Action > Excit

Executes the modal analysis for forces given in an excitation spectrum.

Setting	Description
Action	Code of the selected Action. It is possible to switch to defining an other action without leaving and re-entering the input function.
Action will be skipped (Option)	The action will be skipped in the calculation process if the option is selected.
Input-1 > Load case name	Name of the load case, containing the (normalized) load vector. In the solution process all loads will be multiplied by the frequency dependent spectral value as defined in the excitation spectrum.
Input-2 > Spectrum	Name of a user defined variable, which defines the excitation spectrum. Abscissa values are interpreted as given in Hz (rotations per second). Ordinate values are dimensionless factors of the given (normalized) loading. Note: The spectrum must be given as table (formula not allowed), as the frequency in terms of Hz is not available as internal variable.
Input-2 > D-constant	Damping factor, logarithmic decrement! (absolute value, not in percent). Note: Input of 0.01 means 1% decrease of the amplitude per cycle. Note that most design codes do not specify the decrement (Delta) but the damping ratio to critical (Zeta = Delta/(2*pi)). The recommended values of the design codes are varying to a very great extent.
Input-3 > Modal file	Name of the file (*.mod) containing the natural modes to be considered
Input-3 > ALL or ACTIVE	The calculation can be done for all or only for active elements.
Output-1 > Superposition file name (*.sup)	Name of the envelope (superposition file), where the min/max. results will be stored
Output-2 > List File	Name of list file, where the results will be stored. Default: excit.lst
Delta-T	Duration of the Action (not applicable for this action)
Description	Descriptive text for the selected Action (max. 80 characters)