The fictitious notch rounding approach applied to V-notches with root holes subjected to mode I loading

Abstract

The fictitious notch rounding concept is applied here to V-shaped notches with root holes subjected to mode I loading. The fictitious notch radius ρ_f is determined as a function of the real notch radius ρ, the microstructural support length ρ* and the notch opening angle 2α, at first using the normal stress criterion. Two analytical methods have been developed resulting in closed-form expressions for the multiaxiality factor s in the well-known relationship ρ_f = ρ + sρ*. The first method expresses the notch stress averaged over the microstructural support length at pointed V-notches by the maximum notch stress of fictitiously rounded V-notches (with root hole), taking advantage of a newly developed analytical solution. The second method considers V-notches with root holes both in the real and in the fictitious configuration. It uses a procedure given by Neuber. Finally, different failure criteria are considered using the first method. Plane stress and plane strain conditions, respectively, are evaluated.