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2002-07-09
Technical Paper
2002-01-2030
Val A. Kagan, Stephan P. Weitzel
Previously we reported to SAE 2002 the basic principles in materials selections for the fastening of plastics. In this current paper, we will try to increase the understanding of the automotive community regarding the usefulness and applicability of aluminum made self-tapping screws in the fastening of various thermoplastic components. Utilization of the light alloys for the manufacturing of fasteners for plastic applications allowed us to manage efficiently the stiffness considerations, short- and long-term performance of the assembled plastic components. The results presented in this study will help designers, technologists, thermoplastic and fastener developers and fastener manufacturers, to optimize mechanical performance of assembled automotive components, where self-tapping screws will be used.
2002-07-09
Technical Paper
2002-01-2031
Arndt Nottrott
Weight reduction in automotive bodies is becoming increasingly significant. The use of lightweight materials like aluminium is one of the most effective ways of decreasing vehicle weight /1/. Automotive body designs with hydrocalibrated extrusions are quite well known. Hydroforming is proven to provide lighter parts with better performance for structural components. This report shows the combination of the use of lightweight material and hydroforming to create integrated structural components for an automotive body structure, thus reducing the weight and number of components. The base material for this research program was extruded aluminium, to keep costs down, and a higher flexibility in blank material distribution to facilitate the best boundary conditions for the hydroforming process. The process was conducted using the three typical main process steps bending - pre-forming - hydroforming to get an actual shaped structural component.
2002-07-09
Technical Paper
2002-01-2029
R. Pasino, R. Brun, A. Fuganti
This paper describes the research activities founded by the European Commission under the 5th Frame Work Programme, titled “Lighter and Safer Automotive 3D-Structures at Low Investments through the Development of the Innovative Double Sheets Hydroforming Technology”. As described into the project title, the objective is to develop and optimise double sheets hydroforming (DSH) in order to manufacture 3D automotive structures. A moch-up, representative of an automotive side frame, was designed both to evaluate the process limits and to validate the developed methodology for process numerical simulation. Design guidelines for application of this technology are the final output of the project. After a general overview description of the European project and its objectives, the following points will be described: mock-up design; process numerical simulation; experimental results.
2002-07-09
Technical Paper
2002-01-2028
Pádraig Naughton, Jan Röttger, Bill Bowser, Peter Cate
There are two main requirements for a front-end carrier (FEC). One role is to integrate various components like the cooling unit, headlights, latches and other parts into a front-end module. The main driver behind the modular approach is the need for a lean production process in the OEM plant. The ability to easily build design variants offline is an extra benefit. Design variations in the field of front-end modules are linked to the colour and style of the bumper fascia, size of the cooling unit, headlamp style and various other factors. In the end the modular approach leads to cost savings during the production process and higher quality. The other role of the FEC is to provide structural performance to resist various mechanical, thermal and chemical loads. This paper outlines an approach that enables flexibility of design while ensuring the performance of the system.
2002-07-09
Technical Paper
2002-01-2026
Christian Donhauser, Franz - Josef Lenze, Hartwig Rösen
The lightweight construction strategies that are demanded by the automobile industry are being employed more and more. These strategies lead to the increasing importance of the forming method and types of materials used. Especially forming technologies based on liquid media have the potential to meet these demands. These forming technologies make it possible to produce parts that have both, more complex geometries and optimized characteristics. This forming technology constitutes an intelligent process management including the significant materials parameters and behavior, the simulation and some new developments especially for the optimization of the quality and the cycle time. Hydromechanical sheet forming (AHU®) is an alternative production (forming) process, with very interesting results and developments for the manufacture of specific automobile components.
2002-07-09
Technical Paper
2002-01-2027
Takashi Sawamura, Noboru Tomioka, Toshi Matsumoto, Akifumi Okabe
In this paper, a new theory to obtain the nominal structural stress to the cross tension and the bending moment is described and, the method of the fatigue life estimation for the spot welding structure is proposed using this theory. Proposed method can do away with D value decision problem that is the current problem in D.Radaj's method for fatigue life estimation. Moreover, a nominal structural stress that is the fatigue strength evaluation parameter can be estimated in accuracy good, because the deformation around the nugget to which it pays attention in the spot welding structure is introduced into the analysis.
