High initial stiffness in abaqus

[Hayderalsaaty7981]

Dears,
I would like to thanks you in advance for any help.
My problem is that I am modeling a T-Girder bridge reinforced concrete beam under a cyclic load in Abaqus. I modeled the reinforcement as an embedded (truss elements) elements inside the concrete elements 8-node brick elements. I used the concrete damage plasticity to model the concrete with concrete compression hardening (stress-strain curve )and concrete compression damage for the compression case, for the tension case I used the concrete tension stiffening (stress-strain curve) with the tension damage. For the steel I used the plastic model to inter the stress-strain curve for the steel. I used the dilation angle equal to 38deg, eccentricity equal 0.1., K=0.667, and the stress ratio =1.12.
My problem is that the behavior of the girder that I am modeling is stiffer and the initial stiffness of the Abaqus model is a lot higher than the experimental initial stiffness. Also the model strength in general is higher than the experimental strength. I tried also to model a reinforced concrete column under a cyclic load and the same results pop-up (higher initial stiffness and higher strength).
I would be grateful for any help in this problem.
Thanks in advance.

 

[rstupplebeen]

I am not familiar with your specific application, however, I routinely tune my material models based on test data. Rarely have published material properties provided accurate results. I hope this helps.

Rob Stupplebeen

http://www.optimaldevice.com

https://sites.google.com/site/robertkstupplebeen/