Dear Mabrouk,

I am sorry because I thought the question is asked by Valeria Corinaldesi but I hope I could help you. In addition to, I am also agree with the comment about elastic modulus by Valeria Corinaldesi. Plastic materials and fibers have different elasticity modulus against to concrete.

Kind Regards,

Taner

Because of the great difference on the elastic modulus between concrete and FRP (the higher is the fiber content the higher will be this difference).

Perhaps the paper in attachment can be useful for you.

Best regards,

Valeria

Dear Valeria,

I think it is because of thermal expansion coefficient. Concrete has thermal expansion coefficient of 10.10-6. However, plastics has very big thermal expansion coefficient like 70-160x10-6. This makes it more sensible to moving and termal difference.

I hope I have helped you.

Kind Regards,

Taner

Dear Mabrouk,

I am sorry because I thought the question is asked by Valeria Corinaldesi but I hope I could help you. In addition to, I am also agree with the comment about elastic modulus by Valeria Corinaldesi. Plastic materials and fibers have different elasticity modulus against to concrete.

Kind Regards,

Taner

You can try cohesive contact to simulate the FRP-concrete interface

Dear Mehdi Lima

I am really interested with your answer. Where to set the cohesive contact in Abaqus. Is there any consideration to input the value or not?

 Dear Asdam,

you can define cohesive contact using "interaction properties" option. 

Dear S. Taner Yildirim

i did not define thermal coefficients in the material property. how this will affect ?

 Dear Mehdi Lima 

I tried the cohesive interaction but i have penetration error. How can i solve this error ??

Dear Abdelrahman, 

Would you please describe the procedure that you applied the cohesive contact? Have you applied surface to surface contact or node to surface?One noteworthy point is that the penetration is not allowed in surface to surface contact while penetration is happening in node to surface contact. 

Dear Mehdi Lima 

Thanks for your advice. Is the surface to surface doesn't allow penetration also for the tangential interaction ??