Seismic

Definition of earthquake events as numbered objects with related basic parameters, or modification of these parameters and definition of the parameters describing the earthquake event (direction and intensity of the excitation (base movement), relevant response spectra).

Setting	Description
Number	Number of the considered earthquake event.
Modal-File	Name of the file containing the results of the calculation of Eigen frequencies and Eigen forms (natural modes) (extension .mod). Selection from the pull-down menu is possible, when the Eigen frequency calculation has been previously performed.
Rule	Selection of the combination rule used for combining the contributions of the individual natural modes. One of the available combination rules can be selected. Available rules: ABS, SRSS, DSC, CQC, CQCX.
Type of response spectrum graph	Displacement: The excitation and the response spectrum are defined in terms of displacements. Velocity: The excitation and the response spectrum are defined in terms of ground velocities Acceleration: The excitation and the response spectrum are defined in terms of ground accelerations.
Vec-Vx, Vec-Vy, Vec-Vz	The components defining the design value (peak value) of the amplitude of the ground displacement, ground velocity or ground acceleration respectively.
Damp-Fact	Damping factor - ratio between actual and critical damping. The value specified in this menu is used for calculating the correlation factors for the combination rules DSC, CQC and CQCX, and specifies, for which damping ratio the specified spectrum is valid.
Response Spectra	User can select predefined response spectra for different codes from drop down menu. If user selects one of the predefined response spectra, Var-Name in the next row will be filled automatically.
Var-Name	Name of the table characterizing the respective response spectrum.
Duration	Duration of principal part of the seismic event (Seconds). Only used for calculating the correlation factors for the rules DSC and CQC. Must be higher than 5 times the period of the lowest natural mode.
Description	Descriptive text for the earthquake event.