STAAD - Change material after analysis for service check

RE: STAAD - Change material after analysis for service check

Saul Cuen — Mon, 22 May 2023 14:31:58 GMT

Thanks. Yes, that's the same input as mine.

Checking what Modestas mentioned, if I make a member change from GUI, the CONSTANTS and MATERIAL command after an ANALYSIS command, disappear. What I was not aware of is that if I make ANY CHANGE FROM GUI, these commands will disappear.

So I didn't change member size from GUI, but maybe loads or design parameters I did and had this problem.

So OK, so far any edit in GUI will delete CONSTANTS command after an ANALYSIS command.

Got it, thanks to you both.

RE: STAAD - Change material after analysis for service check

Jeremy Jacobs — Fri, 19 May 2023 14:15:00 GMT

See the attached file.

communities.bentley.com/.../7608.MaterialChange.STD

RE: STAAD - Change material after analysis for service check

Saul Cuen — Thu, 18 May 2023 22:58:25 GMT

That's great, can you share your input to check your syntax?

RE: STAAD - Change material after analysis for service check

Jeremy Jacobs — Thu, 18 May 2023 22:38:42 GMT

The CONSTANTS and the following command MATERIAL input does not disappear for me.

RE: STAAD - Change material after analysis for service check

Saul Cuen — Thu, 18 May 2023 22:09:36 GMT

Thanks. Yes, me too, the second analysis is not removed, the problem is that the command CONSTANTS and the following command MATERIAL input after an analysis, are removed. So I have to type them back again and again.

RE: STAAD - Change material after analysis for service check

Jeremy Jacobs — Thu, 18 May 2023 22:06:34 GMT

I can use the Command File and change member sizes without the second analysis being removed.

RE: STAAD - Change material after analysis for service check

Saul Cuen — Wed, 17 May 2023 18:18:56 GMT

Thanks Modestas. In fact, I'm talking about edition directly using STAAD Editor when this problem happens.

RE: STAAD - Change material after analysis for service check

Modestas — Wed, 17 May 2023 12:33:51 GMT

If you change the members size through the GUI, the material assignment will mess up, as the program will not understand which material assignment should be used for the new section size. To avoid this, you should be changing section sizes directly in the input file by using the STAAD Editor, I believe.

RE: STAAD - Change material after analysis for service check

Saul Cuen — Tue, 16 May 2023 16:37:49 GMT

Thank you Jeremy.

My version is the same v22.12. Maybe, if I can ask you to carry out an edition, any, like changing a member size and before run analysis, please check if CONSTANTS command is still there. That is the point when is deleted for me.

Naturally when I'm constantly working in a model, I can "forget" to type it back so my analysis is for previous material and have to run again. For a model that could take up to 20 minutes, is quite time consuming.

RE: STAAD - Change material after analysis for service check

Jeremy Jacobs — Tue, 16 May 2023 13:49:18 GMT

I made a simple model using the items you described above. I do get the warning about CONSTANTS appearing after an analysis command, but the CONSTANTS/MATERIAL input doesn't disappear for me after the CHANGE command. What version of STAAD are you using? I'm using v.22.12. Maybe that is why the analysis command disappears for you. The two analyses for me proceed without error (only get the previously mentioned warning) and comparing the results from the lateral only load cases shows the different results for the different material assignments. Maybe Modestas or Abhisek M or Sye can provide an answer about changing CONSTANTS after an analysis to get around the limitations of STAAD with tension only members and the Direct Analysis Method.

communities.bentley.com/.../MaterialChange.STD

RE: STAAD - Change material after analysis for service check

Saul Cuen — Fri, 12 May 2023 20:17:29 GMT

Thanks, yes, that person had a similar question. But I'm still looking for an answer.

Most likely is just the way it is and I have to constantly input and re-input the constants command just before run analysis, or run analysis two times each one with each type of material, because the constant command keeps disappearing.

RE: STAAD - Change material after analysis for service check

Jeremy Jacobs — Wed, 10 May 2023 13:29:19 GMT

See the link below. Someone had a similar question.

Change Command and Material Properties - RAM | STAAD Forum - RAM | STAAD | ADINA - Bentley Communities