International journal of rock mechanics and mining sciences, 70. The combined finite discrete element method is a relatively new. The virtual geoscience workbench for discontinuous systems is a computer software environment for modelling. We have made the combined finitediscrete element method femdem the core of our solids technology. The simulations use a numerical tool called the voronoi cell finite element method vcfem, which the present work extends to allow accurate analysis of the flow of fluid through a porous medium, deformation of a granular material under load and coupled analysis of these phenomena. Coupled seepage and deformation analysis using the vcfem incorporating body forces allows accurate analysis of earth dams. The new method is termed the combined finitediscrete element method. The combined finite discrete element method femdem is ideally suited to the simulation of both the multibody pellet dynamic packing and quasistatic interactions as well as the stress eld of each individual pellet, its deformations and fragmentation. This work introduces the finite particle method fpm 2 to solve this problem. The purpose of this paper is to propose a novel combined finitediscrete element method fdem, based on the cohesive zone model, for simulating rockslide problems at the laboratory scale. We have made the combined finite discrete element method femdem the core of our solids technology.
The purpose of this paper is to propose a novel combined finitediscrete element method fdem, based on the cohesive zone model czm, for simulating rock failure problems. On the use of combined finitediscrete element method for. This book also provides support to postgraduate students, computer programmers, scientists and researchers who wish to increase their knowledge of the finitediscrete element method. Numerical methods that will handle numerous interactions of particles will be useful to solve this problem. Pdf recent developments in the combined finitediscrete. Viennamath provides the symbolic math kernel, viennagrid with viennadata allows for a.
Solid domains are discretized into finite elements in the usual way dictated by the finite element method. Numerical modelling of a discontinuous medium has gained much popularity in recent decades. In this work, the application of the numerical model for dynamic analysis of masonry structures based on a finite discrete element method 1 is presented. Space decomposition based parallelization solutions for the. 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. However, it cannot model the fracturing process of rock driven by hydraulic pressure. Multiscale analysis using a coupled discretefinite. Structural applications of the combined finitediscrete.
Multiscale analysis using a coupled discretefinite element model 3 j i t i 2 where u i is the element centroid displacement in a fixed inertial coordinate frame x, i the angular velocity, m i the element mass, j i the moment of inertia, f i the resultant force, and t ithe resultant moment about the central axes. Pdf combined finitediscrete element method for simulation. Within the context of rock mechanics, the combined finitediscrete element method fdem has been applied to many complex industrial problems such as block caving, deep mining techniques tunneling, pillar strength, etc. Pdf discontinua modeling techniques, such as discrete element method dem, discontinuum deformation analysis dda, combined. Thus, finite element based analysis of continua is combined with discrete element based transient dynamics, cd and contact interaction solutions. Vgw launch workshop virtual geoscience workbench department of earth science and engineering, ic. Prediction of blastinduced ground vibration and rock. The development and testing of this numerical tool for use in. The applied methodology is a combination of three technologies, i. It features a symbolic math kernel, which manipulates the strong or weak form of the problem and automatically derives the discrete form. The combined finitediscrete element method for structural.
The combined finitediscrete 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. Here, we introduce a twodimensional implementation of the combined finite discrete element method fdem, which merges the finite element. Application of finite discrete element method in dynamic. Combined finitediscrete element method modeling of rock. Combined finitediscrete element method for simulation of. A bridging subdomain is used, the hamiltonian is chosen as a linear combination of discrete and continuum hamiltonians. The numerical modelling of masonry structures especially in the nonlinear range. Pdf modeling simultaneous multiple fracturing using the. This book also provides support to postgraduate students, computer programmers, scientists and researchers who wish to increase their knowledge of the finite. Housner, the behavior of inverted pendulum structures during earthquakes, bulletin of the seismological society of. The combined finitediscrete element method a natural extension of both discrete and finite element methods allows researchers to model problems involving the deformability of. Space decomposition based parallelization solutions for. Applications of finitediscrete element modeling to rock.
Pdf combined finitediscrete element method for simulation of. The combined finitediscrete element method femdem is a stateoftheart numerical modelling technique pioneered in the mid1990s. The combined finitediscrete element method is an excellent reference for mechanical and civil engineers working with and involved in developing finitediscrete element programmes. Numerical simulation of particle stress and fracture using. The combined finitediscrete element method is a recently developed numerical method aimed at modelling failing, fracturing andor fragmenting solids. Each method has its own advantages and limitations. Fdem is an innovative numerical technique that combines the advantages of continuumbased modeling approaches and discrete element methods to overcome the inability of these methods to capture progressive damage and failure. The development of a novel approach for simulating granular material behaviour using the combined finitediscrete element method vcfemdem provides new insights into strain localization in granular materials.
