Elastic-Plastic Analysis of Blunt Notched CT Specimens and Applications

Abstract

An elastic-plastic plane strain analysis of blunt notched compact tension specimens used in fatigue crack initiation tests is presented. Using this analysis it is shown that under conditions of constrained plastic flow in the notch region, the functional relationship between total notch strain and an elastically calculated notch stress is nearly the same for different notch sharpnesses. This material dependent functional relation is shown to hold for some other geometric stress concentrations as well. Under conditions where this relationship is the same it should be possible to correlate fatigue crack initiation data by means of the elastically calculated notch stress.