Stell deck roof

[Anonymous]

Hi,

1. I want the roof panel work like a diaphragm steel deck (only steel); I have two warnings (isolated node, and cohesion of calculation model)

2. I need the loads will be transfer by the beams in alphabetic address.

3. and have the trapezoidal plate in the same orientation

Could do you give me some advises please?

Thanks

[Rafal.Gaweda]

Do not use kinematic links.

Correct meshing options in attached file.

Loads are correctly transfered:

[Anonymous]

Hi,

1. If I run analyse of your corrected mesh file I have instability type 3 at node 394, If I ignore this first warning (and maybe all following) I can't find the desired behaviour (see figure 2 attached)

2. I try also to follow all I find in your file to correct my original mesh (I want learn) but I can't (see attachment) What’s wrong please?

Thanks

[Rafal.Gaweda]

Diaphragm has not connected nodes on one roof edge due do model inaccuracies.

For example all roof nodes should have Z=48,67. But the are not on this level.

(Other coordinates are also not so accurate)

Run Detailed Correct for Whole Model to Structural Axes to correct geometry.

Corrected file attached.

You will not obtain the behavior like on figure 2 using diaphragm  \ rigid links.

http://docs.autodesk.com/RSA/2013/ENU/filesROBOT/GUID-88C4C842-5D90-4E85-8F8C-D47D6E474E29.htm

[Anonymous]

A roof steel deck diaphragm (semi rigid because there are not concrete slab) must work in plane to transmit horizontal forces to lateral resistance system. It works like a W beam lying where the flanges are the edge beams. Then the edge beams work in compression or tension (and bending due gravity loads).

In my model the edge beams in this moment don’t take force due to horizontal forces

 My question is how I modeling a roof steel deck in Robot?

Thanks

[Rafal.Gaweda]

As far as we understood you correclty you should define ordinary shell panel (without diaphragm).

If not - expain more precisely with drawings showing what behavior you really want to obtain.

[Anonymous]

please see http://www.canam-steeljoist.ws/www/v4/epublica.nsf/va_doc/3231CF07C4CAB3AA8525796B004D913F!opendocum...

page 16 method

page 23 calcul exemple

My mainly interest is in the way load comes to structure

Thanks

[Rafal.Gaweda]

Tricky thing.

We will our apporaches how to model  it in the best way tomorrow.

[Rafal.Gaweda]

Approach 1: - apply loads proportionally to beams

Approach 2: pair of rigid links connecting beams (in attached example I have also connected middle beam) and remove releases from these beams

[Anonymous]

Like my other tread "instability" your file report instabilities

See attachment please

[Rafal.Gaweda]

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Instability/m-p/3856660/highlight/false#M124... - message 5

[Anonymous]

Repply to message 9

For approach 2, I can do the rigid links in address x-x and y-y at the same time? Because I have load cases in two address.

Thanks

[Rafal.Gaweda · Accepted solution]

You can do but in one model all of them will work in all cases.

[Krzysztof_Wasik]

Hi @fayasfayas 

This structure is not supported. Model is not stable and should be supported.