... ABSTRACT: Circular disc specimens under indirect tensile testing often fail abruptly, especially in brittle materials like rock and concrete. Despite widespread popularity, such testing methodologies are incapable of capturing snapback (or class II) behavior of circular disc specimens made...

... Abstract In this work, we investigate the development of scratch-induced fractures for brittle materials. A micro-scratch device, a surface non-destructive test, is used to collect experimental data, including tangential force, scratch depth before and after scratching, and Acoustic Emission...

... ABSTRACT: Tensile strength is the most critical design parameter of brittle materials in a wide range of engineering applications. However, although the rock mechanics literature is replete with direct and indirect testing methods to estimate rock tensile strength, the available procedures...

... equation flow in porous media modeling pressure equation brittle material Fluid Dynamics two-phase flow-driven fracture subdomain Upstream Oil & Gas displacement global pressure equation fracture model two-phase flow-driven fracture unknown variable permeability saturation unbroken...

... ABSTRACT: The fracture response of rock, as a quasi-brittle material, is highly sensitive to its microstructural design. We present a statistical damage formulation to model dynamic rock fracture. The damage model is rate-dependent and the corresponding damage evolution is a dynamic equation...

... of standard Brazilian dicks comprising hard and brittle materials. A series of tests with a wide range of hard and brittle materials, including various types of rocks and ceramics, was carried out. In all tests performed, a single straight plane of fracture was observed. Through finite element numerical...

... points can be effectively eliminated through a change in the size of the disc in the Brazilian test. Reservoir Characterization high brittleness diameter Williams size dependency hydraulic fracturing Brazilian test Masoumi brittle material Upstream Oil & Gas basalt specimen brittle...

... Abstract Sudden and violent fracturing of brittle materials, such as natural-forming rocks and artificial aggregates like concretes, still remain one of the leading causes of fatalities in mining, civil and geotechnical industries today. The primary aim of this research work...

... dilation brittle material flow rule ARMA 12-413 Comparison of approaches for modelling dilation of brittle rockmasses around circular excavations and associated issues Walton, G. Queen s University, Kingston, Ontario, Canada Diederichs, M.S. GeoEngineering Centre, Queen s-RMC, Kingston, Ontario...

... complete definition of risk and safety. This paper outlines a method for the selection of appropriate Hoek-Brown parameters for variable brittle materials using a combination of the Damage Initiation and Spalling Limit (DISL) method and Griffith’s theory of microcrack initiation. A standard RBD approach...

... The cracking processes in a brittle material consisting of a matrix with inclusions are important mechanisms for both natural materials (rocks) as well as synthetic composite materials (e.g. concrete). There have been many past studies regarding the cracking processes in brittle materials, which contain pre...

... vertical direction will decrease critical chipping load [10]. hydraulic fracturing maximum principal stress normal force linear rock pick performance Reservoir Characterization Engineering brittle material point-attack pick principal stress goktan Upstream Oil & Gas experiment...

... such geological phenomena, an experimental method for creating a shear fracture in brittle materials under pure shear loading conditions was developed. Based on the results of the experiments, expressions for estimating shear fracture toughness were derived by using the geometry of the specimen. The test method...

... failure borehole internal friction angle brittleness residual strength MPa brittle material foundation pillar ARMA 08-72 In situ measurements of pillar behaviour in the Bushveld Platinum deposits of South Africa B.P. Watson CSIR, Johannesburg, Gauteng, South Africa J Kuijpers. CSIR...

... be determined post-test making it impossible to determine when the damage occurred. In brittle materials, the processes that produce AE, such as pore collapse, microcrack growth and grain boundary slip, are all readily accepted as damage. Thus it is inviting to connect damage with AE activity. Using AE...

... of crack propagation e in the ductile samples is presented. 1 INTRODUCTION Brittle materials adjacent to slopes, underground openings, and room and pillar underground mine systems exist in a fissured state, but nonetheless the brittle materials comprising these systems remain stable. The fissures develop...

... reservoir geomechanics non-stepping crack kaolinire clay brittle material Reservoir Characterization Upstream Oil & Gas crack formation metals & mining compression uniaxial compressive stress uniaxial compression hydraulic fracturing Rock mechanics productivity tensile...

... studied: (Table 3) 1. A plastic mixture (sand, mica, paraffin - 100:3:3.5):simulates argillaceous sedimentary rocks. 2. A brittle material of moderate strength (sand, cement, water - 100:5:6) simulating more competent types of sedimentary rocks Four experiments were performed in each case: 1. without...

... ABSTRACT Most brittle solids are relatively weak in tension and this weakness can be very significant in determining their performance in structures and excavations. Consequently, accurate knowledge of the tensile strength of brittle materials has long been recognized as important...

...Chapter 5 INITIAL AND SUBSEQUENT FRACTURE CURVES FOR BIAXIAL COMPRESSION OF BRITTLE MATERIALS By B. Paul and M. Gangal It may be seen from Maurer's survey (Maurer, 1966) that most of the common methods used in rock drilling today depend upon mechanical loading of the rock. In order to predict...