Base

In the Basic tab, you can assign the analysis types and define additional parameters. To do this, select the load case on the left in the ' list '.

01 Defining Analysis Type "Response Spectrum Analysis" for Load Case

Analysis

In this section, the basic settings for the spectral analysis of the load case are to be made.

Analysis Type

If the add-on 'response spectrum method' is activated in the model basic data, the response spectrum method is available for selection in the list. Assign this analysis type to each load case for which an earthquake analysis is to be performed.

Spectral Analysis Settings

In the list of 'Spectral Analysis Settings' ( SPS ), select the specifications according to which the load case is to be examined. These are, for example, the combination rule or damping. These parameters are described in chapter Spectral Analysis Settings .

Use the button to add new spectral analysis settings, and the button to edit the selected setting.

Import modal analysis from load case

In the list of defined modal analysis load cases , specify which eigenvalue analysis should form the basis of the seismic investigation. In the register Choice of Shapes you can then select the relevant mode shapes for the calculation.

Options

The check box 'Consider random torsion' offers the possibility to record the random torsional action of the masses according to EN 1998-1 Refer [1 ] Sections 4.3.2 and 4.3.3.3. This takes into account uncertainties in the arrangement of the masses. The eccentricities e_X and e_Y describe the shifts of the center of mass from its planned position. With the button you can switch between the relative and absolute input of the values.

The 'building length' is determined automatically from the geometry of the model. If you want to change the dimensions, check the 'Custom Building Lengths' check box and then enter the values Δ_X and Δ_Y. With the button you can determine the lengths graphically by selecting two nodes of the model. The button restores the original building lengths.