Show Response Spectrum Curves

Form:  Response Spectrum Generation, Response Spectrum Curves, Response Spectrum Named Sets, Select Resp Spec Named Set

Note:  A Time History function and a Time History load case must be defined for the model and an analysis must be run for this command to be available.  

1. Click the Home > Display > More > Show Response Spectrum Curves command or the Advanced > Define > Named Sets > Joint TH Response Spectrum command to display the Response Spectrum Generation form. The form has six tabs: Define, Axes, Direction, Options, Frequency and Damping. Clicking on any tab selects it. Click the appropriate tab and use the various options to set up display of the response spectrum curve.

Define Tab

1. 1. Use the Time History Case drop-down list to select the Time History Case for which the Response Spectrum Curve is to be generated.

   2. Specify the joint for the response spectrum curve. If joints are listed in the Choose a Joint list, select a joint by clicking on it. If no joints are listed, use the following buttons to add, modify, or delete joints in the list.

      • Add Joint button. Type a joint label in the Choose a Joint edit box and click the Add Joint button to add a joint to the list. If a joint label is entered in the edit box, but that joint is not included in the model, CSiBridge will display an error message.

      • Modify Joint button. Highlight a joint in the Choose a Joint list, type the change in the edit box, and click the Modify Joint button to make the change.

      • Delete Joint button.  Highlight a joint in the Choose a Joint list and click the Delete Joint button to delete the joint from the list. Deleting the joint from the list does not remove the joint from the model.

   3. Use the other tabs on the form to complete the set up for generating the response spectrum curve.

Axes Tab

1. • Select the Abscissa to be displayed as Frequency or Period.

   • Select the Ordinate to be SD (Spectral Displacement), SV (Spectral Velocity), PSV (Pseudo Spectral Velocity), SA (Spectral Acceleration) or PSA (Pseudo Spectral Acceleration).

Direction Tab   

• Select the Coordinate System for the selected joint from the drop-down list.

• Select the direction X, Y or Z  to define the direction for which the spectrum is to be generated. By default the X (global X-direction) is checked.

Options Tab

1. • Set the Abscissa scale to Arithmetic or Log. By default Log is selected.

   • Changing the percentage of Spectrum Widening will change the peaks of the response spectra curves. The default is set to zero.

   • Set the Ordinate scale to Arithmetic or Log. By default Arithmetic is selected.

   • Changing the ordinate Scale Factor will scale the spectral values. The default is 1.0.

   • Unchecking the Grid Overlay check box will turn off the generation of a grid through the major divisions of the axes.

Frequency/Period Tab

Either a Frequency or Period tab will be available depending on the Abscissa selection made on the Axes tab.

• • Unchecking the Default check box will exclude the built-in set of frequencies/periods in the generation of response spectrum.

  • Unchecking the Structural check box will disable merging of the structural frequencies/periods into the set of frequencies used in the generation of response spectrum.

  • Check the User check box and define frequencies/periods as follows:

  • 1. Enter the value in the User Frequencies/Periods edit box.

    2. Click the Add Value button.

    3. Repeat to include all frequencies/periods.

To change a user-defined frequency/period, highlight a previously defined user frequency/period, type a new value in the User Frequencies/Periods edit box and click the Change Value button. To delete a user-defined frequency/period, highlight a previously defined user frequency/period and click the Delete Value button.

Damping Tab

Use this tab to add a new damping value or edit the default damping values.

Add Value button. Use the Add Value button to add a new damping value.

1. Type a new value in the edit box.

2. Click the Add Value button.

Change Value button. Use the Change Value button to change one of the default damping values.

1. • 1. Click on the damping value to be changed in the Damping Values list box.

     2. Change the value in the edit box.

     3. Click the Change Value button.

Delete Value button. Use the Delete Value button to remove one of the values from the set.

1. • 1. In the Damping Values list box, click on the damping value to be deleted.

     2. Click the Delete Value button

2. Click the Display button to open a floating Response Spectrum Curves form in which the response spectra are graphically displayed. (Note that when this form is accessed using the Advanced > Define > Named Sets > Joint TH Response Spectrum command, this button is inactive.) A small Legend window displays the joint number direction, scale factor, widening percentage and damping ratios color coded to correspond to the spectra curves. Another small window just below it displays the coordinates of the pointer.

Note:  With the floating Response Spectrum Curves form displayed on screen, use the mouse to window over an area of the plot to enlarge the area enclosed within the window. Click the right mouse button to restore the original display.

2. • File menu > Print Setup for Graphics command. Click the File menu > Print Setup for Graphics command at the top of the Response Spectrum Curves form to select and set up the printer to be used for printing the on-screen display.

   • File menu > Print Graphics command. To print the currently displayed response spectrum curve, click the File menu > Print Graphics command at the top of the Response Spectrum Curves form.

   • File menu > Print Tables command. To print output tables for the currently displayed response spectrum curve, click the File menu > Print Tables command at the top of the Response Spectrum Curves form.

   • File menu > Print Tables to File command. Use the File menu > Print Tables to File command to send the output tables for the currently displayed response spectrum curve to file. CSiBridge will prompt you for a file name and storage location for the file.

   • File menu > Capture Picture command. The subcommands for this command can be used to capture a picture of the Entire Form, the Form w/o (without) Title Bar, and the Plot Only. SCi Bridge will prompt you for a file name and storage location of the picture file, which will be saved in .jpg format.

OK button. Click the OK button to close the Response Spectrum Curves form.

Save Named Set button. After all of the setting have been specified on all of the tabs, click the Save Named Set button to access the Response Spectrum Named Sets form.

1. • Type a name in the Resp Spec Set edit box to name the set of values specified before the Save Named Set button was clicked. Click the Save New RS Set button.

   • If the name of a previously Named Set needs to be modified, select the Named Set in the Resp Spec Set display area; type a new named in the Resp Spec Set edit box and click the Change RS Set Name button.  

   • If a previously Named Set needs to be deleted, select the Named Set in the Resp Spec Set display area and click the Delete RS Set button.

Show Named Set button. The Show Named Set button will only be available if a Named Set has been saved. Click the Show Named Set button to access the Select Resp Spec Named Set form. Highlight the Named Set to be displayed. Click the OK button. The value settings stored in the Named Set will be applied to the Response Spectrum Generation form. Select a joint and click the Display button to display the response spectrum curve based on the Saved Named Set.

3. Click the Done button to exit the Response Spectrum Generation form.