topic Re: RC beam/column warnings & pinned linear joint problem in Robot Structural Analysis Forum

RC beam/column warnings & pinned linear joint problem

Anonymous — Fri, 14 Sep 2012 10:23:16 GMT

Morning All,

Apologies for the probably basic questions which follow. I'm learning as I go along. I have a few problems when trying to run reinforcement analysis:

1) Referring to screenshot, the bottom of the stairs simply provides a small amount of dead weight on the garage slab. They are cast seperately. I've provided a linear edge pin at the stair slab base where it touches down on the garage slab. However the RC slab analysis is still quoting a huge 2156mm^2 reinforcement requirement. Any idea what I've done wrong?

2) in the reinforcement results, I can't see all the text in the remarks column, theres no way to stretch the column wide enough to read the text?

3) on some 300x600 RC columns I have no errors but warning remarks. ... represents the chopped off text "...ternal calculation nodes. The calculations of reinforcement may be incorrect". I've got no idea what the warning is going on about or how to fix it. Any ideas? If it's (I'm guessing) a clash between RC wall/slabs FE mesh nodes and RC columns is there a way of fixing this fairly painlessly?

4) when running calculation, I get a warning "required types are not ascribed to SLS combinations". However I have set up serviceability and ULS load combinations. I've attached my model in case someone can spot what I've missed.

5) I also have a spike in reinforcement of approx 1500mm^2 in the left hand corner where the garage roof slab meets the front central wall. Is there any way of releasing this corner? In practise there wont be a moment connection at the corner, the reinforcement will be lapped at the flat faces only.

Many thanks, any feedback is greatly appreciated. Robot model is attached here:

https://www.filemail.com/dl.aspx?id=EDSSXKRVVRLUQOF

Scott

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Fri, 14 Sep 2012 11:47:23 GMT

4) when running calculation, I get a warning "required types are not ascribed to SLS combinations". However I have set up serviceability and ULS load combinations. I've attached my model in case someone can spot what I've missed.

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/SLS-combination/m-p/3316923/highlight/true#M2483

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Fri, 14 Sep 2012 14:05:09 GMT

2) in the reinforcement results, I can't see all the text in the remarks column, theres no way to stretch the column wide enough to read the text?

Why not possible? Just drag the border lines.

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Fri, 14 Sep 2012 14:20:08 GMT

1) Referring to screenshot, the bottom of the stairs simply provides a small amount of dead weight on the garage slab. They are cast seperately. I've provided a linear edge pin at the stair slab base where it touches down on the garage slab. However the RC slab analysis is still quoting a huge 2156mm^2 reinforcement requirement. Any idea what I've done wrong?

Your support is applied to stairs + slab

So either separate these objects or remove support or apply lienear release at the bottom egde of stairs (be carefull about release directions).

Re: RC beam/column warnings & pinned linear joint problem

Anonymous — Fri, 14 Sep 2012 14:44:23 GMT

Thanks for the input Rafal 🙂 I've tried releasing "Edge 4" of the panel 459 as "pinned-pinned" but it seems to only release all edges as pinned, and after applying the release there is no was of checking which edge of an object has release conditions. Is it possible to specify only 1 linear edge release at the base of the stairs panel?

Re: RC beam/column warnings & pinned linear joint problem

Anonymous — Fri, 14 Sep 2012 14:46:16 GMT

Also regarding item 2) How can I remove internal nodes from within a column to remove the warnings that are popping up without having to manually (and painfully) trim back all the wall panels?

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Mon, 17 Sep 2012 10:05:55 GMT

These warnings are presented for columns in walls \ panels so you neede mesh nodes along column to properly connect these elements.

Re: RC beam/column warnings & pinned linear joint problem

Anonymous — Mon, 17 Sep 2012 11:50:33 GMT

Hi Rafal,

Regarding item 5) above - I've attached a screenshot of the reinforcement hot spot. The screenshot is of a roof slab connecting to an RC wall corner. In practise the reinforcement will be lapped along edges, so is there a way of releasing the nodal corner only at the wall corner - slab?

Many Thanks,

Scott

Re: RC beam/column warnings & pinned linear joint problem

Anonymous — Mon, 17 Sep 2012 12:09:26 GMT

Hi Rafal,

Regarding the earlier problem I had:

"These warnings are presented for columns in walls \ panels so you neede mesh nodes along column to properly connect these elements."

Could you give a bit more guidance please on how I acheive the above please? I had nodes all over the building to start with but a lot of them have been removed during FE meshing, FE mesh removal (for editing), and panel alterations. I have quite a few cases where the wall panels seem to clash with the embedded RC columns and assumed Robot could distinguish between the two rather than having to manually (and painfully) separate panels from columns at all intersections?

Many Thanks,

Scott

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Mon, 17 Sep 2012 12:33:00 GMT

. In practise the reinforcement will be lapped along edges, so is there a way of releasing the nodal corner only at the wall corner - slab?

No you can apply linear releases to panels. Divide \ create shorter edge nead the corner and apply there releases

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Mon, 17 Sep 2012 12:47:01 GMT

Opel5 wrote:

Thanks for the input Rafal 🙂 I've tried releasing "Edge 4" of the panel 459 as "pinned-pinned" but it seems to only release all edges as pinned, and after applying the release there is no was of checking which edge of an object has release conditions. Is it possible to specify only 1 linear edge release at the base of the stairs panel?

Example

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Mon, 17 Sep 2012 13:13:53 GMT

Scott

Could you give a bit more guidance please on how I acheive the above please? I had nodes all over the building to start with but a lot of them have been removed during FE meshing, FE mesh removal (for editing), and panel alterations. I have quite a few cases where the wall panels seem to clash with the embedded RC columns and assumed Robot could distinguish between the two rather than having to manually (and painfully) separate panels from columns at all intersections?

See below.

Look also at difference between results.

Re: RC beam/column warnings & pinned linear joint problem

Anonymous — Tue, 25 Sep 2012 07:15:50 GMT

Hi Rafal,

I've finally got a chance to go back and follow your advice concerning below:

. In practise the reinforcement will be lapped along edges, so is there a way of releasing the nodal corner only at the wall corner - slab?

No you can apply linear releases to panels. Divide \ create shorter edge nead the corner and apply there releases

But can't seem to find a way of neatly dividing a small L-shaped peice of the roof slab panel at the outward wall corner in the attached screenshot to remove the reinforcement spike?

Re: RC beam/column warnings & pinned linear joint problem

Rafal.Gaweda — Tue, 25 Sep 2012 15:10:02 GMT

Scott

Divide \ create shorter edge nead the corner and apply there releases

Divide WITH node generation, then select panels edge.

Re: RC beam/column warnings & pinned linear joint problem

Artur.Kosakowski — Thu, 04 Oct 2012 13:58:34 GMT

Scott,

The procedure as requested.

Re: RC beam/column warnings & pinned linear joint problem

Anonymous — Thu, 04 Oct 2012 14:25:12 GMT

Thanks Artur 🙂 Got the hang of the procedure now