Estimation of Apparent Fracture Toughness of Alumina Based Ceramic Laminate

Abstract

The main aim of this contribution is the fracture behavior of layered ceramic composite with residual stresses. The influence of laminate composition on crack propagation (influence of material interfaces on crack shielding, effect of residual stresses, etc.) was investigated. The crack behavior was described by procedures based on linear elastic fracture mechanics (LEFM) and generalized LEFM. Computations were performed in 2D geometry under plain strain assumptions. For determination of the real crack front shape during the crack propagation the three dimensional FEM models were developed. Both (2D/3D) approaches were compared and differences were closely discussed. The influence of laminate composition with residual stresses on critical values for crack propagation through laminate interfaces was also determined. The results obtained can be used for a design of new layered composites with improved resistance against propagation of cracks.