2002-07-09
Technical Paper
2002-01-2024
Rajiv B. Verma, Ralph Burger, Floyd Jackson, John Walkees
In manufacturing assembly process, since its inception, the production quality system(s) have remained very operator dependent and regular missed operations have often proved it out to be uncontrolled variables. The whole system gets more complex with the rotational nature of jobs (ergonomic need), dynamically moving assembly lines (production needs) and two/more completely different parts coming together on each workstation (nature of assembly). Control monitors, line-interlocked systems and many other ways of confirming that a quality product is built, prove out to be failures in the above-mentioned cases. This has often caused million dollar recalls, reduced product quality and other sensitive business issues eventually leading to loss of market share, bad name etc.
2002-07-09
Technical Paper
2002-01-2025
Francesc Perarnau, Stéphane Tondo
Strategic aims of the automotive industry are the minimisation of the costs and the optimisation of its product's performances. Looking for alternative production processes to improve weight, parts reduction, strength characteristics and rigidity, hydroforming offers interesting technical and economic potentials. Traditionally used in exhaust and chassis applications, the use of hydroforming is now being rapidly extended to Body in White application, like structural reinforcements or closures frames. To take benefits both from the material and the process sides, a Spanish components supplier and major steelmaker have developed optimised turn-key solutions using advanced high strength steels combined with hydroforming. Some of these solutions on modules like the front-end module or back-doors and showing interesting performances in terms of weight lightening will be detailed, including description of the manufacturing process and comparative costs estimations.
2002-07-09
Technical Paper
2002-01-1989
Rainer Neumann
Within the last decade we have noticed considerable improvements in Automotive lighting devices. Xenon headlights, Systems with low beam and high beam out of one Xenon bulb, so called Bi-Function headlights and in the near future, advanced front lighting systems (AFS) will lead to an important contribution in terms of safety when driving at night. In parallel the philosophy of automotive engineering has changed from individual technical solutions contributing to improved value within the vehicles to a system integration concept, where individual technical solutions will be combined to one specific innovation. The use of various sensors and information tools for different and multiple applications within a vehicle is highly appreciated and will lead to synergies with reduced costs for the individual components. This philosophy will also be applied for lighting systems in the future. The potential applications and possible solutions will be described within this paper.
2002-07-09
Technical Paper
2002-01-1990
Michael Hamm
Adaptive Lighting systems generate different lighting patterns according to the environmental situation that is evaluated by electronic control units. On one side, the photometrical performance will be shown in measurements, e.g. photometric data and visibility/detection distances, reaction distances and braking distance calculation. A second approach will be the evaluation how the improved light performance is accepted by the driver when driving adaptive lighting systems. It can be assumed that the fact that during night time driving the fixation is mostly oriented in front of the car in illuminated areas, the visible change of light performance will lead to clear statements about acceptance among drivers. For this reason, a questionnaire is currently evaluated in order to find an acceptance rating for the different driving situations. The paper will address both fields of interest and describe the results in terms of traffic safety and comfort acceptance.
2002-07-09
Technical Paper
2002-01-1992
M.K. El-Adawi, S. A. Shalaby, G. M. Behery
Abstract The daily temperature variation of the car's glass windows, supported with a metallic mesh being embedded in it and subjected to incident global solar radiation is obtained. A heat balance equation with terms considering heat losses by convection and thermal radiation is solved. A heat diffusion equation for the car's salon is also solved using Fourier sine transform technique. The effect of the mesh parameters and other main features on the salon climate are clarified through the obtained relations.
2002-07-09
Technical Paper
2002-01-1986
C. Mattheck, I. Tesari
Based on the axiom of uniform stress, which is a basic design rule for biological load carriers, and by use of the Finite Element Method (FEM) the computer program CAO (Computer Aided Optimisation) has been developed at Forschungszentrum Karlsruhe to transfer this biological optimisation mechanism to mechanical engineering. CAO leads to an optimised shape with a high fatigue resistance due to homogeneous stresses on the surface of the component. The conventional CAO method has been modified for the optimisation of shell structures. One modification of the CAO method allows a variation of the wall thickness of shell or membrane elements. Another modification is for the optimised corrugation of sheets of uniform thickness. The methods can be combined and are very useful for the reduction of the maximum stress or the minimization of the weight of load bearing sheets.
