A question on formulation of Concrete02 material

[MMUCQC]

Hi,

I am trying to use Concrete02 material in a concrete section analysis. However, I am somehow confused on how this material model works. My questions regarding this material model are as:

1- Referring to Yassin's thesis which is introduced as the reference of development for this material model, the concrete can go under tension loading only twice and will not have any tension capacity thereafter (Yassin 1994, Page 46). However, the hysteretic loops presented for Concrete02 material in OpenSees documentation shows that concrete material can go under tension loading for many times. Could you please clarify how this material model is defined in OpenSees?

2- Referring to Yassin's thesis, could you please clarify how the tension reloading stiffness is defined? I.e. is this stiffness a duplication of pervious tension unloading or initial tension unloading (Yassin 1994, Page 46)?

Thanks.

[linguan118]

You can find them in the source code of this model

[fmk]

I asked Prof. Filippou to respond. This is what he sent:


I am confused by the first question. Mohd shows two excursions
but it is clear that any number of excursions are allowed. How
many did the user expect to be shown in the plot? 10, 100 or 1000?

The reloading stiffness is clearly defined in Fig. 2.11. I do not
believe that words are required. Simply follow the arrows.