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Viewing 1 to 30 of 298
1989-09-01
Technical Paper
892149
Edward T. King, Granger K. Chul
A 22 hour engine test was developed to evaluate the effects of fuels, lubricants, and valvetrain dynamics on the wear of OHC 2.3L engine camshafts and finger followers. Procedures include a break-in to improve test repeatability and a test sequence to allow single-shift operation. A surface analyzer capable of measuring cam lobe wear profiles to micro-inch accuracy provided a quantitative wear comparison. A pure mineral oil, as expected, resulted in higher camshaft wear than using a fully formulated SF lubricant. Cam and follower wear increased significantly when ethanol replaced gasoline as fuel. The combination of ethanol, mineral oil and heavy duty valve springs was selected to increase test severity for hardware discrimination. The average wear of the intake lobes was greater than the exhausts. Kinematic analysis and visual inspection of the valve train mechanism revealed differences in the relative motion and contact stress pattern.
1986-02-01
Technical Paper
860109
J. J. Vincent, C. L. Coon
The proliferation of Unibody construction, for vehicle weight reduction, and the expanded use of precoated steel, for improvement in outer body rust-through protection, has significantly increased the number of bimetallic and crevice unions on U.S. manufactured vehicles. Cyclic corrosion and proving ground testing has shown that these unions are highly active electrochemically, resulting in extensive anodic corrosion and cathodic de-lamination of the paint film. This work examines the individual contribution of each layer of the applied protective coatings package, with respect to applied film thickness, to the reduction of permeation by water, oxygen, and NaCl and resultant corrosion.
1984-11-01
Technical Paper
841695
W. W. Shope, L. A. Ardisana, S. A. Mazzola
The unitized construction Aerostar compact van and wagon models have been engineered to meet a variety of consumer transportation needs. The broad range of functional and image objectives have been attained by traditional design and development programs augmented by new developmental methods and isolation components. State-of-the-art development methodologies applied early in the Aerostar program enabled prediction of the effects of design revisions intended to improve subsystem response characteristics and isolation. Developmental methods used included finite element analysis, modal analysis and synthesis, transmissibility measurements, torsional powertrain measurements, continuous wave laser holography, acoustical mode determination, acoustical intensity mapping and sensitivity studies used to project production ranges of quality.
1984-11-01
Technical Paper
841694
M. A. Kapadia, R. T. Eifert
Ford's continued effort to improve fuel economy in automotive applications has emphasized the need for lightweight components that retain all the toughness associated with Ford truck vehicle characteristics. The application of an impact extrusion process to wheel design and manufacture, for Ford Aerostar, provides strength, performance and style more efficiently than other traditional processes. It results in a valuable 33% weight saving over comparable HSLA steel wheels, and provides the customer with uncompromised value. The Ford Aerostar Impact Extruded Aluminum Wheel was designed to be of one-piece construction, manufactured from a less than 1″ thick aluminum wafer-shaped blank. The process permits manufacture in half the steps of a conventional stamped steel wheel, and eliminates extensive machining required with forged or cast aluminum wheels.
1984-11-01
Technical Paper
841697
S. B. Carl, C. M. Foster
This paper summarizes the design features of the Aerostar aluminum driveshaft and the analytical techniques used in its development. The Aerostar aluminum driveshaft was designed for lightweight and smooth operation. The aluminum driveshaft uses magnetic impulse metal forming to attach the tube yokes to the tube. This process does not produce a significant amount of heat preserving tube's mechanical properties. Computer aided design techniques were used to optimize the design of driveshaft components and driveline geometry. Finite element analysis was used to refine the tube yoke design for minimum weight within the torque requirement. Finite element analysis was also used to determine resonant frequencies of the powertrain.
2009-05-19
Technical Paper
2009-01-2054
Prakash T. Thawani, Zhengyu Liu
Air-conditioning (A/C) induced moan is a very commonly observed phenomenon in automotive refrigerant systems. Since most of the automotive A/C systems cycle ON/OFF four to six times every minute, the A/C induced moan is quite readily audible under engine idle and even while driving, especially under lower engine/vehicle speeds. It is not unusual for an A/C compressor to moan or not, on some vehicle/s under certain operating conditions. Most of the OEMs resolve or suppress the A/C moan potential to barely audible levels. However, under some unique and extreme operating conditions, A/C moan is quite readily induced and often results in customer complaints. This paper discusses A/C moan related root-causes, sources and paths of propagation. A systematic diagnostic test-procedure is also described to diagnose and develop the needed most cost-effective design-fixes. Finally, based on this case-study - some objective targets are recommended to suppress the A/C moan to acceptable levels.
