topic Re: Mode Shape X & Y components of Center of Diaphragm in Robot Structural Analysis Forum

Mode Shape X & Y components of Center of Diaphragm

Anonymous — Thu, 13 Sep 2012 04:14:40 GMT

Hi,

I'm using Robot for a 63 story building. My Boss ask me to generate the X and Y components of the Mode Shape displacement (unitless) for every floor similar to the attached table from ETABS. Can we do it in Robot? This data wil be used for wind tunnel test. Thanks

Kind Regards,

Jan

Re: Mode Shape X & Y components of Center of Diaphragm

Rafal.Gaweda — Thu, 13 Sep 2012 07:34:56 GMT

Not for a floor = center of diaphragm; for real nodes only , you an get them in Modal Analysis Results table

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Wed, 26 Sep 2012 17:54:13 GMT

Thanks, I found it.

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Sun, 18 Aug 2013 09:53:11 GMT

Hi Dian021 ,I had the same problem but i could not find the result as you found.Can you show me where is it in the Robot program or just post some picture of it.

Thank regard !!

This is the result i hae in Etabs but I can't find it In Robot .Please help !

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Mon, 19 Aug 2013 06:19:57 GMT

in the name of GOD .
hello rafal
please attach a picture for this your answer....thanks

Re: Mode Shape X & Y components of Center of Diaphragm

Rafal.Gaweda — Mon, 19 Aug 2013 07:28:01 GMT

Re: Mode Shape X & Y components of Center of Diaphragm

Tuctas — Mon, 19 Aug 2013 12:00:30 GMT

The displacement values of any node of the structure corresponding to a given eigenshape can be viewed when choosing the option “Deformations” in the “Diagrams for buildings” (see attached). They should also be displayed in a table form.

Keep in mind that the values that are viewed with the above option are the total ones (i.e the square root of the sum of squares of each component) and that they are not normalized to 1.

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Wed, 21 Aug 2013 11:26:54 GMT

Thank Rafal ,Tuctas for answer

I am sorry for my question but when i try to follow your post it does not happen as you said .I use RSAP 2011.And the value of Eigenvector in modal analysis table are all node of modal,it hard for me to find the value i need as Etab.Sorry for my English

Many thanks!

my modal

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Wed, 21 Aug 2013 11:36:04 GMT

This is my modal

http://www.mediafire.com/?a163310kn83ne00

Re: Mode Shape X & Y components of Center of Diaphragm

Rafal.Gaweda — Wed, 21 Aug 2013 12:56:20 GMT

Every node belonging to each diaphragm in your model will have the same UX UY so take any of them: http://screencast.com/t/47Nmw6Ti

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Wed, 21 Aug 2013 15:51:30 GMT

I really apreciate your help.Thank you very much !!!

Re: Mode Shape X & Y components of Center of Diaphragm

Tuctas — Wed, 21 Aug 2013 16:49:03 GMT

That similarity of the values between any node of each diaphragm was "by accident" because of the total symmetry of the model. Obviously, this is not the case in general.

It seems that in the program the "deformation" values that are displayed for the center of diaphragm corresponding to each mode appears occasionally (maybe they don't appear when there are too many nodes, like it is for F.E of panels).

It would be useful if that information of displacements of eigenvalues for the center of diaphragm was displayed in a table form together with the other nodes of the structure.

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Wed, 21 Aug 2013 17:31:34 GMT

"It would be useful if that information of displacements of eigenvalues for the center of diaphragm was displayed in a table form together with the other nodes of the structure"

yes i think so,.thank Tuctas for your explain !

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Tue, 12 Nov 2013 08:10:17 GMT

Hi,

I would like to know what causes my mode shape to be not the same as etabs?

mode 1 supposed to be drifting x

mode 2 supposed to be drifting y

mode 3 supposed to be twisting

also, i would like to know how to get the natural period of a structure using robot

I attach my file here

thanks!!

Re: Mode Shape X & Y components of Center of Diaphragm

Μηχανικος — Tue, 21 Apr 2015 17:53:48 GMT

Hello everyone,

How can i see the mode shapes of the structure in a modal analysis. I want to see it on the actual model not just numbers in a table. does robot have this feature?

Re: Mode Shape X & Y components of Center of Diaphragm

Rafal.Gaweda — Wed, 22 Apr 2015 06:07:51 GMT

http://forums.autodesk.com/t5/robot-structural-analysis/modal-analysis-outputs/m-p/4847275#M21152

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Wed, 27 May 2015 03:51:44 GMT

hi Rafal,

I have the same questions with djan0521. for snip 2 code. I must use drift ratio ( of each story and each mode). The dyamic wind is caculated based on it.

how export this value.

please help us, thanks you

Re: Mode Shape X & Y components of Center of Diaphragm

Rafal.Gaweda — Wed, 27 May 2015 07:39:07 GMT

I told you yesterday - there are no such results for Modal case in Robot.

Re: Mode Shape X & Y components of Center of Diaphragm

Anonymous — Wed, 27 May 2015 09:49:53 GMT

Thanks Rafal.

I hope them will active soon.

🙂