topic Re: Only reaction for new model (API) in Robot Structural Analysis Forum

Only reaction for new model (API)

Refaat — Mon, 15 Oct 2012 09:09:12 GMT

Hi sirs

I have large strucutre model . Can you help me to get only reaction of structure model and export to a new model of robot to analysis and design only raft foundation?

Note : When i saved the raft as (Substructure) , I couldnt do any changes such as (elastic coeficient value). because i will lose every thing .

Thanks

Refaat

Re: Only reaction for new model

Artur.Kosakowski — Mon, 15 Oct 2012 08:43:05 GMT

You may try to use the following approach:

1. Calculate the entire model and display reactions in the table for the part you want to analyze in the separate model

2. Convert this table to Excel and modify so that it has the load table arrangement. The goal is to replace reactions with nodal forces for the substructure model

3. Save the substructure with the part of the model you want to design

4. Open the substructure and make the necessary geometrical changes

5. Replace the loads with the modified one from the Excel table

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: Only reaction for new model (API)

Rafal.Gaweda — Mon, 15 Oct 2012 09:08:52 GMT

I am attaching Excel file with macro doing that.

Mininmum force value - forces, moments with values lower than indicated (in N) will not be applied to target model.

Let me know if you need more explanations.

Re: Only reaction for new model (API)

Refaat — Mon, 15 Oct 2012 14:57:09 GMT

Thanks all ,

Dear Rafal

It is great to use this micro for the nodal support case , but I will be very happy if I get help (micro) for my case in the attached file . I want to get the forces and moments in columns and wall then I will use them in separate file(target file) to analysis and design raft foundation only.

Thanks a lot

Refaat

Re: Only reaction for new model (API)

Rafal.Gaweda — Tue, 16 Oct 2012 07:35:51 GMT

This macro transfer reactions from supports but you need something else = different macro, I have such macro but I need to adjust it to your needs. Also model must be modified in certain way.

Re: Only reaction for new model (API)

Refaat — Tue, 16 Oct 2012 07:34:34 GMT

Thanks all ,

Dear Rafal

It is great to use this macro for the nodal support case , but I will be very happy if I get help (macro) for my case in the attached file . I want to get the forces and moments in columns and wall then I will use them in separate file(target file) to analysis and design raft foundation only.

Thanks a lot

Refaat

Re: Only reaction for new model (API)

Refaat — Tue, 16 Oct 2012 07:54:48 GMT

Dear Rafal

I very much appreciate your effort, and I'm waiting for the right macro for my case , I will be very happy to get it.

Thanks in advance

Refaat

Re: Only reaction for new model (API)

Rafal.Gaweda — Tue, 16 Oct 2012 12:12:50 GMT

Macro takes internal forces from bottom (geometricaly lower Z coordinate nodes) of selected bars and adds them as loads (transfered to GCS) to target file. It is recommended to keep node numbers the same in both files like in previous macro.

So your original model must be changed a little. Wall must be disconnected from slab and connected by bars with very high stiffeness (similar to rigid link). Take a look at attached files

Re: Only reaction for new model (API)

Refaat — Wed, 17 Oct 2012 07:15:03 GMT

Dear Rafal

I would like to greet you for your assistance , and could i know if there is any other way (macro) to get the internal forces in RC walls specially when we have large structure with many RC walls?

Thanks

Refaat

Re: Only reaction for new model (API)

Rafal.Gaweda — Wed, 17 Oct 2012 07:44:31 GMT

You can get all results (almost?) from robot by API but I guess you are not looking for internal force results maybe reduced forces.

I guess the simplest procedure should be like that:

- from original model copy foundation slab to new file

- remove this slab and apply supports under walls \ columns attached previously to foundation slab, calculate model and save it.

- use macro to transfer reactions as loads into slab only model

- play with slab only model.

- when you are happy with slab results please update slab data in original model and calculate it

Re: Only reaction for new model (API)

Refaat — Wed, 17 Oct 2012 11:30:39 GMT

Dear Rafal

If I use the elastic supports under RC walls/columns,

e.g. (K=40000 KN/m (constant elastic coef. At support nodes is active) & K=40000 KN/m) respectively. Knowing that the raft slab has (K=40000 KN/m3).

My question is

Does it give me more accurate results than if I use the fixed supports?

Thanks

Refaat

Re: Only reaction for new model (API)

Rafal.Gaweda — Wed, 17 Oct 2012 11:38:34 GMT

Use fixed supports then play with slab as I recommended.

Re: Only reaction for new model (API)

Refaat — Wed, 17 Oct 2012 14:33:33 GMT

Wonderful , Thank you:smileyhappy:

Refaat

Re: Only reaction for new model (API)

RRufino — Tue, 01 Oct 2013 11:48:08 GMT

Hi Rafal,

Any caution is needed when using your API with diagonal bars (as vertical bracing) or with tension bars?

Thanks

Re: Only reaction for new model (API)

Rafal.Gaweda — Tue, 01 Oct 2013 12:45:14 GMT

Reaction macro - does not matter type of bar.
Force macro - does not matter type of bar; Macro takes internal forces from bottom (geometricaly lower Z coordinate nodes) or if bar is horizontal -> forces from endnode of selected bars and adds them as loads (transfered to GCS) to target file.

Re: Only reaction for new model (API)

RRufino — Tue, 01 Oct 2013 13:27:50 GMT

Rafal,

Please take a look at this case: http://we.tl/ibjhCT8qtX

I've used internal force macro. I'm getting this issues:

- on target nodes corresponding from nodes with vertical bracing on source file, some forces aren't ok. Per example: node 8

- some nodes, like 2571 have 3 nodal cases but on source file there exist just to bars.

Thanks in advance,

RRufino

Re: Only reaction for new model (API)

Rafal.Gaweda — Tue, 01 Oct 2013 21:11:11 GMT

I have changed terget filename onto NFC#26.rtd

min force =1

Re: Only reaction for new model (API)

RRufino — Wed, 02 Oct 2013 09:00:00 GMT

Hi Rafal,

But isn't "Minimum force: forces, moments with values lower than indicated (in N) will not be applied to target model"?

How putting Minimum force equal to -10000000000000000 (N) is affecting my target file forces? This was just a way to get all forces on target file.

And about node 2571?

Re: Only reaction for new model (API)

Rafal.Gaweda — Wed, 02 Oct 2013 09:07:58 GMT

How putting Minimum force equal to -10000000000000000 (N) is affecting my target file forces? This was just a way to get all forces on target file.

It does not matter. Minimal force is kind of tolerance .....Abs(fx) > MIN_VAL....

And about node 2571?

Explain please.

Re: Only reaction for new model (API)

RRufino — Wed, 02 Oct 2013 09:27:23 GMT

"It does not matter. Minimal force is kind of tolerance"

So can i put zero?

"Explain please."

Some nodes, like 2571 have 3 nodal cases on target file but on source file there exist just two bars.

P.S.: I forgot to say thank to this two macros you create 😉