Modeling opening in steel column

Modeling opening in steel column

antonio.lafuente
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Message 1 of 16

Modeling opening in steel column

antonio.lafuente
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Hi there!

 

How could I model the reduced capacity of a steel column (HEA 160) with an opening like the one in the figure below? Thanks in advance for your comments

Picture1.png

Cheers

Antonio

 

 

 

 

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Accepted solutions (2)
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Message 2 of 16

Rafacascudo
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I never tried , but maybe you can try modelling an equivalent section on the region of the hole using "Special" Section.

Special.jpg

 

Check here https://help.autodesk.com/view/RSAPRO/2020/ENU/?guid=GUID-07F57C8A-E5C6-4A00-A92A-956EA0626D69 to see how equivalent properties are calculated

 

Or maybe you can create a custom section on "Section definition" module and then go to Ruser`s  Section database and edit the section properties to what you need/want

Rafael Medeiros
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Message 3 of 16

antonio.lafuente
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Thanks Rafa

 

I created a superbar made from two standard HEA160 and a custom special profile. That seems to work but at the steel design phase I get an error saying that the section is not supported by the code. Are there any standards I can use that allow this type of special sections? It should still be compatible with Eurocode 3 since is the standard I have to evaluate the structure to. Thanks in advance

 

Antonio 

Picture2.pngCapture_1.JPG

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Message 4 of 16

antonio.lafuente
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Okay, I just read in the link you sent that only do this type of assessment under the Polish code PN90/B03200. I wonder how this compares to Eurocode and/or if I should just have two separate Autodesk Robot files one using the Polish code for this column and the standard one for the rest...

 

 

Also in the report I'm getting results for my superbar (#400) and just one of the smaller bars (#70) but not the other two (#66 and #68). Since I checked that components of superbars should not be taken into account I'm not sure why do I still see results for bar #70. Any ideas?

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Message 5 of 16

Rafacascudo
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In this case that you want the bar to be designed ,maybe you should follow the last sugestion I made on my last message .

" Or maybe you can create a custom section on "Section definition" module and then go to Ruser`s Section database and edit the section properties to what you need/want"

 

HEA opened in section definition.jpg

Then ,save it to user´s database with the appropriate section on the dropdown menu, so it can be designed.

Open the section database and edit properties you want .Leave the section line before closing database

properties edited.jpg

Fully Close RSA ,so user´s database can be updated.

Open and load the edited section into your model

loading edited section.jpgproperties edited2.jpg

Then on the the design module , edited properties will be used.

properties edited used in design.jpg

Rafael Medeiros
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Message 6 of 16

antonio.lafuente
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Hi Rafael

 

Let me see if I understood. What you are suggesting is to create a super bar made of three chunks, where the middle one is made from a user-defined section with the modified properties corresponding to a section with a hole in the middle? If so, is there a way use robot to calculate the section properties of the section with the hole?

 

Thanks in advance

Antonio

 

 

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Message 7 of 16

Rafacascudo
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Ax ,Ay,Az, Iy and Iz are easy to calculate. Just suppress the web area contribution caused by the hole presence.

For Ix , you can try creating the section on section definition module ,and see what it gives for IX.

Or you can use that equivalent compound section to check all these properties

Rafael Medeiros
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Message 8 of 16

antonio.lafuente
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Thanks again. How would you check these properties in the original compound section? Would you please mind guiding me a bit?

 

 

 

 

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Message 9 of 16

Rafacascudo
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just check the equivalent compound section on the properties table

Rafael Medeiros
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Message 10 of 16

antonio.lafuente
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HI Rafa

I'm not sure that will work. I have here a toy problem with four possible definitions and can't see any difference in the results. I have attached the file in case you can have a look. What do you think?

 

Then I don't see how to modify Wply and Wplz. And finally the section area properties don't seem to match those used in the member evaluation

 

Capture.JPG

 

Cheers

Antonio

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Message 11 of 16

Rafacascudo
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Antonio ,

I am not familiar with Eurocode , but ,

 

1- Yes Ay and Az are different on the section design module compared to the values on properties tables and databases. This happens to all databases. I don´t know if it is code related.

2-Wply and Wplz are available on the database columms MSY and MSZ and correspond to the values used on design module.

3- One difference I noticed is that Your modified section has S275 as material while all the others on your model have Stainless steel 304L

 

Sorry to be not more useful. Maybe someone more familiar with Eurocode can help you better.

Did you try manual calculation for this example?

 

 

 

Rafael Medeiros
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Message 12 of 16

antonio.lafuente
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HI again

 

Could you do the analysis of this column out of panels? And if so how would this be done? 

 

 

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Message 13 of 16

Rafacascudo
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Yes , something like below.

HEA FE model.jpgrigid links FE model.jpgmaps for normal forces.jpgcrosses for normal forces.jpgMoment on section.jpg

 

But design would have to be done manually

Rafael Medeiros
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Message 14 of 16

antonio.lafuente
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Interesting... I had never seen this in Robot. Are there any webminars where this is described? I wouldn't know where to start... Thanks in advance

 

Antonio

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Message 15 of 16

Rafacascudo
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Accepted solution

Just model the bar as a group of panels ( Search for and addin made by @Rafal.Gaweda  that transforms a bar section on FE panels ) and then , connect this FE bar to the bar end nodes using rigid links as I shown above.

Rafael Medeiros
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Message 16 of 16

Rafal.Gaweda
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Accepted solution
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