RSTMAC

RSTMAC

RSTMAC, File1, Lstep1, Sbstep1, File2, Lstep2, Sbstep2, TolerN, MacLim, Cname, KeyPrint, UNVscale, KeyMass, TolerR
Calculates modal assurance criterion (MAC) and matches nodal solutions from two results files or from one results file and one universal format file.

POST1: Special Purpose

File1

File name (248 characters maximum) corresponding to the first results file (.rst or .rstp file). If the file name does not contain the extension, it defaults to .rst.

Lstep1

Load step number of the results to be read in File1.

N

—

Reads load step N. Defaults to 1.

Sbstep1

Substep number of the results to be read in File1.

*`N`*	—	Reads substep `N`.
All	—	Reads all substeps. This value is the default.

File2

File name (248 characters maximum) corresponding to the second file (.rst, .rstp, or .unv file). If the file name does not contain the extension, it defaults to .rst.

Lstep2

Load step number of the results to be read in File2.

N

—

Reads load step N. Defaults to 1.

Sbstep2

Substep number of the results to be read in File2.

*`N`*	—	Reads substep `N`.
All	—	Reads all substeps. This value is the default.

TolerN

Tolerance for nodes matching.

If TolerN = -1, the nodes on File2 are mapped into the selected elements of File1.

If TolerN is positive, it is taken as an absolute tolerance and the selected nodes of File1 are matched to the nodes of File2. The default value is 0.01.

If TolerN = -2, the selected nodes of File1 are matched to the nodes of File2 with the relative tolerance TolerR.

MacLim

Smallest acceptable MAC value. Must be 0 and 1. The default value is 0.90.

Cname

Name of the component from the first file (File1). The component must be based on nodes. If unspecified, all nodes are matched and used for MAC calculations. If a component name is specified, only nodes included in the specified component are used. Not applicable to node mapping (TolerN=-1).

KeyPrint

Printout options:

0	—	Printout matched solutions table. This value is the default.
1	—	Printout matched solutions table and full MAC table.
2	—	Printout matched solutions table, full MAC table and matched nodes table.

UNVscale

Scaling of the nodal coordinates when File2 is a universal format file (.unv).

Blank or 0	—	No scaling (default).
Non-zero value	—	Scaling factor applied to the nodal coordinates.

KeyMass

Key to include the mass matrix diagonal in the calculations.

ON	—	Include the mass matrix diagonal. This is the default.
OFF	—	Do not include the mass matrix diagonal.

TolerR

Relative tolerance for nodes matching (TolerN = -2). It is a fraction of the minimum element dimension. The selected nodes of File1 are matched to the nodes of File2. Defaults to 0.5 (50%).

Notes

The RSTMAC command allows the comparison of the solutions from either:

Two different results files
One result file and one universal format file

The modal assurance criterion (MAC) is used.

The meshes read on File1 and File2 may be different. If TolerN > 0, the nodes are matched. This is the default. If TolerN = -1, the nodes are mapped and the solutions are interpolated from File1. If TolerN = -2 and TolerR > 0, the nodes are matched using a relative tolerance (TolerR).

Units and coordinate systems must be the same for both models. When a universal format file is used, the nodal coordinates can be scaled using UNVscale.

The corresponding database file (.db) for File1 must be resumed before running the command in the following cases:

A component (Cname) is used.
The nodes are mapped (TolerN = -1).
The nodes are matched using a relative tolerance TolerR (TolerN = -2).

Results may be real or complex; however, if results from File1 have a different type from results in File2, only the real parts of the solutions are taken into account in MAC calculations. The analysis type can be arbitrary.

Only structural degrees of freedom are considered. Degrees of freedom can vary between File1 and File2, but at least one common degree of freedom must exist.

When node mapping and solution interpolation is performed (TolerN=-1), File1 must correspond to a model meshed in solid and/or shell elements. Other types of elements can be present but the node mapping is not performed for those elements. Interpolation is performed on UX, UY, and UZ degrees of freedom.

The solutions read on the results files are not all written to the database, therefore, subsequent plotting or printing of solutions is not possible. A SET command must be issued after the RSTMAC command to post-process each solution.

RSTMAC comparison on cyclic symmetry analysis works only if the number of sectors on File1 and File2 are the same. Also comparison cannot be made between cyclic symmetry results and full 360 degree model results (File1 – cyclic solution, File2 – full 360 degree model solution). Comparing cyclic symmetry solutions written on selected set of node (OUTRES) is not supported.

The modal assurance criterion values can be retrieved as parameters using the *GET command (Entity = RSTMAC).

For more information and an example, see Comparing Nodal Solutions From Two Models (RSTMAC) in the Basic Analysis Guide.

Menu Paths

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