A fracture toughness model describing the fracture behavior of fibrous monolithic ceramics, based on the analysis of the energy of interfacial cracks is presented. The results reveal that the only factor that contributes to the fracture toughness in ceramics was the actual energy absorbed by crack propagation and not the total work of fracture. The load-displacement curve and the crack propagation path were predicted using a derived model which was the mirror image with that of the experimental data. The influence of unit cell dimension, strength, and interfacial bonding strength on properties of the ceramics were predicted using a fracture toughness model which matched with the experimental results. The deviation in results was less than 10% which indicates the validity of the proposed model.

Keywords: Fracture toughness model, Fibrous monolithic ceramics, Actual energy absorbed by crack propagation