Diaphragms

Forms:  Define Diaphragms, Diaphragm Data

Use the Define menu > Diaphragms command to add, modify, or delete diaphragm definitions.

Note:  The Define Diaphragms form also displays when the Modify/Show Definitions button is clicked on the Joint Assignment - Diaphragms form or the Shell Assignments - Diaphragms form.  

1. Click the Define menu > Diaphragms command to access the Define Diaphragms form. The Diaphragms display list shows the names of all of the currently defined diaphragms.

2. Choose from the following buttons to add, modify or delete the diaphragm definition:

   • Add New Diaphragm button.

   • 1. Click the Add New Diaphragm button to access the Diaphragm Data form.

     2. Use the default name suggested in the Diaphragm edit box, or enter another name.

     3. Specify the rigidity of the diaphragm by choosing the Rigid or Semi Rigid option. These options affect only the analysis of the model. If the rigid option is selected, a fully rigid diaphragm is assumed. If the semi rigid option is selected, the in-plane rigidity of the diaphragm comes from the stiffness of the objects that are part of the diaphragm.

     Note: If the floor shell object is post-tensioned (i.e., contains tendons), only the Semi Rigid diaphragm option is appropriate, and this is what the program will use even if the Rigid option is specified.

     4. Click the OK button.

1. • Modify/Show Diaphragm button.

   • 1. Highlight the name of the diaphragm to be modified/shown in the Diaphragms display list.

     2. Click the Modify/Show Diaphragm button to access the Diaphragm Data form.

     3. Change the name of the diaphragm by typing a new name in the Diaphragm edit box, or change the rigidity of the diaphragm by selecting the appropriate option.

     4. Click the OK button.

1. • Delete Diaphragm button.

   • 1. Highlight the name of the diaphragm to be deleted in the Diaphragms display list.

     2. Click the Delete Diaphragm button

     3. Click the OK button.

After the diaphragm(s) has been defined, use the Assign menu > Joints > Diaphragm command or the Assign menu > Shells > Diaphragm command to assign the diaphragm to selected joint and shell objects, respectively.

See Also

Seismic Loading Form