vddam

SpectrumOptions.vddam(vf='', va='', vb='', vc='', **kwargs)

Specifies the velocity spectrum computation constants for the analysis of shock resistance of shipboard structures.

Mechanical APDL Command: VDDAM

Parameters:

vfstr

Direction-dependent velocity coefficient for elastic or elastic-plastic analysis option (Default = 0).

vastr

Coefficients for the DDAM velocity spectrum equations. See Dynamic Design Analysis Method

vbstr

Coefficients for the DDAM velocity spectrum equations. See Dynamic Design Analysis Method

vcstr

Coefficients for the DDAM velocity spectrum equations. See Dynamic Design Analysis Method

Notes

This command specifies velocity coefficients to analyze shock resistance of shipboard equipment. These coefficients are used to compute mode coefficients according to the equations given in Dynamic Design Analysis Method addam and sed commands, is used with the spectrum ( antype,SPECTR) analysis as a special purpose alternative to the sv, freq, and svtyp commands.

In order to perform a DDAM spectrum analysis using a units system other than BIN (default), you must specify the units system complying with the mass and length units of the model using the units command. Issue the units command before defining the shock spectrum computation constants ( vddam ). The vddam command is not supported with the user-defined units system ( Label = USER on the units command).

ddaspec may alternatively be used to calculate spectrum coefficients.

This command is also valid in PREP7.