The SAP2000 analysis & design application is written by Computers & Structures, Inc. Full product details can be found on their website.
The SAP2000 analysis & design application can export and import cis/2 and ifc files, and export SDNF files.
If Tekla Structures and SAP2000 are installed on the same computer, then a direct link can be used.
It is important that you run SAP2000 for the first time as a standalone application before your load the link. Just start SAP2000 and create a new model, save it and close SAP2000. This will then update your registry which is needed by the link.
To get more information and to download, go to Tekla Warehouse.