Side-groove effects in three-dimensional small-scale yielding: A load and thickness-scaling model

This study investigates the influence of side grooves on near-front fields that drive cleavage fracture processes in ferritic steels under 3D small-scale yielding conditions. High-fidelity, finite-strain analyses of boundary-layer models for initially straight crack fronts provide elastic–plastic fields. Numerical solutions demonstrate that non-dimensional, self-similar scaling of crack-front fields for plane-sided specimens also holds for the side-grooved configurations. Furthermore, Weibull stress values exhibit a non-dimensional, thickness scaling controlled by a single non-dimensional parameter. This thickness scaling holds for low-to-high hardening rates typical of ferritic steels under imposed loading levels that range in a 3D setting from near plane-strain to near plane-stress conditions.

► Employs extraordinarily refined 3D models to compute high-fidelity deformations in the crack-front region.
► Reveals an improved, quantitative understanding of side-groove effects.
► K-bar scaling (K-bar = K/(yield stress * sqrt[B]) in 3D SSY fields is shown to also hold for side-grooved specimens.
► Weibull stress values exhibit K-bar scaling.
► A new non-dimensional parameter is introduced to describe this outcome.
► Probabilities of fracture are compared for plane-strain, 3D plane-sided and 3D side-grooved configurations.