topic Re: Adding a different thickness to part of a slab in Robot Structural Analysis Forum

Adding a different thickness to part of a slab

Anonymous — Sat, 11 Aug 2012 09:43:03 GMT

Consider the slab on the image, 250mm thick.

I need to make the gray area on the right thicker, 500mm. Is there a way to "divide" the slab into two?

I tried the "divide" tool but it doesn't work on slabs in Robot 2012. I then created the slab in gray to the right, on top of the original red one. But then there's another problem: is it possible to trim the red slab somehow? The "trim" tool also seems not to do the job.

I'm trying not to have to remodel the slab from scratch and re-apply all the loads.

Thanks in advance

Joao

Re: Adding a different thickness to part of a slab

Anonymous — Mon, 13 Aug 2012 05:45:48 GMT

For the slab highlighted in red there are 3 options.

Redraw it
After slecting it (and it goes red) hover the mouse on one of the edges you want to move, the edge will go blue. Then click this edge and you will be able to drag it to the new location (at the edge of the grey panel).
Click on contour definition in the object inspector and manually edit the coordinates of the edge to be changed.

Tony

Re: Adding a different thickness to part of a slab

Artur.Kosakowski — Mon, 13 Aug 2012 06:57:01 GMT

If you create a smaller panel inside a larger one the properties assigned to the smaller one will be assigned to surface elements generated there. There is no need to trim the red panel (the overlapped part of the larger panel will not be 'double' meshed).

For the loads: you have to add smaller panel number (list of elements column in the loads table) to already defined surface loads or define them in the way shown below:

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: Adding a different thickness to part of a slab

Anonymous — Mon, 13 Aug 2012 07:04:27 GMT

Artur,

You won't get the "overlapping panels" error with this method?

Tony

Re: Adding a different thickness to part of a slab

Artur.Kosakowski — Mon, 13 Aug 2012 07:38:46 GMT

No, you will not. This is a panel within a panel rather than a part of the panel over a part of a panel

This 'cuts off' a part of a larger panel - in the same way you create openings (then it is just an inner contour with no new thickness assigned).

Re: Adding a different thickness to part of a slab

Anonymous — Sat, 18 Aug 2012 08:10:18 GMT

The problem with this slab particularly is that it's made of lines and curves. By selecting an edge or node, it will drag the adjacent elements - if they're a curve, it will grow really big.

Probably the best way is to redraw it node by node with lines, two separate slabs. The problem with having one slab on top of the other is that the columns below would be connected to both slabs. That means that the node rigidity would not be calculated right, unless both the slabs would have the same equivalent moment of inertia as one 500mm slab, which is very unlikely!

Just wanted to know if there was a way to divide the slab into two, like you can do with the bars. But it seems there isnt.

Thanks for the reply though.

Joao

Re: Adding a different thickness to part of a slab

Artur.Kosakowski — Mon, 20 Aug 2012 06:52:04 GMT

1. Draw a line at the border of the thinner and the thicker parts

2. Mesh the panel as it is

3. Open the panel definition dialog and define the thicker/thinner part based on the selection of surface elements from either side of the line

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: Adding a different thickness to part of a slab

Mirko.Jurcevic — Wed, 25 Sep 2013 08:59:16 GMT

O M G !!

The whole morning I've been trying to do a simple task like that and I can't do it.

I want to change some part of slab to be 45cm thick (rest of the slab is 20cm thick), but there is no way to do it.

Why is panel manipulation so complicated?!

I am going to try that FE thing, but I am not optimistic..

Re: Adding a different thickness to part of a slab

Rafal.Gaweda — Wed, 25 Sep 2013 09:36:15 GMT

This way http://screencast.com/t/sTCYALMgO maybe?

Re: Adding a different thickness to part of a slab

Mirko.Jurcevic — Wed, 25 Sep 2013 09:53:19 GMT

I'm sorry, but that's just not working for me.

I will send you link to my model and try to do that there.

Re: Adding a different thickness to part of a slab

Rafal.Gaweda — Wed, 25 Sep 2013 09:54:50 GMT

Re: Adding a different thickness to part of a slab

Mirko.Jurcevic — Thu, 26 Sep 2013 07:55:35 GMT

I must admit that I didn't read carefully posts made by Artur.

The solution / explanation that Rafal gave me is, in fact, already explainded by Artur's posts.

However, to share information with others in need, solution is simple:

If you need another type of panel thickness within one panel type, you just draw it like you draw oppening.

As Rafal says: "Properties of most inner panels are considered in such areas" (when generating FE mesh).

Re: Adding a different thickness to part of a slab

Rafal.Gaweda — Thu, 26 Sep 2013 07:57:21 GMT

Screen shot to above post