1999 MSC Worldwide Automotive Conference

The conference proceedings for the 1999 MSC Worldwide AutomotiveConference are available on-line in Adobe Acrobat PDF format. (The Adobe Acrobat Reader software is available for free download from Adobe's web site at www.adobe.com.) When printed, these PDF files will produce a better quality image than the one shown on your computer screen. All papers have been categorized by topic.

Categories

• CAE Processes
• Durability
• Numerical Methods
• NVH

CAE Processes

WORK - AND JOBFLOW MANAGEMENT WITH MESY (PowerPoint 7.8 MB)

ANALYSIS AND EVALUATION OF MINIVAN BODY STRUCTURE FINITE ELEMENT METHODS (NOT PRESENTED) (Acrobat 1.3MB) #4099, 15 pgs.
Jin ya-min--Harbin Hafei Motor Co., Ltd., China

ABSTRACT: The paper describes the application of MSC product in Harbin Hafei Motor Co., Ltd and then describes how the finite element methods can be used for analysis and evaluation of minivan body structure. Including static, dynamic, fatigue, crashworthiness analysis, optimization and sensitivity and so on. In this paper, Author use MSC-NASTRAN calculate the strength and stiffness in both bending and torsion loadcase. Summarized the strength and stiffness evaluation standards for minivan. And then done the normal model analysis in order to consider the influence of tyre unbalance and engine idle excite. The calculations and analysis were verified by test.

APPLICATION OF FEM ANALYSIS IN ENGINE DEVELOPMENT (Acrobat 780K) #3299, 13 pgs.
Naohisa Mamiya--Nissan Motor Co. Ltd. Japan

ABSTRACT: To address environmental issues and at the same time supply products that are attractive and a high quality to the market, Nissan is adopting predictive development based on the latest computer-aided engineering (CAE) technology in engine development.

To achieve efficiency in the development from an early stage of engine development to the making of a highly complete prototype and finally to the mass production stage, a tool for advance evaluation of engine performance, function, and reliability is needed. The use of computer simulation technology has become indispensable for that purpose.

Here, we briefly introduce the incorporation of CAE technology into actual engine design work and the current state of affairs, presenting some specific examples that focus on finite element method (FEM) analysis.

APPLICATION OF FEM-TOOLS IN THE ENGINE DEVELOPMENT PROCESS (Acrobat 18MB) #2399, 10 pgs.
H. Petrin and B. Wiesler--AVL List GmbH, Austria

ABSTRACT: The requirements for the development of a new engine are the considerable reduction of development time and costs as well as the reduction of production costs, considering a higher number of product variants and higher product quality, are boundary conditions for the actual engine development. To achieve this goal the automotive industry worldwide tries to organize their development activities more efficiently in "Development Processes" and searches for optimization potential.

AVL is working together with a various number of automotive companies all over the world trying to adjust its services (e.g. FEM-calculations) for best fitting into the "Engine Development Process" of each of the customers. AVL also takes over to some extend working parts of the customer's processes and is even asked to optimize the processes.

The paper discusses the effective use of FEM-tools in engine development processes, as derived in co-operation with many automotive companies and in-house engine development, under special consideration of latest tools for mesh generation and calculation performance.

The optimized correlation between the different calculation tasks and the development process, the right starting time and extend (time frame) for the use of the simulation and the application of fast and validated simulation software assures reliable results in time.

The proper application of the FEM-tools in the design phase and the best support during the testing phase reduces the risk and the testing effort in the prototype and pre-production phase and is the essential basis for the reduction of development time and costs.

AUTOMATIC SHAPE OPTIMIZATIONS OF ELASTOMERIC PRODUCTS (Acrobat 1.5MB) #2199, 15 pgs.
M. Friedrich and J. Baltes--Freudenberg Forschungsdienste KG
M. Schütz and H. Gärtner--Freudenberg Dichtungs- und Schwingungstechnik KG

ABSTRACT: In increasing international competition, technologically oriented companies can only survive, if they can also provide cost efficient products as well as a high technological innovation strength. Therefore, in modern development philosophies, like "Simultaneous Engineering" the calculations engineer is more and more consulted in the conceptional phase of product development. Consequently, it is compellingly necessary in an effective procedure that all tools and data be placed at everyone's disposal. This way, everyone is better able to assist the conceptional design of new products as well as to make detailed improvements on already existing designs. Therefore, efficiently implemented optimisation algorithms complement the proven discrete calculation procedures (FEM, BEM) of mechanically loaded structures .

