Ultimate limit state
Bending moment with/without normal force is verified in accordance with EN 1992-1-1, chapter 6.1
The verification of ultimate limit state is based on following assumptions:
- plane sections remain plane
- the strain in reinforcement is the same as in the surrounding concrete
- the tensile strength of the concrete is ignored
- the stresses in the concrete in compression are derived from the design stress-strain relationship (parabola-rectangle diagram)
- the stresses in the reinforcing steel are derived from the design curve with an inclined top branch with a strain limit