Stress intensity factor

The stress intensity factor ( SIF short ) is a measure of the intensity of the stress field in the vicinity of a crack tip. It is a scalar quantity, which depends on the external load as well as the geometry of the crack and of the component. The strength of the stress intensity factor depends on the crack growth.

The one stress intensity factor at which it comes to violent rupture, is the critical stress intensity factor. This material parameter is also known as crack or fracture toughness.

In general, three types are distinguished crack opening, each associated with a stress intensity factor:

• The index characterizes the crack opening perpendicular to the crack surface (german opening mode). He has the greatest importance in practice.

• The tension in the component cross-section without cracks (nominal)
• A is the crack length
• F and Y is a correction factor which depends on the crack and component geometry.

• The opening types and describe longitudinal ( sliding mode) and transverse shear ( tearing mode).

• Materials Science