Robot Structural Analysis

## Robot Structural Analysis

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Posts: 139
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Message 1 of 8 (364 Views)

# Tables - Sum of values

364 Views, 7 Replies
02-27-2012 01:36 AM

What does "sum of val", "check val" precision mean? What does it show?

Does Sum val(ue) give me the sum of forces responsable for the reactions?

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Message 2 of 8 (363 Views)

# Re: Tables - Sum of values

02-27-2012 01:43 AM in reply to: AlexDT
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Message 3 of 8 (352 Views)

# Re: Tables - Sum of values

02-27-2012 02:20 AM in reply to: Rafal.Gaweda

Thanks! Sum of value is still not very clear to me though.

"Sum of val. - An arithmetic sum of values of forces and moments for a given direction for the currently-filtered nodes."

Sum of what values and which direction?

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Message 4 of 8 (348 Views)

# Re: Tables - Sum of values

02-27-2012 02:48 AM in reply to: AlexDT

Take a look below:

- selection in green

- direction = columns (yellow, blue)

Rafal Gaweda
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Message 5 of 8 (344 Views)

# Re: Tables - Sum of values

02-27-2012 03:04 AM in reply to: Rafal.Gaweda

Thanks. It is simply the total of the reactions of the selected nodes then?

In my case I selected all the nodes, but the the sum of value for the moments are not  equal to the sum of forces.

In fact I changed all my supports to pinned so I didnt have any moments in them, but the sum of reaction for those nodes still remain? I dont get how that adds up.

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Message 6 of 8 (338 Views)

# Re: Tables - Sum of values

02-27-2012 04:28 AM in reply to: AlexDT

So either you have elastic supports  \ ground on model or you are looking on nonconverged results of nonlinear case.

Example below

Rafal Gaweda
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Registered: ‎10-08-2011
Message 7 of 8 (192 Views)

# Re: Tables - Sum of values

05-31-2013 11:39 AM in reply to: Rafal.Gaweda

from the RSA Help it is stated that :

"In quadratic combinations for cases of the seismic or spectral analysis, the sum of reactions and the sum of forces are calculated by adding the values of the respective sum of values and the sum of forces for individual vibration modes"

Can we have a little more explanation ie : the somme of reactions are equal to ....

and the somme of forces are to....

in this case (quadratic combination) the "somme of values" have no signification ( it still just a arithmetic somme below)

Thank you

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Message 8 of 8 (150 Views)

# Re: Tables - Sum of values

06-07-2013 02:09 AM in reply to: faisal.aaouatif

It is answered in the mesage 2 of this post:

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Reaction-Table-query/m-p/3949469#M14317

Regards,

Pawel Pulak

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