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Distinguished Contributor
Posts: 155
Registered: ‎10-10-2012

Vertical eccentricity of columns

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12-27-2012 01:56 PM

  When we have a (R/C) column upon which it is placed with vertical eccentricity a column with smaller section dimensions, the usual way is to define manually an artificial rigid member between the C.W of the two members (since it isn’t generated automatically from the program) with high values of basic and mechanical properties.

  Is there any chance for that kind of modeling to be generated in a “less manual” way? For instance, if we try to define an internal node along the beam that ends to that column but in a point that belongs to offset length that has been already defined between beam and column (see attached screen capture), would that modeling be precise?

 

  And also a question that concerns the manual way: what kind of magnitude of values should we assign to properties of that artificial rigid member in order not to face numerical problems? (I am getting a message “Instability of type (2) detected at node” of rigid member).

 

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Distinguished Contributor
Posts: 155
Registered: ‎10-10-2012

Re: Vertical eccentricity of columns

12-27-2012 10:21 PM in reply to: Tuctas

  I forgot to mention that usually we are not able to define a rigid link (instead of a rigid member) because in that case we are not able to include that node to the diaphragm of the corresponding floor (diaphragm=rigid links and a node cannot belong to more than one master node)..

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Product Support
Posts: 4,459
Registered: ‎04-26-2010

Re: Vertical eccentricity of columns

12-27-2012 11:05 PM in reply to: Tuctas


  And also a question that concerns the manual way: what kind of magnitude of values should we assign to properties of that artificial rigid member in order not to face numerical problems? (I am getting a message “Instability of type (2) detected at node” of rigid member).

 


I usually define them with such data:

 

StiffSectionData.SetValue I_BSDV_AX, 100000000
StiffSectionData.SetValue I_BSDV_IX, 100000000
StiffSectionData.SetValue I_BSDV_IY, 100000000
StiffSectionData.SetValue I_BSDV_IZ, 100000000

 

 



Rafal Gaweda
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Distinguished Contributor
Posts: 155
Registered: ‎10-10-2012

Re: Vertical eccentricity of columns

12-28-2012 07:36 AM in reply to: Tuctas

  I use similar properties too. I also assign a material with no weight (for a more rational modeling), i don't know if that is the reason of getting the error message ?

 

  What about my first question, can we create a node that belongs to the offset lenght? Or, is there any other way of making such modeling?

 

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Product Support
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Re: Vertical eccentricity of columns

12-28-2012 08:23 AM in reply to: Tuctas

Tuctas wrote:

  I use similar properties too. I also assign a material with no weight (for a more rational modeling), i don't know if that is the reason of getting the error message ?

 

Send me example to check.

 

  What about my first question, can we create a node that belongs to the offset lenght? Or, is there any other way of making such modeling?

 

Use offset , if not create offseted bar manually.

 



Rafal Gaweda
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Distinguished Contributor
Posts: 155
Registered: ‎10-10-2012

Re: Vertical eccentricity of columns

12-28-2012 12:05 PM in reply to: Rafal.Gaweda

  I changed the equation solver ( I turned it to Skyline) and the error message of instability of type2 didn’t occur (an instability of type 3 occurred for another node that I think is less important).

 

  I am not sure if my question concerning the definition of internal node was clearly enough.

  In the new attached picture, member (RC beam) 98 is subdivided by the “Division” tool and after that a new (internal) node #122 was created. Beam’s ending node is #66 and an offset has been previously defined as it is shown in the picture. The new internal node (122) is placed in the offset length (=0.55m) and it supposed to be the starting node of the steel column. So actually the offset is splited in to two parts. Is this definition precise?  

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Distinguished Contributor
Posts: 155
Registered: ‎10-10-2012

Re: Vertical eccentricity of columns

01-07-2013 06:58 AM in reply to: Tuctas

  Any opinion?

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Product Support
Posts: 4,459
Registered: ‎04-26-2010

Re: Vertical eccentricity of columns

01-07-2013 08:01 AM in reply to: Tuctas

Why \ what is the purpose to define it this way?

Maby any 3d screen shot because we do not understand clearly your description.



Rafal Gaweda
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Distinguished Contributor
Posts: 155
Registered: ‎10-10-2012

Re: Vertical eccentricity of columns

01-08-2013 03:03 AM in reply to: Tuctas

The purpose is just for simplicity. Many programs do this rigid link connection automatically so i an wondering ifin ARSA there is any similar ("automatic") way.

 See the new attached picture, maybe it's more clear.

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Product Support
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Registered: ‎04-26-2010

Re: Vertical eccentricity of columns

01-08-2013 04:27 AM in reply to: Tuctas

Use manually defined rigid links.



Rafal Gaweda
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