load envelopes and serviceability and strength checks

Hi

I have assigned some load combinations(101 to 114) as serviceability load cases , and some (201 to 236) as strength load cases in load envelopes.

after that I have mentioned LOAD LIST ENVELOPE 1 2 before parameter 1. so now staad should perform serviceability checks for load combination 101 to 114  and strength checks for 201 to 236.

But when I am going to post processing > unity checks , it is showing deflection check is critical for load cases 201 to 236 .

please have a look at staad file and suggest corrections

.M703-IA-P0.std  

Parents
  • Please refer to the attached modified model. Please note that Envelop 1 is created for serviceability check and envelop 2 is created for strength check.. Just before PARAMETER 1, LOAD LIST ENVELOPE 1  is used and after the parameter lists CHECK code command is used like DFF etc.  It will tell the program to go for deflection checking and the output contains deflection checking results. Similarly, before PARAMETER 2, LOAD LIST ENVELOPE  2 is used and it tells the program to go for strength checking.

    0602.M703-IA-P0.std



  • Hi

    I have reviewed staad model modified by you.

    If we do like this then in post processing >unity check staad shows results only for parameter mentioned later i.e. parameter 2 (strength check).

    but if we mention parameter 1 later (deflection check)as in the case of model attached with this comment by me, than in post processing >unity check staad shows results only for deflection checks.

    That means staad is taking parameter which is mentioned later as critical , whereas what staad should have done is, checked utilisation ratios for both parameters and than should have mentioned ratio which is critical out of this two in

    post processing >unity check.

    please review model sent by me.

    this problem is there in staad since many year , please have a look at the conversation with  and  in below link

     

    communities.bentley.com/.../92737

    communities.bentley.com/.../85977

    4760.0602.M703-IA-P0.std

  • Hi
    please first clear weather I have to mention LOAD LIST ENV 1 and LOAD LIST ENV 2 separately above parameter 1 and parameter 2 respectively or I can mention LOAD LIST ENV 1 2 above parameter 1 as in the case of file attached by me.
    because some people are saying I have to mention it separately .
    I have tried both ways , and I am getting different results for the two cases.
  • Hi   one more issue when I am not assigning any load envelopes .

    all members are safe (all passed).

    but when for same staad file if I assign load envelopes than some members are failing and that too in strength checks , if they would have been failing in deflection check , I can understand , because staad SS6 doesn't performs deflection checks automatically , unless serviceability envelope is defined. but strength check is performed by default , so  I think this issue should not be there .

    please have a look at attached staad file . in this STAAD file I have defined load envelopes .after running this file you can see some members are failing in strength checks. but when you remove load envelopes these members are not failing. please check by removing load envelopes for same attached staad file.

    M703-IA-P1.std

  • Regarding your most recent post (Tuesday, Sept 15, 7:19 PM)

    You wrote:

    one more issue when I am not assigning any load envelopes .

    all members are safe (all passed).

    when you remove load envelopes these members are not failing. please check by removing load envelopes for same attached staad file.

    Our response:

    The results I get don't match yours. What I find is that, when both the LOAD LIST ENV commands are removed, several members are failing - 101, 114, 115, 116, 119, 120, 126, etc.. Strength cases govern in all these failures.

    The results of the second code check of the model with the load envelopes removed are identical to those for the second code check in the model containing those load envelopes from your aforementioned posting.



  • Hi
    you are correct .
    this problem was there in SS5 , but now in SS6 it has been resolved I think.
    Is there any way I can call you or any Bentley technical support team member and talk to you directly.
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