Modeling and Analysis of Access
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Holes in Tub Girders
Access holes may be required based depending on specific project requirements. These features introduce significant stress concentrations in the localized areas, necessitating a more refined analysis approach. Here's how such situations needs. When incorporating access holes into the design and analysis of tub girders, the following considerations should be addressed:
Workflow for Modeling and Analyzing Access Holes
Separate Workflow for Access Holes:
Since access holes require detailed analysis, users must model this object in a separate Tub Girder Workflow. This separation ensures that the global model's simplicity is maintained while allowing for focused analysis on the refined mesh needed for the access hole region.Refined Mesh Requirements:
A refined finite element mesh is critical to accurately capture the stress concentrations around the edges of the access holes.
Use smaller elements around the hole and transitions to a coarser mesh away from the critical region to balance accuracy and computational efficiency.
Load Application via Access Hole Load Object:
To account for the stresses caused by axial loads in the vicinity of the access hole, users should use an Access Hole Load Object.
This object allows for precise application of forces that simulate the stress concentrations expected on the hole edges.
Validation of Results:
Carefully review stress distribution to ensure the model accurately reflects the behavior near the access hole.
Verify compliance with relevant design codes or project-specific criteria for allowable stress levels.
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Localized Stress Concentrations
Access holes introduce significant stress concentrations in localized areas. To accurately capture these effects, generate Finite Element Models (FEM) with a more refined mesh for the specific access hole regions.Simplified Global Models
To maintain the simplicity and efficiency of the global model, create a separate model tailored specifically for the access hole using the Steel Tub Girder Workflow. This workflow accommodates the unique characteristics of access holes, allowing the refined analysis to focus on localized regions without complicating the overall global model.
This two-model approach ensures the global model remains efficient while the detailed model addresses the critical stress concentrations caused by access holes effectively.
For comprehensive instructions on using Access Hole objects, refer to the relevant section in the documentation.
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