PERMEABILITY OF POROUS MATERIAL WITH DIFFERENT CRACK DISTRIBUTIONS

The effective permeability of cracked porous material depends on the microstructure of material and it is of great significance to practical engineering applications. Cracked porous material is considered to be a two-phase composite material with a porous matrix and cracks. Firstly, based on the homogenization theory, a dilute solution,an interaction direct derivative (IDD) solution and a modified IDD solution are derived to evaluate the permeability with four different crack distributions. Then a new method which combines embedded element technique with elastic analogy is developed to analyze the effective permeability and its convergence. Afterwards, the numerical result derived from the new method was compared with theoretical solutions. It can be concluded that the variation of the finite element results decreases by increasing the crack number. Moreover, an appropriate number of cracks can ensure both the convergence and computation efficiency. On the other hand, compared with the dilute solution, the IDD solution can provide a superior estimation for the numerical results with different distributions, but it underestimates the finite element results at higher crack density as the near-field interaction among cracks grows stronger. The modified IDD solution takes both the near-field interaction and edge effect into consideration, so it can estimate the permeability of cracked porous material more precisely.