Mode shape vectors

[sergey.churilov]

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).

[Anonymous]

Do you mean the mode shape diagram?

Or a numerical representation?

[sergey.churilov]

Numerical representation with values.

[Artur.Kosakowski · Accepted solution]

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.

[Anonymous]

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

[Rafal.Gaweda]

RMB - right mouse button

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

[Anonymous]

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.

[Rafal.Gaweda]

This is Robot forum, not Inventor.

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

[Anonymous]

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 ?  

[Anonymous]

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? 

[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 ?  

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See below

[Rafal.Gaweda]

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:

[Anonymous]

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

[Pawel.Pulak · Accepted solution]

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,