2002-07-09
Technical Paper
2002-01-1985
M. Brughmans, S. Goossens, V. Cibrario
Design of a vehicle system involves satisfying competing objectives for various attributes Noise and Vibration (NVH), Durability, Safety, and Vehicle Dynamics. To achieve an optimal design, dedicated CAE analysis tools are used to evaluate the functional vehicle performances for the different attributes and to quantify trade-offs when analyzing different design variants. Presently, CAE tools have been playing a reactive role in this engineering process. Different design proposals (CAD) are verified against functional requirements and feedback is given to the design department for the next design iteration. This paper aims at describing an engineering process where CAE (simulation) plays a more proactive role in the design process.
2002-07-09
Technical Paper
2002-01-1988
Jan P. Löwenau, Martin H. Strobl
The Advanced Lighting Simulation (ALS) is a development tool for systematically investigating and optimizing the Adaptive Light Control (ALC) system to provide the driver with improved headlamps and light distributions. ALS is based on advanced CA-techniques and modern validation facilities. To improve night time traffic safety the BMW lighting system ALC has been developed and optimized with the help of ALS. ALC improves the headlamp illumination by means of continuous adaptation of the headlamps according to the current driving situation and current environment. BMW has already implemented ALC prototypes in real vehicles to demonstrate the advantages on the real road.
2002-07-09
Technical Paper
2002-01-1987
Hong Jae Yim, Sang Beom Lee, Sung Don Pyun
In this paper, an optimization technique for thin walled beams of vehicle body structure is proposed. Stiffness of thin walled beam structure is characterized by the thickness and typical section shape of the beam structure. Approximate functions for the section properties such as area, area moment of inertia, and torsional constant are derived by using the response surface method. The approximate functions can be used for the optimal design of the vehicle body that consists of complicated thin walled beams. A passenger car body structure is optimized to demonstrate the proposed technique.
2002-07-09
Technical Paper
2002-01-2000
Yoshimasa Ureshino, Osamu Nakano, Kohichi Fukuda, Terumoto Fujiwara
Gas carburizing is a surface hardening method that is used for automobile steel parts such as gears. The conventional gas carburizing(at 1223K) takes longer time. Shortening the carburizing time will contribute greatly to the energy saving and CO2 reduction of parts production. The new carburizing process at higher temperature,1273K, and vacuum is made without adding reheating and quenching process. That process can shorten treatment time to one-fourth of conventional process. The new alloy steel for high-temperature vacuum carburizing is developed in order to prevent the grain coarsening. This paper describes the outline of this alloy steel.
2002-07-09
Technical Paper
2002-01-1998
André Galtier, Jean-Noel Gacel
Weight reduction and economy in the use of materials are the most important aim of automotive industries. Steel manufacturers develop high strength steel in order to increase mechanical properties. Fatigue behavior of assemblies is an important issue to consider, and in the case of thin steel sheet spot welding is the widely technique used. Is this paper, other techniques have been studied such as clinching and riveting. Fatigue tests were performed on different steel grades and several sheet thickness on a single spot specimen subjected to shear-tension loading. Results show that the fatigue strength of these assemblies is strongly dependant of the steel grade on the contrary of spot welds. Some tests on two spots specimens confirm that the fatigue strength is proportional to the number of spots. Then relationships in order to predict the fatigue strength from plate thickness are proposed from experimental results.
2002-07-09
Technical Paper
2002-01-2004
Asif A. Rizvi
The main element of dimensional management is specification cascading where customer requirements are translated into dimensional targets. It also includes GD&T, datum strategy, and tolerance optimization. These elements can only be effective if all of the work is done concurrently among various disciplines of an organization that have a stake in the fit, finish, and performance of the final product. When setting static dimensional goals during product development, vehicle performance targets and dynamic goals have to be defined simultaneously. One example is of the final door appearance for gaps and flushness on an automotive body from static standpoint. The wind-noise and door flutter are examples of dynamic performance goals. It becomes very costly to fix static fit and finish issues caused by the dynamic state of the vehicle late into the product development cycle or at the customer locations.
