Educational content reviewedGeneral engineering principles; project application still requires the applicable official standards.
Elastic and inelastic responseDuctilityEnergy dissipationOverstrengthDemand redistribution
Learning objectives
In this lesson
- Ductility is controlled deformation, not simply flexibility.
- Dissipation must occur in intended stable mechanisms.
Engineering explanation
Design may accept localized yielding under severe action if deformation occurs in intended regions with stable cyclic behaviour. Brittle loss of resistance and unintended mechanisms remain unacceptable. A lower-ductility strategy relies more on elastic resistance; a higher-ductility strategy intentionally mobilizes greater deformation and energy dissipation, demanding stricter configuration, capacity design and detailing. Neither label guarantees performance without execution quality.
Key takeaways
What to carry forward
- Ductility is controlled deformation, not simply flexibility.
- Dissipation must occur in intended stable mechanisms.
- Higher ductility creates stronger detailing obligations.