), using a number of factory-fill and service-fill ATFs obtained in Japan and in the US. In many cases, the ATFs were more severely oxidized after the ABOT procedure than after the same duration of the ISOT procedure. The relative severity of these two tests was influenced by the composition of the ATFs. The bench test oxidation data were compared with the transmission and the vehicle oxidation test data.

The usage of Boron steel in the South American automotive industry has been increasing in recent years. Considering its high hardening properties, sheet metal parts can only be manufactured using a hot forming process, as compared to a conventional cold forming process; however, the hot stamping process offers the advantage to stamp a part in a single die vs. multiple dies using a regular cold stamping process. The main objective is to present the advantages of constructing the whole AB ring reinforcement out of Boron steel and made out of a single die, and no welding among the A pillar reinforcement, B Pillar reinforcement and rocker panel. This type of design has helped to achieve crash safety performance goals, enhance the structural characteristics of joints, improve dimensional control, reduce the number of welds, manage BIW overall weight and improve torsion rigidity.

Mill oils and prelubes are applied by the steel producer to prevent corrosion and to enhance formability. During coiling, shipping, and storage the lubricant migrates due to pressure and gravity. The redistribution of the lubricant results in widely varying lubricant weights. The move to reduce and eliminate press-applied lubricants has lead to concerns that the variation in lubricant weight as a result of this migration would adversely affect press performance. The Drawbead Simulator (DBS) and Twist Compression Test (TCT) were used to evaluate friction response of electrogalvanized and galvanneal sheet to varying lubricant weight. Results showed the electrogalvanized sheet was sensitive to lubricant type while the galvanneal sheet was sensitive to the amount of lubricant.

As-cast or as-solution treated cast aluminum A319 has copper solutions within its aluminum dendrite. These copper solutions precipitate out to form Al2Cu through a sequence of phase changes and bring with them volume changes at elevated temperatures. These volume changes, referred to as thermal growth are irreversible. The magnitude of thermal growth at a material point is decided by the temperature history of the material point. When an under aged or non heat treated cast aluminum is exposed to non-uniform temperature such as that during engine operation, thermal growth leads to non-uniform volume change and thus additional self balanced stresses. These stresses remain inside material as residual stresses even when the temperature of the material is uniform again. In the present paper, numerical analysis method for thermal growth is developed and integrated into engine operation analysis.

In this paper, a nonlinear dynamic model for automotive cushion-human body combined structure is developed based on a nonlinear seat cushion model and a linear ISO human body model. Automotive seat cushions have shown to exhibit nonlinear characteristics. The nonlinear seat cushion model includes nonlinear stiffness and nonlinear damping terms. This model is verified by a series of tests conducted on sports car and luxury car seats. The transfer functions from the tests for human body sitting on an automotive seat changes with the vibration platform input magnitudes. This indicates that the combined structure possesses nonlinear characteristics. The nonlinear model is validated by the transfer functions from the test. The paper discusses the influence of the parameters of the nonlinear structure on the design of seat and assessment of human body comfort.

Demand for enhanced infotainment systems with features like navigation, real-time traffic, music streaming service, mirroring and others is increasing, forcing automakers to develop solutions that fulfill customer needs. However, many of those systems are too expensive to be fitted to an entry-level vehicle leaving a gap in the market that fails customer’s expectation. This gap is usually filled by a smartphone which may have all the features the customer wants but in many cases it cannot be properly fitted in the vehicle due to lack of specific storage space. This paper describes how the engineering team developed an innovative, flexible and effective solution that holds a smartphone in an ergonomic location.

Material authenticity is an important factor for appearance and perceived quality of the vehicle interior. The term authenticity implies ambivalence: For the product designer, it means identification and trueness of the origin of the material. The customers, however, can only access information on the nature of the materials via their own perception of surface features. Thus, the intended authenticity of a material always needs to be conveyed by its surface. Specific cases illustrate the context: 1. The customer touches a part of known matter, but various layers prevent from directly touching the natural material: e.g. leather at the steering wheel, applications of wood. 2. Perception of a thin surface layer indicates authentic material, which is not fulfilled by the whole part: e.g. plastic parts plated with metal. 3. A part consists of authentic material, but newly composed, so that it is not easily identified, such as recycled materials, e.g. leather fiber layers for seats.