Structural failure refers to loss of the load

Structural load

Structural loads or actions are forces, deformations or accelerations applied to a structure or its components.Loads cause stresses, deformations and displacements in structures. Assessment of their effects is carried out by the methods of structural analysis...

-carrying capacity of a component or member within a structure

Architectural structure

An architectural structure is a free-standing, immobile outdoor constructed element. The structure may be temporary or permanent.Structures include buildings and nonbuilding structures . Examples of building structures include houses, town halls, libraries, and skyscrapers...

 or of the structure itself. Structural failure is initiated when the material is stressed to its strength

Strength of materials

In materials science, the strength of a material is its ability to withstand an applied stress without failure. The applied stress may be tensile, compressive, or shear. Strength of materials is a subject which deals with loads, deformations and the forces acting on a material. A load applied to a...

 limit, thus causing fracture or excessive deformations. In a well-designed system, a localized failure should not cause immediate or even progressive collapse of the entire structure.