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panel reaction output rather than FE nodal reactions?

18 REPLIES 18
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Message 1 of 19
Anonymous
1596 Views, 18 Replies

panel reaction output rather than FE nodal reactions?

Afternoon All,

 

I've been trying to export the base reactions for an RC building made up of FE meshed panels. Unfortunately Robot seems to only export reactions for every individual FE node, leading to a HUGE file of thousands of nodes.

 

I just want basic uniform distributed load KN/m, and KNm/m reactions along the base of the walls in order to design up a chunky raft outside of Robot. Is there any add-in / plug-in that I could use to acheive this with minimal pain?

 

I'd rather not have to work out approximate reactions by hand, or absorb a large volume of time decyphering the FE nodal reaction output. Expert help appreciated! ๐Ÿ™‚

 

Thanks,

Scott

 

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18 REPLIES 18
Message 2 of 19
Artur.Kosakowski
in reply to: Anonymous

 

http://docs.autodesk.com/RSA/2013/ENU/filesROBOT/GUID-67D72F99-C7D5-4C15-BE1A-45E8AE0A4330.htm?highl...

 

http://docs.autodesk.com/RSA/2013/ENU/filesROBOT/GUID-3936FDA3-5DFD-4F31-B16A-F0208A451282.htm

 

Display results at the bottom edge of walls. You may add cut (wall) length in the display of the Reduced Results table so that you know the value of bending per unit length if needed.

 

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 3 of 19
Anonymous
in reply to: Artur.Kosakowski

Thanks Artur ๐Ÿ™‚ Ok I'll see if I can get some useful results from that. The building has many wall panels at foundation level though.... Is the option of displaying foundation reactions per m length in the development list for Robot? It seems pretty fundamental. It wasn't a pleasant suprise to find out this was missing last week.

 

Message 4 of 19
Artur.Kosakowski
in reply to: Anonymous

linear reactions.PNG



Artur Kosakowski
Message 5 of 19
Anonymous
in reply to: Artur.Kosakowski

In order to design the foundation i also need the overturning moment in order to calculate the excentricity. I have tried to i uncheck the Fz value but Robot doesn't print any value for My any ideas?

 

Robot.jpg

 

Message 6 of 19
Rafacascudo
in reply to: Anonymous

You donยดt have a fixed support!!!!

Rafael Medeiros
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Message 7 of 19
Artur.Kosakowski
in reply to: Anonymous


christian_jessen wrote:

In order to design the foundation i also need the overturning moment in order to calculate the excentricity. I have tried to i uncheck the Fz value but Robot doesn't print any value for My any ideas?

 

As the sum of reactions is done with the reference to point of (0,0,0) coordinates the easiest would be to define the line of supports according to which you want to calculate the overturning moment at the 0 coordinate line and check the value of the sum of moments.

 

overturning moment.png

 

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 8 of 19
Anonymous
in reply to: Artur.Kosakowski

That works fine for a plane situation but as far as I know this will not be a practicable way for 3D building where a load along for instance the Y-axis also can introduce forces along the z-direktion due to torsion i the building. I need the moment My for each wall, in order to calculate the excentricity for the loading on each undation. Please se sketch.

 

 

 

 

Robot with moments.jpgfo

Message 9 of 19
Rafacascudo
in reply to: Anonymous

as I said before , youยดll never get My reactions through "diagrams for bars" when you have linear pinned supports!!.

Maybe what you need is a fixed node support in the center of your wall base and then connect this node to the other base nodes through rigid links.

 

See attached picture

Rafael Medeiros
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Message 10 of 19
dimogrec
in reply to: Anonymous

 

christian have you tried to define the vertical walls as core wall? Perhaps by doing this and then viewing the results -> diagramms for building ->core wall diagamms you'll get the My for your walls

I don't know if this helps...

 

Message 11 of 19
Artur.Kosakowski
in reply to: Anonymous

That works fine for a plane situation but as far as I know this will not be a practicable way for 3D building where a load along for instance the Y-axis also can introduce forces along the z-direktion due to torsion i the building. I need the moment My for each wall, in order to calculate the excentricity for the loading on each undation. Please se sketch.

 

Do you need in plane bending in each of the walls or out of the plane bending?



Artur Kosakowski
Message 12 of 19
Anonymous
in reply to: Anonymous


@Anonymous wrote:

Afternoon All,

 

I've been trying to export the base reactions for an RC building made up of FE meshed panels. Unfortunately Robot seems to only export reactions for every individual FE node, leading to a HUGE file of thousands of nodes.

 

I just want basic uniform distributed load KN/m, and KNm/m reactions along the base of the walls in order to design up a chunky raft outside of Robot. Is there any add-in / plug-in that I could use to acheive this with minimal pain?

 

I'd rather not have to work out approximate reactions by hand, or absorb a large volume of time decyphering the FE nodal reaction output. Expert help appreciated! ๐Ÿ™‚

 

Thanks,

Scott

 

 

We've been using RSAP for quite a while.

 

Why don't you model the Raft in RSAP instead? provide Soils springs then use soil reactions on Results>Panel Map>Detailed>Soil Reactions to obtain what you are looking for. You'll be able to display Moments and Shear Forces needed.

Message 13 of 19
Anonymous
in reply to: Artur.Kosakowski

Yes, I need the in-plane bending for designing the stripfoundation under the wall.

 

Using the elastic solution from Robot isn't practicable if the excentricity of the normal force i greather than 1/3 of the wall length, as this leads to tensile forces between the foundation and the soil will will not occur in real life.

 

I would like to design the foundation for a centric load and an effective length as shown on the sketch below. In order to do that i need the normal force, and the in-plane bending moment. In order to check against sliding the total in-plane shear would also be appriciated.

 

Defining a spring stiffness of the soil seems for me a bit over the target for the building I am designing.

 

Sketch wall.jpg

Message 14 of 19
Artur.Kosakowski
in reply to: Anonymous

Yes, I need the in-plane bending for designing the stripfoundation under the wall.

 

Then you can get this value in the reduced results for panels table.

 

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 15 of 19
Anonymous
in reply to: Artur.Kosakowski


@Artur.Kosakowski wrote:

Yes, I need the in-plane bending for designing the stripfoundation under the wall.

 

Then you can get this value in the reduced results for panels table.

 

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.


As what Artur said, model your doundation as panel then use reduced forces over supports for panel forces that doesn't need ofsetting from support face.

Message 16 of 19
Anonymous
in reply to: Artur.Kosakowski

Thanks for your patience so far. Based on what i find elsewhere on this forum I se that the panel cuts will solve my problem.

 

But i have a smal problem I do not get any results in the "panel cut table" only stars, see attached figure. Any idea what the problem can be? I have tried to build a new model but same problem. As you can see i do get reactions in the nodes. Snap5.jpg

Message 17 of 19
Artur.Kosakowski
in reply to: Anonymous

Attach file please.



Artur Kosakowski
Message 18 of 19
Anonymous
in reply to: Artur.Kosakowski

Please find Robot-file as questened. I hope you can sort out the problem.

Message 19 of 19
Artur.Kosakowski
in reply to: Anonymous

It seems like you used ACIS objects to define panels which is not recommended. I'd recommend switching this setting off, restarting Robot and create the model again.

 

Please check:

http://forums.autodesk.com/t5/Robot-Structural-Analysis/Cant-make-openings-on-shells/m-p/3949057

http://forums.autodesk.com/t5/Robot-Structural-Analysis/Problem-with-Meshing-Options-in-RSA/m-p/4461...

 

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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