In structural mechanics, there are three levels of optimisation:

•Topology
•Shape
•Sizing

Topology optimisation, like that from Bendsoe and Kikuchi, has the capability to support the design level. Presently, for the industrial application of topology optimisation only a small number of commercial codes is available. The shape optimisation has been used for industrial applications for some time, but it is used to handle almost exclusively linear problem sets. The sizing optimisation is offered from almost every large FEM-package. It is industrially applied mainly for complex beam and shell structures.

While not as complex as the topology optimisation is, shape optimisation will be strengthened and widely applied in industry in the near future. This results from the necessity to apply a detail shape optimisation to already topology optimized components, too. In this paper the special case of shape optimisation for handling models with hyperelastic materials is focussed.

BONDING AREA OPTIMIZATION FOR REDUCING WAVEFRONT ERROR IN OPTICAL ELEMENTS (Acrobat 683K) #1299, 15 pgs.
Yair Soffair--Electro-Optics Industries Ltd., Israel

ABSTRACT: The objective of this analysis is to recommend an optimal bonding configuration for a large Dove prism for minimal wavefront error, maintaining bond strength while subjected to severe environmental conditions.

DRIVING YOUR DESIGNS WITH MSC.SOFTWARE'S AUTOMOTIVE SOLUTIONS (Acrobat 455K) #0199, 5 pgs.
Ken Blakely--MSC.Software Corporation

ABSTRACT: The automotive industry accounts for nearly 30% of MSC.Software's business. It is truly global in nature for us, with our business being spread equally around each of the world regions (Americas, Europe, and Asia-Pacific). "Automotive" includes cars, trucks, SUVs, buses, motorcycles, tires, engines, and components, from OEMs to third-tier suppliers.

This paper briefly describes MSC.Software's automotive solutions. These are comprised of our core software, our automotive-specific software, and our automotive services. This paper provides a glimpse of things you will learn about in more detail during the Conference.

A FINITE ELEMENT VEHICLE ANALYSIS LIBRARY FOR COMMERCIAL VEHICLES (Acrobat 130K) #2799, 9 pgs.
Ir. J. Maasdam--DAF Trucks N.V.

ABSTRACT: MSC/NASTRAN is one of the general purpose finite element programs used at DAF Trucks N.V. Performing a finite element analysis of a commercial vehicle may be time consuming for two reasons. Firstly, many variations in vehicle specification exist, due to customer request. Secondly, the investigation of the static and dynamic behaviour of commercial vehicles often requires a full vehicle model. The resulting large numerical model has typically several hundred thousand degrees of freedom.

In order to perform the requested static and dynamic analysis on time, DAF Trucks N.V. applies component mode synthesis and automatically assembles a full vehicle model from a vehicle analysis library.

This paper addresses some aspects of the vehicle analysis library and shows examples of a full vehicle model used for static and dynamic analysis. The dynamic analysis example shows how frequency response functions, calculated with MSC/NASTRAN, are post-processed with the aid of a toolbox. This toolbox enables fast evaluation of e.g. ride comfort and load spectra for a variety of operating conditions. Furthermore, online sensitivity or optimisation studies are possible.

HIGH PERFORMANCE, PROCESS ORIENTED, WELD SPOT APPROACH (Acrobat 325K) #2599, 14 pgs.
Daniel Heiserer and Juergen Siela--BMW AG Muenchen
Mladen Chargin--CDH GmbH

ABSTRACT: Simulation of automotive vehicles has become a more important step in car development in the last few years. Rapid prototyping, which offers a close-to-market product, with less hardware, requires a fast and accurate computer simulation to guarantee a quality product.

