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Optimize-mesh

The OPTIMIZE-MESH module allows compaction, compression, equivalencing, and resequencing of the finite element mesh. Different criteria and methods may be used to achieve the best mesh order for a particular problem.

This documentation is taken directly from the Moviestar help files and included here in a hyper-text format for your convenience.

More information available:

• Compact
• Compress
• Equivalence
• Resequence

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Compact

The COMPACT command renumbers the nodes and elements of the model to eliminate gaps in the numbering sequence. For example, if the node numbers range from 1 to 5 and from 11 to 15, the COMPACT command would renumber the node array such that the node numbers would be now numbered from 1 to 10.

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Compress

The COMPRESS command deletes node which are not referenced by the element connectivity. When this command is executed, the unreferenced nodes are deleted from the data base.

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Equivalence

The EQUIVALENCE command compares either the entire geometry or selected topological features for duplicate nodes.

Geometry

Search the geometry for duplicate nodes, delete all but one and replace references in the element connectivity to them with the remaining node number.

Tolerance

Set the tolerance for the EQUIVALENCE command. Nodes that are closer together than the tolerance are considered to be the same node.

Topology

Search the selected topology (i.e. line, surface, or solid) for duplicate nodes, delete all but one and replace references in the element connectivity to them with the remaining node number.

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Resequence

The RESEQUENCE command allows the user to optimize the element stiffness matrix using different criteria and methods.

Criteria

The CRITERIA command specifies which method should be used in reducing the element stiffness matrix.

Bandwidth

Select the bandwidth as the criteria. The stiffness matrix is resequenced to have the minimum bandwidth.

Profile

Select the profile as the criteria. The stiffness matrix is resequenced to have the minimum profile.

Rms_bandwidth

Select the root mean squared bandwidth as the criteria. The stiffness matrix is resequenced to have the minimum root mean squared bandwidth.

Wavefront

Select the wavefront as the criteria. The stiffness matrix is resequenced to have the minimum wavefront.

Ignore

The IGNORE command identifies grid points that are to be ignored by the resequencing algorithms. Grid points ignored are eliminated from the connection table and are sequenced last.

Method

The METHOD command selects the method used by the resequencing algorithm.

Both

Select both the Cuthill-McKee and Gibbs-Poole-Stockmeyer methods for resequencing the nodes.

Cuthill-mckee

Select the Cuthill-McKee method for resequencing the nodes.

Gibbs-poole-stockmeyer

Select the Gibbs-Poole-Stockmeyer method for resequencing the nodes.

Process

The PROCESS command begins the execution of the resequencing algorithm.

Save

The SAVE command is used to save the optimized finite element mesh to the data base. The optimized mesh is not written to the data base until this SAVE command is issued. This allows the user to examine his optimized mesh to verify that it is truly a better mesh than his original mesh before saving it in the data base.

Start

The START command allows the user to supply the Cuthill- McKee algorithm with specific starting nodes. Starting nodes are the first nodes in the resequencing process and are labeled node number 1 in the optimized mesh. If the user specifies more than one starting node, the algorithm returns only the best sequence.

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On-line documentation

Jason K. ________________________________________________________________________________ Note: This documentation is being developed currently. Information is subject to change and is on a use at your own risk basis.

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