Porosity Analysis Based on CT Images of Coal Under Uniaxial Loading

Abstract

According to the character of CT image, surface porosity and voxel porosity are defined from pixel and voxel scale respectively. Digital Terrain Model (DTM) method is applied to calculate the surface porosity, and the method of voxel porosity is also presented based on Industrial CT grey image. With proposed methods, CT images of coal under different uniaxial loading are analyzed, and the relation curves between two kinds of porosity and stress separately are shown. All of these porosities reflect inner damage of coal. The surface porosity shows the pore with pixel scale, and voxel porosity denotes the pore inner pixel. The voxel porosity reflects the character of CT image better.

Mechanical Properties of Bump‐Prone Coal with Different Porosities and Its Acoustic Emission‐Charge Induction Characteristics under Uniaxial Compression

“…en, more and more rock mechanics experiments have introduced the exploration of the damage characteristics of samples. Relevant studies have been carried out by Ray et al [7], Konecny and Kozusnikova [8], Mao et al [9], and Cai et al [10]. e results show that the cracks in coal can be observed by CT scan, and the variation of porosity reflects the opening and closing cracks.…”

“…e measured result of the damage variable obtained according to equation (8) re ected the evolution of damage caused preferably by crack propagation, but it did not measure up to the ideal value of D 1 as the general theoretical derivation. According to Rabotnov's de nition of the damage variable, D [32,33] is the ratio of the defect area to the nominal, which is expressed by equation (9). In the process of coal failure, any section will not be lled with defects formed by cracks (0 < A/A < 1).…”

Anisotropy of Magnetic Susceptibility and Preferred Pore Orientation in Lava Flow from the Ijen Volcanic Complex, East Java, Indonesia

“…We analyzed lava flow direction using images of pores inside the specimens. The images were generated using the micro-computed tomography (µCT) method, which has been applied for geoscience purposes in several studies [17][18][19][20][21][22].…”

Microstructure and pore system analysis of Barren Measures shale of Raniganj field, India

“…Different filters like eluclidean distance, smooth distance map, watershed transform, cluster region mergin etc. were used to enhance the resolution quality of the tomogram images (Frederk et al, 1997;Karacan and Okandan, 2001;Taud et al, 2005;Mazumder et al, 2006;Yao et al, 2009;Mao et al, 2012;Golab et al, 2013;Hemes, 2015). There are commonly two methods for calculating porosity of rock using m CT images i.e.…”

“…At low energies, m will be primarily a function of Z; and at high energies m will be primarily a function of rb (Frederik et al, 1997;Taud et al, 2005;Yao et al, 2009;Mao et al, 2012;Golab et al, 2013). For acquisition of image, the magnification was set by adjusting the ratio of the distance between the X-ray source and the specimen to the X-ray source and the camera.…”