Plate Girder [SIG]
Girder Parameters
Girder Layout: The girder layout is utilized to determine the position of the girder in both the longitudinal and transverse directions.The user is not required to input the vertical elevation of the plate girders. The vertical positions of the plate girders will be generated automatically based on the alignment, deck thickness, and haunch thickness.
If the top flange width, bottom flange width, top flange thickness, and bottom flange thickness are changing at the same stations, the user can select all columns and view all parameters in one spreadsheet by clicking "Edit (Spreadsheet)”.
Top Flange Width: The width of the top flange can be specified by defining this parameter.
Top Flange Thickness: The thickness of the top flange can be specified by defining this parameter.
Web Depth: The depth of the web (vertical portion of the I-girder) can be specified using this parameter.
Web Thickness: The thickness of the web can be specified by defining this parameter.
Bottom Flange Width: The width of the bottom flange can be specified using this parameter.
Bottom Flange Thickness: The thickness of the bottom flange can be specified by defining this parameter.
Users have the option to specify changes in the plate girder section dimensions either along the PGL or along the length of the girder. To access the editor, click on the three dots and choose "Edit (Spreadsheet)". If the user enters the length along the girder, the end station will be calculated automatically. Conversely, if the user enters the end station, the length data will be calculated automatically.
Girder webs can have nonprismatic variations, which are supported. To access the variation features, the user can click on the three dots and select "Variation" to open the pop-up window. From there, the user can define variations using linear, parabolic, circular, polynomial, or custom functions. The finite element mesh takes into account the locations of section changes and various other mesh quality parameters such as aspect ratio, mesh element size, orthogonality, and skewness.
Haunch Thickness: The haunch thickness is defined as the measurement between the bottom of the deck and the bottom of the top flange. Like plate girder dimensions, nonprismatic variations and various haunch values can be added by selecting "Edit (Spreadsheet)" from the three dots menu. Additionally, nonprismatic variations can be entered using the "Variation" pop-up window.
Additional Haunch Width: The additional haunch width is measured from both the right and left extensions of the top flange. During deck construction, the automatic haunch load computation is impacted by both the haunch thickness and additional haunch width.
Hybrid girders are supported, allowing the assignment of different materials to the top flange, bottom flange, and web. Furthermore, it is possible to use varying steel materials between different stations through station-dependent material definitions.
Top Flange Material: The material definition for the top flange can be made using this parameter. Materials can either be imported or assigned from previously defined ones.
Web Material: The material definition for the web can be made using this parameter. Materials can either be imported or assigned from previously defined ones.
Bottom Flange Material: The material definition for the bottom flange can be made using this parameter. Materials can either be imported or assigned from previously defined ones.
Plate Girder / Rolled Section: This parameter defines whether the girder is modeled as a built-up plate girder or a standard rolled section. If “Plate Girder” is selected, flange and web dimensions are manually defined. If “Rolled Section” is selected, the section can be directly chosen from the AISC database. Custom sections should not be used, as AISC profiles already include the required parameters—such as flange thickness, web depth, and other geometric properties—needed for design calculations. The steel I-girder code checks rely on these predefined parameters
Transfer Girder: This parameter specifies whether the selected girder functions as a transfer girder. If set to “YES,” it indicates that a kicker girder connects to the main girder rather than being supported directly between abutments or piers. This setting influences the FEA meshing behavior of the deck–girder system. When enabled, the mesh configuration under the deck object must also be updated, as the default GridMesh algorithm may not perform well for complex geometries. In such cases, using the Frontal-Delaunay for Quads meshing algorithm is recommended, as shown in the example below.
Connecting Girder: This parameter indicates whether the selected girder is connected to another girder for meshing purposes. It helps adjust the mesh generation along the deck where girders intersect or share connectivity. This parameter does not affect load transfer or continuity behavior.
FEA Settings
Mesh Size (Longitudinal): 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.
# of Result Extraction St.: The result extraction segment 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.
Additional Result Extraction Station: The results of FEComposite elements are generated for stations by default. If additional results are needed at a specific station, this parameter can be used. The FEA will not be affected; only the “Composite Element Forces” and “Composite Element Stresses” are calculated based on the “Additional Result Extraction Station” inputs.
Girder End Holes
Hole Count: The number of girder holes may be defined using this parameter.
Hole Radius: The radius of girder holes may be defined using this parameter.
Vert. Dist. Hole Outer Edge to Web Edge: This parameter may be used to set the distance between the outer edge of the plate and the edge of the web in the vertical direction.
Long. Dist. Hole Outer Edge to Web Edge: This parameter may be used to set the distance between the outer edge of the plate and the edge of the web in the longitudinal direction.
Quantities
The quantities obtained from parameter definitions are presented to the user as read-only values under this tab.
Min Section Area: For varying sections in the row defined, the minimum cross-section area will be displayed under this column.
Max Section Area: For varying sections in the row defined, the maximum cross-section area will be displayed under this column.
Total Surface Area: The combined surface area of all elements is summed up and presented under this column. Each side of the element’s surfaces is accounted for in the calculations.
Min Cross-Section Perimeter: For varying cross-sections, the minimum perimeter obtained from the smallest cross-section is presented under this column.
Max Cross-Section Perimeter: For varying cross-sections, the maximum perimeter obtained from the largest cross-section is presented under this column.
Volume: The total volume of the entire girder is presented under this column.
Min Length Path: The shortest vertical length of the girder is presented under this column.
Length @ COG Path: The length of the girder along its center of gravity (COG) axis is presented under this column.
Max Length Path: The longest vertical length of the girder is presented under this column.
Weight: The weight of the girder is calculated based on its properties and assigned materials.
Length/Top Width: A table showing the top flange width at various lengths along the girder.
Length/Top Thickness: A table showing the top flange thickness at various lengths along the girder.
Length/Web Depth: A table showing the web depth at various lengths along the girder.
Length/Web Thickness: A table showing the web thickness at various lengths along the girder.
Length/Bottom Width: A table showing the bottom flange width at various lengths along the girder.
Length/Bottom Thickness: A table showing the bottom flange thickness at various lengths along the girder.
IFC
Predefined Type: The IFC Predefined Type is specified using this parameter. Available options include:
BEAM
CORNICE
DIAPHRAGM
EDGEBEAM
GIRDER_SEGMENT
HATSTONE
HOLLOWCORE
JOIST
LINTEL
PIERCAP
SPANDREL
T_BEAM
USERDEFINED
NOTDEFINED
Parent [Bridge/Superstructure/Deck/Substructure/Foundation/Approach_Structure/Retaining_Structure]: The IFC Parent is specified using this parameter to define the hierarchy relationship in the IFC model.
Last updated