Brittle failures at rounded V-notches: a finite fracture mechanics approach

Finite Fracture Mechanics (FFM) is applied to investigate the brittle failure behavior of rounded V-notched elements subjected to mode I loading. According to the criterion, fracture does not propagate continuously, but by finite crack extensions, whose value is determined by the contemporaneous fulfilment of a stress requirement and an energy balance. Consequently, the crack advance becomes a structural parameter. By assuming the generalized apparent stress intensity factor as the governing failure parameter, as expected for a brittle structural behavior, the expression of the apparent generalized fracture toughness as a function of the material properties as well as of the notch opening angle and root radius is achieved. FFM predictions are then successfully compared to experimental data available in the Literature and to results provided by other theoretical approaches based on a critical distance.