# NOTCH SENSITIVITY

In cyclic loading ,the effect of the notch or the fillet is usually 'ess than predicted by the use of the theoretical factor as discussed before.The different depends upon the stress gradient in the region of the stress concentration and on the hardness of the material The term notch sensitivity is to the behaviour. It may be defined at the degree to which the theoretical effect of stress concentration is actually reached.The stress gradient depends mainly on the radius of the notch,hole or fillet and on the grain size of the material .Since the extensive data for estimating the notch sensitivity factor is not available therefore the curves may be used for determining the value of q for two steels.

When the notch sensitivity factor q is used in cycle loading then fatigue stress concentration factor may be obtained from the following relations .
Kt=1+q(Kt - 1)
Kfg=1+q(Ktg -1)

THIS ARETICAL WAS TAKEN BY R.S. KHURMI AND J.K. GUPTA