ansys.mapdl.core.Mapdl.sed

Mapdl.sed(sedx='', sedy='', sedz='', cname='', **kwargs)

Defines the excitation direction for response spectrum and PSD analyses.

Mechanical APDL Command: SED

Parameters:

sedxstr

Global Cartesian coordinates of a point that defines a line (through the origin) corresponding to the excitation direction. For example: 0.0, 1.0, 0.0 defines global Y as the spectrum direction.

sedystr

Global Cartesian coordinates of a point that defines a line (through the origin) corresponding to the excitation direction. For example: 0.0, 1.0, 0.0 defines global Y as the spectrum direction.

sedzstr

Global Cartesian coordinates of a point that defines a line (through the origin) corresponding to the excitation direction. For example: 0.0, 1.0, 0.0 defines global Y as the spectrum direction.

cnamestr

The component name corresponding to the group of excited nodes. Only applies to base excitation multi-point response spectrum analysis ( spopt, MPRS) and power spectral density analysis ( spopt, PSD). Defaults to no component.

Notes

In single-point response spectrum analysis ( spopt,SPRS), the excitation direction without rocking ( rock ) is normalized to one so that the SEDX, SEDY, and SEDZ values do not scale the spectrum. The excitation direction with rocking is not normalized. The SEDX, SEDY, and SEDZ values must be consistent with the linear components of OMX, OMY, and OMZ values on the rock command. The calculated direction then scales the spectrum. For more information, see Participation Factors and Mode Coefficients.

In multi-point response spectrum analysis ( spopt,MPRS) and power spectral density analysis ( spopt,PSD), the excitation direction is normalized to one so that the SEDX, SEDY, and SEDZ values do not scale the spectrum. The component name ( Cname ) is required. The constraints corresponding to the excitation direction are applied to the component nodes.

This command is also valid in PREP7.