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An L18 Taguchi-style Design of Experiments (DOE) with eight factors was used to optimize exterior mirrors for wind noise and drag. Eighteen mirror properties were constructed and tested on a full size greenhouse buck at the Lockheed low-speed wind tunnel in Marietta, GA. Buck interior sound data and drag measurements were taken at 80 MPH wind speed (0° yaw angle). Key wind noise parameters were the fore/aft length of mirror housing and the plan view angle of the mirror housing's inboard surface. Key drag parameters were the fore/aft length of the mirror housing, the cross-section shape of the mirror pedestal, and the angle of the pedestal (relative to the wind).

North American drivers particularly dislike wheel dust (brake dust on their wheels). For some vehicle lines, customer surveys indicate that wheel dust is a significant concern. For this reason, Ford and its suppliers are investigating the root causes of brake dust and developing test procedures to detect wheel dust issues up-front. Intuitively, it would appear that more brake wear would lead to more wheel dust. To test this hypothesis, a gage was needed to quantitatively measure the wheel dust. Gages such as colorimeters were evaluated to measure the brightness (L*) of the wheel, which ranged from roughly 70-80% (clean) to 10-20% (very dirty). Gage R&R's and subjective ratings by a panel of 30 people were used to validate the wheel dust gages. A city traffic vehicle test and an urban dynamometer procedure were run to compare the level of wheel dust for 10 different lining types on the same vehicle.

Weld lines occur when melt flow fronts meet during the injection molding of plastic parts. It is important to investigate the weld line because the weld line area can induce potential failure of structural application. In this paper, a weld line factor (W-L factor) was adopted to describe the strength reduction to the ultimate strength due to the appearance of weld line. There were two engineering thermoplastics involved in this study, including one neat PP and one of talc filled PP plastics. The experimental design was used to investigate four main injection molding parameters (melt temperature, mold temperature, injection speed and packing pressure). Both the tensile bar samples with/without weld lines were molded at each process settings. The sample strength was obtained by the tensile tests under two levels of testing speed (5mm/min and 200mm/min) and testing temperatures (room temperature and -30°C). The results showed that different materials had various values of W-L factor.

Austempered cast irons have a unique microstructure (ausferrite) that provides for excellent wear properties. This paper will examine the available data in the literature on wear in several modes: abrasive wear, adhesive wear (frictional or sliding and rolling), and erosive wear. Additional wear data, including that from competitive materials as well as from private communications, will be presented along with examples of applications of austempered ductile cast irons where wear properties are of concern

Vehicle chassis mounted cantilevered components should meet two critical design targets: 1) NVH criterion to avoid resonance with road noise and engine vibration and 2) satisfied durability performance to avoid any incident in structure failure and dysfunction. Generally, two types of testing are performed to validate chassis mounted cantilevered component in the design process: shaker table testing and vehicle proving ground testing. Shaker table testing is a powered vibration endurance test performed with load input summarized from real proving ground data and accurate enough to replicate the physical test. The proving ground test is typically performed at critical milestones with full vehicles. Most tests are simplified lab testing to save cost and effort. CAE procedures that virtually replicate these lab tests is even more helpful in the design verification stages.

High gas prices combined with demand for improved fuel economy have prompted increased interest in diesel engine applications for both light-duty and heavy-duty vehicles. The development of aftertreatment systems for these vehicles requires significant investments of capital and time. A reliable and robust qualification testing procedure will allow for more rapid development with lower associated costs. Qualification testing for DPFs has its basis in methods similar to DOCs but also incorporates a PM loading method and regeneration testing of loaded samples. This paper examines the effects of accelerated loading using a PM generator and compares PM generator loaded DPFs to engine dynamometer loaded samples. DPFs were evaluated based on pressure drop and regeneration performance for samples loaded slowly and for samples loaded under accelerated conditions. A regeneration reactor was designed and built to help evaluate the DPFs loaded using the PM generator and an engine dynamometer.

Through the use of hybrid technology, Ford Motor Company continues to realize enhanced vehicle fuel economy while meeting customer performance and drivability targets. As is characteristic of all Ford Hybrid Electric Vehicles (HEVs), the basis for resolving these competing requirements resides with its Vehicle System Control (VSC) strategy. This strategy implements complex high-level executive controls to coordinate and optimize the desired operational state of the major HEV powertrain subsystems. To ensure that the VSC software meets its intended functionality, a software validation process developed at Research and Advanced Engineering has been integrated as part of the vehicle controls development process. In this paper, this VSC software validation process implemented for a next generation hybrid powertrain is presented. First, an overview of the hybrid powertrain application and the VSC software architecture is introduced.

