Evaluation of fracture toughness of zrO2 − 3.0 mol%Y2O3 ceramics utilizing wedge splitting loading of double cantilever specimen with a chevron notch

•The FEM model is built to elucidate the experimental findings.•The nonlinear behavior is observed at stable stage of crack propagation.•Results of the numerical simulation are in good agreement with experiment.•The crack demonstrates a pop-in behavior at stable stage of propagation.•The fracture surface roughness should be considered when evaluating the KIC. A ZrO2-3.0mol%Y2O3 double-cantilever specimen with a chevron notch is manufactured to study the material toughening during a stable crack advancement. The shape of the resulting crack does not allow using the techniques currently available for the evaluation of the energy release rate. A recent publication reporting an experimental study of the deformation and fracture of the double-cantilever specimen subjected to wedging up to failure, in a contradiction with a typical brittle behavior of this material, has revealed a large nonlinear section in the loading diagram. In the present work, an FEM simulation-based approach is used to simulate the processes of deformation and fracture, and an interpretation of the experimental findings is provided. The Drucker-Prager yield criterion, modified for the purpose of this study, is employed as a part of the non-linear model, which reduces overcomplications in the constitutive response. All model parameters are validated against the experimental data obtained or those reported by other authors. The first law of thermodynamics is used for evaluation of the dissipated energy related to inelastic strain accumulation and crack propagation. The fracture toughness value obtained in numerical simulation is KIC≈ 5.45 MPa·m(1/2). The results of numerical simulation are in a satisfactory agreement with our experimental data and in a good agreement with the other available data. An important finding for the engineering applications is that the fracture surface roughness has to be taken into account in evaluating the fracture toughness. Otherwise, the KIC values would be overestimated because the real crack surface area is larger than its planar projection. For the material considered, the overestimation of KIC is in the range of 8–10%.