Girder [CSB]

To model custom girders, the parameters below can be defined.

Girder Parameters

Girder Layout: This parameter can be used to specify the girder layout for the girder to be modeled.

Girder Start-End Section:

• Reference Support Line: A minimum of two rows of definitions must be made for a girder to be generated correctly. Support lines, one being the start and one being the end station, for a section must be defined.

• Longitudinal Distance Along Girder Line Layout: For varying girder sections, if a section is needed until a certain station and then a variation (for instance, a linear variation) is needed after a certain point, this parameter can be used to define the constant section length along the girder layout.

• Section: This parameter can be used to assign the section to the girder at the specific station. A section can be imported or assigned from the previously defined ones under Properties > Sections.

• Variation (from previous point) [None/Linear/Parabola/Circular]: The variation must be defined for varying sections. If this parameter is set to "None," the girder will be generated as a constant section girder.

• Radius (for Circular Variation): For variations defined with the "Circular" option, the radius can be specified by this parameter. Otherwise, this parameter will be N/A.

FEA

Supports: In OpenBrIM, all bearings are generated at the center of the bottom of a custom girder. This applies when there is one bearing per girder at a specific station. To change the location or assign additional bearings, this parameter can be used.

Longitudinal Mesh Size: The maximum distance between nodes in the longitudinal direction is specified using the longitudinal mesh size. In most cases, a smaller mesh size can be generated based on the bracing locations, deck pouring or deconstruction definitions, or section change locations.

Expansion Joint End Releases:

Rigid Section: This parameter’s definition is used only when there are two or more bearings at the same station. Rigid beams are employed to link the bottom nodes of girders with bearing locations/supports.

Mesh at Section Edges:

Number of Result Extraction Stations: The result extraction station settings are solely for viewing FEA composite results in either the spreadsheet or FEA view, and do not impact standard finite element analysis results like member end forces, node displacement, and node reactions. For girder code checks, exact code check stations will be utilized for FEA composite results.