• Profant, Tomas
• Sevecek, Oldrich
• Bermejo, Raúl
• Kotoul, Michal

Abstract

<p>The main goal of ceramic laminates designed with residual stresses is to increase the fracture energy of the system during fracture through energy dissipating mechanisms such as crack deflection or crack bifurcation. A computational tool based on Finite Fracture Mechanics (FFM) is implemented in this work to predict the propagation of cracks in ceramic laminates. The crack path is defined by the direction where maximum rate of the potential energy is released during fracture. Laminates studied here consist of two materials alternated in a layered structure designed with high compressive residual stresses, which are developed during cooling phase after sintering process. Different volume ratios of the material components are chosen in order to demonstrate the influence of the level of compressive residual stresses on the type of propagation (single crack deflection / crack bifurcation) and direction of the crack advance. Using the model a single crack deflection or crack bifurcation can be predicted for a given laminate. According to the calculations, the higher compressive stress in the layer is, the more the crack deflects from the straight direction and the more prone to the bifurcation. Results are in good agreement with experimental observations.</p>

Topics

• impedance spectroscopy
• phase
• crack
• layered
• ceramic
• sintering