Geometry and microstructure parameters to predict fracture at notches in a polycrystalline material

The critical stress intensity factor of notched specimen KCV,ρ is influenced by notch geometry (root radius and opening angle) and material microstructure. In this paper, by analyzing 12 groups of measurements on specimens made from materials with average grain size G from 22 to 500 μm and with different notches, a unified model is proposed to describe notch geometry effect on KCV,ρ related to G. Additionally, normal distribution theory is incorporated to consider inevitable scatter of measurements. The results show that the model can probabilistically predict KCV,ρ of notched specimens made from polycrystalline materials with 96% reliability.