Numerical studies of frictional sliding behavior and. Munjiza the combined finitediscrete element method antonio a. The combined finitediscrete element method a natural extension of both discrete and finite element methods allows researchers to model problems involving the deformability of either one solid. The rock mass is represented as a collection of elastic bulk elements glued by. Simulation of crack induced nonlinear elasticity using the combined. Finitediscrete element models for assessment and repair of. Fdem is an innovative numerical technique that combines the advantages of continuumbased modeling approaches and discrete element methods to overcome the inability of these methods to. A statistical analysis of ten scaleddistance empirical formulae was performed by. Shot peening simulation using discrete and finite element.
Simulations of punch through experiments were performed using a three dimensional discrete element method and a two dimensional combined finite discrete element method. Sep 22, 2015 the combined finite discrete element method fdem proposed by munjiza is an innovative numerical technique to capture progressive damage and failure processes in rock. Direct numerical simulation of particle saltation in. Application of finite discrete element method in dynamic analysis of. In this approach, all the particles are modelled within the framework of the dem. The development of a novel approach for simulating granular material behaviour using the combined finite discrete element method vcfemdem provides new insights into strain localization in granular materials. 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. Introduction to the combined finite discrete element method.
Thus, the study of hydraulic fracturing is of particular importance for petroleum industry. A combined finitediscrete element method is proposed for the prediction of reinforced concrete structure response under severe dynamic loads as impacts due to natural or anthropic hazards. The combined finite element discrete element method fdem is a hybrid computational method developed by that exploits the advantages of the finite element method fem e. The combined finitediscrete element method femdem has been used to simulate processes of brittle fracturing and associated seismicity. A graphical user interface and preprocessor for the. Combined finitediscrete element method for simulation of hydraulic fracturing article pdf available in rock mechanics and rock engineering 494 september 2015 with 1,007 reads. Rock failure process is a complex phenomenon that involves elastic and plastic deformation, microscopic cracking, macroscopic fracturing, and frictional slipping of fractures. The purpose of this paper is to propose a novel combined finite discrete element method fdem, based on the cohesive zone model czm, for simulating rock failure problems. The combined finite discrete element method can be an advantageous tool for modelling of masonry structures. The pure continuum fem models rely on a combined coupled damage and tensile constitutive model e. Munjiza 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. A combined finitediscrete element analysis of dry stone masonry structures, engineering structures, 52, 89100 20. The combined finitediscrete element method fdem proposed by munjiza is an innovative numerical technique to capture progressive damage and failure processes in rock. Multiscale analysis using a coupled discretefinite element model 3 j i t i 2 where u i is the element centroid displacement in a fixed inertial coordinate frame x, i the angular velocity, m i the element mass, j i the moment of inertia, f i the resultant force, and t i the resultant moment about the central axes.
Comparison of different polyhedral dem models based on the. Fdem combines finite element based analysis of continua with discrete element based. The combined finite discrete element method femdem is a stateof the art numerical modelling technique pioneered in the mid1990s. The combined finitediscrete element method bridges the gap between finite and discrete element methods. The combined finitediscrete element method by antonio a. Hydraulic fracturing is widely used in the exploitation of unconventional gas such as shale gas. The purpose of this paper is to present ygeo, a new numerical code for geomechanical applications based on the combined finitediscrete element method fdem. Y2d is a robust twodimensional femdem research code developed by munjiza in 2004. Owena combined finitediscrete element simulation of shot peening processes part i study of 2d interaction laws eng comput, 17 5 2000, pp.
Discontinuity method ddm the geomechanical and flow models 15,16,17, the combined femdem discrete element method 18 technique plus the more recent extended finite element method xfem 4,19. With the newly extended femdem algorithm, two topics involving rock mechanics and geophysics are investigated. The combined finite discrete element method is an excellent reference for mechanical and civil engineers working with and involved in developing finite discrete element programmes. This chapter presents a general overview of the combined finite discrete element method femdem which is considered as a stateof the art technique for the. Therefore, in combined finitediscrete element simulations the number of. The various branches of the dem family are the distinct element method proposed by peter a. Understanding this complex behaviour has been the focus of a significant amount of research. The combined finite discrete element method femdem has been used to simulate processes of brittle fracturing and associated seismicity. Masonry is a heterogeneous structural material consisting of bricks joined by mortar layers. The numerical modelling of masonry structures especially in the nonlinear range represents an.
