Simulations of Fracture and Fragmentation of Geologic Materials Using Combined FEM/DEM Analysis

Simulations of Fracture and Fragmentation of Geologic Materials Using Combined FEM/DEM Analysis

Author: M. B. Rubin

Publisher:

Published: 2005

Total Pages: 22

ISBN-13:

DOWNLOAD EBOOK

Results are presented from a study investigating the effect of explosive and impact loading on geological media using the Livermore Distinct Element Code (LDEC). LDEC was initially developed to simulate tunnels and other structures in jointed rock masses with large numbers of intact polyhedral blocks. However, underground structures in jointed rock subjected to explosive loading can fail due to both rock motion along preexisting interfaces and fracture of the intact rock mass itself. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model these types of problems, we have implemented Cosserat point theory and cohesive element formulations into the current version of LDEC, thereby allowing for dynamic fracture and combined finite element/discrete element simulations. Results of a large-scale LLNL simulation of an explosive shock wave impacting an elaborate underground facility are also discussed. It is confirmed that persistent joints lead to an underestimation of the impact energy needed to fill the tunnel systems with rubble. Non-persistent joint patterns, which are typical of real geologies, inhibit shear within the surrounding rock mass and significantly increase the load required to collapse a tunnel.


Simulations of Fracture and Fragmentation of Geologic Materials Using Combined FEM

Simulations of Fracture and Fragmentation of Geologic Materials Using Combined FEM

Author:

Publisher:

Published: 2007

Total Pages: 9

ISBN-13:

DOWNLOAD EBOOK

An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC, permitting the simulation of fluid-structure interaction. We will present results from a study of detonation-induced fracture and fragmentation of geologic media surrounding a tunnel using LDEC.


Dynamic Simulations of Geologic Materials Using Combined FEM

Dynamic Simulations of Geologic Materials Using Combined FEM

Author:

Publisher:

Published: 2008

Total Pages: 28

ISBN-13:

DOWNLOAD EBOOK

An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, there are many application involving geologic materials where fluid-structure interaction is important. To facilitate solution of this class of problems a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC to simulate fully coupled systems involving geologic materials and a saturating fluid. We will present results from a study of a broad range of geomechanical problems that exercise the various components of LDEC in isolation and in tandem.


Multiscale and Multiphysics Processes in Geomechanics

Multiscale and Multiphysics Processes in Geomechanics

Author: Ronaldo I. Borja

Publisher: Springer Science & Business Media

Published: 2011-05-10

Total Pages: 223

ISBN-13: 3642196306

DOWNLOAD EBOOK

This state-of-the-art book contains all results and papers of the International Workshop on Multiscale and Multiphysics Processes in Geomechanics at Stanford University Campus, June 23–25, 2010.


The Combined Finite-Discrete Element Method

The Combined Finite-Discrete Element Method

Author: Antonio A. Munjiza

Publisher: John Wiley & Sons

Published: 2004-04-21

Total Pages: 348

ISBN-13: 0470020172

DOWNLOAD EBOOK

The combined finite discrete element method is a relatively new computational tool aimed at problems involving static and / or dynamic behaviour of systems involving a large number of solid deformable bodies. Such problems include fragmentation using explosives (e.g rock blasting), impacts, demolition (collapsing buildings), blast loads, digging and loading processes, and powder technology. The combined finite-discrete element method - a natural extension of both discrete and finite element methods - allows researchers to model problems involving the deformability of either one solid body, a large number of bodies, or a solid body which fragments (e.g. in rock blasting applications a more or less intact rock mass is transformed into a pile of solid rock fragments of different sizes, which interact with each other). The topic is gaining in importance, and is at the forefront of some of the current efforts in computational modeling of the failure of solids. * Accompanying source codes plus input and output files available on the Internet * Important applications such as mining engineering, rock blasting and petroleum engineering * Includes practical examples of applications areas Essential reading for postgraduates, researchers and software engineers working in mechanical engineering.


Rock Mechanics: Meeting Society's Challenges and Demands, Two Volume Set

Rock Mechanics: Meeting Society's Challenges and Demands, Two Volume Set

Author: Erik Eberhardt

Publisher: CRC Press

Published: 2007-05-17

Total Pages: 1772

ISBN-13: 1439856575

DOWNLOAD EBOOK

Ore extraction through surface and underground mining continues to involve deeper excavations in more complex rock mass conditions. Communities and infrastructure are increasingly exposed to rock slope hazards as they expand further into rugged mountainous terrains. Energy needs are accelerating the development of new hydroelectric dams and exploit


High-Pressure Shock Compression of Solids II

High-Pressure Shock Compression of Solids II

Author: Lee Davison

Publisher: Springer

Published: 1996

Total Pages: 512

ISBN-13:

DOWNLOAD EBOOK

This volume concerns the fracture and fragmentation of solid materials that occurs when they are subjected to extremes of stress applied at the highest possible rates. The plan for the volume is to address experimental, theoretical, and com putational aspects of high-rate dynamic fracture and fragmentation, with emphasis on recent work. We begin with several chapters in which the emphasis falls on experimental methods and observations. These chapters address both macroscopic responses and the microscopic cause of these re sponses. This is followed by several chapters emphasizing modeling-the physical explanation and mathematical representation of the observations. Some of the models are deterministic, while others focus on the stochastic aspects of the observations. Often, the ov\!rall objective of investigation of dynamic fracture and fragmentation phenomena is provision of a means for predicting the entire course of an event that begins with a stimulus such as an impact and proceeds through a complicated deformation and fracture pro cess that results in disintegration of the body and formation of a rapidly expanding cloud of debris fragments. Analysis of this event usually involves development of a continuum theory and computer code that captures the experimental observations by incorporating models of the important pheno mena into a comprehensive description of the deformation and fracture pro cess. It is to this task that the work of the last few chapters is devoted.


Static Conceptual Fracture Modeling

Static Conceptual Fracture Modeling

Author: Ronald A. Nelson

Publisher: John Wiley & Sons

Published: 2019-10-07

Total Pages: 221

ISBN-13: 1119596955

DOWNLOAD EBOOK

Modelling of flow in naturally fractured reservoirs is quickly becoming mandatory in all phases of oil and gas exploration and production. Creation of a Static Conceptual Fracture Model (SCFM) is needed as input to create flow simulations for today and for prediction of flow into the future. Unfortunately, the computer modelers tasked with constructing the gridded fracture model are often not well versed in natural fracture characterization and are often forced to make quick decisions as to the input required by the software used to create these models. Static Conceptual Fracture Modelling: Preparing for Simulation and Development describes all the fracture and reservoir parameters needed to create the fracture database for effective modelling and how to generate the data and parameter distributions. The material covered in this volume highlights not only natural fracture system quantification and formatting, but also describes best practices for managing technical teams charged with creating the SCFM. This book will become a must on the shelf for all reservoir modelers.


Advances in Rock Dynamics and Applications

Advances in Rock Dynamics and Applications

Author: Yingxin Zhou

Publisher: CRC Press

Published: 2011-05-25

Total Pages: 524

ISBN-13: 0203093208

DOWNLOAD EBOOK

The study of rock dynamics is important because many rock mechanics and rock engineering problems involve dynamic loading ranging from earthquakes to vibrations and explosions. The subject deals with the distribution and propagation of loads, dynamic responses, and processes of rocks and rate-dependent properties, coupled with the physical environm