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A unique opportunity arose to make a direct comparison of aluminum, sheet molding compound (SMC) and steel using a common hood design. In considering all possible material combinations of inner and outer panels, it was discovered that some of the combinations were incompatible due to material properties. Only the compatible material combinations were considered. Three different joining techniques - welding, bonding and bonded hem flanging - were evaluated. The cost, weight and structural performance of the chosen hood material combinations were established. Areas of further development were identified, including design optimization for specific material combinations.

The paper presents a new method, based on standard laboratory cup tests, for predicting the formability of materials; in the example provided, the forming potentials of four new materials are shown. The properties of stretchability and drawability, which are the principal factors defining a material's forming limits, may be assessed using the Olsen spherical cup test and the Swift flat-bottomed cup test. In the shape analysis procedure described, the minimum amount of deformation needed to fix a desired shape is determined. Then necessary adjustments to tooling for optimum sheet metal usage are made based on calculations from a new type of chart showing stretch forming ratio and draw forming ratio, providing a comparison of the formabilities of a number of materials.

Resistance to dents and dings, caused by plant handling and in-service use, is generally recognized as an important performance requirement for automotive outer body panels. This paper examines the dent resistance improvements that can be achieved by maximizing surface stretch, through adjustments to the press settings, and substitution of a higher strength steel grade. Initially, the stamping process was optimized using the steel supplied for production: a Ti/Nb-stabilized, ultra low carbon (ULC) grade. The stamping process was subsequently optimized with a Nb-stabilized, rephosphorized ULC steel, at various thicknesses. The formed panels were evaluated for percent surface stretch, percent thinning, in-panel yield strength after forming, and dent performance. The results showed that dent resistance can be significantly improved, even at a reduced steel thickness, thus demonstrating a potential for weight savings.

The true output of racing engines is normally a closely guarded secret. This is particularly so in Formula One. Also, the consistency of output between engines of identical specifications is of interest to all those involved. This paper outlines a study that was done on the 1993 3.5L Chrysler-Lamborghini CL-01 Formula 1 Engine, and will cover: The output variation of one specific engine configuration/fuel combination over the course of the season, The output variation of a second build/fuel combination over a significant number of builds, The output improvements due to fuels, The output changes due to mechanical developments during the season. The paper will also show that if engine output has been designated as one of the criteria for accepting or rejecting an engine, very small differences in either the acceptable level of performance or the recorded output can make a very significant difference to the number of engines rejected.

A better understanding of turbulent kinetic energy is important for improvement of fuel-air mixing, which can lead to lower emissions and reduced fuel consumption. An in-cylinder flow study was conducted using 1548 Laser Doppler Velocimetry (LDV) measurements inside one cylinder of a 3.5L four-valve engine. The measurement method, which simultaneously collects three-dimensional velocity data through a quartz cylinder, allowed a volumetric evaluation of turbulent kinetic energy (TKE) inside an automotive engine. The results were animated on a UNIX workstation, using a 3D wireframe model. The data visualization software allowed the computation of TKE isosurfaces, and identified regions of higher turbulence within the cylinder. The mean velocity fields created complex flow patterns with symmetries about the center plane between the two intake valves. High levels of TKE were found in regions of high shear flow, attributed to the collisions of intake flows.

This study analyzes the vibration characteristics of the valve train of a 2.0L SOHC Chrysler Corp. Neon engine over a range of operating speeds to investigate and demonstrate the advantages and limitations of various dynamic measurements such as displacement, velocity, and acceleration in this application. The valve train was tested in a motoring fixture at speeds of 500 to 3500 camshaft rpm. The advantages of analyzing both time and frequency domain measurements are described. Both frequency and order analysis were done on the data. The theoretical order spectra of cam displacement and acceleration were computed and compared to the experimental data. Deconvolution was used to uncover characteristic frequencies of vibration in the system. The theoretical cam acceleration spectrum was deconvolved from measured acceleration spectra to reveal the frequency response function of the follower system.

Gasoline direct injection technology is receiving increased attention among automotive engineers due to its high potential to reach future emission and fuel economy goals. This paper reports some of the design and development techniques in use at Chrysler as applied to four-stroke Direct Injection Spark Ignition (DISI) engines. The spray characteristics of Chrysler's single-fluid high-pressure injector are reported. Tools used in the design process are identified. Observations of the in-cylinder fuel/air mixing process using laser diagnostic techniques and Computational Fluid Dynamics (CFD) are described. Finally, combustion and emissions characteristics using Design of Experiment (DoE) tests are presented.

INDUCTION heating is a process or method by which metal parts are heated by simply placing them in an alternating magnetic field. The action is that of the transformer, whereby electrical energy is transferred or passed over to another isolated electric or secondary circuit by means of the magnetic field; thus, no physical attachments or electrical contacts are necessary to have electrical currents, which are dissipated as heat, flow in the parts to be processed. The strength and frequency of the alternating magnetic field can be selected to produce any desired rate of heating and ultimate temperature. A circuit can be set up to dry lacquer at 160 deg. fahr. on thin sheet-metal parts or to melt in record time immense steel ingots. Induction heating is now commercially applied in automotive production to many processes, and these are specified.

Strain analysis of stampings is explained. The system is based on the strain distributions obtained from 0.2 in. inter-locking circle grid patterns etched on blanks. The strain distributions are related to a developed formability limit curve and the mechanical properties of the gridded blank. The evaluation of the graphic relation of the strains to the formability limit enables the press shop to determine what factors should be changed to produce stampings with less scrap and lower cost.

