OpenBridge Modeler

To add a variable constraint

To define the variation in a template value along the length of the bridge, use the following procedure.

Variable constraints are added and defined in the Solid Constraints Definition dialog.

Variable constraints are defined in a table, where each row represents a segment of the bridge. You define the starting point of a segment and the segment ends at the following segment's start point. You then define the start and end values for the variable over that segment length and how it varies between the points.

  1. Select one of the variable types from the Variables drop-down list and click Add. A new tab for this variable type is added.
  2. Click the Add Row tool (). A table row is added with some of the basic parameters populated.
  3. Select the Location Type and then type the distance from this type in the Relative Location cell.
    Location Type Description
    Station Type a station value in the Relative Location cell. The From cell is inactive for this option.
    From SupportLine Type a distance from the supportline in the Relative Location cell and then select the supportline name in the From cell drop-down list.
    Ratio Type a ratio value in the Relative Location cell and then select the corresponding segment in the in the From cell drop-down list. Note that this can be the entire bridge or one span of the bridge.
    Tip: To use a supportline or start of a span, select either the From SupportLine or Ratio options and simply use a Relative Location value of 0.000.
  4. Type the Start Value and End Value to use for the variable and the start and end of the segment, respectively.
  5. Select the Transition type from the drop-down list.
  6. (Optional) Repeat steps 2 through 5 to add more rows to define additional segments.
    Tip: Set the Automatically Sort Rows option so they rows will appear in order from the start to the end of the bridge.
  7. Click Apply.
The Solid Constraints Definition dialog closes and the bridge is redrawn with the variable constraints added.