3D Finite‐Element Simulation of Wedge Splitting Test of Non‐Standard Ceramic Double Cantilever Beam with Chevron Notch

Abstract

Zirconia ceramic is a material of great scientific and practical importance because of its beneficial combination of properties. However, fracture properties of ceramics are the major properties that need enhancement to satisfy high requirements for advanced applications in industry and medicine. Experimental studies have also shown that the fracture toughness of a given material can be considerably dependent on the size and geometry of the cracked body. [1,2] In the previous study, [3] it was shown that with the size of the specimen increasing, the fracture toughness is strongly dependent on the specimen size, and only when the length of the specimen approximates 1 m, the fracture toughness reaches closer to the constant value. In our contribution, we do not address the size problem, taking the same specimen sizes in simulations and in experiment. There exist several methods of fracture toughness determination, including nanoindentation, [4-6] compact tension tests experiments, [7] and method of dynamic fracture toughness determination using short beams. [8] Traditionally, fracture tests are carried out on geometries, such as the compact tension specimen, [7] which have a highly constrained crack tip and provide a lower bound estimation of fracture toughness. Moreover, for fracture testing of ceramics, compact tension tests experiments are impossible to carry out due to high brittleness of the material. Other possibilities are the three-and four-point bending testing. The standard size bending specimen provides the fracture toughness for the large specimens, but not for the small-scale ones. The miniaturization of items from ceramics in different sections of industry and medicine requires the development of a new method of fracture toughness determination for small-scaled specimens. For small-scale specimens, a non-standard method of fracture toughness determination should be developed and applied. The problem of double cantilever beam (DCB) testing of the material has recently received much attention, but not many works have been devoted to finite elements method (FEM)-simulations of fracture testing of a DCB with a chevron notch (CN) because of the complex geometry of the specimen. Mostly, articles are devoted to the DCB with a straight notch. [9-14] For example, a new data reduction scheme is proposed owing to the difficulty in monitoring the crack length in this material. [15] This method is based on the specimen compliance and the crack