Problem with Building Modeler to SeismoStruct conversion – local modes in first 10 modal shapes

[psemiao]

Hello,

I am having a problem with a model converted from Building Modeler to SeismoStruct.

After importing the model into SeismoStruct and running a modal analysis, the first 10 modes are showing local vibration modes instead of global structural modes. Because of this, I suspect that there may be an issue either with the converted model itself or with the conversion process.
Initially, the model also included a basement level, and I first assumed that this could be the source of the problem. However, after removing the basement and repeating the analysis, the same issue remained.
I was advised to increase the number of derived eigenvalues in the Project Settings, but this does not seem to address the core problem. Increasing the number of extracted modes may extend the modal results, but it does not change the fact that the first modes are still local rather than global, which suggests that the issue lies elsewhere.

I am attaching both the model file and the plan drawings in case someone is able to review them and help identify the source of the problem.
Any help or suggestions would be greatly appreciated.
https://drive.google.com/file/d/1Fgqbkp ... sp=sharing
https://drive.google.com/file/d/1dWmaDI ... sp=sharing

Thank you.

[seismosoft]

We checked your model, and the first modes are the global ones, not local ones. There are 2-3 modes out of the first 10 that are vertical modes, but this is probably due to excessive vertical loading, rather than the modelling of the building.
If you feel that there is a problem with the creation of the model by he Building Modeller, you can check the details of your model in SeismoStruct's main screen. However, we really doubt that there might be a problem with the modelling, since the Building Modeller has been extensively checked by thousands of users both in SeismoStruct and SeismoBuild. In any case, you need to be more specific, when reporting potential problems.
Seismosoft Support