Modelling the damage of porous ceramics under internal pressure Original Research Article

A numerical model is presented for microcrack formation and damage evolution in brittle porous solids under internal fluid pressure. The stress estimation in the microstructure relies on analytical solutions for elementary cavity geometries. Fracturing is allowed on the grid of grain boundaries, and an energy criterion is employed to decide on the survival or failure of the individual grain interfaces. Particular attention is paid to the fracture of grain interfaces adjacent to pores, which is most likely to occur under the considered conditions. Progressive microcracking leads to networks of connected pores and cracks, and ultimately to percolation. The significance of basic structural parameters for the strength of the material is investigated.