buildingSMART Forums

Rigid link representation in structural analysis model


Hi All,

I’m writing an export of a structural analysis model to IFC. I map connection nodes on IfcStructuralPointConnection and analysis axes on IfcStructuralCurveMember, but I’m unsure about rigid links (i.e. short infinitely stiff connection bars). Is there a dedicated ifc object for this or some guidelines on how to map rigid links? My current implementation maps them on IfcStructuralCurveMember with a dedicated rigid link material attached.


Jürgen De Zaeytijd


Please send example of how you are writing export for reference.


I seem not to be allowed to upload files. I get a message “Sorry, new users can not upload attachments”. Any ideas on how to fix this?


Hi Tandeep,

Attached is an export of the following simple situation: two columns connected by two beams. The lower beam is attached to the side of the columns and since, for this export, we want all axes centered on the physical elements, two rigid links (purple) are inserted to connect the lower beam to the columns. Point connections are indicated by the red discs and curve members by the red lines.
The export contains both physical elements and analysis elements, but at this moment lacks profile and material information linked directly to the analysis elements.

ExampleExportRigidLink.ifc (65.0 KB)


You can use this IfcStructuralCurveMember,
But if you use IfcStructuralCurveMemberVarying (subtype) of above you can easily differentiate them in IFC and help in future extraction or use.
I think it will work same in both Case.
and Good this is you had exported analysis data in good way as it is also viewed in many viewers.
I am also working on structure analysis view of concrete members, but after exporting it is not opened in another software . only import/export in itself.


Thanks for the inspection and the suggestion! Talking about viewers, do you happen to know any free viewers that are capable of showing the analysis model? The ones I know only seem to display the physical elements.


No viewers is showing analysis model and data as per my research.
i am using approx 8 to 10 viewers but they only show physical model.
I had used softwares like ETBS, AxisVM, sofistik, RFEM etc for concrete analysis and many more. These transfer analysis data to IFC , but that file is not opened in any viewers or any other software .
I had point out this issue many times at their forums but no solutions till now.


try the FZK Viewer from Karlsruhe - it shows (at least to some degree) the analytical model. It shows for sure the model in the test file.




Super! Thanks.


Good two see in viewer, Thanks.


Have you tried Constructivity?


Have you tried Constructivity?

Dont know what’s this , please provide us some information about it or website of it.
Thank you