The subject of this paper is the analysis of crack initiation and propagation in barium titanate ceramic using the boundary element method. In micro-mechanical analyses, it is very important to have information on the real microstructure of a material. A barium titanate pellet was prepared using a solid-state technique. The boundary element method is used so that it can be combined with three different grain boundary formulations for the investigation of micromechanics as well as crack initiation and propagation in a piezoelectric actuator. In order to develop a numerical programming algorithm, suitable models of polycrystalline aggregate and representative volume elements have been prepared for boundary element analysis.Keywords: barium titanate, boundary element method, ceramics, microstructure
IntroductionA The boundary element method (BEM) is one of the favourite optimised numerical computational methods used by scientists in many areas of engineering and science including fracture mechanics, fluid mechanics, and geology. In order to use the boundary element method, one only needs to fit the boundary of the system without calculation of parameters inside the solid body analysed, so the dimension of the problem can decrease and the size of the algebraic equations can be considerably smaller than the finite element equation [1,2]. In the area of fracture mechanics and mechanical engineering, some researchers have utilised the boundary element method [3,4], the Voronoi tesselation method [5] or the finite element method [6,7]. These methods are very suitable for use in determining the behaviour of a solid body which contains several cracks and holes. It is worth mentioning that both finite and infinite bodies can be studied via the BEM. In order to use this method, one must pay attention to the fact that the traction fundamental solution and displacement fundamental solution for isotropic bodies are different to those for anisotropic bodies. This is the most important fact that researchers have to consider before using the BEM [8,9] or discrete element method [10] for investigations. The application of the boundary element method in micromechanics and multiscale modelling has been studied by a number of researchers [11][12][13]. In some of these studies, researchers only modelled materials at micro scale and with the cohesive law, averaging theory or nonlocal theories were not used. Several researchers have utilised some basic concepts