The USDOT and the Crash Avoidance Metrics Partnership-Vehicle Safety Communications 2 (CAMP-VSC2) Consortium (Ford, GM, Honda, Mercedes, and Toyota) initiated, in December 2006, a three-year collaborative effort in the area of wireless-based safety applications under the Vehicle Safety Communications-Applications (VSC-A) Project. The VSC-A Project developed and tested communications-based vehicle safety systems to determine if Dedicated Short Range Communications (DSRC) at 5.9 GHz, in combination with vehicle positioning, would improve upon autonomous vehicle-based safety systems and/or enable new communications-based safety applications.

The United States Department of Transportation (USDOT) and the Crash Avoidance Metrics Partnership-Vehicle Safety Communications 2 (CAMP-VSC2) Consortium (Ford, General Motors, Honda, Mercedes-Benz, and Toyota) initiated, in December 2006, a three-year collaborative effort in the area of wireless-based safety applications under the Vehicle Safety Communications-Applications (VSC-A) Project. The VSC-A Project developed and tested Vehicle-to-Vehicle (V2V) communications-based safety systems to determine if Dedicated Short Range Communications (DSRC) at 5.9 GHz, in combination with vehicle positioning, would improve upon autonomous vehicle-based safety systems and/or enable new communications-based safety applications.

The increasing trend toward electric and hybrid-electric vehicles (HEVs) has created unique challenges for NVH development and refinement. Traditionally, characterization of in-vehicle powertrain noise and vibration has been assessed through standard operating conditions such as fixed gear engine speed sweeps at varied loads. Given the multiple modes of operation which typically exist for HEVs, characterization and source-path analysis of these vehicles can be more complicated than conventional vehicles. In-vehicle NVH assessment of an HEV powertrain requires testing under multiple operating conditions for identification and characterization of the various issues which may be experienced by the driver. Generally, it is necessary to assess issues related to IC engine operation and electric motor operation (running simultaneously with and independent of the IC engine), under both motoring and regeneration conditions.

A vehicle integrated sensing and analysis system has been designed, implemented, and demonstrated to nonintrusively monitor several biological signals of the driver. The biological driver signals measured by the system are the heart electrical signals or pseudo Lead-I electrocardiography (pLI-ECG), the galvanic skin response (GSR) or electrical conductance measured from the driver's fingers to palm, the palm skin temperature, the face skin temperature, and the respiration rate. The pLI-ECG and GSR measurements are made through direct contact of the driver hands with stainless steel electrodes integrated in the steering wheel rim. The temperature measurements are made with non-contacting infrared temperature sensors, also located on the steering wheel. The respiration rate was measured using a flexible thin film piezoelectric sensor affixed to the seatbelt.

To manage the function of a vehicle's engine, transmission, and related subsystems, almost all modern vehicles make use of one or more electronic controllers running embedded software, henceforth referred to as a Powertrain Controller System or PCS. Fully validating this PCS is a necessary step of vehicle development, and the validation process requires extensive amounts of testing. Traditionally, this validation testing is done with open-loop signal generators, powertrain dynamometers, and real vehicles. Such testing methods either cannot simulate complex control system interactions, or are expensive and subject to variability. To address these concerns while decreasing development time and improving vehicle quality, Ford Motor Company is placing increasing focus on validating a PCS through simulation. One such testing method is a Hardware-in-the-Loop (HIL) simulation, which mates the physical elements of a PCS to a real-time computer simulation of a powertrain.

For suspension systems, fatigue and strength simulations are accomplished mostly at the component level. However, the selection of loading conditions and replication of boundary conditions at the component level may be difficult. A system level simulation eliminates most of the discrepancy between component level and vehicle level environment yielding realistic results. Further advantage of system level simulation is that the boundary conditions are limited to suspension mounting points at body or frame and the loading is limited to wheel-end or tire patch loading. This provides for a robust set of boundary constraints that are known and repeatable, and loads that are simpler and of relatively higher accuracy. Here, the nonlinear transient dynamic behavior of a suspension system along with its frame and mounting was simulated using a multibody finite element analysis (FEA).

