RC T cross section

[AndreVieira]

Hello,

I am new on OpenSees and also with scripts. I am trying to build a T cross section for a reinforced concrete element. The cross section has 250 mm high, 125 mm web thickness, and a slab centralized on the top of the beam with 80 mm thick and 500 mm width. So the total high of the beam (250 mm) includes the thickness of the slab (80 mm). I don't know also how to divide it in many fibers. Should it be divided in confined core and unconfined cover? Or it does not worth?

Does anyone have a suggestion on how to do that with a script?

Thank you !

[fmk]

it depends on the reinforcement .. it is just a bunch of blocks .. you should do some sensitivity analysis to see how many fibers are needed .. start small 10-15 fibers if 2d.

[AndreVieira]

Hello fmk,

Thank you for your response.

I couldn't even build the T cross section yet. That is the main problem to me.

fmk wrote:
> it depends on the reinforcement .. it is just a bunch of blocks .. you
> should do some sensitivity analysis to see how many fibers are needed ..
> start small 10-15 fibers if 2d.

[selimgunay]

The BuildRCrectSection.tcl file in the following link defines a reinforced concrete rectangular section. You can use it as guidance to develop your T section. Please let me know if you have questions.

http://opensees.berkeley.edu/wiki/index ... te_Section

[AndreVieira]

Thank you for your response selimgunay.

I am using this file, however I don't know how to build a T cross section from there, since the information the script BuildRCrectSection.tcl request is to build a rectangular section.

"proc BuildRCrectSection {id HSec BSec coverH coverB coreID coverID steelID numBarsTop barAreaTop numBarsBot barAreaBot numBarsIntTot barAreaInt nfCoreY nfCoreZ nfCoverY nfCoverZ} {"



selimgunay wrote:
> The BuildRCrectSection.tcl file in the following link defines a reinforced
> concrete rectangular section. You can use it as guidance to develop your T
> section. Please let me know if you have questions.
>
>
> http://opensees.berkeley.edu/wiki/index ... te_Section

[apapaso]

I suppose it is possible to do this using two patches, one for the flange and one for the web:

section Fiber 1 {
patch quad 1 12 6 -6 -3 3 -3 3 3 -6 3
patch quad 1 3 24 3 -15 9 -15 9 15 9 3
layer straight ...
}

In the above example, the cords 0,0 correspond to the centre of gravity.

Someone more experienced may confirm if this is the proper way.

[selimgunay]

Yes, concrete can be defined with two rectangular patches and reinforcement can be defined with the layer command. Please check "patch rect" command and "layer straight" command.

http://opensees.berkeley.edu/wiki/index ... ch_Command
http://opensees.berkeley.edu/wiki/index ... er_Command

[AndreVieira]

Thank you all for your responses