NO RIGID DIAPHRAGM WARNING

This query is posted on behalf of user Gautam Paul :

I think this warning is because of out of plane load. Does this warning mean that the structure is going to collapse. How to avoid such warnings??

Tray Support- ELECTRICAL (Area 2D).std

Parents
  • This note regarding floor diaphragm is a generic one and the purpose is to make the user aware that if there is a floor diaphragm definition, that should precede any wind load definition. In your case there is no floor diaphragm and so this warning is not applicable.

    Couple of side notes.

    You need to use the LOAD LIST ENV 1 2 command to ensure that serviceability and strength checks are carried out for the respective envelopes.

    The PERFORM ANALYSIS after the LOAD LIST is also redundant and can be taken out.

    *

    *LOAD LIST 101 TO 143

    LOAD LIST ENV 1 2

    *PERFORM ANALYSIS

    PARAMETER 2

    CODE AISC UNIFIED 2010

    You will also need to add a DFF parameter if deflection checks are to be carried out.

    You have added a ACC 1 parameter to your UBC load. In general the accidental torsion factor should be 0.05 ( or -0.05 ). Also for your model, in order for the accidental torsion to be accounted, you have to check the box Include Accidental torsion within the seismic definition.

    Last but not the least, please do not post STAAD/RAM related questions in the Files section of the Bentley Communities. These queries should be posted in the STAAD|RAM forum.



    Answer Verified By: Seth Guthrie 

Reply
  • This note regarding floor diaphragm is a generic one and the purpose is to make the user aware that if there is a floor diaphragm definition, that should precede any wind load definition. In your case there is no floor diaphragm and so this warning is not applicable.

    Couple of side notes.

    You need to use the LOAD LIST ENV 1 2 command to ensure that serviceability and strength checks are carried out for the respective envelopes.

    The PERFORM ANALYSIS after the LOAD LIST is also redundant and can be taken out.

    *

    *LOAD LIST 101 TO 143

    LOAD LIST ENV 1 2

    *PERFORM ANALYSIS

    PARAMETER 2

    CODE AISC UNIFIED 2010

    You will also need to add a DFF parameter if deflection checks are to be carried out.

    You have added a ACC 1 parameter to your UBC load. In general the accidental torsion factor should be 0.05 ( or -0.05 ). Also for your model, in order for the accidental torsion to be accounted, you have to check the box Include Accidental torsion within the seismic definition.

    Last but not the least, please do not post STAAD/RAM related questions in the Files section of the Bentley Communities. These queries should be posted in the STAAD|RAM forum.



    Answer Verified By: Seth Guthrie 

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