2011-04-12
Technical Paper
2011-01-1060
Jody Hall, Tareena Mulholland, Darryl Young, J.P. McGuire
Advanced High-Strength Steels (AHSS) have become an essential part of the lightweighting strategy for automotive body structures. The ability to fully realize the benefits of AHSS depends upon the ability to aggressively form, trim, and pierce these steels into challenging parts. Tooling wear has been a roadblock to stamping these materials. Traditional die materials and designs have shown significant problems with accelerated wear, galling and die pickup, and premature wear and breakage of pierce punches. [1] This paper identifies and discusses the tribological factors that contribute to the successful stamping of AHSS. This includes minimizing tool wear and galling/die pick-up; identifying the most effective pierce clearance (wear vs. burr height) when piercing AHSS; and determining optimal die material and coating performance for tooling stamping AHSS.
2011-04-12
Technical Paper
2011-01-1054
Ram S. Iyer, Timothy Montroy, Shawn Morgans, Kevin Gustafson
The front bumper of a current production vehicle, which is made of hot-stamped 15B21 aluminized steel, was studied for mass and cost reductions using the Advanced High Strength Stainless Steel product NITRONIC® 30 (UNS Designation S20400) manufactured by AK Steel Corporation. This grade of stainless steel offers a combination of high ductility and strength, which was utilized to significantly modify the design of the bumper beam to incorporate geometry changes that improved its stiffness and strength. The structural performance of the bumper assembly was evaluated using LS-Dyna-based CAE simulations of the IIHS 40% Offset Full-Vehicle Impact at 40 mph with a deformable barrier, and the IIHS Full Width Centerline 6 mph Low-Speed Impact. Optimization of the bumper beam shape and gauge was performed using a combination of manual design iterations and a multi-objective optimization methodology using LS-Opt.
2005-05-16
Technical Paper
2005-01-2509
Prakash Thawani, Suhas Venkatappa, Zhengyu Liu
The automotive refrigerant systems can occasionally exhibit a transient hoot/whistle type noise under certain operating conditions. High pressure/velocity refrigerant flow through an evaporator core can readily excite the inherent acoustical and/or structural modes, resulting in audible transient tones. This condition if present can be experienced while driving away from a short stop and can last 2 to 10 seconds. The ambient conditions suitable for creating this noise are - moderate/high air-conditioning (A/C) load during days at 85-95° F temperatures with high humidity. Possible noise generating mechanisms have been discussed in earlier publications and our findings during this study indicate that they are excited by the high velocity superheated refrigerant vapor flow through the evaporator core plates. Examples of this transient noise and its spectral characteristics are presented to characterize this refrigerant system induced issue.
2005-05-16
Technical Paper
2005-01-2501
Prakash Thawani, Zhengyu Liu, Suhas Venkatappa
Automotive refrigerant system induced noise and vibration transients usually accompany A/C compressor engagement/disengagement. These transients include audible/perceivable metallic impact/slip (clink, chirp, etc.), engagement thump, delayed accumulator thump, orifice tube/TXV induced hiss, and occasionally very loud slugging. In this paper, the inherent noise source mechanisms of these transients are described, and a set of psychoacoustics based objective metrics quantifying these transients in terms of loudness and sharpness is developed. Some of the recommended design-fixes and noise control approaches for the related transient noises are also discussed.
2006-04-03
Technical Paper
2006-01-0511
Jacob W. Zindel, Kelly A. Kofeldt, L. A. Godlewski, R. Vijayaraghavan, W. T. Donlon
Previous studies on the effect of Mg on the hardness of 319-type alloys are contradictory. The present study was conducted in an attempt to resolve this confusion and allow for a more rational choice of Mg concentration specifications. Four 319-type alloys were prepared with the following target Mg concentrations: 0.00, 0.15, 0.35 and 0.45 wt%. The addition of only 0.15 wt% Mg had a significant effect on the hardness of the alloy but further incremental additions of Mg did not produce the expected trends in hardness. Two hypotheses for this unexplained behavior are presented. This work suggests that the Mg concentration can be allowed to vary between 0.15 wt% and 0.45 wt% without significantly impacting the aging response (hardness) of the alloy.
