A stress concentration is a location in a component where the stress is much larger than the stress in the surrounding material.
“The conditions that cause the stresses to be greater than those given by the ordinary stress equations of mechanics of materials are called discontinuities or stress raisers. These discontinuities cause sudden increases in the stress (stress peaks) at points near the stress raisers.
The term stress gradient is used to indicate the rate of increase of stress as a stress raiser is approached. The stress gradient may have an influence on the damaging effect of the peak value of the stress. Often, large stresses due to discontinuities are developed in only a small portion of a member. Hence, these stresses are called localized stresses or simply stress concentrations.
In many cases, particularly in which the stress is highly localized, a mathematical analysis is difficult or impracticable. Then, experimental, numerical, or mechanical methods of stress analysis are used.” [1]
[1] Advanced Mechanics of Materials 5th ed., Boresi and Schmidt
This page is part of The Encyclopedia of Stresses in Solids