Inclined Torsion beam issues

[Anonymous]

Morning All,

Please refer to attached screenshots and RTD file. Inclined beam 33 is supporting torsional loads from panel 36. Beam 33 is chemical anchored to a wall which offers vertical support only. Torsion moments are transferred by beam 33 to beams 13 & 7.

On analysing "provided reinforcement" of beam 33 RC element the following issues arise:

1) Screenshot below of axial force warning - the path indicated in the warning does not correspond to the path in Rorobt 2013, so not sure how to activate this "advanced analysis option"?.

2) I have added nodal pinned supports along beam 33 to represent chemical anchors. These anchors solely resist vertical load as the wall is not sufficient to take chemical anchor pullout (hence requirement of torsion beam 33). The problem is that the provided reinforcement analysis only considers a small segment of beam 33 - is it possible to analyse torsion in the full 4.7m length of beam 33 and get correct torsion reinforcement while still benefiting from intermediate PINNED chemical anchor supports?

Many Thanks,

Scott

[Anonymous]

If anyone gets this axial load warning, it's not in the main Robot "analysis" pull down menu, it's within the provided reinforcement module - transfer affected beam to PR modle, click past the axial load warnings, there is an option in "calculation options - general - advanced".

 However.. on enabling this option, a similar warning pops up regarding inclined elements. See screenshot below. If anyone can shine some light on issues 1 & 2 listed here and above it would be greatly appreciated.

[Anonymous]

interestingly, the warning popping up in post 2 seems to be creating random reinforcement outside of the beam, see attached screenshot?

[Artur.Kosakowski]

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@Anonymous wrote:

Morning All,

1) Screenshot below of axial force warning - the path indicated in the warning does not correspond to the path in Rorobt 2013, so not sure how to activate this "advanced analysis option"?.

As shown on the attached picture.

2) I have added nodal pinned supports along beam 33 to represent chemical anchors. These anchors solely resist vertical load as the wall is not sufficient to take chemical anchor pullout (hence requirement of torsion beam 33). The problem is that the provided reinforcement analysis only considers a small segment of beam 33 - is it possible to analyse torsion in the full 4.7m length of beam 33 and get correct torsion reinforcement while still benefiting from intermediate PINNED chemical anchor supports?

I'm not sure if I understand this point. If you activate torsion calculation it will be done along the whole beam length.

P.S. Mind the accuracy of the definition of the model (beam and panel are separated - see the attached picture).

Many Thanks,

Scott

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[Artur.Kosakowski]

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If anyone gets this axial load warning, it's not in the main Robot "analysis" pull down menu, it's within the provided reinforcement module - transfer affected beam to PR modle, click past the axial load warnings, there is an option in "calculation options - general - advanced".

 However.. on enabling this option, a similar warning pops up regarding inclined elements. See screenshot below. If anyone can shine some light on issues 1 & 2 listed here and above it would be greatly appreciated.

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http://docs.autodesk.com/RSA/2013/ENU/index.html?url=filesROBOT/GUID-324EEFCA-AC75-416D-B249-4F62797...

[Artur.Kosakowski]

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interestingly, the warning popping up in post 2 seems to be creating random reinforcement outside of the beam, see attached screenshot?

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As far as I can see the reinforcement generator was not able to correctly distribute rebars in the beam. This will need to be further investigated by the development team. Thank you for notifying us about this issue. To get the information about required amount of reinforcement for this beam you can try to use the RC Members trequired reinforcement module instead.

[Anonymous]

Hi Artur,

Extract from that link:

"

Comments concerning generation of reinforcement for inclined beams

Currently:

• Torsion reinforcement is not generated
• Bielle reinforcement (for BAEL) is not generated
• Stirrups are always perpendicular to the beam edge
• Deflection is ignored

"

ouch, inability to deal with torsion or deflection are pretty major concerns. Is this going to be resolved in any recent Robot update and if not is there any work-around possible to get this reinforcement for now?

Many Thanks,

Scott

[Artur.Kosakowski]

You can use the other design module ( RC Members required reinforcement) which will provide you the necessary amount of both main and transversal reinforcement with torsion being taken into account. You can use ASD Reinforcement to produce final drawings based on this information.