2006-04-03
Technical Paper
2006-01-0522
Joy A. Hines, Robert C. McCune, John E. Allison, Bob R. Powell, Larry J. Ouimet, William L. Miller, Randy Beals, Lawrence Kopka, Peter P. Ried
Over the past five years, the US Automotive Materials Partnership (USAMP) has brought together representatives from DaimlerChrysler, General Motors, Ford Motor Company and over 40 other participant companies from the Mg casting industry to create and test a low-cost, Mg-alloy engine that would achieve a 15 - 20 % Mg component weight savings with no compromise in performance or durability. The block, oil pan, and front cover were redesigned to take advantage of the properties of both high-pressure die cast (HPDC) and sand cast Mg creep- resistant alloys. This paper describes the alloy selection process and the casting and testing of these new Mg-variant components. This paper will also examine the lessons learned and implications of this pre-competitive technology for future applications.
2006-04-03
Technical Paper
2006-01-0537
Robert Shang, William Altenhof, Henry Hu, Chao Zheng, Naiyi Li
Explicit finite element simulations were conducted on an aluminum wheel model where a rotating bend moment was applied on its hub to simulate wheel cornering fatigue testing. A post-processor was developed to calculate equivalent von Mises alternating and mean stresses from stress tensor. The safety factors of fatigue design for each finite element were determined to assess the fatigue performance by utilizing the Goodman linear relationship. Elements with low safety factors were identified due to the prescribed boundary conditions and stress concentrations arising from wheel geometry.
2006-04-03
Technical Paper
2006-01-0291
C. W. Maranville, H. Ohtani, D. D. Sawall, J. T. Remillard, J. M. Ginder
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.
2006-04-03
Technical Paper
2006-01-0300
A. Joaquin, A. N. A. Elliott, C. Jiang, V. Rajan, D. Hartman, C. Karas
Gas Metal Arc Welding (GMAW) is used in the automotive industry, for joining heavier gauge mild and HSLA 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, however, do not offer the same ease of welding, and process control is significantly more critical. The process window represents the range of acceptable process parameters, primarily heat inputs, to achieve an acceptable weld; which is a measure of the robustness of the process. AHSS differ from mild steels in chemical composition and thermal processing, resulting in a different microstructure; designed with a richer chemistry to have higher strength at equivalent thickness compared to mild steels. As a result, the sensitivity to heat input is greater and AHSS has a narrower process window in which acceptable welds can be achieved.
2006-04-03
Technical Paper
2006-01-0301
R. Koganti, A. Joaquin, J. Velez, M. Zaluzec, C. Karas
Aluminum alloys are becoming more lucrative in automotive structural applications. In recent automotive history, 5xxx and 6xxx aluminum alloys are being used in various structural applications. Various joining methods are also popular for joining 5xxx, and 6xxx series alloys. In this study, gas metal are welding (GMAW) also referred as metal inert gas (MIG) welding is used to join a non-heat-treatable alloy. The objective of this paper is to develop optimum weld process factors for double lap joint configuration for non-heat-treatable 5754 aluminum alloy. Ultimately, these optimum weld factor settings (also referred as weld schedules) will be used in the plant level for joining 5754 alloy materials. Also, the MIG welding equipment used in this study is OTC TP 350 DF weld power supply and DR-4000 robotic system. The weld factors selected for this study to understand the influence on lap shear load failure are power input (torch speed, voltage, current, wire feed), and gas flow rate.
2006-04-03
Technical Paper
2006-01-0302
R. Koganti, J. Velez, A. Joaquin, M. Zaluzec, C. Karas
Joining methods for spaceframe architectures using extruded structural elements are getting popular. At present, the development of lightweight vehicles, in particular aluminum intensive vehicles, requires substantial development of manufacturing processes for the joining and assembling. Joining methods, such as electric arc resistance, and laser beam fusion welding together with nonfusion ultrasonic welding rise as possible alternatives for high volume joining of aluminum. In this study, metal inert gas (MIG) welding was used to join heat treatable extruded 6063 T6 aluminum alloys. The purpose of this study was to find optimum MIG welding parameters for joining 6063-T6 extruded aluminum. Also, the MIG welding equipment used in this study is OTC TP 350 DF weld power supply and DR-4000 robotic system. The welding process factors considered were power input (voltage, current, and torch speed), pulse frequency, gas flow rate, torch angle and arc intensity.
2006-04-03
Technical Paper
2006-01-0312
Ruth Gao, Ligong Pan, Tau Tyan, Kumar Mahadevan, Omar Ghouati, Horst Lanzerath, Mark Kessen
The objective of this study is to evaluate the influence of the hydro-forming process and the effect of strain rate on crash performance and develop a modeling approach to improve the accuracy of crash prediction. Work hardening, thinning and strain rate effects are investigated in both component and full vehicle analyses to understand their sensitivities. Gages measured and material properties tested from post-formed tubes are compared with hydro-forming simulation results to confirm accuracy of the modeling methodology proposed in the paper. Front crash simulation using strain rate and forming effects are correlated with the test data for both component and full vehicle analyses and conclusion has been drawn from this comparison.
