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Active Contributor
Hallvard
Posts: 34
Registered: ‎08-09-2011
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Deformation vs displacement

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10-27-2011 02:03 AM

Hi

 

When reviewing results regarding deformation and displacement I have some problem with the model Im working on currently.

 

See attached pdf. From the graphic deformation view it seems like the displacement for node 7 is 4 mm for case 3000. From the displacement table the displacement for node 7 is 34 mm for case 3000.

 

Maybe a stupid question, but why does Robot show 4mm graphically and 34 mm in the table?

 

Is it possible to view all nodal displacements from the table graphically?

 

Thanks

 

- Hallvard

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Artur.Kosakowski
Posts: 4,849
Registered: ‎12-17-2010

Re: Deformation vs displacement

10-27-2011 02:46 AM in reply to: Hallvard

Hallvard,

 

My assumption is that you compare different types of results. Could you send me the rtd file saved with the deformation diagram displayed and the opened table so that I could check what you actually set to be displayed please? The descriptions on the diagram shows extreme values (which can be at any locations along bars) rather than nodal values.



Artur Kosakowski
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Active Contributor
Hallvard
Posts: 34
Registered: ‎08-09-2011

Re: Deformation vs displacement

10-27-2011 03:10 AM in reply to: Hallvard

I tried to attach the model, I dont know if there is a file size limitation, but hopefully it will work.

 

You are probably right that I am comparing different types of results.

 

I would like to view:

- Nodal displacement, with description graphically

- Bar displacement, with description graphically

 

 

 

 

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Artur.Kosakowski
Posts: 4,849
Registered: ‎12-17-2010

Re: Deformation vs displacement

10-27-2011 03:27 AM in reply to: Hallvard

Hallvard wrote:

I tried to attach the model, I dont know if there is a file size limitation, but hopefully it will work.

 

The model has not been updated but ..

 

You are probably right that I am comparing different types of results.

 

I would like to view:

- Nodal displacement, with description graphically

Display diagram of Deformation. Mind that the shape of structure deformation between nodes (along bars) may be inaccurate for this type of the display.

 

- Bar displacement, with description graphically

Display the exact deformation.

 


Hope this helps.

 

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
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Active Contributor
Hallvard
Posts: 34
Registered: ‎08-09-2011

Re: Deformation vs displacement

10-27-2011 04:15 AM in reply to: Artur.Kosakowski

The model is too large for e-mailing and it didnt work to attach it to my reply.

 

You are probably right that I compared different types of results. But from general structural estimations, the nodal displacement and maximum--bar-deflection should be approximately the same.

 

I did define geometrical imperfections for bars in the structure, I have now removed all geometrical imperfections, and now the results seem ok.

 

So my question will be redefined :smileyhappy:

 

I want my analysis to consider initial curvature of the timber elements, especially columns. That is the reason i defined geometrical imperfections. Further reading in Eurocode5 Point 6.3.2 for timber show that the factors ky, kz, kc,y, kc,z and beta_c take initial curvature into account. So I dont think I need to define geometrical imperfections anyway.

 

Artur: Last week you provided a chart regarding lateral buckling. If you could provide a chart for the factors mentioned above it will be appreciated.

 

Thanks

 

- Hallvard

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Artur.Kosakowski
Posts: 4,849
Registered: ‎12-17-2010

Re: Deformation vs displacement

10-27-2011 05:00 AM in reply to: Hallvard

Further reading in Eurocode5 Point 6.3.2 for timber show that the factors ky, kz, kc,y, kc,z and beta_c

Last week you provided a chart regarding lateral buckling. If you could provide a chart for the factors  mentioned above it will be appreciated.

 

I'm sorry but I'm not sure if I understand your request correctly. All these factors are calculated according to the formulas given in EC5 based on the cross sectional properties of a profile you used and its material. You don't select them in the user interface directly.



Artur Kosakowski
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Active Contributor
Hallvard
Posts: 34
Registered: ‎08-09-2011

Re: Deformation vs displacement

10-27-2011 05:06 AM in reply to: Artur.Kosakowski

I would like to see the calculations, to be sure that I define everything correctly, so that the factors come out correctly

 

. But nevermind I can check it myself versus calculations by hand.

 

Thanks:-)

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Artur.Kosakowski
Posts: 4,849
Registered: ‎12-17-2010

Re: Deformation vs displacement

10-27-2011 05:19 AM in reply to: Hallvard

Please check http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Autodesk-Robot-Verification-and-Theory/m-p/3...

 

and look at the last verification example in Verification Manual EU codes.pdf

 

 



Artur Kosakowski
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Active Contributor
Hallvard
Posts: 34
Registered: ‎08-09-2011

Re: Deformation vs displacement

10-27-2011 05:24 AM in reply to: Artur.Kosakowski

Perfect! Thanks:-)

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