To consider strength degradation and stiffness degradation

[wcq19811982]

In the OpenSees analysis, the concrete02 model and the hysteretic material model are used as the material model of the concrete and steel bar, respectively.
I wonder whether the stiffness degradation and strength degradation can be considered in the calculation.
Thank you

[vesna]

Yes, both materials have capability of capturing stiffness and strength degradation.

[wcq19811982]

Dear vesna:
The modified Kent-Park model cannot consider strength degradation in the Ref. [1], the following sentences quoted from the Ref.[1]:
“The concrete damage considered in the present model is in the form of unloading and reloading stiffness degradation for increasing values of maximum strain. But actual concrete damage also includes the reduction of the monotonic envelopes under cyclic loading. This effect is not taken into account in the present model.”

Reference:
[1] Mohd Hisham Mohd Yassin, "Nonlinear Analysis of Prestressed Concrete Structures under Monotonic and Cycling Loads", PhD dissertation, University of California, Berkeley, 1994.

I am so confused now, and can you help me?
Thanks

[kengawk]

Dear wcq
could you please sent me a copy of this dissertation?
I can not find it on line.
my email is kenmonarch@gmail.com.

best regards，

[vesna]

The best way to see what is true is to test the material in compression. Do a monotonic push first and then do a cyclic test. If you you see a difference in the envelope between the two results that means that the material is capable of capturing the strength degradation.

[diegososacaiza]

Dear wcq

Could you please sent me a copy of Reference [1] Mohd Hisham Mohd Yassin, "Nonlinear Analysis of Prestressed Concrete Structures under Monotonic and Cycling Loads", PhD dissertation, University of California, Berkeley, 1994.

I really appreciate it

my email is diegososacaiza@gmail.com

best regards，