Seismosoft | Earthquake Engineering Solutions

Hello!

I modelled a structure defining the element types according to formulation infrmFBPH. I included infills but I'm having some difficulties understanding the best way to perform local verifications on the structure, regarding shear mechanisms, since I don't know how (or where) to extract the real forces/moments on the elements. Since one infill model has 4 different nodes on a specific column, the forces which are readable on the post-processor don't seem to be accurate to be used as the maximum in presence of panels. Any suggestion to overcome it?

Best regards!

Hi,

We are not sure we understood your query fully, but, have you tried creating a simple model consisting of two columns and an infill panel only, and use that as a starting point to understand the amount of shear being carried out by the panel?

Alternatively, you may perhaps also "play" with the panel shear strength, to appreciate the amount of shear it is carrying.

Hope the above helps, somehow.

Seismosoft Support

Hello. Thank you for the answer but it wasn't exactly what I wanted to know. My fault, I will try to be more clear.

As I told, I am interested in extracting the forces/moments of the concrete members to perform local verifications, according to the Eurocode 8. My query is not about the modelling itself or the behaviour of the infills.

The results from post-processor of a structure modelled without the infill panels, don't present any difficulties, since those forces/moments can be used directly on the local verifications. But considering the infill panels in the modelling, isn't possible to use directly the forces/moments of the concrete elements because it seems to still be missing the component of the struts.

One simple example of what I am trying to expose, using the results at the base level, is on the comparison of internal forces of the base columns and the foundations nodes. Without the infill panels they are identical, but completely different in presence of the struts. (Evidently, the gap between the internal and dummy nodes of the struts and the integration section of the element prevents the readout of the increase of stress on the element, which I pretend.) On this level is possible to capture the maximum demand on the columns, reading the values on those nodes, but I would also like to achieve it for different columns, to perform more local verifications.

So, is possible to suggest any way, inside the program, to extract the 'right' forces/moments? If not, do you recommend some approach?

I thank in advance for the time spent in helping in this issue. Best regards.

Why don't you use the frame forces results for the checks?
In the absence of infills the results will be equal to the nodal load values, hence the latter could be used too. However, in the presence of infills only the frame forces values can be used for the checks.
Generally, the forces of the RC members are expected to be smaller in the model with infill.

Note that the infill strut forces are displayed in the infill forces panel and should not be confused with the R/C members forces. Also note that the dummy infill nodes are internal in the infill element, and should not be confused with the nodes defined in the SStruct input.