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GreenZone Driving for Plug In Hybrid Electric Vehicles

2012-05-29
Plugin Hybrid Electric Vehicles (PHEV) have a large battery which can be used for electric only powertrain operation. The control system in a PHEV must decide how to spend the energy stored in the battery. In this paper, we will present a prototype implementation of a PHEV control system which saves energy for electric operation in pre-defined geographic areas, so called Green Zones. The approach determines where the driver will be going and then compares the route to a database of predefined Green Zones. The control system then reserves enough energy to be able to drive the Green Zone sections in electric only mode. Finally, the powertrain operation is modified once the vehicle enters the Green Zone to ensure engine operation is limited. Data will be presented from a prototype implementation in a Ford Escape PHEV Presenter Johannes Kristinsson
Technical Paper

Eliminating Drum Brake Squeal by a Damped Iron Drum Assembly

2007-04-16
2007-01-0592
Control of drum brake squeal is difficult to accomplish. After many trials guided by CAE and previous experience, for a passenger car it was felt that changing the metallurgical characteristics of the drum would lead to improved noise performance. The chemistry of the drum casting material was altered. The carbon equivalent was modified by increasing carbon and silicon content of the castings as well as changing the other materials. The integral hub and drum assembly was tested on two different dynamometers. The results were also verified by finite element complex eigenvalue analysis. Finally the solution was validated through vehicle level testing - Los Angeles City Traffic (LACT). For the structural consideration rotary fatigue was evaluated by CAE comparison followed by test rig confirmation. The higher carbon equivalent material drums successfully eliminated the annoying squeal in customer vehicles.
Technical Paper

Effect of Weld Geometry and HAZ Softening on Fatigue Performance of DP780 GMAW Lap Joint

2007-04-16
2007-01-0632
With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive materials for automobile makers. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures, especially when durability of the welded structures is required. In this study, 2.0 mm uncoated DP780 was investigated. GMAW welding parameters for lap joints of this steel were developed in order to obtain different weld geometries defined by weld toe angle, weld leg sizes, and weld penetration. Metallurgical properties of the joints were evaluated using optical microscopy and scanning electron microscopy (SEM). Static and fatigue tests were conducted on the welded joints. Effect of weld geometry and HAZ softening on fatigue performance including fatigue life, crack initiation site and propagation path of the joints will be analyzed.
Technical Paper

Effect of Materials Stack-ups on Fatigue Performance of DP780 and Aluminized Coated Boron Steel GMAW Lap Joint

2007-04-16
2007-01-0634
In this study, fatigue performance of Gas Metal Arc Welded (GMAW) joint for 1.5 mm uncoated DP780 and 1.0 mm and aluminized coated boron (or USIBOR) steel was investigated. Metallurgical properties of DP780 to coated boron steel dissimilar steel lap joints were evaluated using optical microscopy. Microhardness traverse, static and fatigue tests were conducted on these joints. Finite element analysis (FEA) was used to identify the stress distribution of the weld joints with different stack-ups and at same loading conditions. It was found that position of the material (top or bottom in lap joint configuration) had a significant impact on fatigue performance of the dissimilar joint. The amount of heat introduced by welding to coated boron steel is also believed to be important to the fatigue performance of the dissimilar joints. The findings in this study can be used when aluminized boron steel is involved in dissimilar steel and dissimilar thickness GMAW lap joint design.
Technical Paper

Gas Metal Arc Welding of Coated Advanced High Strength Steel (AHSS) - Developments for Improved Weld Quality

2007-04-16
2007-01-1360
Gas Metal Arc Welding (GMAW) is commonly used in the automotive industry for joining heavier gauge mild and High Strength Low Alloy (HSLA) uncoated steels, where it is recognized for its versatility and speed. The only constraints typically encountered relate to fatigue performance of the joint as a result of poor design or manufacturing fit-up. Advanced High Strength Steels (AHSS), now being considered for more and more applications, however, do not offer the same ease of welding and process control is significantly more critical. They differ from mild steels in chemical composition and thermal processing, resulting in a different microstructure; designed with a richer metallurgy to have higher strength at equivalent thickness. As a result, the sensitivity to heat input is greater and the process window in which acceptable welds can be achieved is narrower.
Technical Paper

Resistance Spot Weldability of Three Metal Stack Dual Phase 600 Hot-dipped Galvanized Steel

2007-04-16
2007-01-1363
Fuel economy and federal safety regulations are driving automotive companies to use Dual Phase and other Advanced High Strength Steels (AHSS) in vehicle body structures. Joining and assembly plays a crucial role in the selection of these steels. Specifications are available for the resistance spot welding (RSW) of lower strength sheet steels, covering many aspects of the welding process from the stabilization procedure to endurance testing. Currently, specifications in the automotive industry for RSW with AHSS are limited. It is well known that welding of a thickness ratio greater than 1:2 poses a challenge. To utilize thinner gauge AHSS panels on body-in-white, welding schedules to join the thin to thick sheet steel stack-up are needed. Most of the existing published work was conducted on uncoated sheets and welded to the same thickness.
Technical Paper