Generation of body-in-white nite element models for full vehicle simulation of Linear Statics, Normal Modes, NVH, and Crash is one of the most critical items. This is due to the need to connect various body-in-white components which requires:

•a signicant amount of manpower because of difficult automation possibilities
•a "physically correct" representation of part-connectors such as weld spots, screws, etc., which cannot be easily automated and requires more manpower resulting in delays and a potentially large source of error

In the past, a number of methods were developed for joining these parts together, such as homogenous models and various other weld spot approaches. In the generation of FE-models, each part depended on its connected parts, which made it difficult to shorten the modeling process. Benefits of faster hardware, and some improvements in preprocessors, were diminished by the need for bigger models.

Despite the above improvements, a signi.cant amount of time was still required to generate FE models. CDH and BMW developed a spot welding approach, linchweld, which simultane- ously reduced the modeling time, invested manpower, and increased the quality of simulation (compared to test).

The program containing the linchweld approach is called CDH/SPOT.

INTEGRATION OF CFD AND THERMAL STRESS ANALYSIS FOR TURBOCHARGERS (Acrobat 650K) #3499, 7 pgs.
Mikio Obi, Nobuo Takei and Natsuko Matsuura--Ishikawajima-Harima Heavy Industries Co., Ltd., Japan

ABSTRACT: In the manufacturing industries, there is a trend lately to employ a new manufacturing method using 3D-CADs in the manufacturing process. The purpose of employing the new method is to cut the lead time of a new product and achieve the timely introduction of the product into the market when it meets customers' needs by solving manufacturing problems with 3D-CADS in the design phase. The real effects of introducing 3D-CADs can be realized by not only examining designs in three dimensions in the design phase, but also by converting entire development processes to be based on digital data by reflecting design model data in such production data as those for various analyses and mold production. We also have been changing development processes from drawing-based conventional processes to those based on digital data.

Our company develops such rotating machinery as turbochargers and turbo-compressors. Because they are fluid machinery with complex geometry consisting of many free form surfaces, many good results can be expected by employing 3D-based development. Further, because we produce products by partially altering the design of our standard specification products for general-purpose applications according to the customer's requirements, we can expect to improve design speed by establishing the new development processes mentioned about and by re-using existing data effectively. Generally, rotating machinery consists of many machine elements and some of them are put into such severe conditions as high-speed rotation under high temperature. Therefore, analysis is very important in the developing processes and it is fundamental to implement analysis procedures smoothly in the development processes. We analyzed the thermal stress of a turbine housing of turbocharger by transferring the results of temperature distribution analysis, which is based on the results of thermofluids analysis, to structural analysis. By comparing the flow of the analysis with the conventional analysis procedures, we will describe the effects and problems of the new procedures, which we encounter when applying them to design procedures.

INTEGRATION OF INNOVATIVE CAE METHODS IN CHASSIS ENGINEERING AT PORSCHE (Acrobat 748K) #1899, 11 pgs.
Harald Bähr--Porschestraße

ABSTRACT: The consistent application of CAE methods in Porsche's Chassis Engineering helps to clearly lower development times and costs while improving both quality and reliability.

This presentation describes the CAE-assisted development procedures used by Porsche in chassis engineering. It outlines the results obtained and the development activities planned for the future.

The CAE process chain is presented and software packages for various tasks such as linear and non-linear statics, dynamics, optimization, misuse and life are explained.

Further new subjects such as process simulation (casting, forming) are discussed.

Due to the rapid development in the field of CAD-integrated calculation tools, standard calculations are increasingly done in the design departments themselves. This trend will further intensify in future, since the scope and complexity of the calculation tasks to be accomplished by the calculation engineers keeps increasing.

Some examples of current chassis developments are given.

METALLIC GASKET MODELING USING MSC/PATRAN ADVANCED FEA (Acrobat 98K) #3399, 8 pgs.
Michael de Jesus Fernandes--Sabó Indústria e Comércio Ltda, Brazil

ABSTRACT: This work presents the modeling methodology for multi-layer and single-layer-steel gaskets, MLS and SLS. Among the approached themes discussed are some concepts regarding metallic gaskets, the design methodology itself, main considerations and assumptions, as well as the most common problems in regards to the input data acquisition, and in the convergence process. The entire approach is carried out considering a fictitious problem example.

