Linear Elastic Fracture Mechanics
Stress distribution around the crack tip is of great significance for crack propagation and occurring of fracture. Even though the presence of plastic strain on the crack tip itself is unavoidable, elastic theory solutions have considerable theoretical and practical significance.Stress intensity factors are proportional to stresses around the crack tip, thus they define the amplitude of stress singularity.
The stress intensity factor, K is used in fracture mechanics to predict the stress state ("stress intensity") near the tip of a crack caused by a remote load or residual stresses. It is a theoretical construct usually applied to a homogeneous, linear elastic material and is useful for providing a failure criterion for brittle materials. In other words, a single parameter, i.e. the stress intensity factor, defines the stress, strain and displacements around the crack tip.