Effects of pore(s)-crack locations and arrangements on crack growth modeling in porous media

Most of geometerials in engineering practices are considered as porous media. Failure in such materials is related to their physical and mechanical properties, which are highly affected by their porous structure. For example, crack initiation, growth and propagation depend on relative locations of pores and crack. In this paper, the effect of pore(s)-crack distances and angles as well as their arrangements are investigated on crack growth modeling using eXtended Finite Element Method (XFEM). The results showed that when a pore is located next to the crack (side pore) it treats as a resistant pore. However, by doubling the side pore-crack distance, more than 24% of its resistant is decreased. Also, by increasing the side pore-crack angle from 0 to 47°, the stress intensity factor decreases about 16% and a higher resistance pore is obtained. In addition, when a pore is located in front of a crack (front pore), it could be resistant or destructive depending on being inside or outside of a critical distance. We found that this critical distance could be described as DC=θ10r, where θ is pore-crack angle in degree and r is pore radius. Finally, the crack growth path in samples with randomly distributed pores arrangements was analyzed using our previous findings. The results showed that it is possible to predict the crack growth path by consideration of the pore type (i.e., side or front pore), the pore angle and the pore distance to the crack tip.