topic Re: Cladding Load Distribution in Robot Structural Analysis Forum

Cladding Load Distribution

Max-88 — Tue, 07 Jul 2015 08:21:45 GMT

Hello,

I'm new to the Autodesk Robot world 🙂

While learning the ropes, I have noticed that the cladding element does not appear to distribute a uniform planar load on contour correctly, attched screen capture and model. Beams are spaced at 6m and the load is 1kPa.

Anyone having the same problem and would you please be able to indicate a resolve?

With thanks.

Max

Re: Cladding Load Distribution

Rafal.Gaweda — Tue, 07 Jul 2015 08:59:20 GMT

Add nodes as shown below:

Re: Cladding Load Distribution

Max-88 — Tue, 07 Jul 2015 09:13:13 GMT

Thanks mate.

Re: Cladding Load Distribution

Rafacascudo — Tue, 07 Jul 2015 11:56:45 GMT

I mentioned the below doubt on http://forums.autodesk.com/t5/robot-structural-analysis/moving-loads-on-claddings/td-p/5704129

but the focus of that post was another .

I made a example model to show. Two identical slabs .

One with finite elements with a " jelly" stiffness so the load can be only resisted by the border beams that are placed only at the longer sides.

The other is a cladding.

1- For load case 1 where a concentraded load is placed at the exact center of the slab , the result is pretty similar and acceptable.

2- For a almost equal load case except by the fact that the concentrated load is 1cm off the slab center , results (forces and reactions) are completely different for the 2 slabs. For the cladding slab , load goes entirely to the closer beam

3- for a load case with a contour load on half area of the slab , results are also completely different.Again , load goes entirely to the closer beam.

Is there any workaround for this or should I understand that this is a limitation (concentraded and contour loads) for the "triangular and trapezoidal method" of claddings load distribution??

Re: Cladding Load Distribution

Artur.Kosakowski — Tue, 07 Jul 2015 14:28:49 GMT

Hi Rafael,

The cladding load distribution is based on the assumption of tributary areas. Loads defined within each of the "regions" are assigned only to elements which "support" them.

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.

Re: Cladding Load Distribution

Rafacascudo — Tue, 07 Jul 2015 15:02:03 GMT

I know that Artur .

But ,as you can see by the pictures I posted above , this assumption can lead to very very wrong results when the load applied is concentrated type , or distributed on contour.

A jelly panel, even with a very coarse mesh, will always give much better results when compared to cladding results , in this particular case.

Re: Cladding Load Distribution

Artur.Kosakowski — Tue, 07 Jul 2015 15:17:33 GMT

Please mind that the cladding load distribution was not intended as the replacement of the exact solution but as the simplified approach for most typical situations such as e.g. uniform load on deck or cladding wall. This is why you can see how the load is distributed and decide for or against use of this method for particular types of loads. Of course there is an option to make such distribution based in entirely different rules (e.g. like meshing claddings > running them as separate substructues with boundary conditions > removing meshes and replace supports with corresponding loads along the supported edges or nodes) but this should go to the idea station part of the forum

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.

Re: Cladding Load Distribution

teixeiranh — Tue, 07 Jul 2015 20:44:44 GMT

Really nice discussion guys 🙂 thank you guys so much for sharing this!