This article explains how to send a Tekla Structures model to ETABS, using BIM Expert.
1. Preparation in Tekla Structures
The transfer is based on the analytical model. So in Tekla Structures you need to create an analytical model first. The quality and coherence (connection between elements) of the analytical model will determine the quality of the structural calculations. It is therefore essential to build a good analysis model in Tekla Structures.
Learn here how to make a good analysis model in Tekla Stuctures.
2. Send model from Tekla Structures to ETABS
2.1 From Tekla Structures to BIM Expert
In the BIM Expert menu ‘File > Settings > Tekla Structures’, opt for ‘Apply default actions in conversion’s dialogs’.
This option will reduce the number of conversion dialogs whenever possible. You only be prompted with dialogs when user input is required.
There is more than 1 way to send models from Tekla Structures to BIM Expert. You can either start from
Click the BIM Expert icon to launch the transfer. Next you need to select what items to include, in addition to the Analysis model:
- Additional data: data that came from a previous transfer, but is not supported by Tekla Structures. This information is kept and can now be taken along in the current transfer (e.g. seismic information, soil layers, …)
- Rigid links
- Connection: full or only haunches
- Internal forces from ‘End Conditions’. The End Conditions tab can be found in the element’s UDA (User Defined Attributes):
Alternatively, you can start in BIM Expert: click ‘Model > Import’ and select the Tekla Structures plugin. Choose the Tekla Structures version and what elements to import (see above).
No matter the way you have chosen, BIM Expert will now take over.
2.1.1 Settings
If you have more than one analytical model in Tekla Structures, you need to select the analysis model that you want to transfer
Next, the Tekla Structures sections and materials must be mapped with BIM Expert’s section and material database. BIM Expert will try to find as many automatic mapping matches as possible. In case all sections and materials find a match, you will not see any dialogs for mapping.
2.1.2 Material mapping
In case you have turned off the option to reduce dialog windows, you might see a material mapping dialog for mapping unknown materials. In the ‘reduce dialog window’ case, unknown materials will be added as new.
Database materials such as steel (e.g. S235, ASTM-Grades), concrete (e.g. C25/30, M50) and timber (e.g. C24, D50, GL28c) are mapped automatically. In some cases, the match is not automatically found, because the name differs (Concrete grade C25 instead of Concrete grade C25/30). In that case, you can select the correct material from the database.
Tip: When searching an item in the database, type the first letters of the name to find it more quickly.
If you cannot find a suited counterpart in the BIM Expert database, the material can be added as new.
2.1.3 Section mapping
In case you have turned off the option to reduce dialog windows, you might see a section mapping dialog for mapping unknown sections. In the ‘reduce dialog window’ case, unknown sections will be added as new.
Database sections (such as I, H, UB, UC, W, C, U, O, ☐ and L sections) are mapped automatically. In some cases, the match is not automatically found, because the name differs (e.g. name is HEB300 – S235 instead of HEB300). In that case, you can select the correct cross-section from the database.
Tip: When searching an item in the database, type the first letters of the name to find it more quickly.
Parametric sections (e.g. rectangles, circle, trapezium, …) and user defined sections are not in the database. They should always be added as new.
2.1.4 Connections and component bundles
In case you have chosen to export connections and there are connections in the model, BIM Expert will now start the connection conversion.
If you have turned off the option to reduce the dialog windows, you will get an overview of all connections components in the model and the possibility to bundle components.
In this window you can do 2 things:
- Select the connections to be included in transfer, via the checkbox in the ‘Accept’ column
- Bundle connection components into larger complex connection groups:
- Position this window in a corner of your screen, because once you start adding groups, the window position is locked.
- Click ‘Add group’ to select the components.
- Select the components by clicking the component arrow. All components should logically be around a single node of course.
- Confirm the selection with the middle mouse button.
- The group is now listed with the reference ids of the individual components.
If there are materials of bolt elements to be mapped, they will appear in the next pop-up window.
The model is now in BIM Expert.
2.2 From BIM Expert to ETABS
In the Model tab, select ‘Export’. Next, choose the destination software manufacturer, namely ‘Computer and Structures, Inc’ (CSI). Click 
to continue.
Choose ‘ETABS’
2.2.1 Settings
Select your ETABS version, the destination and analysis model. The destination can be either:
- To a new empty model in a new instance
- To current instance and new empty model
ETABS will launch automatically in case of ‘new instance’ choice.
Next, the BIM Expert sections and materials must be mapped with ETABS’ section and materials. BIM Expert will try to find as many automatic mapping matches as possible. In case all sections and materials find a match, you will not see any dialogs for mapping.
2.2.2 Material mapping
In a new file, ETABS only has 2 materials present: Steel S355 and Concrete 30/37. Chances are real that you see the material mapping dialog. If you cannot find a suited counterpart in the ETABS model, the material can be added as new.
2.1.3 Section mapping
A new ETABS model has no cross-sections. So all will be added as new.
3. Final steps in ETABS
Depending on the chosen destination: launch ETABS and open the file. Or continue working in the open version of ETABS.
