# Stress Concentration Factor Calculation

Last updated: December 31, 2018

## What Does Stress Concentration Factor Calculation Mean?

The stress concentration factor for openings of specific geometries and known dimensions can be calculated using an elastic theory approach. For an elliptical-shaped opening in an infinite plate, for example, the maximum stress at the ends of the opening’s major axes are given by Inglis’ equation:

σmax = σ.(1 + 2b/a)

Where:

σmax = the maximum stress in the section

σ = the average uniform stress in the section

a = the width of the elliptical hole

b = the length of the hole

The stress concentration factor Kt is given by:

σmax

or

(1 + 2b/a)

## Corrosionpedia Explains Stress Concentration Factor Calculation

In addition to traditional elastic methods, stress concentration factors may also be calculated by experimental methods including photoelastic stress analyses, brittle coating techniques, strain gauge methods, or grid methods. While experimental methods have proved widely successful, they are often bound by environmental conditions and measurement accuracy limitations.

Perhaps the most common method of determining theoretical stress concentrations in materials is through the use of design charts and graphs. However, numerical methods, such as finite element analysis (FEA), produce the most accurate estimations. 