Effect of Materials Stack-ups and Microhardness Distribution on Fatigue Performance of DP600 and Boron Steel GMAW Lap Joint

2007-04-16
2007-01-1356
With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive materials for automobile makers. The usage of AHSS materials is projected to grow significantly in the next 5-10 years with new safety and fuel economy regulations. These new materials have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures, especially when durability of the welded structures is required. In this study, 2.0 mm uncoated DP600 and 2.0 mm uncoated boron (heat treated) steel lap joint configuration was investigated. Metallurgical properties of the DP600 to boron steel dissimilar steel lap joints were evaluated using optical microscopy. Static and fatigue tests were conducted on these joints.
Technical Paper

Method Development for Evaluating Microbiological Growth on and Attachment to Aluminum Air Conditioner Evaporator Core Surfaces

2006-04-03
2006-01-1645
Corrosion failures of aluminum air conditioner evaporator cores have been reported in regions where the climate is relatively warm and humid. Microbiologically-influenced corrosion [MIC] has been implicated in these failures. Application of surface-treatment chemicals may inhibit microbiological (bacterial) growth and/or attachment, thereby reducing the potential for MIC. In this study, two laboratory methods were developed to evaluate selected surface-treatment chemicals for their ability to inhibit bacterial growth and reduce bacterial attachment to treated surfaces. Using the developed methods, two controlled-atmosphere brazed aluminum core materials and three surface-treatment chemicals were evaluated. Neither of the untreated core materials was found to inhibit the growth of the bacteria tested.
Technical Paper

Die Wear Severity Diagram and Simulation

2007-04-16
2007-01-1694
Die wear is a significant issue in sheet metal forming particularly for stamping Advanced High-Strength Steels (AHSS) because of their higher strength and microstructure composition. Reliable predictions of the magnitude and distribution of die wear are essential if cost-effective wear-protection strategies are desired in the early stages of tooling development. A die Wear Severity Index (WSI) is introduced in this paper to quantify the magnitude of die wear, which in essence characterizes the frictional energy dissipation per unit area on the die surface throughout the entire forming cycle. It can be readily obtained as part of any finite element simulation of stamping process utilizing incremental solution techniques.
Technical Paper

Effects of Surface Treatment (Lubricant) on Spot Friction Welded Joints Made of 6111-T4 Aluminum Sheets

2007-04-16
2007-01-1706
The effects of lubricant on lap shear strength of Spot Friction Welded (SFW) joints made of 6111-T4 alloys were studied. Taguchi L8 design of experiment methodology was used to determine the lubricant effects. The results showed that the lap shear strength increased by 9.9% when the lubricant was present at the top surface compared to that of the baseline (no lubricant) whereas the lap shear strength reduced by 10.2% and 10.9% when the lubricant was present in the middle and at the bottom surfaces compared to that of the baseline (no lubricant), respectively. The microstructure analysis showed a zigzag interface at the joint between the upper and the lower sheet metal for the baseline specimen, the specimens with the lubricant at the top and at the bottom. However, a straight line interface is exhibited at the joint between the upper and the lower sheet for the specimen with the lubricant in the middle. The weld nugget sizes of the lap shear tested specimens were measured.
Technical Paper

IMPACT Phase II - Study to Remove 25% of the Weight from a Pick-up Truck

2007-04-16
2007-01-1727
This paper describes a joint project between Ford, the American Iron & Steel Institute, the University of Louisville, and the U. S. Army to reduce the weight of a full size pick-up truck by 25%, while keeping incremental costs to a minimum. Several alternate technologies were evaluated for each system, subsystem, and component of the vehicle and based on analysis of all combinations of these technologies, the solution which yielded the best overall cost and weight balance, while meeting all of the functional requirements, was selected. The major focus of the project was to develop new steel architectures and materials, since this would assure the maintenance of the lowest possible cost, though the study was not restricted to steel alone. The project was successful in meeting all of its targets, and a vehicle was built to demonstrate the feasibility of the various concepts.
Technical Paper

Oxidation Stability of Automatic Transmission Fluids -A Study by the International Lubricants Standardization and Approval Committee (ILSAC) ATF Subcommittee

2001-05-07
2001-01-1991
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.
Technical Paper

Aluminum Vehicle Side Impact Design, Test and CAE

2002-03-04
2002-01-0249
Ford designed and built a midsize family sedan for the PNGV (Partnership for a New Generation of Vehicle). The side impact performance of the aluminum vehicle and the current CAE capability was studied. The vehicle was tested according to the specifications of FMVSS 214. The results show the vehicle meet the federal safety requirements. The impact performances of the front and rear dummies were comparable to those of the steel counterpart. CAE analysis was conducted to develop the body component design and to predict the structural and dummy responses. The results show that without modeling of the joint (rivet and weld) separation, the accuracy of the CAE crash analysis for this aluminum vehicle was inadequate. When empirical separation criteria were incorporated to model the joint, analysis results correlated with the test. Further development of robust modeling methods for joint separation is needed to improve the prediction of aluminum structure crash responses.
Technical Paper

