> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/templates/steel-tub-girder-bridge-workflow/superstructures-code-check-stg/access-hole-design-stg/bottom-flange-access-hole-load-stg.md). # Bottom Flange Access Hole Load \[STG] The modeling of the bottom flange access hole for both FEM and 3D involves applying loads to the plate around the access hole to analyze the critical stress regions and their values. To achieve this, the FEComposite results for **Fx** on the related tub girder, and at the location of the access hole, must be defined in the **Bottom Flange Access Hole Load** object. {% hint style="info" %} To gather the related axial forces (specifically for the Strength Limit State), 1.Analyze the global model. 2. Then, on the FEA tab, go to **Composite Element Forces (Sectional)**. ![image-20241130-110754.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-110754.png?api=v2) 3. Navigate to the relevant stage for which you are interested in the results. The results can be viewed for the Construction Stages, ![image-20241130-110933.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-110933.png?api=v2) ...or for Combination Cases, including LL cases, Composite/Non-composite cases, or for Limit States (max/min). ![image-20241130-111112.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-111112.png?api=v2) ![image-20241130-111139.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-111139.png?api=v2) 4. After specifying the case for viewing the results, the results can be filtered to see only the bottom flange results. For further clarification, refer to the video attached below.![Results.mp4](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/Results.mp4?api=v2) 5. After specifying the case, the results at the position (station) where the access hole will be created can be obtained and applied to the access hole plate object. ![image-20241130-112208.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-112208.png?api=v2) {% endhint %} **Plate:** Specify the Bottom Flange Access Hole Model on which this load case acts. **Fx on Each Side:** Specify the Fx force applied to the plate. Refer to the info panel above for information on extracting the axial force from the global model. ## Edge Loads The plate around the access hole has four edges — **Left**, **Right**, **Top**, and **Bottom** — each taking the same six load components. Enter each component separately per edge. Forces follow the global (x, y, z) axes; moments are about the same axes. **Fx:** Axial force along x applied to the edge. **Fy:** In-plane shear along y applied to the edge. **Fz:** Out-of-plane force along z applied to the edge. **Mx:** Moment about the x axis applied to the edge. **My:** Moment about the y axis applied to the edge. **Mz:** Moment about the z axis applied to the edge. {% hint style="info" %} After defining the parameters for the Bottom Flange Access Hole Load object and analyzing the model, users can go to the FEA view. ![image-20241130-113832.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-113832.png?api=v2) Switch to **Surface Stresses**. ![image-20241130-113905.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-113905.png?api=v2) **Von Mises Stress:** ![image-20241130-113931.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-113931.png?api=v2) To obtain the desired FEM: ![image-20241130-114039.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-114039.png?api=v2) ![image-20241130-114232.png](https://openbrim.atlassian.net/wiki/download/attachments/2805596175/image-20241130-114232.png?api=v2) {% endhint %} --- # Agent Instructions This documentation is published with GitBook. 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