SDOF with Spring

[Jamildouier]

Dear STKO Team,
I am currently trying to model a SDOF system. I have already set up the model, but something seems to be wrong with the analysis. There is an issue I don't fully understand and have not been able to resolve.
It appears to be related to the modeling of the spring – specifically the combination of Uniaxial Material and ZeroLength Element.
Would you mind taking a quick look?
Thank you very much in advance for your support.

Best regards,

[STKO Team]

There are some conceptual mistakes in your model (therefore I suggest you watch the introductory webinars about STKO):

• Your model does not need all those floating vertices and lines, just 3 nodes. Bottom one will be fixed. Bottom and Mid ones will be connected with an interactions (spring with 3 DOFs as per your sketch). Mid and Top one will be connected either with a spring with horizontal stiffness = k, or with a beam element if you want transversal-rotational coupling.
• You cannot assign a unixial material directly to a zero length. You have to define a physical_property->special_purpose->zeroLenfthMaterial and put there all the uniaxial material you want for the available DOFs

[Jamildouier]

thank you very much

[STKO Team]

You're welcome