OBM: Varying the Girder

OpenBridge Modeler CONNECT Edition offers options for varying the bridge girder elements heights or cross-sections.

If you are not initially creating the new girder from the action Place Beam from the Superstructure Ribbon Group you can still modify your first version of the girders: In the Main menu, using the Element Selection from the Ribbon Group Selection, scroll over the elements and click to select the Girders. Then, to have access to the Girder Properties, either right-click or stand still with the mouse over an area of the girders with no lines, to wait until Properties is shown and click at it, as shown in the screenshots below. Then, click at the ... (three points) button to SELECT to Edit at Beam Definition and access the Beam Definitions window.

ElProp   BeamDef

At the Beam Definitions window note that, initially, the bottom options show as Drawing Disabled and Apply to All Beams as not selected, as shown below. Modify both options to get all beams changed in once and to visualize the graphical displays as shown below. At the top change the selection for Beam Type from the default to Custom, then you can use all the library you had loaded or created. 

  beamGirderDef      ChangeDefault

Note that these sections should be modified and saved as accordingly at the Beams template Manage beams in the Utilities main menu at the Ribbon Group Libraries. Standard Sections could be used for the base to be then Copy, Rename, and Modify their basic properties before being used as references.

beamUtil    ChangeDef

The Point Details should be used to create Variables at Edit Details, as shown below. Key Point shows the main points, the extreme points, where the variables are usually needed as references to become parametric.

  KeyPoints  CSVar

In this example, to make the girder wider at the bearings and to wider the flange all internal points are also selected in the Mode Horizontal and the button Save is hit to move to the next definition. Create also the Variables names and apply them to the necessary boundary conditions, as shown below.


At OBM the Custom girder initially uses a Location Type SupportLine and this can be modified to Head, Tail, Ratio By Span, or Ratio By Beam, as shown below. 

Loctype  Templ  

Moreover, the Start Template and End Template should be changed. If needed the option Different End Template should be selected to create an incremental or linear variation between the references. If this is not selected the cross-section will just immediately change from one template to another. Use the InsertAfter (+) button to add definition lines and modify them accordingly.

InsA  VarG

Rolling the bottom cursor will show the Cross-section drawing changes, as in the screenshot above; and the end result should be solid elements Girders as shown n the screenshot below.


The Cross-sections modifications can also be done at the design software (LBC, LBS, RM Bridge) and later loaded into the modeling by updating the model data.

More details about the Beam Definition and the activation of the Different End Template can be found at the link below: