Due to the heterogeneity

opacity and porosity of rock

it is difficult to truly represent three-dimensional internal meso-structure of rock through physical experiments and numerical simulations. In this study

a 3 D non-uniform numerical method was proposed to simulate the porous rock failure based on the parallel finite element method. The CT technology was used to scan the rock specimens and obtain the picture layers. The edge detection algorithm

filtering algorithm and 3 D matrix mapping method were applied to process the scanned pictures and reconstruct the Brazilian disk finite element model of the rock. Thus

3 D numerical Brazilian disk models were constructed

and the influence of the porosity and pore distribution were analyzed numerically. The results indicated that the pore distribution and porosity had significant effects on the crack propagation and tensile strength. The number of the secondary cracks decreased when the porosity was smaller and pores were sparse

while the number of the secondary cracks increased when the porosity increased. The different porosities of numerical specimens were calculated by using the digital image processing method

and the relationship between the tensile strength and porosity followed an exponential function. The porosity of the specimen was obtained by the digital image processing technology

and the law of porosity and tensile strength was exponentially distributed. The median filtering algorithm improved the accuracy of the digital model in the image processing

and the 3 D numerical simulation model reflected the 3 D meso-structure of rock-like porous materials

which provided an effective method for studying the mechanical behavior of rock.