Fracture of Brittle Solids. III. Experimental Results on the Distribution of Fragment Size in Single Fracture

1962 ◽  
Vol 33 (11) ◽  
pp. 3211-3213 ◽  
Author(s):  
J. J. Gilvarry ◽  
B. H. Bergstrom
Keyword(s):  
Fragment Size ◽  
Experimental Results ◽  
Single Fracture ◽  
Brittle Solids

Fractal crushing of ice and brittle solids

1991 ◽  
Vol 433 (1889) ◽  
pp. 469-477 ◽  
Keyword(s):  
Fractal Dimension ◽  
Fragment Size ◽  
Special Role ◽  
Field Observations ◽  
Linear Elastic ◽  
Brittle Solids ◽  
Wide Range ◽  
Elastic Fracture ◽  
Ice Forces ◽  
Fractal Size

A significant ‘scale effect’ is observed when sea ice forces on structures are measured at field scale: the force per unit contact area is not independent of area, but decreases with increasing area. Fragments of broken materials are found to have a fractal size distribution, with a fractal dimension close to 2.5 over a remarkably wide range of fragment size. The research described in this paper brings these two observations together, and shows that they can be explained by a simple model of crushing, which incorporates the relation between fragment size and splitting force predicted by linear elastic fracture mechanics. The model indicates a special role for the fractal dimension of 2.5, and predicts a relation between force and area, consistent with field observations.

scholarly journals Fracturing in coals with different fluids: an experimental comparison between water, liquid CO2, and supercritical CO2

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jianfeng Yang ◽  
Haojie Lian ◽  
Li Li
Keyword(s):  
Coalbed Methane ◽  
Experimental Results ◽  
Propagation Path ◽  
Experimental Comparison ◽  
Single Fracture ◽  
Methane Recovery ◽  
Fracturing Fluids ◽  
Liquid Co2 ◽  
Before And After ◽  
Fracture Apertures

Abstract The present work conducted laboratory experiments of fracturing in fat coals, anthracites, and mudstones. Three different fluids were selected as the fracturing fluids, including water, liquid CO2 (L-CO2), and supercritical CO2 (Sc-CO2). The resulting fracture morphologies and fracture apertures of the coal specimens were investigated using 3D morphological scanning, and the permeabilities of the samples were measured before and after fracturing. The experimental results showed that the breakdown pressures of Sc-CO2 fracturing were the lowest among the three fracturing fluids, and the average single fracture apertures of the ScCO2-induced cracks were the smallest amongst the three fracturing fluids. In addition, the number of cracks and the roughness coefficients induced by Sc-CO2 fracturing were larger than those caused by water and liquid CO2. The viscosity of the fracturing fluid and the capillary effect are key factors that affect the crack propagation path and fracture surface topography. The results suggest that Sc-CO2 has the largest diffusion length, and thus is capable of permeating the coal matrix through small pores and causing more extensive fractures. Additionally, the effective hydraulic apertures of coal specimens produced by Sc-CO2 fracturing were wider than those induced by water and liquid CO2. The experimental results indicate that Sc-CO2 fracturing has huge potential to enhance coalbed methane recovery.

Sign in / Sign up

Export Citation Format

Share Document