2-dimensional simulation of crack propagation in Al2O3 matrix composites dispersed with SiC particles

Two-dimensional continuous crack path is simulated in 10% SiC particle-dispersed Al2O3 matrix composite along with the related variation of fracture resistance with crack extension. Stress intensity factors at the tip of multiply deflected crack during propagation are calculated numerically by the body force method (BFM), and stresses around the crack tip are represented by superposing mechanical stresses on residual ones. Fracture resistance decreases with crack extension when the crack approaches particles, but increases up to 2.5 times the matrix toughness when propagates along and leaves from interface. Residual compressive stress in the radial direction, resulting from thermal expansion mismatch between particle and matrix, enhances the apparent fracture resistance of the interface. The crack propagation is simulated under the assumption of a hard particle. By averaging the several simulated curves of fracture resistance, the entirely rising R-curve is obtained.