Robot-to-Revit & Reaction (Shear Diagram) Discrepencies

[hazimsal]

Hi All

The issue I need help is two fold:

1. Robot-to-Revit Model Transfer: After transferring the results package to the Revit model, and loading the appropriate shared parameter for the beam tags, I continue to be unable to automatically populate the reaction results and resort to filling them manually. I used to be able to automatically load the reactions pre-Revit/Robot 2016. Any help with this will be extremely appreciated, even if there was a dynamo script to perform this task
2. Reaction Results from Robot: I get major discrepancies when visualizing the reaction/shear diagram results out of the Robot model (Unless I am visualizing the results of a given beam member within the (Composite Beam Design Extension) within Robot. I have
   1. fine-tuned the structural model,
   2. run the "Correct Model" tool, and
   3. manually had the structural model tolerance to 1mm,
   4. all my end bar boundary conditions seem correct as well.
   5. Ran the calculation analysis using the Sparse method with minimal warnings/errors
   6. Checked the meshing for correctness, and changed it to square shapes with a frequency of 0.5 ft for smoother shear/moment diagrams

Please see below for a screen shot showing

(a) the results from Composite Beam Extension in Robot for a reaction of ~9.4 kips matching my hand calculations for a LL = 100 psf, Length = 28.85 ft, and tributary spacing of approx. +/- 6'-0" (R = 1/2 * 28.85 ft * 100/1000 * 6 ft = 8.65 kip)

[Artur.Kosakowski]

HI @hazimsal

1. You created another topic on this point so I'm going to focus on the 2nd point here

2. You are comparing two different types of analysis. The results of static analysis of the deck as defined in RSA and the results 'inside' the composite deck tool are different as they calculate 'different' models. Robot calculates the deck 'as defined' with the slab bi-directional behavior whereas the tool 'isolates' each of the beam > assign the load from the tributary area (rather than calculates internal forces based on the deformation/stiffness of a model) > assumes that beam is supported > calculates beam separately from a model).

In other words if you intend to design the composite deck use the tool rather than the results from the static analysis from Robot.

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

[hazimsal]

Thanks for your prompt response @Artur.Kosakowski

That being the case, if I want a general overview of reactions as applicable by the composite concrete slab, would you recommend running the analysis with my slab revised as a "slab composed with a trapezoid plate" where I can input the slab settings similar to the composite extension?

What else can I do to the model to fine tune or report those reactions globally so I can report those reactions?

[Artur.Kosakowski]

Hi @hazimsal

The composite extension is based on the principle of tributary area slab load being 'assigned' to a simply supported beam with the assumption of the unidirectional load distribution which is not the same as the use of an orthototropic slab. 

The better approach seems to model a slab as a diaphragm (with no mesh) and the assign it the unidirectional load distribution in the direction perpendicular to the defined steel beams.

See also:

https://forums.autodesk.com/t5/robot-structural-analysis-forum/composite-action/m-p/3381625

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

[hazimsal]

Hi @Artur.Kosakowski

Can you be of any assistance with the first issue:

1. Robot-to-Revit Model Transfer: After transferring the results package to the Revit model, and loading the appropriate shared parameter for the beam tags, I continue to be unable to automatically populate the reaction results and resort to filling them manually. I used to be able to automatically load the reactions pre-Revit/Robot 2016. Any help with this will be extremely appreciated, even if there was a dynamo script to perform this task

I have still not gotten any response, I am sure this has been a recurring issue as it has been mentioned many times on the forum but no resolution to it has been found??

The point of staying within the Autodesk suite of software is to facilitate between the documentation and analysis

(The screen shot below shows how we have to manually input the end/start reactions of the beam manually, rather than being able to automatically aggregate the results into the correct Revit parameter)

[Rafal.Gaweda]

Hi @hazimsal

---

1. Robot-to-Revit Model Transfer: After transferring the results package to the Revit model, and loading the appropriate shared parameter for the beam tags, I continue to be unable to automatically populate the reaction results and resort to filling them manually. I used to be able to automatically load the reactions pre-Revit/Robot 2016. 

You are right. The interface between programs was changed at that time and shared parameters are not created. It has been reported to dvlp team to restore this functionality or create new one to allow tagging bar endforces or reactions. Thank You for reporting it.

[hazimsal]

@Rafal.Gaweda Thank you for your response to this matter, I appreciate your time looking into this issue.

Will there be a way to keep users like ourselves informed of a fix if it issued?

[gavin_balls]

Any idea when this will be sorted. Surely it sfundamentla to the whole BIM process.

THanks

[hazimsal]

@Rafal.Gaweda and @Artur.Kosakowski

Kindly ensure to also remind the developers that in addition to the reaction values, we are also concerned about the (Stud Number) and (Camber Value) parameters that also dont transmit back into Revit.

As @gavin_balls mentions, this is debilitating and contrary to what a BIM software should be capable of. That being said, are you able to provide an update on this matter? This seems an easy enough task to repair