MSC.ACUMEN EXPERT SYSTEM ACCELERATES TRUCK STRUCTURE DESIGN (Acrobat 664K) #3199, 21 pgs.
Les Grundman--Navistar International Transportation Corp.
David Bremmer, Sue Rice, and Geetha Bharatram--MSC.Software Corporation
Tom Phillips--Thermal Engineering Services, Inc.

ABSTRACT: Navistar Technical Engineering Center has teamed with MSC to exploit a new technology with the goal of significantly enhancing the impact of concurrent simulation on the truck structure design process. MSC.Acumen was used to build an expert system of designer tools. Design Engineers use these tools to perform up-front concurrent simulation, yielding the same quality of results that the dedicated simulation experts produce. The specific best practices and methods for simulating particular design categories were captured from the experts at the NTEC structural analysis group and cast into customized and automated applications.

By using this system, component structural performance takes place on the same day that the design form is first rendered in CAD, as opposed to waiting in a queue for 4-to-6 weeks. If fact, design iteration for changes of material dimension, shape, or structural reinforcements is now supported by high quality simulation on the same day.

The custom MSC.Acumen applications are unique because they drive a Navistar specific process. They serve the collaboration and review process through automatic output of supporting data and simulation results in the form of web page HTML reports.

Navistar has selected two "work flow categories" for the first application set. They consist of eleven different "simulation templates" for structural brackets. These categories were chosen as very common and frequently designed structural components. The "simulation templates" will therefore see a high usage rate and yield the maximum impact to the design process. An additional benefit is that the structural analysis group experts are freed to pursue more complex and challenging tasks.

OPTIMIZATION OF CAR COMPONENTS USING MSC/CONSTRUCT (Acrobat 1.9MB) #2099, 15 pgs.
Dr. F. Dirschmid--IABG

ABSTRACT: New CAE tools are necessary to fulfill the increasing demands for new car components. Typical demands are lightweightness, costs and developing time. Efficient tools and methods have to be used in the very early stage of development to achieve these goals. As soon as the design space, the boundary conditions and the loads are fixed, the topology optimization is an appropriate method to define a first design of the component. The topology optimization is a method that change the density and stiffness distributions in an iterative process to achieve a homogeneous stress distribution. This design proposal must be transferred in a real component by taking into account manufacturing and design points of view. The industrial application of this optimization method using MSC/CONSTRUCT is demonstrated in this paper for different car components.

STRUCTURAL OPTIMIZATION IN VEHICLE DEVELOPMENT (Acrobat 878K) #0899, 10 pgs.
Leo W. Dunne--CDH GmbH

ABSTRACT: This paper presents an overview of structural optimization and some closely related subjects in the automobile industry. An historical review of the development of structural optimization is given. Some of the fundamental steps which were taken and the nature of the problems that had to be overcome will be highlighted. The current state of technical affairs relating to the optimizer algorithms, analysis and pre/post processing is reviewed, considering theoretical as well as application oriented aspects. Finally, the application of structural optimization during the development process of an automobile is discussed, including identification of its major benefits. Examples and case studies will demonstrate the applicability and limitations of structural optimization in daily engineering practice. The paper ends with a review of future trends in structural optimization applications and their implications.

Durability

FATIGUE LIFE ANALYSIS OF VOLVO S80 BI-FUEL (Acrobat 195K) #0499, 7 pgs.
M. Fermér, G. McInally and G. Sandin--Volvo Car Corporation, Sweden

ABSTRACT: The dimensioning of Volvo S80 Bi-Fuel has been totally performed in a virtual environment. Several design solutions have been numerically investigated using two dominant load cases. The robustness of chosen solutions have been investigated by calculations with critical spotwelds removed from the FE-model. The final design has been verified with a full four poster shake rig test. Although the rear floor is totally redesigned for the gas tank installation, no fatigue failure has been observed in this area.

