Mode I fracture toughness prediction for multiwalled-carbon-nanotube reinforced ceramics

Eshelby-Mori-Tanaka models with a continuum damage mechanics approach are developed to predict the elastic damage and fracture toughness of multiwalled-carbon-nanotube (MWCNT) reinforced ceramics as a function of MWCNT fraction. This damage model is introduced in a modified boundary layer modeling approach to predict damage accumulation leading to crack propagation from a pre-existing crack tip in a process window where damage and fracture are captured under plane-strain Mode I loading. The model is validated against experimental fracture toughness data for a MWCNT 3-mol% yttria-stabilized zirconia composite and successfully predicts the observed saturation in fracture toughness at about 25% volume fraction MWCNTs.