A new pore-strength model for the quantitative strength prediction of ceramics under mode-I loading

Abstract

Strength prediction under the action of pores is crucial for the safety of ceramics. Here, a quantitative prediction model of pore-strength response under mode-I loading was developed based on the new mapping relationship between stress intensity factor and tip radius. The new model was proved to have great application after comparison and analysis of the pore-strength test data of three typical ceramics as well as the pertinent data as-reported in the literature. Results indicated that when the tip radius of pore (ρ) exceeds the critical value (ρc = KIc2/(πσ02)), the stress intensity factor increases as a power function with increasing ρ, at which point the strength decay is significantly weakened, and when the ρ is lower than the ρc, the pore can be equated to a crack problem. This work can not only forecast and assess the failure strength of ceramics containing pores, but also provide guidance for the design of extremely dependable ceramics.