Introduction to the combined finite discrete element method. The combined finitediscrete element method books pics. The method combines aspects of both finite elements and discrete elements. The combined finite discrete element method femdem has been used to simulate processes of brittle fracturing and associated seismicity. This book also provides support to postgraduate students, computer programmers, scientists and researchers who wish to increase their knowledge of the finite. Combined finitediscrete element method modeling of. In a finitediscrete element analysis the main issues which require consideration, for both dynamic and quasistatic. The purpose of this paper is to present ygeo, a new numerical code for geomechanical applications based on the combined finitediscrete element method fdem. In this work, the combined finitediscrete element method fdem was first employed. Vgw launch workshop virtual geoscience workbench department of earth science and engineering, ic. Solid domains are discretized into finite elements in the usual way dictated by the finite element method. Each method has its own advantages and limitations. Understanding this complex behaviour has been the focus of a significant amount of research. Space decomposition based parallelization solutions for.
The methods were developed during this work for the research on ice mechanics. Rearrange individual pages or entire files in the desired order. The combined finite discrete element method femdem is a stateof the art numerical modelling technique pioneered in the mid1990s. Applications of finitediscrete element modeling to rock. 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. Fdem combines finite element based analysis of continua with discrete element based. This chapter presents a general overview of the combined finitediscrete element method femdem which is considered as a stateoftheart technique for the. Damage characterization during laboratory strength testing. Pdf combined finitediscrete element method for simulation of. 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. 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. Space decomposition based parallelization solutions for the. A framework for grand scale parallelization of the combined.
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. Pdf discontinua modeling techniques, such as discrete element method dem, discontinuum deformation analysis dda, combined. Numerical studies of frictional sliding behavior and. 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 applied methodology is a combination of three technologies, i. Direct numerical simulation of particle saltation in. 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. New combined finitediscrete element numerical code. 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. The numerical modelling of masonry structures especially in the nonlinear range. Viennamath provides the symbolic math kernel, viennagrid with viennadata allows for a.
Pdf modeling simultaneous multiple fracturing using the. Numerical methods that will handle numerous interactions of particles will be useful to solve this problem. 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. Viennafem is built on top of the following libraries. Therefore, in combined finitediscrete element simulations the number 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 either one solid. 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. 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. The combined finitediscrete element method applied to the study of rock fracturing behavior in 3d. The combined finite discrete element method is a relatively new computational tool aimed at problems involving static and or dynamic.
In the first topic, a velocityweakening law is implemented to investigate the. Combined finitediscrete element method modeling of rock. Coupled seepage and deformation analysis using the vcfem incorporating body forces allows accurate analysis of earth dams. 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 by antonio a. A framework for grand scale parallelization of the.
The development and testing of this numerical tool for use in. 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. The new method is termed the combined finitediscrete element method. 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. Simulating the behavior of laminated glass under impact using. It features a symbolic math kernel, which manipulates the strong or weak form of the problem and automatically derives the discrete form. Application of finite discrete element method in dynamic analysis of. Thus, the study of hydraulic fracturing is of particular importance for petroleum industry. Introduction to the combined finitediscrete element method.
Structural applications of the combined finitediscrete. Combined finitediscrete element method for simulation of. Finitediscrete element models for assessment and repair of. 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. A graphical user interface and preprocessor for the.
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. Numerical simulation of particle stress and fracture using. 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. A bridging subdomain is used, the hamiltonian is chosen as a linear combination of discrete and continuum hamiltonians.
A combined finitediscrete element analysis of dry stone masonry structures, engineering structures, 52, 89100 20. Modeling simultaneous multiple fracturing using the combined finitediscrete element method article pdf available in geofluids 201845. The combined scaled boundary finitediscrete element. However, it cannot model the fracturing process of rock driven by hydraulic pressure. The combined finitediscrete element method for structural. Housner, the behavior of inverted pendulum structures during earthquakes, bulletin of the seismological society of.
