Where are hinges placed in ductile seismic detailing?

• A. Near diaphragms.
• B. Near mid-span.
• C. In foundations.
• D. Near columns/beams ends.

Answer: (D)

In ductile seismic detailing, you want to localize plastic deformations to controlled zones that can yield without sudden, brittle failure, allowing the structure to dissipate energy through a stable mechanism. The most effective place for these plastic hinges is at the ends of beams, immediately adjacent to columns. This location aligns with where lateral loads create large bending moments and where a beam can undergo significant flexural rotation while the column and joint region are protected by proper detailing. By forming hinges near beam ends, the frame can rotate and absorb energy through a predictable sequence, reducing the risk of brittle collapse in columns or joints. Hinges mid-span or in foundations would not provide the same controlled rotation or protect the critical elements, and hinges placed away from the beam-column ends would undermine ductility and the overall mechanism.