topic Re: Concrete flat slab deflection results in Robot Structural Analysis Forum

Concrete flat slab deflection results

Anonymous — Wed, 28 Oct 2015 10:06:50 GMT

Hi helpdesk

I have analysed a concrete flat slab and the deflection results are unrealistic; very low 0-1mm for a 600mm thick slab spanning 4.5m in one direction and 5m in the other!

Can you review the model and see if everything is ok please as I cannot find the error?

Thanks Patrice

Re: Concrete flat slab deflection results

Anonymous — Wed, 28 Oct 2015 10:14:14 GMT

Upload the file please.

Cheers.

Re: Concrete flat slab deflection results

Anonymous — Wed, 28 Oct 2015 10:16:32 GMT

The file is too big and it won't load it, I am trying to reduce the file any suggestions as I read before that you can't open zipped files?
P

Re: Concrete flat slab deflection results

Anonymous — Wed, 28 Oct 2015 10:20:37 GMT

Save without results and zip the file.

If the file is big, try this. http://forums.autodesk.com/t5/robot-structural-analysis/sending-bigger-files/td-p/3795062

Re: Concrete flat slab deflection results

Anonymous — Mon, 02 Nov 2015 10:32:32 GMT

Hi autodesk

the file zipped and without results attached.

Can you review the model with regard to the deflection results; it gives 1mm total which seems unrealistic?

Thanks Patrice

Re: Concrete flat slab deflection results

Anonymous — Mon, 02 Nov 2015 10:56:22 GMT

In my opinion, the results (displacements) are ok. You have a slab with 500mm thickness with relative short lenght span. In consequence, the displacements are shorts.

Re: Concrete flat slab deflection results

Rafal.Gaweda — Mon, 02 Nov 2015 10:57:41 GMT

Yor slab is 500mm thick

So if you look at simply supported 5m beam with your slab section, under selfweight you get elastic (FEM) deflection of 0.3mm

So the rest seems to be OK.

Re: Concrete flat slab deflection results

Anonymous — Tue, 03 Nov 2015 10:47:16 GMT

Thanks for reviewing the model and the deflection results. However there is approximately a 6m high cantilever wall 250mm thick and it does not flag up any deflection issues at all stating 1mm max which I find hard to accept as it would be of the order of 37.5mm (in the x direction) or so by quick hand calculation.

Am I not looking at it correctly or what value is it showing for the lateral deflection of the walls?

Thanks Patrice

Re: Concrete flat slab deflection results

Anonymous — Tue, 03 Nov 2015 11:05:59 GMT

Which is the wall that you refer? The maximum height wall in the file is 3.75m.

This is the displacement along the wall (Self Weight)

Re: Concrete flat slab deflection results

Rafal.Gaweda — Tue, 03 Nov 2015 11:57:42 GMT

1. Walls are 3,75m high
2. There are no loads on them except sw