Basic forces of Elastic Beam column element

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SadeghSalimian
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Basic forces of Elastic Beam column element

Post by SadeghSalimian »

Hi dear friends I want to record basic forces of a series of elastic beam columns in my model. in fact I need to record axial force and moments of each end of element as well as shears on each joint, but I found the recorder for this type of elements includes force command which records forces in the global coordinate. it does not record even local forces. I do not know how to deal with this issue. especially when the model is 3D. I was wondering if someone could help me and share his or her experience about this matter.

best regards.
selimgunay
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Re: Basic forces of Elastic Beam column element

Post by selimgunay »

Actually you can record forces in the local coordinate with the following command:

recorder Element -file ele1local.out -time -ele 1 localForce
venkateshyadav
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Location: IIT Patna

Re: Basic forces of Elastic Beam column element

Post by venkateshyadav »

selimgunay wrote:
> Actually you can record forces in the local coordinate with the following
> command:
>
> recorder Element -file ele1local.out -time -ele 1 localForce

Hi,
By using this command localForce, get an output as
4641.94 -1.48777 892839 -3995.07 1.48777 -897303
Can you explain me in this which is Axial force column and which is shear force column in that list?
venkateshyadav
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Location: IIT Patna

Re: Basic forces of Elastic Beam column element

Post by venkateshyadav »

It is a 2d problem.
So you mean 4641.94 is the axial force?
So as you said, if it is axial force. Then how to find out the shear forces in that particular element
selimgunay
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Re: Basic forces of Elastic Beam column element

Post by selimgunay »

The first three are the forces at node i and the last three are forces at node j. The first one should be axial (local x), second one should be shear (local y) and the third should be moment, but please check the column headings by using -xml instead of -file in the recorder syntax.
venkateshyadav
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Location: IIT Patna

Re: Basic forces of Elastic Beam column element

Post by venkateshyadav »

selimgunay wrote:
> The first three are the forces at node i and the last three are forces at
> node j. The first one should be axial (local x), second one should be shear
> (local y) and the third should be moment, but please check the column
> headings by using -xml instead of -file in the recorder syntax.

Hi selimgunay,
Thanks for your reply. I checked by changing the heading -xml. And it is displaying as below the 6 columns:
<ResponseType>Px_1</ResponseType>
<ResponseType>Py_1</ResponseType>
<ResponseType>Mz_1</ResponseType>
<ResponseType>Px_2</ResponseType>
<ResponseType>Py_2</ResponseType>
<ResponseType>Mz_2</ResponseType>

So here you mean that Px1 is the axial force at end 1 and Py1 is the shear force at end 1 and so on...
Is the interpretation correct?
fmk
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Re: Basic forces of Elastic Beam column element

Post by fmk »

yes
venkateshyadav
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Location: IIT Patna

Re: Basic forces of Elastic Beam column element

Post by venkateshyadav »

fmk wrote:
> yes

Hi, thanks for your reply.
Is there any way to model shear hinge i.e., shear capacity failure criteria in opensees.
By section aggregator one can aggregate the shear with fiber section. But before aggregating how to define the shear capacity of the column so that the column after reaching that limit it goes to failure zone. Am doing pushover analysis
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