Location
Girders: Choose the two girders that are connected by the cross frame.
Skew Angle: A positive skew value rotates the cross frame in a clockwise direction, while a negative skew value rotates it in a counterclockwise direction. It is important to remember that the cross frames are positioned at the specified station along a line perpendicular to the PGL, which is then rotated according to the entered skew value.
Station [Start/End]: Enter the station along the PGL. When dealing with curved girder bridges, collecting distance along the girder length can lead to different inputs for the right and left girder that are connected by cross frames, causing ambiguity. Therefore, collecting the station along the PGL is a more reliable solution to avoid such issues. Furthermore, since cross frames are typically continuous in the transverse direction, entering the same station for all cross frames ensures that their locations are consistent between each girder.
The same principle can be applied for skewed cross frames. If the user enters the same station and skew values for the cross frames between Girder 1-2, Girder 2-3, and Girder 3-4, it ensures continuity between the cross frames. It should also be noted that the cross frames are positioned along a line perpendicular to the PGL, which is rotated according to the entered skew value.
Inaccurate finite element models and disconnected nodes/elements in the cross frame can occur if the entered station values are not >= the girder start station or <= the girder end station. This can cause stability issues in the finite element model. To ensure correct station input, users should select the start/end options from the station input. This approach is especially recommended for cross frames located at the beginning or end of girders.
Sections
Assign a section for the top, bottom, or diagonal chord, which can be imported from the AISC database by users. The section data will be utilized for the 3D model of the object and will directly influence the Finite Element Analysis (FEA) and Finite Element Model (FEM).
Top Chord Section:
Bottom Chord Section:
Diagonal Chord Section:
Gusset Plate
The parameters listed below are used for 3D representation. While gusset plates do not have finite element model (FEM) and do not provide additional stiffness to the elements, they can still be applied as weight loads and used for code checks, depending on user-defined settings and specifications.
Top Gusset Plate: Gusset plates that exist under Superstructure > Connections can be assigned to the related column.
Bottom Gusset Plate: Gusset plates that exist under Superstructure > Connections can be assigned to the related column.
Center Gusset Plate: Gusset plates that exist under Superstructure > Connections can be assigned to the related column.
Offset From Top of Web (Top Plate):
Offset From Bot. of Web (Bot. Plate):
Offset From Bot. of Web (Center Plate):
Horizontal Dist. btw Web Centerline and Plate Edge:
Stiffener
The parameters listed below are used for 3D representation. While cross-frame stiffeners do not have finite element models (FEM) and do not provide additional stiffness to the elements, they can still be applied as weight loads, depending on user-defined settings and specifications.
Stiffener Used [YES/NO]:
Vertical Stiffener Thickness:
Vertical Stiffener Width:
Material:
Geometry
These parameters are used for both computing the member end offset of cross frame truss elements in finite element analysis and 3D representation.
Top Chord - Vertical Distance of WP from Top of Web:
Top Chord - Horizontal Distance of WP Center of Web:
Top Chord - Inner Offset from WP:
Diagonal Chord - Vertical Offset from WP of Top Chord:
Diagonal Chord - Horizontal Offset from WP of Top Chord:
Diagonal Chord - Vertical Offset from WP of Bottom Chord:
Diagonal Chord - TopSide Inner Offset from WP:
Diagonal Chord - BottomSide Inner Offset from WP:
Bottom Chord - Vertical Distance of WP from Bottom of Web:
Bottom Chord - Horizontal Distance of WP from Center of Web:
Bottom Chord - Inner Offset from WP:
FEA
Top Chord Axial Rigidity Coefficient:
Bottom Chord Axial Rigidity Coefficient:
Diagonal Chord Axial Rigidity Coefficient:
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