The paper gives some insight into the dimensioning process, with special focus on spotweld fatigue analysis. All fatigue calculations were performed using MSC/Fatigue.

FE-BASED WHEEL FATIGUE ANALYSIS USING MSC.FATIGUE (Acrobat 130 K) #0599, 5 pgs.
S.C. Kerr and N.W.M. Bishop--MSC.Software, UK
D.L. Russell and U.S. Patel--BF Goodrich Aerospace, OH

ABSTRACT: A validation exercise is currently underway at BF Goodrich to evaluate the fatigue life of a rotating wheel using a new "WHEELS" capability within MSC.FATIGUE. BF Goodrich will shortly be using this capability to automate fatigue calculations for rotating aircraft wheels subject to vertical and lateral loads. As part of a validation exercise, an FE model of the wheel was analysed by applying a bearing roller load around the inner surface of the wheel hub at 15 ^o increments. A linear static analysis was conducted at each increment to produce a stress tensor history ( s_x, s_y, and t_xy) for all surface nodes. Due to the nature of a rolling wheel, it was expected that the principal stresses and their directions would vary for each increment. For this reason, the stress tensors were also rotated on the model surface through 360 ^o, at 10 ^o increments, to calculate the components of the principal stresses in those directions. All stress data was run through an S-N fatigue life analysis with no mean stress correction. Although not complete, the results are expected to show contour plots of fatigue life and fatigue damage for all nodes at the worst (most damaging) surface angle. MSC.Software envisions that this new capability can also be applied to any rotating body, especially automotive wheels.

THE IGNORED FAILURE MODE: SPOTWELD UNDER INPLANE ROTATION (Acrobat 683K) #0399, 11 pgs.
Pey Wung--Ford Motor Company, USA

ABSTRACT: Spot weld failures of complicated structure, such as automobile bodies, are difficult to explain using current multiaxial spot weld failure theory. After introducing the in-plane rotational failure mode, some unexplainable spot weld failures become explainable. The purpose of this report is to introduce the spot weld rotational test, its relative strengths and its finite element simulation. It is found that the strength of a spot weld under the in-plane rotational mode is far below the strengths of the same spot weld under other failure modes such as in-plane shear. Hence, the work conducted in this study could be a foundation for a new generation of multiaxial spot weld failure theory development.

USING MSC.Fatigue TO ESTIMATE THE FATIGUE DAMAGE CAUSED TO VIBRATING AUTOMOTIVE COMPONENTS (NOT PRESENTED) (Acrobat 650K) #3899, 7 pgs.
Neil Bishop, Stuart Kerr, and Alan Caserio--MSC.Software

ABSTRACT: An earlier paper demonstrated that vibration fatigue techniques can be a powerful tool in the design of automotive components subjected to vibration loadings. This paper extends the work by utilizing new techniques in the software program MSC.Fatigue. In particular, new techniques now exist which enable principal stresses to be computer over the entire surface region of interest. Complete results are included in this paper.

Vibration testing of components using accelerated test tracks or laboratory simulators is widely used in automotive design, as is fatigue testing for reliability. Furthermore, there are many common features between these two disciplines. However, problems often arise when engineers who are skilled in one field have to use techniques and concepts more generally used in the other. One example of such a situation concerns the use of frequency domain descriptions of structural response, which are commonplace in vibration. Many engineering applications, such as offshore structures and wind turbines, have already seen the benefits of using frequency domain fatigue analysis for reliability assessment. The purpose of this paper is to assess the benefits of frequency domain fatigue analysis and compare it with more conventional time domain techniques. A typical automotive component has been analyzed using MSC.Nastran and MSC.Fatigue using both time and frequency domain methods. Probability density functions and fatigue lives computed using output from these two different approaches show good agreement.

