fiber section

[abazarnejad]

i need to model a square fiber section, i wanna know which material command for concrete and steel has a better response for cyclic loading
any guidance will be appreciated.

[vesna]

Steel02 and ReinforcingSteel are proven to work well for modeling reinforcing bars. Concrete01, Concrete02, Concrete06, and Concrete07 are all good for modeling concrete.

[abazarnejad]

thanks
I will try them

[abazarnejad]

how about confinedconcrete01? I need to model confined concrete.
I tried steel02+concrete04 & concrete07 and also confinedconcrete01, but I can't set the accuracy of the results as i change the steel02 parameters like Bs, R0 , cR1 , cR2 .

[vesna]

You can try confineconcrete01 too.

Try to find experimental results from a similar column and calibrate your materials against experimental results. PEER has a good database of experiments on columns: http://www.ce.washington.edu/~peera1/main.htm

[abazarnejad]

I need to do a push-over analyse but the strength of the model does not fall!! it continually increases.
How can i fix it? I used concrete07 and steel02 for RC column modeling.
any help would be appreciated

[vesna]

Record stress-strain relationships of steel and concrete fibers to see what is the state of your materials at the largest displacement you applied on your column. That will help you understand your problem better.

[sadaf_rkh]

i need an example of this code,i mean "concrete07" in (Mpa) if any one try it and it works correct

[amir70007]

Hi...

How can I decide about number of subdivisions in a fiber section?
Does it give better results If I model it with more subdivisions?

[salehi]

salAm amir,

For developing fiber-sections you must use patch commands (for more information about the detail of these commands I refer you to OpenSees Command Manual); of course, more fibers along the direction you have stress distribution, results in more accuracy (I mean perpendicular to moment axes). I hope you get the point

Good Luck,
Salehi

[wuhaoshrek]

vesna wrote:
> You can try confineconcrete01 too.
>
> Try to find experimental results from a similar column and calibrate your
> materials against experimental results. PEER has a good database of
> experiments on columns: http://www.ce.washington.edu/~peera1/main.htm

Hi, vesna,

I was wondering about the material calibration. Most test data in the PEER database
is on the flexural behavior of columns, so how can we use the data to calibrate the material,
can you explain a little more in detail? thx.

[vesna]

To calibrate material based on experimental results you need to play with material parameters to figure out the set of parameters that would produce the response of the column similar to one observed experimentally.