*SELECT EIGENMODES
18.7 *SELECT EIGENMODES: Select the modes to be used in a modal dynamic analysis.
This option selects the modes to be used in a dynamic analysis basedon m odesor in a complex eigenvalue
extraction analysis. Only one option per step can be used. If this option is not used, all modes extracted in
the prior *FREQUENCY step will be used, including residual modes if theyw ereactivated.
Product: ABAQUS/Standard
Type: History data
Level: Step
References:
•“Implicit dynamic analysis using direct integration,” Section 6.3.2 of the ABAQUS Analysis User’s
Manual
•“Complex eigenvalue extraction,” Section6.3.6 of the ABAQUS Analysis User’s Manual
•“Transientm odal dynamic analysis,” Section6.3.7 of the ABAQUS Analysis User ’sManual
•“Mode-based steady-state dynamic analysis,” Section6.3.8 of the ABAQUS Analysis User’s Manual
•“Subspace-basedsteady-state dynamic analysis,” Section 6.3.9 of the ABAQUS Analysis User’s Manual
•“Response spectrum analysis,” Section 6.3.10of the ABAQUS Analysis User ’sManual
•“Random response analysis,” Section 6.3.11of the ABAQUS Analysis User’s Manual
•*MODAL DAMPING
Optional parameters:
GENERATE
If this parameter is included, each data line should give a first mode, ; a last m ode, ;andthe
increment in mode numbers between these modes, i. Then all modes going fr om to in steps
of iwill be added to the set. imust be an integer such that is a whole number (not a
fraction).
This parameter can be used only with DEFINITION=MODE NUMBERS.
DEFINITION
Set DEFINITION=MODE NUMBERS (default) to indicate that the selected modes are given as a
collection of mode numbers.
Set DEFINITION= FREQUENCY RANGE to indicate that the modes are selected from the
specified frequency ranges including frequency boundaries. Frequencyranges can be discontinuous.
Ifbo th the *MODALDAMPING and *SELECT EIGENMODES options are used in the same
step, the DEFINITION parameter must be set equal to the same va lue in both options.
18.7–1
ABAQUS Version 6.1 Module: ID:
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