Which describes the 'Failure' definition?

• A. The part yields but maintains load
• B. Elastic deformation without fracture
• C. The cross-section area increases under load
• D. Component fractures releasing all load to supporting structure

Answer: (D)

Failure means the part can no longer perform its intended function because it can no longer carry the load—typically when it fractures and the load path to the rest of the structure is lost. Describing a fracture that releases all load to the supporting structure captures this complete loss of load-carrying capability, which is the hallmark of failure. In contrast, yielding indicates plastic deformation while the part still carries load, elastic deformation means the part has not been damaged, and a cross-section increasing under load does not describe a failure mode.