2002-07-09
Technical Paper
2002-01-2013
Marius Vasilescu, Ioana Vasilescu
The aluminium-lithium alloys are modern materials capable to present higher mechanical properties reported to specific gravity being from this point of view very interesting for aerospace industry. By means of optimal correlation's between the chemical composition, the mode of elaboration and casting, the conditions of plastic deformations and heat treatment, these alloys can present mechanical and plasticity properties comparable with those of the DURAL (2024) types, on the lower density conditions. In the paper are presented the results of the studies and experimental researches made upon some lithium-lithium based alloys of the 2090 type, supplementary alloyed with Ti, for the use in aerospace constructions. There are made structure and property researches on the cast semi-manufactured product, plastic deformed and respective heat-treated to obtain the maximum mechanical characteristics.
2002-07-09
Technical Paper
2002-01-2005
Emilio Brahmst, Richard Gerth, Jay Baron, Steve Geddes
This paper discusses the results of a door benchmark study performed on 14 vehicles. The major focus is on the selection of datums or reference points and its impact on the product quality of the door system. The results indicate that there can be a relationship between datum utilization and quality metrics at any stage in the production process. Specific examples show the impact of various strategies on product performance.
2002-07-09
Technical Paper
2002-01-2006
Richard J. Gerth, Jay Baron, Emilio Brahmst, Steve Geddes
A comparative benchmarking study of the dimensional door quality 14 vehicles from Ford, General Motors, Daimler-Chrysler, Toyota, Nissan, BMW, Volvo, and Renault was conducted. Various aspects of the door design, manufacturing, assembly and hanging system were studied. This paper focuses on the dimensional quality of the doors and relates it to the final vehicle quality in terms of gaps and flush as well as customer satisfaction as established by J. D. Power Initial Quality Survey (IQS). For confidentiality reasons, all vehicles in the study are referred to by a coded designation.
2002-07-09
Technical Paper
2002-01-2007
Magdalena Les, Zbigniew Les
For many years, time series analysis methods have been applied to develop models linking serious road crashes with the effects of socio-economic and other factors. Classical time series models, such as log-linear regression or ARIMA, are useful in describing observed road trauma but are typically poor when used for forecasting road safety trends. In recent years, a new method of forecasting has been developed called an artificial neural network (ANN). The main focus of this research was on examining the possibility of using ANNs for prediction and to find complex relationships ‘hidden’ in time series models that classical modelling techniques often fail to reveal. Application of structural time series models for this purpose was also investigated.
2002-07-09
Technical Paper
2002-01-2009
Michael Kreimeyer, Florian Wagner, Gerd Sepold, Marion Joly, Bernard Criqui
The use of high power laser sources (CO2) enables the joining of aluminum and zinc-coated steel sheets in butt configuration, using a combined welding-brazing process. Comparable to conventional thermal joining technologies, like resistance spot welding, intermetallic phases are formed in the contact zone leading to a decrease of the mechanical properties of the joint. With locally restricted energy input and high joining speeds the formation of these phases can be minimized to a none critical level. For the characterization of the seam morphology optical, X-ray and electron microscopy examinations have been carried out, demonstrating a phase layer thickness of about 2 μm. In mechanical tests, fracture stresses of 144 N/mm2 have been achieved.
2002-07-09
Technical Paper
2002-01-2020
Roger Andersson, Erik Schedin, Claes Magnusson, Jonny Ocklund, Arne Persson
To increase crash performance in automotive vehicles it is necessary to use new techniques and materials. Components linked to crash safety should transmit or absorb energy. The energy absorbing capability of a specific component is a combination of geometry and material properties. For these components the chosen material should have high yield strength and relatively high elongation to fracture. These demands have led to increasing interest in the use of high strength stainless steels. The relative performance of three high strength carbon steels and two high strength stainless steel grades was evaluated through intrinsic and simulative tests. The rear bumper for a Volvo Car model in current production was manufactured using the five sheets tested to verify formability and behaviour under load. The bumpers were clamped in a rig that allowed quasi-static impact tests to be made.
