Effect of pores on crack propagation behavior for porous Si3N4 ceramics.

The mechanism of interaction between crack-tips and pores in the porous ceramics was investigated in this paper. By using the J -integral numerical method, the effect of the pores on the stress-intensity factors of the crack tips is analyzed quantitatively. The presence of the pores may enhance or weaken the stress-intensity factors. The simulation results show that the pores in front of the crack will enhance the stress-intensity factors of the crack tip and promote the crack propagation and the pores at the side of the crack will weaken the stress-intensity factors of the crack tip and prevent the crack propagation. At the same time, the effects of different pores on the stress distribution around the crack-tip, with different pore-crack tip distance or positions, are presented. [ABSTRACT FROM AUTHOR]