FE meshed slabs

At the levels where two-way spanning¹ slabs exist, Tekla Structural Designer applies FE meshing as follows:

Two-way spanning slabs are always meshed in the FE chasedown analysis that occurs as part of the static design process.
Two-way slabs are by default not meshed for 3D building analysis or grillage chasedown analysis. This ensures the quickest solution time. A 3D pre-analysis process (in which the slabs are meshed) is used to decompose loads from the slabs on to supporting members.
Alternatively, you can choose to mesh two-way slabs for 3D building analysis and grillage chasedown analysis, either at all, or selected construction levels. In this case Tekla Structural Designer does not perform the load decomposition during 3D pre-analysis for the two-way slabs at those levels.

In all of the above mentioned situations, the slab mesh density is set globally, but can be overridden at individual levels if required.

By default two-way slabs are created with isotropic analysis properties; orthotropic properties can be specified if required. This could be particularly useful when designing: precast slab units, profiled steel decking, timber decks on floor joists, and cross-laminated timber (CLT) elements.

Adjust global slab mesh properties

Initially, the same mesh properties are applied globally to all meshed slabs. In order to adjust the global slab mesh properties, see the following instructions.

Go to the Project Workspace.
In the Structure tree, click Structure.
Go to the Properties window.
Accept or adjust the Slab Mesh Size.
Accept or adjust the Slab Uniformity Factor.
At 100% uniformity all slabs in the mesh will be of approximately equal area.
Tip: To optimize solution time, you can use a coarser mesh during design development. Later, at the final design stage, you can switch to a more refined mesh.
Accept or adjust the Slab Mesh Type:
- QuadDominant: mainly consists of quadrilateral 2D elements, but may use occasional triangular elements to create a better mesh.
- QuadOnly: only consists of quadrilateral 2D elements.
- Triangular: only consists of triangular 2D elements.

Apply different mesh properties at different levels

If you need to apply different mesh parameters at a specific level, you can do so by creating sub models. For more information, see the following instructions.

First you will need to create a sub model.
Then, in the Structure tree, expand the Sub Models branch.
Select the sub model that you created.
In the Properties window, select the Override model's option.
Adjust the mesh size and uniformity factor according to your needs.

Review the slab mesh before the analysis

In order to review the existing slab mesh in your model before running a particular analysis, see the following instructions.

In the Status bar at the bottom of the window, click Solver View.

The solver view opens.
Right-click anywhere in the solver view.
In the context menu, go to Solver models.
In the list, select the solver model appropriate to the analysis that you want to run.

If the slab mesh is applicable to the selected solver model, it is displayed.

Note: The slab mesh is not displayed in the working solver model. This is because the working solver model displays the model in its form before any analysis, and 2D elements are only formed during the analysis.

Footnotes

¹ One-way spanning slabs are also treated as two-way spanning if Analyze slab is selected in slab item properties