Engineering the Ford H2 IC Engine Powered E-450 Shuttle Bus

2007-10-29
2007-01-4095
As a part of a continuous research and innovation effort, Ford Motor Company has been evaluating hydrogen since 1997 as an alternative fuel option for vehicles with internal combustion engines. Hydrogen fuel is attractive in that it is the cleanest fuel. Hydrogen, when used in an internal combustion engine, produces an exhaust emission consisting mainly of water vapor, with no carbon dioxide and trace amounts of other regulated pollutants. Hydrogen can be produced from renewable sources which will help reduce the dependence on foreign oil. The implementation of the hydrogen powered IC engine is seen as a strategy to help transition from a petroleum economy to a hydrogen economy and drive development of hydrogen storage, fueling infrastructure and other hydrogen related technologies.
Technical Paper

Macroscopic Constitutive Behaviors of Aluminum Honeycombs Under Dynamic Inclined Loads

2007-04-16
2007-01-0979
Macroscopic constitutive behaviors of aluminum 5052-H38 honeycombs under dynamic inclined loads with respect to the out-of-plane direction are investigated by experiments. The results of the dynamic crush tests indicate that as the impact velocity increases, the normal crush strength increases and the shear strength remains nearly the same for a fixed ratio of the normal to shear displacement rate. The experimental results suggest that the macroscopic yield surface of the honeycomb specimens as a function of the impact velocity under the given dynamic inclined loads is not governed by the isotropic hardening rule of the classical plasticity theory. As the impact velocity increases, the shape of the macroscopic yield surface changes, or more specifically, the curvature of the yield surface increases near the pure compression state.
Technical Paper

Mass Efficient Cross-Sections Using Dual Phase Steels For Axial and Bending Crushes

2007-04-16
2007-01-0978
Because of their excellent crash energy absorption capacity, dual phase (DP) steels are gradually replacing conventional High Strength Low Alloy (HSLA) steels for critical crash components in order to meet the more stringent vehicle crash safety regulations. To achieve optimal axial and bending crush performance using DP steels for crash components designed for crash energy absorption and/or intrusion resistance applications, the cross sections need to be optimized. Correlated crush simulation models were employed for the cross-section study. The models were developed using non-linear finite element code LS-DYNA and correlated to dynamic and quasi-static axial and bending crush tests on hexagonal and octagonal cross-sections made of DP590 steel. Several design concepts were proposed, the axial and bending crush performance in DP780 and DP980 were compared, and the potential mass savings were discussed.
Technical Paper

Failure Loads of Spot Friction Welds in Aluminum 6111-T4 Sheets under Quasi-Static and Dynamic Loading Conditions

2007-04-16
2007-01-0983
In this investigation, spot friction welds in aluminum 6111-T4 lap-shear specimens were tested under both quasi-static and dynamic loading conditions. Micrographs of the spot friction welds after testing were examined to understand the failure modes of spot friction welds in lap-shear specimens under different loading conditions. The micrographs indicate that the spot friction welds produced by this particular set of welding parameters failed in interfacial failure mode under both quasi-static and dynamic loading conditions. The load and displacement histories for lap-shear specimens were obtained under quasi-static and dynamic loading conditions at three different impact velocities. The failure loads of spot friction welds in lap-shear specimens under dynamic loading conditions are about 7% larger than those under quasi-static loading conditions.
Technical Paper

Fatigue Overload Response of Aluminum Spot Welds

2002-03-04
2002-01-0576
The fatigue overload behavior of single overlap 5754 aluminum spot welds has been investigated. As a baseline, constant amplitude tension-tension tests with an R=0.1 (=Pmin/Pmax) were conducted. These tests were compared both with several different series of high but variable mean constant maximum load tests, and with periodic overload tests. The high mean load tests, tested with maximum loads of 3560N, 2670N, 1780N, and 1330N all showed a significant reduction in the fatigue limit which ranged from less than ½ to almost 1/3 of the baseline fatigue curve. Further, the fatigue limit reduction from the periodic overload tests was below 1/3 of the constant amplitude baseline tests. The results of these tests indicate that mean loads and variable amplitude loading can both have a significant deleterious impact on fatigue life.
Technical Paper

Thermal Fatigue Analysis of Cast Aluminum Cylinder Heads

2002-03-04
2002-01-0657
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.
Technical Paper

Effects of Engine Oil Formulation Variables on Exhaust Emissions in Taxi Fleet Service

2002-10-21
2002-01-2680
The relationship between engine oil formulations and catalyst performance was investigated by comparatively testing five engine oils. In addition to one baseline production oil with a calcium plus magnesium detergent system, the remaining four oils were specifically formulated with different additive combinations including: one worst case with no detergent and production level zinc dialkyldithiophosphate (ZDTP), one with calcium-only detergent and two best cases with zero phosphorus. Emissions performance, phosphorus loss from the engine oil, phosphorus-capture on the catalyst and engine wear were evaluated after accumulating 100,000 miles of taxi service in twenty vehicles. The intent of this comparative study was to identify relative trends.
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