inelastic response spectrum

An inelastic response spectrum is a tool used in structural engineering to assess how buildings or structures respond to strong earthquakes when they experience permanent damage or yielding. Unlike elastic behavior, where materials return to their original shape after stress, inelastic response considers situations where the structure bends or deforms permanently. The spectrum shows the maximum expected response (like displacement or force) across different building periods, accounting for potential damage. It helps engineers design buildings that can withstand severe earthquakes without collapsing, by understanding both the initial elastic response and the inelastic, or damage-tolerant, behavior.