How to create thin walled sections??

[FilRib]

Hi,

When i create a thin walled section in section definition, it is analysed like a solid section in the steel design module. (please see picture attached). Does i have to "check some box" to make it a real thin walled section that can be analysed has it should be?

Thanks in advance!

Cheers!

[Artur.Kosakowski]

You may consider two options:

1. Verify them as standard double C section

2. Create two separate bars connected with rigid links at the locations of the connecting plates.

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[e_winner]

I think that the second variant is right.
If it works, why not? But it takes a few time...

please be so kind!
Show me how to realize the rigid link in my situation.

[Artur.Kosakowski]

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.

[e_winner]

Thank you very much. It helped me. 

The composition of section is closer to reality.

[Artur.Kosakowski]

I'm glad I was able to help. Good luck with your project.

[e_winner]

There is the result of my work.

When the program runs verification of this compaund section what kind of area it takes Aeff or Ax?

The shape type number is 39.

[Artur.Kosakowski]

As bar 1301 section class is 4 then Aeff is used.

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[e_winner]

Thank you very much!

[Artur.Kosakowski]

The number of the bar in the model you attached the results for:

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[e_winner]

ok! thank you for your time! 

[michaliseng]

Hello,

I have some questions.

1. I have two custom thin walled sections that are similar to S+ but they have also, one the first and two the second section, channels in the upper and bottom flanges.

If i characterise the section in the section database as 1002 in SHAPE_TYPE can Robot recognise it as S+ or I cannot code check this section?

2. Can I import in section definition a custom thin walled section, solve it as solid(because robot cannot solve it as thin walled), save it as user defined section, then in section database characterise it as a thin walled section type eg. 1002 SHAPE_TYPE and check the thin walled box and then use it in the model as thin walled with the right section characteristics?

3. If I don't know some section characteristics of a thin walled section when I change e.g. the thickness of an existing Z section, can I solve the model with this section with the wrong characteristics and see the right characterictics of the results of code check?

Or else how I can find the right section characteristics when I copy-paste an existing section in a standar section database eg SADEF and then I change the thickness or the height of the new section?

I am asking this because I want to design some purlings with different dimentions from those in the section databases and I cannot open an existing thin walled section in section definition, change there its characheristics and then save it as user section.

3. Which is the difference between the two paths of the section databases. I mean the one from C:\Programdata\Autodesk\Structural\etc. and the other in C:\Users\Username\Appdata\etc. ?

I attached one custom section that I want to use. 

[Artur.Kosakowski]

Robot can only design thin walled sections from the types which are implemented therefor you will not be able to correctly code checking the ones as yours.

3. Which is the difference between the two paths of the section databases. I mean the one from C:\Programdata\Autodesk\Structural\etc. and the other in C:\Users\Username\Appdata\etc. ?

The later contains users one (there may be more than one user of Robot on a particular computer and they may have different databases created).

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[michaliseng]

Thank you Artur!

And what about:

If I don't know some section characteristics of a thin walled section when I change e.g. the thickness of an existing Z section, can I solve the model with this section with the wrong characteristics and see the right characterictics of the results of code check?

Or else how I can find the right section characteristics when I copy-paste an existing section in a standar section database eg SADEF and then I change the thickness or the height of the new section?

I am asking this because I want to design some purlings with different dimentions from those in the section databases and I cannot open an existing thin walled section in section definition, change there its characheristics and then save it as user section.

This question is for Z, C, etc sections and not for the custom section in the attachment.

[Artur.Kosakowski]

Please check this article. 

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[michaliseng]

Thank you for your fast replies and sorry for my many questions.

I have done all these. But I cannot understand how I can calculate the section properties of the new section when I edit the parameters of an existing thin-walled section.

I attached an image of SADEF Database in a C section. 

Here where I change d=150mm in red box A, all the section parameters in red boxes B and C must be changed manually. How can I calculate all those new parameters manually? 

[Artur.Kosakowski]

You can calculate the thin walled section properties in the Section Builder module of Robot. Please watch the recording of the 8th Robot webinar available from:

http://forums.autodesk.com/t5/robot-structural-analysis-forum/robot-structural-analysis-webinars/td-...

See also this article

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[michaliseng]

Thank you Artur.

As for my last question I have problem opening only the SADEF Database in section definition Robot tool. It opens other databases with thin-walled sections such as AusPro.xml. 

The following links were really usefull for me:

http://forums.autodesk.com/t5/robot-structural-analysis-forum/thin-walled-section-definition-and-per...

http://forums.autodesk.com/t5/robot-structural-analysis-forum/custom-sections/m-p/3331167

http://forums.autodesk.com/t5/robot-structural-analysis-forum/cross-section-definition/m-p/3475124

[Artur.Kosakowski]

I'm not sure if I understand you correctly. If you import a section from a section database to the Section Builder it opens as a solid section whereas you need to calculate the thin walled properties. In other words you should draw (or import as a dxf) a line that stands for a thin walled section shape and assign it a thickness being in the thin walled mode of the Section Builder module:

[conny.f.93]

Hi,

how do I verify a double C-section if I want to have two C-profiles back to back?

Can I make or edit a C-profile and put in the properties of what the double section would have ? And in that case is shape type for that section still for example 1004?

[Artur.Kosakowski]

Please check posts 19 and 21 above. 

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