The measured drive-point conductance of a typical passenger car tire was seen to drop steadily for frequencies above 1000 Hz. This behavior is a-typical since SEA theory predicts such conductance should remain relatively flat for high frequencies. It was found that, one has to pay careful attention to errors introduced by the added mass of the measuring transducer and “local” effects due to contact stiffness of the tread rubber. Such effects are investigated and their contributions quantified. Compensation schemes are also developed and implemented. It is shown that, for a 20 grams transducer, the measured and corrected conductances are off by 12 dB. The effects of the local contact stiffness of the rubber at the attachment point are less significant.

The paper describes a new tire cornering/traction trailer designed to measure the traction and steering performance of passenger car tires, outlines related test methods, and provides supporting test data. A general set of specifications is given for the entire test system. The major subsystems described are the trailer with its versatile suspension; the tow vehicle and its performance capabilities; the transducer system which measures the normal load, lateral force, fore-and-aft force, aligning torque, steer angle and speed; and the instrumentation. The calibration method is described. The test methods described include those for straight-line braking, maximum lateral traction, steady state and transient steering response, and combined braking and cornering traction. Supporting data and discussion are presented for each test method.

Thermally sprayed coatings have used in place of iron bore liners in recent aluminum engine blocks. The coatings are steel-based, and are sprayed on the bore wall in the liquid phase. The thermal response of the block structure determines how rapidly coatings can be applied and thus the investment and floor space required for the operation. It is critical not to overheat the block to prevent dimensional errors, metallurgical damage, and thermal stress cracks. This paper describes an innovative finite element procedure for estimating both the substrate temperature and residual stresses in the coating for the thermal spray process. Thin layers of metal at a specified temperature, corresponding to the layers deposited in successive thermal spray torch passes, are applied to the substrate model, generating a heat flux into the block. The thickness, temperature, and application speed of the layers can be varied to simulate different coating cycles.

Modern approaches for thermal fatigue damage assessment in automotive components are discussed. Three prominent methods are reviewed, and issues with related material testing, numerical implementations and applications to general thermal cycles are presented. In summary, the chosen methods can produce good thermal fatigue life predictions. Common difficulties include first, prolonged experimental programs to determine the required material parameters, and second, significant computational times involved in analysis of realistic models and loading histories.

Thermal fatigue presents a new challenge in cast aluminum engine design. Accurate thermomechanical stress analysis and reliable failure criterion are the keys to a successful life prediction. It is shown that the material stress and strain behavior of cast aluminum is strongly temperature and strain rate sensitive. A unified viscoplasticity constitutive relation is thus proposed to simultaneously describe the plasticity and creep of cast aluminum components deforming at high temperatures. A fatigue failure criterion based on a damage accumulation model is introduced. Damages due to mechanical fatigue, environmental impact and creep are accounted for. The material stress and strain model and thermal fatigue model are shown to be effective in accurately capturing features of thermal fatigue by simulating a component thermal fatigue test using 3D FEA with ABAQUS and comparing the results with measured data.

The use of nanotechnology to develop advanced heat-transfer materials is a rapidly growing topic of research at facilities around the world. One class of these materials, nanofluids, has shown promise in the laboratory to dramatically improve thermal conductivity. Quantification of the thermophysical properties of these fluids is important for optimizing the design of automotive powertrains and electrical subsystems in order to produce highly efficient and robust vehicle cooling. A new technique for measuring thermal conductivity, the Transient Planar Source (TPS) method, was used for the first time to investigate the thermal conductivity of automotive coolants and their equivalent nanofluid, as a function of temperature. The results of this study indicate that the TPS method allows for rapid and repeatable measurement of thermal conductivity with an error of between 2-4%. The technique also presents several advantages over other methods which we will briefly describe.

On current competitive scenario for road load transportation in Brazilian market, the operational costs should be reduced as much as possible. The suspension system commonly used on road commercial trucks is based on leaf spring use and Hotchkiss concept for axle locating devices. The use of leaf springs without bolt attachment eyelets are still common for rear suspension systems. When using the leaf spring with direct contact to the brackets, wear plates are placed between them to work as wear elements due to the friction between the parts. The friction will cause wear on the parts, and the wear plate is designed to suffer the damages of this friction instead of the leaf spring, being the cheapest element and can be easily replaced. When the system works on a severe contamination environment with high levels of grit and dirt, the degradation of the parts are accelerated.