I think that you can use the related stress-strain graph for your model. It is difficult to model a micro-structure in ABAQUS and giving all interaction in that scale. 

You have to obtain the actual stress-strain curves experimentally for your concrete patch in both tension and compression. Thus, you can use them in the simulation. The main contribution of the fiber in the ECC appears in the post-peak branch of the stress-strain curve. You feed the ABAQUS by the plastic strain curve so that you can capture the actual behavior of the ECC material. 

Dear Mr. Mehdi Lima and Mr. Hamdy Afefy

Thank you for your suggestion. So, is it correct if I use CDP model to apply both stress and strain in abaqus? or I have to use another plasticity parameter? If it is CDP model, I doubt how to input the proper plasticity parameter such as dilation angle, etc except the stress and strain due to compression and tension. 

Regards,

In ABAQUS, you should provide : Density, Modulus of Elasticity, Poission ratio and concrete damage plasticity parameters included: plasticity, compressive behavior and tensile behavior. You can have tension or compression damage as well.  you can have a look at ABAQUS manual to find more about these parameters. 

Thank you Mr. Mehdi Lime for such advanced commentary. Anyway, I have already used those input parameters for normal concrete and the model ran perfectly. However, I seem a bit confuse to apply those parameters in PVA-ECC Concrete. Is it okay to apply the same plasticity input like normal concrete in PVA-ECC concrete (except the stress-strain relationship for both compression and tension)

Regards

Thank you for the commentaries. I look forward to your post, Mr. Arabzadeh. It is quite difficult for me to understand the whole behavior for fiber reinforced concrete in Abaqus. I never use Kinematic Hardening in the material input.

Dear Asdam, you must use the Lamina option and define the section as a membrane. Also the element that you pick up is membrane such as M3D4R. 

Dear Mr. Mohammadi

How to convert the solid element to membrane? I am modeling slab-column connection.

Dear Mr. Arabzadeh

Thank you, I will look at the report and I will let you know.

I thought your case is FRP sheets attached to concrete or wrapped around it. Yes of course concrete is modeled by another elements.

Thank you for the answer Mrs. Smitha Gopinath.

I also thought so, the use of stress-strain data is a better alternative to model randomly fibers within concrete

Internal fibers act as component of the concrete, like aggregate, in case of fiber concrete. Therefore, it is better to use the actual stress-strain relationships for both compression and tension obtained by experimental tests on standard specimens.

 Dear bro. there is no need to respect the amount of fiber in your abaqus modeling. However, the best way to add the ECC properties is to get some information about CDP for both compression and tensile. 

Dear All Colleagues,

Thank you for your participation to solve my issue. For now, the issue has been solved.

Regards

How can i simulate a frame with fiber?

dear mr asdam

what solution you found about modeling of ECC? kindly explain. i am also working on it.

Hi Mehdi

I am sorry for the late response. I did not check my notification panel. If you are using Abaqus software you can simulate you fiber with two options:

1. You can define the material properties of the fiber only if you are intently modelling the fiber separated with your structural frame

2. You can use CDP properties for your fiber along with your structural frame material. So you do not have to input them separately.

Regards

 Hi Umer

You use CDP properties to add ECC both in compression and tension. In addition, tensile and compressive cover must be taken into account to model the level of stiffness degradation.

Regards

Hi Asdam,

How did you find the Poisson's ratio for your FRC?

hey guys.

I'm new to Abaqus and I don understand how to input the material properties parameters into Abaqus. I already know the value of stresses and strain of my ECC and normal.

I trying to model a composite beam with ECC on the bottom and normal concrete on the top. I know how to model the rebars, but how to input parameter like crushing strain and ultimate tensile strain?

As well do I use plastic-concrete damaged plasticity or Plastic-concrete smeared cracking ?

Any example / video tutorials will be greatly appreciated.

Salam alekum, 

hope that you all doing well,

you have mentioned that we need to obtain the actual stress-strain curves experimentally for the concrete patch in both tension and compression.

My question can we apply the split tensile strength test to obtain thestress-strain curve experimentally for the concrete in  tension.

Dear Abathar,

For the sake of normal concrete, I would recommend to only use the value of tensile strength obtained by splitting test as a validation in your analitical calculation to define the tensile stress-strain curve. You can use the governing equation provided by Wang and Hsu. Cheers.

Hi Adam,

Correct me if i’m wrong, but as i understood from the Abaqus manual, the software only estimates the post-crack behaviour of the fiber reinforced concrete from the elastic stage of compressive/tensilve uniaxial testing - that will be used as input in the CDP. My question;

1. From the modeling that you did, is the post-crack behaviour (plastic stage) shown in the simulation?

2. Did you do triaxial & biaxial tests to be included in Abaqus? as there are 5 manipulating parameters in Abaqus’ CDP. Just wondering if just an input in compressive & tensile uniaxial testing yields accurate results?

Thank you in advance.

there is a similar project in the below link. you could find the abaqus model (file) and buy it;

https://numericalarchive.com/shop?olsPage=products%2Ffinite-element-analysis-of-reinforced-concrete-slab-strengthened-by-frp