External Diaphragm

This section defines external diaphragms that connect adjacent tub girders.

Navigation: Superstructure > Bracing > External Diaphragm

For detailed parameter explanations, see the External Diaphragm Reference.

Steps

Step 1: Navigate to External Diaphragm

Navigate to Bracing > External Diaphragm in the tree view.

External Diaphragm navigation

External Diaphragm spreadsheet

Step 2: Select Girders

Click the three-dot icon on Girders cell and pick both tub girders (G1 & G2) between which the external diaphragm will be placed.

Step 3: Define Diaphragm Locations

Create 5 external diaphragms with appropriate station values and skew angle = 0.

Diaphragm inputs

Step 4: Set Diaphragm Types

• Assign Pier-End type for the first 4 rows (at support locations)
• Assign Intermediate type for the last row (mid-span location)

Diaphragm types

Step 5: Configure Pier/End References

Click the three-dot icon on Select Pier/End cell and pick the appropriate support locations. Enter station = 260 for the intermediate diaphragm.

Pier/End selection

Step 6: Set Offset Values

Enter Offset from Pier/End values as required.

Offset values

Step 7: Assign Material

Click the three-dot icon on Material cell and assign A709_50W to all external diaphragms.

Step 8: Optional Settings

Modify Section Details and Stiffener tabs if desired.

Section details

Stiffener

Verification

The completed external diaphragms are shown below.

Completed external diaphragm plan

Completed external diaphragm 3D

Completed external diaphragm detail