A statistical analysis of ten scaleddistance empirical formulae was performed by. Simulation of crack induced nonlinear elasticity using the combined. We compute the effective uniaxial tensile strength of an ice sheet for several different specimen sizes. Prediction of blastinduced ground vibration and rock. The virtual geoscience workbench for discontinuous systems is a computer software environment for modelling. Thanks to the relatively inexpensive high performance hardware rapidly becoming available, it is possible to consider combined. The rock mass is represented as a collection of elastic bulk elements glued by. The combined finitediscrete element method femdem has been used to simulate processes of brittle fracturing and associated seismicity. Pdf recent developments in the combined finitediscrete. The proposed model 2,3 considers the effects of the behaviour of masonry structures due to dynamic action, crack initiation and. Hydraulic fracturing is widely used in the exploitation of unconventional gas such as shale gas. The combined finitediscrete element method fdem proposed by munjiza is an innovative numerical technique to capture progressive damage. Understanding the discrete element method download ebook.
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. Rock failure process is a complex phenomenon that involves elastic and plastic deformation, microscopic cracking, macroscopic fracturing, and frictional slipping of fractures. Multiscale analysis using a coupled discretefinite element model. 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. 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.
Recent developments in the combined finitediscrete element. Combined finitediscrete element method modeling of rockslides. 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. The combined finite discrete element method applied to the study of rock fracturing behavior in 3d. We have made the combined finite discrete element method femdem the core of our solids technology. We have made the combined finitediscrete element method femdem the core of our solids technology. In this approach, all the particles are modelled within the framework of the dem.
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. As such, it has become a tool of choice for problems involving fracturing, fragmenting and. The combined finite discrete element method bridges the gap between finite and discrete element methods. The pure continuum fem models rely on a combined coupled damage and tensile constitutive model e. This book also provides support to postgraduate students, computer programmers, scientists and researchers who wish to increase their knowledge of the finitediscrete element method. 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. The mechanical behaviour of anisotropic rocks in the laboratory has been recently studied with the combined fdem method by cai et al. Simulations of punch through experiments were performed using a three dimensional discrete element method and a two dimensional combined finite discrete element method. The combined finitediscrete element method is a recently developed numerical method aimed at modelling failing, fracturing andor fragmenting solids. On the use of combined finitediscrete element method for.
Simulating the behavior of laminated glass under impact. 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. 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. The various branches of the dem family are the distinct element method proposed by peter a. 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. With the newly extended femdem algorithm, two topics involving rock mechanics and geophysics are investigated. A phasefield model for brittle fracture is implemented in the commercial finite element software abaqus by means of uel subroutine. 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. Comparison of different polyhedral dem models based on the. The combined finitediscrete element method femdem is a stateoftheart numerical modelling technique pioneered in the mid1990s. Numerical modelling of a discontinuous medium has gained much popularity in recent decades.
The combined finitediscrete element method download. Y2d is a robust twodimensional femdem research code developed by munjiza in 2004. The combined finite discrete element method is a relatively new. In both of these methods, rubble is modelled as a discontinuum. The combined finitediscrete element method a natural extension of both discrete and finite element methods allows researchers to model problems involving the deformability of. Thus, finite element based analysis of continua is combined with discrete element based transient dynamics, cd and contact interaction solutions. The combined finitediscrete element method bridges the gap between finite and discrete element methods. 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. The combined finitediscrete element method fdem, pioneered by munjiza 2004, has become a tool of. Munjiza the combined finite discrete element method antonio a. Munjiza the combined finitediscrete element method antonio a. 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. Discrete element method dem is a method used in particle simulation and it was originally developed by cundall and strack.
The rock mass is represented as a collection of elastic bulk elements glued by cohesive elements with zero thickness. International journal of rock mechanics and mining sciences, 70. The combined finitediscrete element method fdem proposed by munjiza is an innovative numerical technique to capture progressive damage and failure processes in rock. Here, we introduce a twodimensional implementation of the combined finite discrete element method fdem, which merges the finite element. Shot peening simulation using discrete and finite element. Source codes and examples of input and output files, made available on the internet to. Multiscale analysis using a coupled discretefinite. Pdf combined finitediscrete element method for simulation. Complementary hydromechanical coupled finitediscrete. Validation of a threedimensional finitediscrete element method using experimental results of the split hopkinson pressure bar test. Finitediscrete element models for assessment and repair. 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. The combined finitediscrete element method is an excellent reference for mechanical and civil engineers working with and involved in developing finitediscrete element programmes. The numerical modelling of masonry structures especially in the nonlinear range represents an.