EK314

For limit design to be valid, four conditions must be satisfied:

1. Mechanism condition: Sufficient plastic hinges must be formed to transform the whole or part of the structure into a mechanism.
2. Equilibrium condition: The bending moment distribution must be in equilibrium with the applied loads.
3. Yield condition: The factored moment must not be exceeded at any point in the structure.
4. Rotation condition: Plastic hinges must have enough rotation capacity to permit the development of a mechanism.