Bridge Diaphragm Property Form

Use the Bridge Diaphragm Property form to specify the type and parameters for a bridge diaphragm.

Select Diaphragm Type to be used for this definition:

Solid option. A solid diaphragm type applies to a concrete bridge only.
- Diaphragm Thickness edit box. Specify the diaphragm thickness in the current length units.
- Diaphragm Depth edit box. Specify the diaphragm depth in the current length units. This is for the concrete solid girder bridge section only.
Chord and Brace option. The chord and brace diaphragm applies to steel bridges only.
- Include Top Chord check box and drop-down list. When this check box is checked, the top chord will be included in the diaphragm. Use the drop-down list to select a frame section property for the chord. Alternatively, click the + (plus symbol) preceding the drop-down list to access the Frame Properties form and define a new frame property or review/modify an existing frame section.
- Include Brace check box and display area. When this check box is checked, specify the type of brace: V Brace, Inverted V Brace, or X Brace. The selected option will appear in the display area on the right side of the form.
- Include Bottom Chord check box and drop-down list. When this check box is checked, the bottom chord will be included in the diaphragm. Use the drop-down list to select a frame section property for the chord. Alternatively, click the + (plus symbol) preceding the drop-down list to access the Frame Properties form and define a new frame property or review/modify an existing frame section.
- Include Connection Plates check box. When this check box is checked, the Connection Plate Parameters are enabled for editing.
- Brace Work Point Location. Use the options in this area to specify the location of the brace work point.
- - Elevation Change From Top Work Point to Top of Adjacent Girder edit box. Enter a value in the current units for the change in elevation of the top work point of the chord and brace and the elevation of the top of the adjacent girder.
  - Elevation Change From Bottom Work Point to Bottom of Adjacent Girder edit box. Enter a value in the current units for the change in elevation of the bottom work point of the chord and brace and the elevation of the bottom of the adjacent girder.
Single Beam option. The single beam diaphragm applies to steel bridges only.
- Beam Section Property drop-down list. Use the drop-down list to select a frame section property for the chord. Alternatively, click the + (plus symbol) preceding the drop-down list to access the Frame Properties form and define a new frame property or review/modify an existing frame section.
- Include Connection Plate check box. See Chord and Brace option.
  
  As the name suggests, use the Elevation Change From Top of Beam to Top of Highest Adjacent Girder edit box to specify in the current length units the distance from the top of the beam section to the top of the highest adjacent girder.

Steel Plate option. The steel plate diaphragm applies to steel U girder bridges internal diaphragm only.
- Material drop-down list. Use the drop-down list to select a material property for the chord. Alternatively, click the + (plus symbol) preceding the drop-down list to access the Material Properties form and define a new material property or review/ modify an existing material property.
- Web Thickness edit box. Specify the plate web thickness in the current length units.
- Top Flange Width edit box Specify the plate top flange width in the current length units.
- Top Flange Thickness edit box. Specify the top flange thickness in the current length units.

After defining a diaphragm, assign it to a bridge span as part of the bridge object definition.

Access the Bridge Diaphragm Property form as follows:

Click the Components > Superstructure Item > Diaphragms command, or on the Bridge Wizard highlight the Diaphragms item in the Deck Component Properties area and then click the Define/Show Diaphragm button, to display the Define Bridge Diaphragm Properties form.
Click the Add New Diaphragm button or highlight a previously defined definition and click the Add Copy of Diaphragm or Modify/Show Diaphragm button to display the Bridge Diaphragm Property form.

Alternatively, click the Components > Superstructure Item > Diaphragms > New command to display the Bridge Diaphragm Property form identified in the preceding item.

After the diaphragm has been defined, assign it to the bridge model using Bridge Objects.