USING THE MSC/NASTRAN SUPERELEMENT MODAL METHOD TO IMPROVE THE ACCURACY OF PREDICTIVE FATIGUE LOADS OF A SHORT AND LONG ARM TYPE REAR SUSPENSION (Acrobat 228 K) #0699, 24 pgs.
Dr. Hong Zhu, Dr. John Dakin and Ray Pountney--Ford Motor Company Limitd, UK

ABSTRACT: In the fiercely competitive world of today's automotive industry, Computer Aided Engineering (CAE) is playing a more and more important role in shortening the design cycle time, minimising costs and improving the product quality.

For vehicle engineering, an optimised design is to develop a light-weight, safe and durable system. A key aspect of the fatigue/durability process is to quantify the vehicle service loads in the early design phase. Within the constraints of the development time, cost and quality, the trend has been to reduce road measurement, to use more rig simulation, to increase CAE prototypes and to decrease hardware prototypes. The accuracy of the CAE durability process is mandated to achieve a robust design.

This investigation includes an application of the MSC/Nastran superelement modal method to improve the load accuracy of a short and long arm typed rear suspension. Also a comparison is made between the loads obtained using rigid body dynamics and those including MSC/Nastran flexible bodies and to quantify the influence of the elastic suspension components such as links and knuckles.

Rigid body dynamic simulation methods usually neglect the flexibility and the modal properties of the elastic components. An integration of the MSC/Nastran superelement modal method with the MDI/Adams rigid body dynamics method offers an effective tool to improve the quality of the prediction of dynamic fatigue loads in the new product development.

VIBRATION FATIGUE ANALYSIS IN THE FINITE ELEMENT ENVIRONMENT (NOT PRESENTED) (Acrobat 1.3 MB) #3799, 16 pgs.
Neil Bishop--MSC.Software Limited-United Kingdom

ABSTRACT: Fatigue damage is traditionally determined from time signals of loading, usually in the form of stress or strain. However, there are many design scenarios when the loading, or fatigue damage process, cannot easily be defined using time signals. In these cases the design engineer usually has to use a test based approach to evaluate the fatigue life of his structure or component. Or, alternatively, a frequency based fatigue calculation can be utilised where the loading and response are represented using Power Spectral Density (PSD) functions. One very important design problem, which falls into this category, is that of acoustic fatigue. However, there are also many other situations where structures are subjected to a random form of loading such as wing flutter, landing gear runway profiles, engine vibrations and so on. All of these situations can be analysed using new fatigue life estimation techniques now incorporated into the Finite Element Analysis (FEA) environment.

The theory of random vibration fatigue has seen a number of important developments over the last fifteen years. The author has been personally involved in developing new fatigue analysis theories and structural analysis techniques in the frequency domain . More recently this work has focused on the link with FEA because of the powerful design opportunities which this creates. The work has found many important practical applications. This paper presents a state of the art perspective of random vibration fatigue technology and FEA based fatigue analysis. A number of design applications are presented.

Numerical Methods

A BREAKTHROUGH IN PARALLEL SOLUTIONS OF MSC.SOFTWARE (Acrobat 260K) #2899, 12 pgs.
Louis Komzsik, Paul Vanderwalt, Petra Poschmann, and Reza Sadeghi--MSC.Software Corporation
Stefan Mayer--MSC.Software Corporation, München, Germany

ABSTRACT: More than a decade ago MSC offered the first parallel production system of MSC.NASTRAN. During this decade MSC has intensified its effort on parallel processing and is now ready to deliver MSC.NASTRAN V70.7 and MSC.MARC V9.1, both of which contain very important new parallel features.

This paper describes these exciting features and provides preliminary performance results. We believe that these systems mark the best in parallel performance in commercial finite element analysis ever and present a breakthrough in parallel computing in our market.

DISTRIBUTE MEMORY PARALLEL MSC.NASTRAN ON AN IBM WORKSTATION CLUSTER AT FORD COLOGNE (Acrobat 130K) #3099, 16 pgs.
Ulrich Viersbach, Dr. Matthias Weinert, and Christian Wilmers--Ford Werke Aktiengesellschaft, Germany
Dr. Stefan Mayer--MacNeal-Schwendler GmbH, Germany

ABSTRACT: MSC.NASTRAN is the main structural FE code and the second most used CAE code on compute servers at Ford worldwide. To reduce costs, alternative ways of computing are being investigated such as using idle cycles on the large number of available Ford workstations. While smaller analyses run efficiently on single workstations, more complex calculations require larger computer resources as potentially available with several workstations clustered together using a distributing memory parallel code.