2002-07-09
Technical Paper
2002-01-2021
O. Rebuffet, B. Morère, B. Magnin, S. Bompard
The targeted use of aluminium extrusions in automotive crashworthiness applications is a way for a significant weight reduction. Indeed, if the energy absorption is proportional to the mechanical characteristics, it takes important benefits of the thickness increase and of the use of closed sections, advantageously multicellular, allowed by the use of aluminium profiles. But in the case where the material and the geometry of the extruded product are not adapted, some undesirable failures may appear during the crash. Most of the time, these failures remain localised, and have no consequence on the energy absorption levels. Nevertheless, it appears important to predict their apparitions, and to adapt the alloys temper to reduce or eliminate it. An experimental and numerical program was carried out to relate the behaviour of extrusions submitted to different crash conditions. The results were used to fit a damage mechanics based numerical model.
2002-07-09
Technical Paper
2002-01-2022
Heui-Bom Lee, Young-Sik Bang, J.-L. Duval, Jae-Hyung Han
In this paper, the distortion analysis in spot welded area of car body - front side member, it is found out that the optimum condition for panel assembly is closely related to the welding sequence, location of clamping system, number, shape and welding force. The distortion resulting from welding sequence is minimized starting from the surroundings of the clamping system and in the way that the value of the welding force is from large to small. The MCP is determined from the positions inducing the minimum distortion in panel through calculating the deformation and reacting force of the panel. The welding force originating from the manufacturing tolerance of assembly is a critical design factor determining the welding sequence and the clamping system that yield minimum distortion in spot welding of body panel.
2002-07-09
Technical Paper
2002-01-2023
J. Féraille
ABSRACT With the CO2 emission law, new concepts are developed in the automotive industry. Hydroforming is one of those because it can save weight. After three different stages, exploratory stage, product/process feasibility and industrial certification, hydroforming will be reliable enough to manufacture in serial production.
2002-07-09
Technical Paper
2002-01-2014
M.G. Pérez, N.R. Harlan, F. Zubiri, F. Zapirain, K. Gebauer
The goal of the present work is to reduce the environmental impact of car gasoline engines by developing lightweight engine components. The use of light-weight metals such as aluminum results in substantial reductions in CO2 emissions. Traditionally aluminum alloys have been restricted to low temperature applications because of their poor mechanical properties at elevated temperature. However, novel fabrication methods such as spray forming and rapid solidification have overcome the temperature limitation. Coupled with a surface coating designed to withstand corrosion and wear at elevated temperatures, these high performance alloys may be considered to replace steel-based components in automotive engines. In this work, hypereutectic aluminum-silicon (Al-Si) alloys produced via different fabrication routes were tested for laser coating with a nickel-chromium alloy. Experimental results demonstrating the response of these alloys to laser coating are presented.
2002-07-09
Technical Paper
2002-01-2017
Andreas Vlahinos, Subhash G. Kelkar
Although great advances have been made over the last two decades in the automotive structural design process, tradition and experience guide many design choices even today. The need for innovative tools is stronger now more than ever before as the design engineer is confronted with more complex, often contradictory design requirements such as cost, weight, performance, safety, time to market, life cycle, aesthetics, environmental impact, changes in the industry's business models, etc. The ever-increasing use of optimization tools in engineering design generates solutions that are very close to the limits of the design constraints, hardly allowing for tolerances to compensate for uncontrollable factors such as manufacturing imperfections. Optimum designs developed without consideration of uncertainty can lead to non-robust designs.
2002-07-09
Technical Paper
2002-01-2019
Dan Tang, Dave Loosle, Bruno Barthelemy, Yi Liu
A CAE modeling methodology has been developed for modeling laser and MIG (metal-inert-gas) weld separations. This new methodology can simulate weld failure in CAE aluminum vehicle crash analysis using a failure formulation derived from coupon test results. It is a generalized method and is intended to be applicable to any combination of the parameters such as thickness, material, and type of weld and impact speed. The method has been validated on the crash tests on straight and S-type rails with a hat section. The CAE prediction based on the modeling procedure correlates well with the test results for all the rail crush cases. The finite element analysis was conducted in RADIOSS environment. The welds are modeled using the beam-type spring element with the new weld damage parameters. The baseline curves for the spring element and the detailed projection equations developed are provided in this paper.
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