# Ultimate moment of resistance of a rectangular section in bending, `M`_{Rd}

_{Rd}

## Eurocode 2 - Design of concrete sections Method b3

The ultimate moment of resistance of a rectangular section in bending at the ULS are calculated according to method b3.

The parameters needed for the design are the followings:

- •
- Steel class: see Table C.1. The characteristic strain
`ε`and the ductility property_{uk}`k`will be taken equal to their minimum values in the table; `E`_{s}- is the design value of the modulus of elasticity of the reinforcing steel, see § 3.2.7 (4);
`f`_{yk}- is the yield strength of the reinforcing steel, see § 3.2.2 (3)P;
`γ`_{s}- is the partial factor for reinforcing steel at the ultimate limit state, see § 2.4.2.4 (1);
- •
- Steel diagram: is the design stress-strain diagram for reinforcing steel, from which the design strain limit
`ε`and the stress in the steel will be defined. See § 3.2.7 (2) and application stress-strain for reinforcing steel;_{ud} - •
- Coef.(
`ε`/_{ud}`ε`): is chosen by National Annex, see § 3.2.7 (2);_{uk} - •
- Concrete class: see Table 3.1;
`f`_{cd}- is the design compressive strength of concrete, see application;
`b`- is the width of the concrete cross-section;
`d`- is the effective depth of the concrete cross-section;
`d'`- is the distance from the compression fibre to the centre of gravity of the compression steel;
`A`_{s}- is the cross sectional area of the tensile reinforcement;
`A`_{sc}- is the cross sectional area of the compression reinforcement.

This application calculates
the ultimate moment of resistance `M _{Rd}`
from your inputs.
Intermediate results will also be given.