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MSC.Nastran 2001

The world standard in finite element analysis solutions

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MSC.Nastran 2001 Update Information

v The goal of this release of MSC.Nastran is to increase customer satisfaction through the provision of the many enhancements that improve the customer design and analysis process, and which continue to lend tremendous value to our customers’ products and processes.

v All of the new features and enhancements that appear in the release of MSC.Nastran 2001 are customer driven, aiming specifically to increase the value of this product by improving the benefits to MSC.Software customers.

Courtesy of AUDI AG

Courtesy of VW

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NEW CAPABILITIES: Spot Weld Element A new spot weld element has been added to accurately model structural connections and fasteners. Modeling of fasteners up to now has been difficult and error prone with the conventional modeling tools available. However, the new spot weld element overcomes these modeling difficulties by automatically handling singularities, rigid body invariance, and differing mesh densities, while ensuring accurate results. The new CWELD element, and corresponding PWELD property entries can easily establish connections between points, elements, patches, or any of these combinations. Spot Weld Element Modeling with BMW MSC.Software completed the delivery of an assembly and spot welding tool with an adaptable architecture incorporating all connection types, and allowing the integration of the complete process with the flexibility for fast adaptation for process changes. Use of this tool at BMW significantly reduced assembly-modeling time, allowing complete BIW assembly within one day.

Node to Node: for nearly congruent meshes

Element to Element: for non-congruent meshes

Node to Element: for non-congruent meshes

BIW modeling reduced by a factor of 5 to 7 at BMW

Courtesy of BMW

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VW Example Using the Spot Weld Element Body in white model 3,712 CWELD elements 3,562 connecting two parts 105 connecting three parts

Spot Weld Modeling with MSC.AMS FVA MSC.AMS FVA is a spot welding tool that provides a Full Vehicle Assembly environment for integrating PDM, CAD, and connection data like spot welds. MSC.AMS FVA has a flexible architecture that accommodates the customer’s process, product structure and process changes.

NEW CAPABILITIES: Parallel Processing There are two new methods available to partition the model (geometric domain decomposition) prior to parallel modal

analysis: (1) based on the number of processors available, and (2) based on the model topology and size.

Faster time to market!

Courtesy of VW

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GDMODES Geometric Domain Parallel Lanczos Automatic partitioning is based on topology, with one partition per processor. The analysis of the domain interior is performed simultaneously for all domains. Application of this technique reduces memory and disk resource, I/O overhead, and analysis times. This approach is more advantageous for larger problem sizes, and enables the execution of large NVH jobs within the typical 90-minute design cycle time frame. Advantage can also be taken of cost-effective workstation cluster machine configurations.

PACMS Parallel Automated Component Modes Synthesis Partitioning is automatic (user specifies the number of partitions), and based on model size and geometry. Using this technique, large models can easily be subdivided into hundreds of sub-models (automatically using the superelement method), then analyzed in parallel. The use of these powerful tools within MSC.Nastran greatly reduces time and cost for NVH analysis.

Automotive Model 232,649 nodes 232, 404 elements 1,377,677 degrees of freedom

Courtesy of the Ford Motor Company

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Automotive Test Example 12,735 elements 70,860 degrees of freedom

Test example courtesy of AUDI AG

NEW CAPABILITIES: Design Optimization Discrete Variable Optimization Mathematical Programming has long been used in the field of optimization to yield continuous design variables. The design variables generated by the optimizer may not be practical from the manufacturing standpoint (it would be difficult to manufacture a plate of thickness 0.37582 in, for example). With discrete variable optimization, however, the user can now

specify design variables, e.g. 032 and 0.40 gauges that are practical to manufacture. There are two approaches possible: Conservative Discrete Design (CDD), and Design of Experiments (DOE). These methods are implemented as a postprocessing step to a continuous solution. In addition, continuous and discrete variables can be mixed.

Result # FE Runs 1: Continuous Optimization Infeasible 9 2: Continuous rounding up Feasible 9+1 3: Continuous rounding to nearest Infeasible 9+1 4: Discrete DOE Feasible 9+1 5: Discrete CDD Feasible 9+1

Fully Stressed Design The fully stressed design (FSD) optimization method can produce a quick-look design at a fraction of the computational costs required for the more conventional mathematical programming optimization methods. This efficiency allows for a great

number of design variables to be considered. The FSD method is particularly useful in the design of aerospace structures where the overriding requirement is that the structural weight be minimized.

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ENHANCEMENTS Dynamics Enforced motion (displacements, velocities, or accelerations) can be applied directly using equations of motion, and without Lagrange Multipliers or large masses. Modal effective masses are now computed without the need for a DMAP alter. Static and dynamic load data input entries have been much simplified. P-elements are now supported in dynamic solution sequences. Nonlinear TET10 – quadratic tetrahedron – element now has material and geometric nonlinear capability. Grid point forces, element strain energies are now supported in all nonlinear solutions. Convergence tolerances have been revised to improve run times. Buckling analysis can now be performed in a single run. Optimization Complex eigenvalue sensitivities are now available to automate stability analysis. Dynamic response now has additional equation types available, with easier data input. Also, frequency definition input has been modified to allow updated frequencies at each design cycle. Random response is now supported such that RMS quantities can be used with design sensitivity and optimization. Power spectral density sensitivities are now supported.

Element Technologies Element summary output request added to generate model information output. Element geometry checking can be generated with a new output request. Shell normals are now generated automatically. Material coordinate system (user defined) can be used to present shell element output. Composite material definition improved with two new options. Closed hat section has been added to the beam libraries. Checkout and Evaluation Tools Weight check information can now be obtained. Grounding checks have been added to identify unintentional constraints and matrix ill conditioning. Grid point kinetic energy can now be output for normal modes analysis. Element strain energies can now be obtained for a frequency response analysis. Element kinetic energy, and element energy loss (element damping energy) can now be output for various dynamics solutions. In addition to the above, there are many more Aerodynamic analysis enhancements, and other miscellaneous enhancements. Full details can be found in the MSC.Nastran 2001 Release Guide, available on-line at:

www.mscnastran.com

MSC.Software provides the industry’s most comprehensive support system with over 50 offices worldwide to provide local and centralized support. Investing in MSC.Software gives you access to extensive client support through comprehensive documentation, direct technical expertise, and customized training classes.

To find your local MSC.Software office or to learn more about our company and our products, please contact:

Corporate: MSC.Software Corporation 2 MacArthur Place Santa Ana, California 92707 USA 1 714 5 40.8900 Fax: 1 714 784.4056 Information Center: 1 800 642.7437 ext. 2500 (U.S. only) 1 978 453.5310 ext. 2500 (International)

Worldwide Web - www.mscsoftware.com On - l ine Purchases - www.engineer ing-e.com On - l ine Simulat ion -www.simulationcenter.com Europe: MSC.Software GmbH Am Moosfeld 13 81829 Munich, Germany 49 89 43 19 87 0 Fax: 49 89 43 61 71 6 Asia-Pacific: MSC Japan Ltd. Entsuji-Gadel ius Bldg. 2-39,Akasaka 5 -chome Minato -ku, Tokyo 107-0052 Japan 81 3 3505 0266 Fax: 81 3 3505 0914

MSC is a registered trademark of MSC.Software Corporation. Nastran is a registered trademark of NASA. MSC.visualNastran is a trademark of MSC.Software Corporation. All other trademarks are the property of their registered owners. All specifications are subject to change without notice. ©2001 MSC.So f twa r e Co r p o r a t i o n

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