Topic: BFRP RC beam


I'm trying to model a BFRP RC beam with ATENA 2D. But I'm having problems to get good results in comparison to the experiments. Even if I separately type in every information I got about the test and not let ATENA calculate the parameters.

The set-up is a four-point bending test. The model is only one half of the beam with the symmetry axis being fixed to the y-axis.

The concrete is modeled with 3D Non Linear Cementitious 2 and a bond-slip law according to Model Code 1990 is applied to the reinforcement bars.

The solution method is the Newton-Raphson procedure with elastic stiffness type and updating of the stiffness after each step.

I already tried to vary the parameters of concrete and the bond-slip law and the solution method. But it doesn't give me good results.

Thank you for your time and I hope you have some ideas what I can try to solve this problem. The Troubleshooting PDF already helped a bit but didn't give me good answers to my questions.

Kind regards,

Re: BFRP RC beam

Dear nicolas.schoeneweiss,
please follow Troubleshooting, 2.1.1 to send us your model along with a graph comparing the measured and calculated Load-Displacement curves etc.

Just guessing:

Please keep in mind that using the Modified N-R solution typically needs to allow more max. iterations, e.g., 300 instead of 80.

We also recommend to enable the Conditional Break Criteria such that the analysis stops when the convergence errors are large at the end of a step, see Troubleshooting, Recommended settings.

Best regards.

Re: BFRP RC beam

Thank you so far.
I'll let you know if it did not solve the problem.