2006-04-03
Technical Paper
2006-01-0314
Ben-Ren Tang, Sarba Guha, Tau Tyan, Jiamaw Doong, Len Shaner, Dilip Bhalsod
A fuel tank is one of the most critical components in a vehicle crash because it may link to passenger safety. The effect of fuel pressure on the tank boundary in a dynamic impact condition is constantly being studied both numerically and experimentally. In hard braking conditions with a partially filled tank, the fuel slams on to the front wall of the tank. During high-speed impact on the other hand, there is significant bulging of the fuel tank if it is nearly full, while vortices and cavities may form with partial filling. In these cases, the internal fuel and vapor pressure distribution can change; thus, affecting the distribution of stress on the tank. The objective of this paper is to study these phenomena using the currently available ALE (Arbitrary Lagrangian Eulerian) methodology and thus improve fuel tank design by a direct application of CAE.
2006-04-03
Technical Paper
2006-01-0257
D. Sivaraj, P. K. Mallick, P. Mohanty, R. C. McCune
This paper presents a comparison of aqueous corrosion rates in 5% NaCl solution for eight experimental creep-resistant magnesium alloys considered for automotive powertrain applications, as well as three reference alloys (pure magnesium, AM50B and AZ91D). The corrosion rates were measured using the techniques of titration, weight loss, hydrogen evolution, and DC polarization. The corrosion rates measured by these techniques are compared with each other as well as with those obtained with salt-spray testing using ASTM B117. The advantages and disadvantages of the various corrosion measurement techniques are discussed.
2006-04-03
Technical Paper
2006-01-0351
Danielle Zeng, Z. Cedric Xia
Flanging is a secondary operation in sheet metal forming processes. Traditionally, the design of flange shape and trim line is based on an engineer's experience. It takes several iterations to achieve the desired flange geometry because of potential splits. In this paper, an efficient CAE-based tool is developed to quickly predict the formability of a given flange design and enable the optimization of trim lines. A numerical algorithm is formulated in this CAE tool to convert the 3D flanging process into an equivalent in-plane deformation problem. The developed CAE tool is also integrated with the optimization software LS-OPT for trim line design.
2006-04-03
Technical Paper
2006-01-0324
J. V. Lasecki, Xuming Su, John E. Allison
The prediction of residual stresses due to manufacturing is of high importance in product development. For the accurate prediction of residual stresses in metallic components, an understanding of the quenching process that occurs in many heat treatments is required. In this paper, the experimental techniques developed to quantify the temperature fields during quenching and to quantify the residual stresses in the quenched part are presented. The temperature fields were quantified using thermocouples embedded in the components. The residual stresses were quantified using a newly developed strain gauging, sectioning and dynamic data acquisition technique. The techniques were verified using thermal histories and residual stresses for an engine cylinder head quenched at two different quenchant temperatures. The measurements obtained were incorporated into an analytical program (finite element) to study the residual stresses produced during the quenching process.
2006-04-03
Technical Paper
2006-01-0319
Larry A. Godlewski, Xuming Su, John E. Allison, Peter Gustafson, Tresa M. Pollock
Quantification of residual stresses is an important engineering problem impacting manufacturabilty and durability of metallic components. An area of particular concern is residual stresses that can develop during heat treatment of metallic components. Many heat treatments, especially in heat treatable cast aluminum alloys, involve a water-quenching step immediately after a solution-treatment cycle. This rapid water quench has the potential to induce high residual stresses in regions of the castings that experience large thermal gradients. These stresses may be partially relaxed during the aging portion of the heat treatment. The goal of this research was to develop a test sample and quench technique to quantify the stresses created by steep thermal gradients during rapid quenching of cast aluminum. The development and relaxation of residual stresses during the aging cycle was studied experimentally with the use of strain gauges.
2006-04-03
Technical Paper
2006-01-0316
J. Michael Chang, Miinshiou Huang, Tau Tyan, G. Li, L. Gu
The optimization method and CAE analysis have been widely used in structure design for crash safety. Combining the CAE analysis and optimization approach, vehicle structure design for crash can be implemented more efficiently. One of the recent safety desirables in structure design is to reduce vehicle pitch and drop. At frontal impact tests with unbelted occupants, the interaction between occupant's head and interior header/sun visor, which is caused by excessive vehicle pitch and drop, is not desired in vehicle crash development. In order to comply with the federal frontal crash requirements for unbelted occupant, it is necessary to manage the vehicle pitch and drop by improving structure design. In this paper, a systematic process of CAE analysis with optimization approach is applied for discovering the major structural components affecting vehicle pitch and drop.