The presented paper outlines results from evaluating and benchmarking a V70.7 development version of the distributed memory parallel MSC.NASTRAN code on an IBM RS/6000 model 590 workstation cluster at Ford Cologne. It covers linear static (solution 101), normal modes (solution 103) and direct frequency response (solution 108) analyses which were carried out for the first time ever on a workstation cluster. Cluster turnaround times are compared with those on IBM compute servers and Cray C90.

The evaluation showed that the development version has great potential for typical jobs used for the analysis of Ford body structures. Good speed-up with an increasing number of processors is achieved on the workstation cluster. The cluster with 8 workstations showed better turnaround times than the Cray C90 for SOL101 benchmark cases. When using latest technology workstations the cluster is expected to show even better turnaround times with also superior performance to the C90 for SOL103 and SOL108. The turnaround target of overnight completion could be achieved with 8 cluster workstations for all benchmark cases. The IBM SP compute server at MSC.Software's office in Los Angeles which is equipped with similar processors as the cluster workstations showed similar performance as the cluster. The IBM SP compute server at IBM's benchmark center at Poughkeepsie/USA using 8 latest technology processors and a superior I/O subsystem was performing better than the workstation cluster with 8 processors and the Cray for all benchmark cases.

As next steps Ford is planning to carry out runs with the distributed memory parallel version 70.7 on a Ford compute server once this version is officially released and consider production implementation depending on results. Ford is also planning to evaluate the code with our largest CAE models on the above workstation cluster and in a production environment. Ford will encourage MSC.Software to implement several improvements to MSC.NASTRAN such as the integration of the code with a workload management package to enhance cluster robustness.

NVH

ACOUSTIC PREDICTION MADE PRACTICAL: PROCESS TIME REDUCTION WITH PRE/SYSNOISE, A RECENT JOINT DEVELOPMENT BY MSC & LMS (Acrobat 260K), #3699, 10 pgs.
L.Cremers, O. Storrer, and P. van Vooren--LMS International NV

ABSTRACT: Finite element models for structural dynamic analysis and boundary elements models for acoustic radiation analysis have different meshing requirements. Acoustic boundary element analysis requires a mesh of the sound radiating surface with a uniform discretization of about six degrees of freedom per shortest acoustic wavelength whereby small details, relative to the acoustic wavelength, can be omitted. In most cases the acoustic analyst needs to generate the acoustic boundary element mesh from the original detailed structural finite element mesh as no geometry information is available for the model. This so-called mesh coarsening process involves in general four phases, i.e. mesh processing, subdomaining, creation of surfaces and re-meshing. Pre/SYSNOISE, a joint-development by MSC and LMS, is a powerful tool to help the acoustic analyst in this tedious task. It combines both the geometry and finite element meshing tools of v8.0 and an advanced set of automatic mesh coarsening routines. The different techniques involved in the mesh coarsening process will be explained along with a practical real-life example.

BRAKE ANALYSIS AND NVH OPTIMIZATION USING MSC.NASTRAN (Acrobat 423K) #1699, 15 pgs.
Dr. Himanshu Misra--NEC Systems, Inc.
Dr. Wayne Nack--General Motors Corporation
Dr. Tom Kowalski--MSC.Software Corporation
Dr. Louis Komzsik--MSC.Software Corporation
Dr. Erwin Johnson--MSC.Software Corporation

ABSTRACT: Brake Analysis and NVH (Noise, Vibration and Harshness) Optimization have become critically important areas of application in the Automotive Industry. Brake Noise and Vibration costs approximately $1Billion/year in warranty work in Detroit alone. NVH optimization is now increasingly being used to predict the vehicle tactile and acoustic responses in relation to the established targets for design considerations. Structural optimization coupled with frequency response analysis is instrumental in driving the design process so that the design targets are met in a timely fashion. Usual design targets include minimization of vehicle weight, the adjustment of fundamental eigenmodes and the minimization of acoustic pressure or vibration at selected vehicle locations.

