The first step in performing Access Hole-related checks is to define and generate the access hole within a separate Steel Tub Girder project. As outlined in the Access Hole Design (STG), the analysis of access holes requires a refined mesh to ensure the Finite Element Analysis (FEA) is as accurate as possible.
To maintain the simplicity and efficiency of the global bridge model, this separate project approach is the recommended method for modeling access holes.
| Info |
|---|
Applying Loads and Analyzing Access Holes in Steel Tub GirdersFollowing the modeling step, the next phase involves applying the relevant loads, such as axial loads, to the access hole. This is done using the Bottom Flange Access Hole Load object. For detailed instructions on applying these loads, refer to the Bottom Flange Access Hole Load section in the documentation. This process ensures loads are applied accurately and consistently within the refined model. After performing the analysis, the stress concentrations and corresponding values can be displayed, providing a clear understanding of the localized effects caused by the access hole. |
General
The geometric properties of the access hole model for both 3D and FEM can be defined using the parameters on the General Tab.
Plate Length: The plate length (in the X-axis direction on the global coordinate system) can be defined using this parameter.
Plate Width: The plate width (in the Y-axis direction on the global coordinate system) can be defined using this parameter.
Plate Thickness: The thickness of the plate (in the Z-axis direction on the global coordinate system) can be defined using this parameter.
Hole Diameter: The diameter of the hole can be defined using this parameter.
Plate Material: A material must be assigned to the access hole plate. Materials can either be imported or assigned from previously defined ones under Properties > Materials. The material properties will be directly used for FEA (Finite Element Analysis).
Mesh Size: The mesh size definition is the maximum distance between two adjacent nodes. A larger mesh size results in a less refined FEM model.
Circle Segment: This parameter specifies the number of segments used to generate circle of the access hole. A larger number for the circular segment would generate a smoother circle.
Mesh Option:
Left Edge Boundary Conditions
Tx:
Ty:
Tz:
Rx:
Ry:
Rz:
Right Edge Boundary Conditions
Tx:
Ty:
Tz:
Rx:
Ry:
Rz:
Top Edge Boundary Conditions
Tx:
Ty:
Tz:
Rx:
Ry:
Rz:
Bottom Edge Boundary Conditions
Tx:
Ty:
Tz:
Rx:
Ry:
Rz: