Fracture energy determination and critical crack propagation between core and veneer ceramic interface by experiment and finite element method

Fracture energy of a material has a great importance in determining the resistance of a material to crack propagation. The starting point in fracture mechanics analysis is to consider a crack of a certain size located in a component or specimen. The pure tensile specimen, e.g., SENT (single edge notch tension), has the lowest constraint, while specimens dominated by bending have the highest constraint. In this paper, fracture energy of core and veneer ceramic interface was investigated by a laboratory testing and finite element models. For this purpose, the core and veneering ceramic (IPS Empress 2) was prepared with initial notch. Its fracture energy was measured experimentally by using the crack mouth-opening displacement (CMOD) method. The fracture toughness of core and veneer ceramic at room temperature was investigated experimentally using SENT specimens. The finite element study was also carried out by using 2-D model to calculate the fracture energy (J) value numerically with ANSYS finite element code. The result calculated using the CMOD method has been compared with the finite element method results. Comparison of the results illustrated a good agreement between experimental and numerical studies.