Understanding Corrosion in Water Pipelines: A Guide for Pipeline Designers

Stress Intensity Factor (K)

Last updated: August 5, 2020

What Does Stress Intensity Factor (K) Mean?

The stress intensity factor (K) is used in the field of fracture mechanics. It predicts stress intensity near the tip of a crack caused by a remote load or residual stresses.

The magnitude of K depends on:

• Sample geometry
• Size and location of the crack

The stress intensity factor is a single-parameter characterization of the crack tip stress field.

Corrosionpedia Explains Stress Intensity Factor (K)

The following equation describes stress intensity:

Where ß describes the relationship between gross geometrical features to the stress intensity factors. ß can be a function of crack length as well as other geometrical features. K represents nominal stress that is remote from the crack.

The above equation shows that the intensity of the stress field — and therefore the stresses in the crack tip region — are linearly proportional to remotely applied stress and proportional to the square root of half the crack's length.

Stress intensity can be determined by:

• Finite element analysis
• ASTM E1681 standard method
• Weight function method