New combined finitediscrete element numerical code. In this work, the combined finitediscrete element method fdem was first employed. Discrete element method dem is a method used in particle simulation and it was originally developed by cundall and strack. The combined finitediscrete element method fdem, pioneered by munjiza 2004, has become a tool of. The prediction of blastinduced ground vibration and rock fragmentation at the mcgill utility replacement tunnel was investigated using two techniques. The combined finite discrete element method bridges the gap between finite and discrete element methods. A framework for grand scale parallelization of the combined. A phasefield model for brittle fracture is implemented in the commercial finite element software abaqus by means of uel subroutine.
Understanding the discrete element method download ebook. Damage characterization during laboratory strength testing. The combined scaled boundary finitediscrete element. As such, it has become a tool of choice for problems involving fracturing, fragmenting and. The combined finitediscrete element method download. The combined finitediscrete element method femdem is ideally suited to the simulation of both the multibody pellet dynamic packing and quasistatic interactions as well as the stress eld of each individual pellet, its deformations and fragmentation. Rearrange individual pages or entire files in the desired order. Viennafem is built on top of the following libraries. Within the context of rock mechanics, the combined finite discrete element method fdem has been applied to many complex industrial problems such as block caving, deep mining techniques tunneling, pillar strength, etc. These codes allow not only particle flows to be simulated for moving particles the dem part but they also allow detailed stress calculations to be undertaken on any complex particle shapes and complex structures such as packed beds by meshing the.
Modeling simultaneous multiple fracturing using the combined finitediscrete element method article pdf available in geofluids 201845. Combined finitediscrete element method modeling of. The combined finite discrete element method is a relatively new computational tool aimed at problems involving static and or dynamic. The mechanical behaviour of anisotropic rocks in the laboratory has been recently studied with the combined fdem method by cai et al. Recent developments in the combined finitediscrete element.
Introduction to the combined finitediscrete element method. A framework for grand scale parallelization of the. We compute the effective uniaxial tensile strength of an ice sheet for several different specimen sizes. Complementary hydromechanical coupled finitediscrete. The proposed model 25 considers the effects of the behaviour of dry stone masonry structures strengthened with steel clamps and bolts 3 as well as masonry infill 4 and reinforced concrete elements 68 in confined masonry structures due to dynamic action. 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. Thanks to the relatively inexpensive high performance hardware rapidly becoming available, it is possible to consider combined. The method combines aspects of both finite elements and discrete elements. Validation of a threedimensional finitediscrete element method using experimental results of the split hopkinson pressure bar test. The proposed model 2,3 considers the effects of the behaviour of masonry structures due to dynamic action, crack initiation and.
The phasefield method considerably reduces the implementation complexity for fracture problems as it removes the need for numerical tracking of discontinuities in the displacement field that are characteristic of discrete crack methods. Fdem couples dem and fem by generating a finite element mesh separately for each particle discrete element located within the computational domain. The combined finite discrete element method applied to the study of rock fracturing behavior in 3d. This chapter presents a general overview of the combined finitediscrete element method femdem which is considered as a stateoftheart technique for the. In the first topic, a velocityweakening law is implemented to investigate the. The combined finitediscrete element method fdem proposed by munjiza is an innovative numerical technique to capture progressive damage. The combined finitediscrete element method applied to the study of rock fracturing behavior in 3d.
The combined finitediscrete element method books pics. Simulating the behavior of laminated glass under impact. Multiscale analysis using a coupled discretefinite element model. Combined finitediscrete element method modeling of rockslides. The incorporation of deformation kinematics into the discrete element formulation has also led naturally to a combined finitediscrete element approach in which the problem is analysed by a combination of the two methods 5,14,16. 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. Source codes and examples of input and output files, made available on the internet to. In both of these methods, rubble is modelled as a discontinuum. Finitediscrete element models for assessment and repair. In a finitediscrete element analysis the main issues which require consideration, for both dynamic and quasistatic. The rock mass is represented as a collection of elastic bulk elements glued by cohesive elements with zero thickness.
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