**MXPAND**, * NMODE*,

`FREQB`

`FREQE`

`Elcalc`

`SIGNIF`

`MSUPkey`

`ModeSelMethod`

Compatible Products: DesSpc | Pro | Premium | Enterprise | Ent PP | Ent Solver | –

`NMODE`

Number of modes or array name (enclosed in percent signs) to expand and write. If blank or ALL, expand and write all modes within the frequency range specified. If -1, do not expand and do not write modes to the results file during the analysis. If an array name is input, the array must contain 1 for the expanded modes and zero otherwise, where the array index corresponds to the mode number. To specify an array containing the individual modes to expand, enclose the array name in percent (%) signs (for example,

**MXPAND**,%arrname%). Use the***DIM**command to define the array.`FREQB`

Beginning, or lower end, of frequency range of interest. If

and`FREQB`

are both blank, expand and write the number of modes specified without regard to the frequency range. Defaults to the entire range.`FREQE`

`FREQE`

Ending, or upper end, of frequency range of interest.

`Elcalc`

Element calculation key:

**NO**—

Do not calculate element results, reaction forces, and energies (default).

**YES**—

Calculate element results, reaction forces, energies, and the nodal degree of freedom solution.

`SIGNIF`

Expand only those modes whose significance level exceeds the

threshold (only applicable when`SIGNIF`

is defined).`ModeSelMethod`

If

= MODC, the significance level of a mode is defined as the mode coefficient of the mode, divided by the maximum mode coefficient of all modes.`ModeSelMethod`

If

= MODM, the significance level of a mode is defined as the modal effective mass, divided by the total mass.`ModeSelMethod`

If

= DDAM, the significance level of a mode is defined as the modal effective weight, divided by the total weight.`ModeSelMethod`

Any mode whose significance level is less than

is considered insignificant and is not expanded. The higher the`SIGNIF`

threshold, the fewer the number of modes expanded.`SIGNIF`

defaults to 0.001, except for the case of DDAM mode selection method where it defaults to 0.01. If`SIGNIF`

is specified as 0.0, it is taken as 0.0.`SIGNIF`

`MSUPkey`

Element result superposition key:

**NO**—

Do not write element results to the mode file

**Jobname.MODE**.**YES**—

Write element result to the mode file for use in the expansion pass of a subsequent mode-superposition PSD, transient, or harmonic analysis (default if

= YES and the mode shapes are normalized to the mass matrix).`Elcalc`

`ModeSelMethod`

Methods for mode selection (not supported for complex eigensolvers):

**blank**—

No mode selection is performed (default).

**MODM**—

The mode selection is based on the modal effective masses.

**MODC**—

The mode selection is based on the mode coefficients.

**DDAM**—

The mode selection is based on DDAM procedure (see Mode Selection Based on the DDAM Procedure in the Mechanical APDL Structural Analysis Guide for more information).

Mode shapes (displacements) are expanded and output to the results file (so that if you need to inspect the mode shapes, it is not necessary to run the analysis again). Element stresses are not expanded.

Specifies the number of modes to expand and write over a frequency
range for a modal (**ANTYPE**,MODAL) or buckling (**ANTYPE**,BUCKLE) analysis. If used in SOLUTION, this command
is valid only within the first load step.

There is no limit on the number of expanded modes (* NMODE*). However, there

With * MSUPkey* = YES, the computed
element results (

`Elcalc`

If a mode selection method (* ModeSelMethod*) is defined, only the selected modes will be expanded. See Using Mode Selection in the Mechanical APDL Structural Analysis Guide for more details about the procedure.

For array input (* NMODE*), the array
must be dimensioned to be the size of the number of modes extracted
(

`NMODE`

For linear
perturbation modal analyses, you must set both * Elcalc* and

`MSUPkey`

In a Distributed ANSYS analysis, you must issue **MXPAND** to specify the number of modes to expand when computing the modes
and mode shapes. In a Distributed ANSYS run, **MXPAND** cannot be issued in an expansion pass (**EXPASS**).

This command is also valid in PREP7.