Both, Brake Analysis and NVH Optimization are computationally expensive analyses involving eigenvalue calculations. From a computational sense and the viewpoint of MSC.Nastran, brake analysis exercises the CEAD (Complex Eigenvalue Analysis Dmap) module, while NVH optimization invokes the DSADJ (Design Sensitivity using ADJoint method DMAP) module. In this paper, two automotive applications are presented to demonstrate the performance improvements of the CEAD and DSADJ modules on NEC vector-parallel supercomputers. Dramatic improvements in the DSADJ module resulting in approx. 8-9 fold performance improvement as compared to MSC.Nastran V70 were observed for NVH optimization. Also, brake simulations and experiences at General Motors will be presented. This analysis method has been successfully applied to 4 different programs at GM and the simulation results were consistent with laboratory experiments on test vehicles.

FUTURE TECHNIQUES FOR HIGH FREQUENCY NVH (Acrobat 423K) #0799, 11 pgs.
Stan Posey and Cheng Liao, PhD--SGI Mtn View, CA
Christian Tanasescu, PhD--SGI Munich, GR

ABSTRACT: The use of NVH analysis provides essential benefits towards designing vehicles for ride comfort and quietness, an increasingly competitive advantage in today's global automotive market. Requirements for NVH analysis at increasingly higher excitation frequencies is driving NVH modeling promoters beyond practical limits for conventional NVH methods. This paper examines details behind conventional NVH practice, NVH modeling directions for the future, and an alternative to conventional NVH that will allow future modeling targets to be achieved.

LINEARISATION OF STIFFNESS AND DAMPING CHARACTERISTICS OF RUBBER VANISHES IN VEHICLE DYNAMICS BY USING FREQUENCY RESPONSE ANALYSIS OF MSC.NASTRAN (Acrobat 780K) #1399, 14 pgs.
Dr. Plank and Dr. Merk--AUDI AG
Dr. Stefan Dömök--Peters & Zabransky, Germany

ABSTRACT: For vehicle dynamics analysis detailed modelling of bushes is necessary. The following paper describes different possibilities to use measurement data of rubber bushes by linearisation of stiffness and damping characteristics in frequency response analysis.

A NONLINEAR SIMULATION OF CAR VIBRATION BY MSC/NASTRAN (Acrobat 943K) #2999, 12 pgs.
Sergey Sergievsky and Sergey Purgin--OJSC "GAZ"
Boris Shatrov--The MacNeal-Schwendler GmbH, Russia

ABSTRACT: Setting the task of creating a modern competitive vehicle, the designers need the more exact estimation of the degree of their design optimum at the early stages of the work. According to this, besides the traditional methods of analysis (static analysis, normal modes analysis and frequency response analysis), the transient response analysis of the car real loading becomes more interesting. This type of analysis provides the data, which are the close analogue to the test results and allows, later on, to go over to the fatigue analysis.

In this article the example of the nonlinear simulation of the car vibration in time domain by MSC/NASTRAN is considered.

SIMULATION OF VEHICLE PANELS WITH MULTILAYER DAMPING TREATMENT (NOT PRESENTED) (Acrobat 1.1MB) #3999, 17 pgs.
Shu Wang and Hinne Bloemhof--Rieter Automotive, Switzerland

ABSTRACT: By using equivalent material parameters and a special equivalent shell element, multi-layer damping treatments can be integrated into simulations of structural vibrations without significan increase of either modelling or computing efforts. The treatment representations are used to conduct classical single-layer FE calculations and determine the frequency response functions of the structure in which the individually treated panels (non-flat) are now included. The procedure presented here does not increase the number of active degrees of freedom, so that it is possible to include the effect of these treatments in large system level models. Two representative examples have been numberically investivgated and a practical aplication of the procedure to a real car floor has been conducted (comparing simulation with measurement). These examples confirm the accuracy, the efficiency and the flexibility of the procedure.