SDNF

Overview

Steel Detailing Neutral File (SDNF) was originally defined by Intergraph®, for electronic data exchange between structural engineer's analysis and design systems to steelwork modelling systems. Version 3.0 is the latest format supported by the software industry and this format has been used for many years for transferring even complex plant structures between system like Tekla Structures and plant design systems such as Intergraph’s PDS or Aveva’s PDMS applications.

SDNF format

As a quick overview the SDNF files are split into packets and records. The main packets are defined as follows:

Packet 00 - Title packet
Packet 10 - Linear members
Packet 20 - Plate elements
Packet 22 - Hole elements
Packet 30 - Member loads (not supported by Tekla Structures)
Packet 40 - Connection details (not supported by Tekla Structures)
Packet 50 - Grids (not supported by Tekla Structures)
Packet 60 - Curved members

If we look at a SDNF file and just concentrate on Packet 10 (linear member) items, you can see that there are ten lines of records. After the Packet 10 line, units and number of elements, a quick overview of the records would be:

Record 1 - Member ID; Cardinal Point; Status; Class; Type; Mark and Revision
Record 2 – Size; Grade; Rotation etc
Record 3 – Orientation vectors
Record 4 – Offsets information
Record 5 – Offsets information
Record 6 – Release information
Record 7 – Fabrication information
Record 8 – Connection information
Record 9 – Finishes information
Record 10 – Attributes information
 

How to import SDNF file into Tekla Structures

1. In the Advanced options dialog box, go to the Export category and set XS_SDNF_CONVERT_PL_PROFILE_TO_PLATE to FALSE.
This does not convert plate profiles to contour plates, but handles the profiles as beams in the import.
2. Select File > Import > CAD.
3. Select Import model and click the Properties button.

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4. For the SDNF import, only the Conversion, Parameters, SDNF, and Report tabs need to be completed. If required, the Conversion tab can be completed. For more information, see Conversion files.

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5. Select the required SDNF file and ensure Type is set to SDNF.

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6. On the SDNF tab, select the SDNF version number (2.0 or 3.0). See Industry files for more information on identifying various industry files.
NOTE: In most cases, it is important to set Consider offsets to Yes and Position number type to Universal ID.

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7. An import report file can be requested if required.

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8. Define any advanced settings on the Advanced tab. Usually, there is no need to change the default settings.

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9. Click Apply and OK and then click the Import button in the Import Models dialog box.

10.The Import model info dialog box is displayed. Select Accept all.

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11. Confirm that you want to save the imported model for subsequent imports.

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12. After importing a model, we recommended that you right-click the model view and select the Fit work area to entire model option to ensure that the imported model is completely visible. Also, if parts are missing, then the View depth Up and View depth Down values will need to be increased.

Exporting an SDNF file for PDMS

1. We recommend that you set XS_SDNF_CONVERT_PL_PROFILE_TO_PLATE to FALSE in the Export category of the Advanced options dialog box. This does not convert plate profiles to contour plates, but handles the profiles as beams in the export.
2. For the SDNF file creation, only the Conversion, Parameter and SDNF tabs need to be completed.
3. The output file name needs to be modified. For example, you can use extensions .dat or .sdnf for SDNF files, but any extension can be used.
4. In most cases, it is important to set Consider offsets to Yes and Position number type to Universal ID.
5. Click Apply and Create.
6. The file will be created in the current working folder.

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Modeling notes

• For openings to be transferred, the cuts must be created with the Polygon cut command. When you use this command, all the opening will be transferred as Packet 22 (opening) items, and all other cuts will be ignored.
• Curved beams must be created with the Curved beam command as the curvature for curved members created as polybeams will be ignored.
• Note that polybeams are unique to Tekla Structures and are generally not transferred. For example, if a polybeam is created with a change of direction, when the SDNF file is created, only the original straight length will be included in the file and the other elements will be ignored.
• In some cases, the fittings and connections are not included in the SDNF files. In this case, the connections need to be exploded to include the connection parts in the export file.

See also

XS_SDNF_CONVERT_PL_PROFILE_TO_PLATE