PSI - Issue 18

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ScienceDirect

Procedia Structural Integrity 18 (2019) 135–141 Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 00 (2019) 000–000

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© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Abstract In this work we developed a mathematical model that describes the deformation and failure of sandstone specimens subjected to the uniaxial compression. The model is based on the Drucker-Prager equation, as well as on the continuum damage mechanics. The numerical simulation was carried out utilizing finite-di ff erence method. The simulation results show that post-peak behavior su ffi ciently determines the final fracture patterns of loaded specimens. Coalescence of small scale fractures into a macroscopic crack occurs a few share of deformation prior to axial stress turns to residual in loading diagram. Fracture patterns are represented by both tensile and shear cracks which indicates mixed mode of failure. c 2019 The Authors. Published by Elsevier B.V. P er-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: numerical simulation; failure; finite-di ff erence method; damage mechanics; uniaxial compression; Drucker-Prager; 25th International Conference on Fracture and Structural Integrity Nu erical si ulation of failure of sandstone speci ens utilizing the finite-di ff erence continuous da age echanics approach Mikhail Eremin a, ∗ a Institute of strength physics and materials science of Siberian branch of Russian academy of sciences, 2 / 4 Akademicheskii Av., Tomsk, 634055, Russia Abstract In this work we developed a mathematical model that describes the deformation and failure of sandstone specimens subjected to the uniaxial compression. The model is based on the Drucker-Prager equation, as well as on the continuum damage mechanics. The numerical simulation was carried out utilizing finite-di ff erence method. The simulation results show that post-peak behavior su ffi ciently determines the final fracture patterns of loaded specimens. Coalescence of small scale fractures into a macroscopic crack occurs a few share of deformation prior to axial stress turns to residual in loading diagram. Fracture patterns are represented by both tensile and shear cracks which indicates mixed mode of failure. c 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. Keywords: numerical simulation; failure; finite-di ff erence method; damage mechanics; uniaxial compression; Drucker-Prager; 25th International Conference on Fracture and Structural Integrity Numerical simulation of failure of sandstone specimens utilizing the finite-di ff erence continuous damage mechanics approach Mikhail Eremin a, ∗ a Institute of strength physics and materials science of Siberian branch of Russian academy of sciences, 2 / 4 Akademicheskii Av., Tomsk, 634055, Russia Study of mechanical behavior of rocks is an acute problem of modern geomechanics. This is due to widespread problems of mining and petroleum engineering – the need to design both quarries and underground workings, well bore instability, hydraulic fracturing, etc. Rocks in their natural bedding are most often in a compressed state. In this case, rocks might experience failure in compaction mode if they are high porous which produces, e.g. fluid filtration problems. However, rocks don’t loose the structural integrity until the occurrence of tensile stresses when crack open ing becomes possible. In this connection, the number of studies of the mechanical behavior of rocks under the action of tensile stresses has increased significantly. Experimental studies are usually performed using di ff erent indirect ten sile tests, e.g SCB (Semi-Circular Bend test) Wang et al. (2019), CCNBD (Crack Chevron Notched Brazilian Disc test) He and Hayatdavoudi (2018), three point bending test Vavro et al. (2017). A large role has become given to nu merical simulation, which expands the understanding of mechanical behavior of rocks subjected to di ff erent loading conditions Stefanov (2008); Makarov et al. (2014); Wang et al. (2019). Study of mechanical behavior of rocks is an acute problem of modern geomechanics. This is due to widespread problems of mining and petroleum engineering – the need to design both quarries and underground workings, well bore instability, hydraulic fracturing, etc. Rocks in their natural bedding are most often in a compressed state. In this case, rocks might experience failure in compaction mode if they are high porous which produces, e.g. fluid filtration problems. However, rocks don’t loose the structural integrity until the occurrence of tensile stresses when crack open ing becomes possible. In this connection, the number of studies of the mechanical behavior of rocks under the action of tensile stresses has increased significantly. Experimental studies are usually performed using di ff erent indirect ten sile tests, e.g SCB (Semi-Circular Bend test) Wang et al. (2019), CCNBD (Crack Chevron Notched Brazilian Disc test) He and Hayatdavoudi (2018), three point bending test Vavro et al. (2017). A large role has become given to nu merical simulation, which expands the understanding of mechanical behavior of rocks subjected to di ff erent loading conditions Stefanov (2008); Makarov et al. (2014); Wang et al. (2019). 1. Introduction 1. Introduction

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2019.08.148 ∗ Corresponding author. Tel.: + 7-382-228-6937. E-mail address: eremin@ispms.tsc.ru 2210-7843 c 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. ∗ Corresponding author. Tel.: + 7-382-228-6937. E-mail address: eremin@ispms.tsc.ru 2210-7843 c 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.