• Registered: 2026-02-09
  • Posts: 2

Topic: Concrete beam faliure in compression

Hello everyone,

I apologize if this topic has been asked before, but I did not find an answer.

I am modelling concrete beams produced with FRP tensile reinforcement, following a series of laboratory experiments, with the aim of replicating the results in ATENA. The experimental beams all failed in compression as designed. The problem I have been encountering is that the beams in ATENA fail in shear. This is true with concrete material models generated based on Modelcode as well as user defined properties based on accompanying measurements done in the laboratory. I have tried adjusting many variables, increasing the shear reinforcement beyond the actual values but the mode of failure remains inaccurate. Older experiments with different geometry, but similar mode of failure have been successfully replicated.

I thank you for any help in advance!

Quote Post 1

  • Registered: 2019-10-24
  • Posts: 15

Re: Concrete beam faliure in compression

Dear User,
if you try to change the failure mode from shear to flexural I would try to increase the shear factor, the default is 20, you may try even 200. Also the bond between the reinforcement and concrete can help. If it is increased.

BR,
Michaela

Quote Post 2

  • Registered: 2026-02-09
  • Posts: 2

Re: Concrete beam faliure in compression

Dear Michaela,

Thank you for your help. The suggestion helped to solve problem with some calibration. However another issue took its place. The concrete crushing occurs on both sides of the force transfer block. The test is in 4 point bending and no failure was observed in the laboratory outside the central zone of the beams. I recognize that this is probably due to the improper modelling of the transfer block, but I am unsure what a more accurate method would be. The real transfer block was a 6 cm diameter steel rod with a piece of wood placed between it and the beam for better force transfer. In the model it is a 5 cm square cross section prism with elastic 3D material set to 210 GPa elastic modulus to mimic steel.

Best wishes,
Somlai B.

Quote Post 3