2005-04-11
Technical Paper
2005-01-1791
Joseph B. Dierker, Robert H. Thompson, Paul H. Wierenga, Matthew A. Schneider
This paper outlines the design and development of the Fire Suppression System (FSS) option for the 2005 Ford Crown Victoria Police Interceptor (CVPI). The FSS is designed to sense impact and activate two pyrotechnic hybrid devices that discharge fire suppressant foam.
2006-04-03
Technical Paper
2006-01-0089
S. Subramaniam, R. Koganti, A. Joaquin, A. Elliott, T. Coon, A. Wexler
There has been a substantial increase in the use of advanced high strength steel in automotive structures in the last few years. The usage of these 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. Proper understanding of the weldability of these materials is critical for successful application in future vehicle programs. This paper presents our production experience in use of DP600. Development work on the effect of weld tips on button size, and shrinkage voids due to different welding variables is discussed. The paper also provides recommendations from the current experimental knowledge base for applications on higher grades of steel (DP780 and beyond).
2005-04-11
Technical Paper
2005-01-1499
Scott Amman, Perry Gu, Tim Mouch, Ray Meier, Jeff Greenberg
Transient road disturbances excite complex vehicle responses involving the interaction of suspension/chassis, powertrain, and body systems. Typical ones are due to the interactions between tires and road expansion joints, railway crossings and other road discontinuities. Such transient disturbances are generally perceived as “impact harshness” due to the harshness perception as sensed by drivers through both sound and vibration. This paper presents a study of quantifying the effects of sound, steering wheel and seat/floorpan vibrations on the overall perception of the “impact harshness” during impact transient events. The Vehicle Vibration Simulator (VVS) of the Ford Research Laboratory was used to conduct this study. The results of the study show that sound and vibration have approximately equal impact on the overall perception of impact harshness. There is no evidence of interaction between sound and vibration.
2014-09-30
Technical Paper
2014-36-0172
Angela Harris, Ellen Lee, Walmir Peraro, Sandro Nunes, Cristiane Gonçalves, Andrea Latado
Abstract The microcellular foam injection molding process for thermoplastic materials provides design flexibility and cost savings opportunities not found in conventional injection molding. This process allows for plastic part design with material wall thickness optimized for functionality. The combination of density reduction and design for functionality can result in material and weight savings of up to 20%. With the correct equipment configuration, mold design, and processing conditions, these microcellular voids are uniform in size and distribution. The use of microcellular foam molding provides significant reductions in cycle time, material consumption, injection pressure, and clamp tonnage. In this work, a physical foam molding process, MuCell, is applied to a polypropylene (PP) composite.
2015-04-14
Technical Paper
2015-01-0702
Bita Ghaffari, Jonathan Dekam, Kevin Haddix, Kimberly Lazarz, Sergey Titov, Roman Maev
Abstract Adhesive bonding technology has gained ever-increasing significance in automotive industry, especially with the growing use of aluminum (Al) alloy body structures. The variability in thicknesses of the metal and adhesive layers, as well as in joint geometry, of automotive components has presented challenges in nondestructive evaluation of adhesive joints. Though these challenges were recently overcome for steel-adhesive joints using an ultrasonic pulse-echo technique, the difference in acoustic impedances of steel and Al leads to a lack of robustness in utilizing the same algorithm for Al-adhesive joints. Here, we present the results from using a modified version of this technique to inspect Al-adhesive joints in both laboratory and production environments. A 15-MHz, 52-pixel, 10 mm × 10 mm matrix array of ultrasonic transducers was used to obtain ultrasonic pulse echoes from joint interfaces, analysis of which produced C-scan images of the adhesive bead.
2015-04-14
Technical Paper
2015-01-0511
Bradford Johnson, John Henshaw, Nia R. Harrison, S. George Luckey
Abstract Increasing fuel economy is a high priority of the automotive industry due to consumer demand and government regulations. High strength aluminum alloys such as AA7075-T6 can be used in strength-critical automotive applications to reduce vehicle weight and thus improve fuel economy. However, these aluminum alloys are known to be susceptible to stress corrosion cracking (SCC) for thick plate. The level of susceptibility to SCC must be determined before a material is implemented. ASTM standards exist that generate semi-quantitative data primarily for use in screening materials for SCC. For the purposes of this work ASTM G139 (breaking load method) has been used to evaluate sheet AA7075-T6 for use in automotive applications. A tensile fixture applying a constant strain was used to quantitatively measure residual strength of the material after exposure to a corrosive environment.
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