This paper outlines several methodologies which use finite element and experimental models to predict vehicle NVH responses. Trimmed body experimental modal subsystem models are incorporated into the finite element system model to evaluate engine mounting systems for low frequency vibration problems. Higher frequency noise issues related to road input are evaluated using experimentally derived acoustic transfer functions combined with finite element subsystem model responses. Specific examples of system models built to simulate idle shake and road noise are given. Applications to engine mounting, suspension design, and body structure criteria are discussed.

The heater air flow rate is a function not only of the heater itself but also of the size and location of the heater system air inlets, the car body air outlets, and the body surface pressure at these inlets and outlets. Favorable pressure conditions generally exist at the typical top cowl heater air inlet; however, the aerodynamics of each particular vehicle should be studied to confirm the existence of these conditions. Little consideration has been given to body air outlet pressure conditions since body leakage paths have generally served as adequate air outlets; but, as body leakage is reduced, specific air outlets must be considered and a knowledge of aerodynamics is essential to the achieving of appropriately sized and appropriately located air outlets.

Chrysler Corporation's Jeep and Truck platform implemented a new design and prototype process for the body-in -white of a new pickup truck. A team approach achieved concurrent body design, stamping die design, assembly process development, and assembly tooling development. The first domestic US industry use of a 100% electronic design and release system was instrumental in the process. The new process produced a prototype body-in-white on time at 95 WBVP (weeks before volume production) with the highest level of production-intent components ever achieved within Chrysler at this stage of development.

This paper describes the application of the Design for Manufacture and Assembly (DFMA) method at Chrysler. Attention is focused on the development of the clutch and brake pedal and bracketry system of the PL project in the Small Car Platform. The Chrysler DFMA procedure including competitive evaluation and value engineering was utilized during the initial design phase involving product concept development from the original functional and manufacturing requirements. After the first laboratory tests, a number of key design and manufacturing concerns surfaced and led to a second cycle of DFMA analysis. The procedure permits major design functions and manufacturing and assembly process issues and criteria to be incorporated in the initial design stages.

The purpose of this paper is to present numerical solution for three-dimensional flow about rotating short cylinders using the computer program AIRFLO3D. The flow Reynolds number was kept at 106 for all computations. The drag forces on the cylinder were obtained for different rotational speeds. Predictions were obtained for both an isolated cylinder and a cylinder on a moving ground. The standard k-ε model was employed to model the turbulence. Computed drag coefficients agreed well with the previous experimental data up to a spin ratio (=rω/V) of 1.5.

Five heats of vanadium-microalloyed steel with carbon contents from 0.29% to 0.40% and sulfur contents from 0.031% to 0.110% were forged into automotive spindles and air cooled. Three of the steels were continuously cast whereas the other two were ingot cast. The forged spindles were subjected to microstructural analysis, mechanical property testing, full component testing and machinability testing. The microstructures of the five steels consisted of pearlite and ferrite which nucleated on prior austenite grain boundaries and predominantly on intragranularly dispersed sulfide inclusions of the resulfurized grades. Ultimate tensile strengths and room temperature Charpy V-notch impact toughness values were relatively insensitive to processing and compositional variations. The room temperature tensile and room-temperature impact properties ranged from 820 MPa to 1000 MPa (120 to 145 ksi) and from 13 Joules to 19 Joules (10 to 14 ft-lbs), respectively, for the various steels.

This paper discusses the development of criteria necessary to establish reliable lunar exploration and construction vehicle concepts. To establish the basis for the development of these criteria, an exploration mission using the presently conceived Apollo launch vehicle system is described. The criteria resulting from the study of the contribution made by the hostile lunar environment and the life support system requirements within the framework of the selected mission are established. Soils testing in a hard vacuum is described, as are tests of models under simulated lunar terrain environment. Two lunar vehicle configurations are reviewed, including design parameters and subsystem development.

A new 3.5 liter, 60 degrees V6 engine has been designed specifically for Chrysler's 1993 MY line of mid-size sedans - Dodge Intrepid, Eagle Vision, Chrysler Concorde and New Yorker. This new engine features many new components for enchanced performance. The cylinder head has a single overhead cam, four valve-per - cylinder design. The intake system is a cross-flow design equipped with dual throttle bodies, and the manifold also incorporates a vacuum operated tuning valve that increases the mid-range torque of the engine. A windage tray is used on every engine to reduce drag on the rotating components within the crankcase. Dual knock sensors (one per cylinder bank) are used to take advantage of the aggressive spark advance and high compression ratio. The engine also utilizes a plastic, helical, water pump impeller that contributes to low parasitic power losses. The engine incorporates many components and features to ensure durability.

Chrysler Corporation has developed an 8.0-liter engine for light truck applications. Numerous features combine to produce the highest power and torque ratings of any gasoline-fueled light truck engine currently available while also providing commensurate durability. These features include: a deep-skirt ten-cylinder 90° “V” block, a Helmholtz resonator intake manifold that enhances both low and mid-range torque, light die cast all-aluminum pistons for low vibration, a unique firing order for smooth operation, a “Y” block configuration for strength and durability, a heavy duty truck-type thermostat to control warm up, and a direct ignition system.

A system for controlling gasoline evaporation losses from 1970 model Chrysler Corp. cars and light trucks was developed, certified for sale in California, and put into production. Evaporation losses from both the carburetor and the fuel tank are conducted to the engine crankcase for storage while the engine is shut down. The vapors are removed from the crankcase and utilized in the combustion process during subsequent vehicle operation. Particularly interesting in this unique, no-moving parts system, are the reliability and durability, and the vapor-liquid separator “standpipe.”