An improved Finite Fracture Mechanics approach to blunt V-notch brittle fracture mechanics: Experimental verification on ceramic, metallic, and plastic materials

• We investigate brittle fracture in blunt V-notched elements under mode I loading.
• The analysis is based on a Finite Fracture Mechanics approach.
• The energy balance is implemented starting from an analytical relationship for the SIF.
• The crack advance and the apparent generalized fracture toughness result the failure parameters.
• The criterion is validated by comparing its predictions with experimental data (alumina, PMMA, AISI 4340 steel).

The coupled Finite Fracture Mechanics (FFM) criterion is applied to investigate brittle fracture in rounded V-notched samples under mode I loading. The approach is based on the contemporaneous fulfilment of a stress requirement and the energy balance, the latter being implemented on the basis of a recently proposed analytical expression for the stress intensity factor. Results are presented in terms of the critical crack advance and the apparent generalized fracture toughness, i.e. the unknowns related to the system of two equations describing the FFM criterion. A validation of the theory is performed by employing varying root radius notched, as-quenched from 1200 °C, AISI 4340 steel specimens fracture results as well as alumina and PMMA notched samples fracture results.