Hi guys,
I' m trying to make a seismic analysis, using the response spectrum (EC8) from the "load item" list.
In the second phase I' m define one spectrum in x and y direction (direction parameters 1 and 0,3), specifying the masses (selfweight, live and dead loads in x and y) in the reference loads definitions
Unfortunatelly i' m not getting the right results.
Anyone know how to procede to make a seismic analysis following the EC8?
Thanks
You should create a reference load with a Mass type selected and provide the masses in all 3 global directions.
Yes I made the masses from the reference loads definitions.
And the results are still not as expected? In that case please attach the model and let us know what results differ from your expectations.
confronto staad-cds.STD
In the postprocessing mode, the Mz diagrams , for the seismic combinations, are not changing.
Your reference load definition should look like that:
LOAD R1 LOADTYPE Mass TITLE mass
SELFWEIGHT X 1 LIST ALL
SELFWEIGHT Y 1 LIST ALL
SELFWEIGHT Z 1 LIST ALL
MEMBER LOAD
13 TO 18 UNI GY 3
13 TO 18 UNI GY 1
13 TO 18 UNI GX 3
13 TO 18 UNI GZ 3
13 TO 18 UNI GX 1
13 TO 18 UNI GZ 1
END DEFINE REFERENCE LOADS
If that still does not help, please illustrate your issue with a screenshot.
For response spectrum in X+ and X- direction, the Mx diagrams are the same.
Even in Y direction I have the same condition.
The responses obtained from the Response Spectrum analysis are absolute unsigned quantities. If you want to see signed bending moment diagrams, you can use either Dominant or Signed option in the Response Spectrum Load Case settings. You can find some more useful information on this topic here: https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/123938/signed-response-spectrum/376619#376619