ESDU 79008 gives a graph of the stress concentration factor as a function of the notch depth/length ratio and notch corner radius/depth ratio. The curves apply to a semi-infinite plate loaded uniformly in tension in a direction parallel to the notched edge but are applicable to any plate provided its length is at least five times the notch depth; the data can also be used to estimate the stress concentration for the plate under in-plane bending although the value will in that case be over-estimated. The position of the maximum stress is also indicated.
ESDU 79008-1979 history
1979ESDU 79008-1979 Elastic stress concentration factors. Rectangular notch in the edge of a wide flat plate in tension.