Autodesk Robot Structural Analysis

[#1]

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

[#2]

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#M...

[#3]

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.

[#4 · Accepted solution]

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).

[#5]

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?

[#6]

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?

[#7]

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

[#8]

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

[#9]

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

[#10]

. 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