CivilFEM Online Help

~CMBMOD

 

~CMBMOD, LabCMPX, LabCMPY, LabCMPZ, KCS, SGNFACT, CMBMTH

Do the combination of vibration modes

SEISMIC: Spectral Analysis

LabCMPX

Spectrum component that is going to be applied along X-axis of the KCS system. The valid labels for LabCMPX are:

HORIZONT	Horizontal component of the spectrum.
VERTICAL	Vertical component of the spectrum.
NONE	None. (Default value)

LabCMPY

Spectrum component that is going to be applied along Y-axis of the KCS system. The valid labels for LabCMPY are:

HORIZONT	Horizontal component of the spectrum.
VERTICAL	Vertical component of the spectrum.
NONE	None. (Default value)

LabCMPZ

Spectrum component that is going to be applied along Z-axis of the KCS system. The valid labels for LabCMPZ are:

HORIZONT	Horizontal component of the spectrum.
VERTICAL	Vertical component of the spectrum.
NONE	None. (Default value)

KCS

Coordinate system. (Default value 0)

SGNFACT

Significance factor. (Default value 10^-4).

CMBMTH

Mode combination method. The valid labels are:

SRSS	Square root of sum of squares method (Default Value)
CQC	Complete quadratic combination method
DSUM	Double sum method
GRP	Grouping method
NRLSUM	Naval Research Laboratory sum method

Notes

- To use this command the spectrum data must be previously defined (see ~DEFSPEC command) and the vibration modes to combine extracted (see ~MODLSOL command).

- The mode combination methods CQC, DSUM, GRP and NRLSUM allow the spectrum application only in one direction.

- Results corresponding to the combined modes are written in the Data Set following the natural modes of vibration in ANSYS (file.RST) and CivilFEM (file.RCV). This Data Set will therefore correspond to the Load Step following the one containing the natural modes of vibration substep 1 with TIME equals to the frequency corresponding to the last obtained mode +1.

Menu Paths

Main Menu > Seismic Design > Combine Modes

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