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Mode shape vectors

13 REPLIES 13
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Message 1 of 14
sergey.churilov
2266 Views, 13 Replies

Mode shape vectors

Hi to all,

 

How do you present mode shape vectors from each mode after performing modal analysis?

 

I would like to compare the mode shape vectors from numerical analysis with experimental analysis and establish the Modal Assurance Criterion (MAC).

13 REPLIES 13
Message 2 of 14

Do you mean the mode shape diagram?

 

Or a numerical representation?

 

Message 3 of 14

Numerical representation with values.

Message 4 of 14

Press the RMB on the table with results of modal analysis and select table columns. Switch to the Eigenvectors tab.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
Message 5 of 14

i didnt undesrstand what is RMB .in modalanalysis environment i am getting only frequency results. i cant see any table. i need to have mode shape vectors .kindly help me with this

Message 6 of 14
Rafal.Gaweda
in reply to: murali3131

RMB - right mouse button

Click on table using  right mouse button then select Columns....



Rafal Gaweda
Message 7 of 14

i am working in autodesk inventor for modal analysis.i got first 10 modes.but i need to have mode shape vectors to compare with experimental results.i am attaching image of my result.please suggest looking at the figure.

Message 8 of 14
Rafal.Gaweda
in reply to: murali3131

This is Robot forum, not Inventor.

 

Inventor http://forums.autodesk.com/t5/Autodesk-Inventor/bd-p/78



Rafal Gaweda
Message 9 of 14
oyvinkle
in reply to: Rafal.Gaweda

To vertify my structure i have used matlab and plottet the eigenvectors. I am trying to compare the results from robot with the results from matlab. is there a smart way to get the eigenvectors ou from robott.. all i seem to get are -0 +0 and  1 -1 ?  

 

 

Message 10 of 14
oyvinkle
in reply to: oyvinkle

I was also wondering if Robot take into acount crackling of the concrete by code reduction factors for shear and flexular deformation when preforming a modal analysis? 

Message 11 of 14
Rafal.Gaweda
in reply to: oyvinkle


To vertify my structure i have used matlab and plottet the eigenvectors. I am trying to compare the results from robot with the results from matlab. is there a smart way to get the eigenvectors ou from robott.. all i seem to get are -0 +0 and  1 -1 ?  

 

 


See below

 

eigen.jpg



Rafal Gaweda
Message 12 of 14
Rafal.Gaweda
in reply to: oyvinkle

I was also wondering if Robot take into acount crackling of the concrete by code reduction factors for shear and flexular deformation when preforming a modal analysis? 

 

No , reduce E or section properties by your own

Example:

rcred.jpg



Rafal Gaweda
Message 13 of 14
jaascar
in reply to: Rafal.Gaweda

Regarding the Eigenvectors, what is the normalization criteria used? Are all the components of the eigenvector normalized individually, or are they normalized relative to eachother? If they are relative, how is the relation between length components and rotation components taken into account?

 

Thanks,

 

Jose

Message 14 of 14
Pawel.Pulak
in reply to: jaascar

The components of the eigenvector are normalized relative to each other.

 

The relation is "unit independent" because values of rotation components correspond to tangents of appropriate rotation angles.

 

Regards,


Pawel Pulak
Technical Account Specialist

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