OUTLINE OF PRESENTATION:
1) Numerical Modeling and its types
2) Finite Volume Method and its comparison
3) How to decide a Modeling Technique
4) 2D vs 3D Modeling
5) FLAC3D Introduction and its features
6) Mesh, Types of Meshes and Mesh Quality
7) Mesh Generation Tools
8) FLAC3D Interface
This presentation is mainly about the study of slope failure using FLAC 3D software. The authors believe that it will surely help especially 4th b tech guys who are interested in project related to slope stability. Thanks
Stress is a concept fundamental to Rock Mechanics principles and applications. There is a pre-existing state in the rock mass and we need to understand it, both directly, and as a stress state applies to analysis and design.
This document provides an overview of geomechanics concepts for petroleum engineers. It discusses stress and strain theory, elasticity, homogeneous and heterogeneous stress fields, principal stresses, and the Mohr circle construction. It also covers rock deformation mechanisms including cataclasis and intracrystalline plasticity. Key concepts are defined such as normal and shear stress, elastic moduli like Young's modulus and Poisson's ratio, elastic stress-strain equations, and strain measures including conventional, quadratic, and natural strain.
The document discusses several failure criteria for rocks, including:
1) The Mohr-Coulomb criterion, which defines shear strength as a function of cohesion and friction angle.
2) The Hoek-Brown criterion, which models the non-linear relationship between principal stresses and incorporates rock mass quality.
3) The Griffith failure criterion, which postulates that stress concentrations at flaws like cracks cause propagation and failure.
It also briefly mentions the Drucker-Prager yield criterion and that empirical criteria tailored to a specific rock type may provide the most precise failure prediction.
This document provides an overview of laboratory and field testing methods for rocks. It discusses index property tests such as unit weight, porosity, permeability, electrical resistivity, and sonic velocity that are used to characterize and classify rocks. It also describes mechanical property tests like unconfined compressive strength testing, triaxial testing, point load strength testing, and beam bending tests. Common field testing methods mentioned include pressuremeter testing, in-situ direct shear testing, and hydraulic fracturing. The document provides details on sample preparation, equipment used, procedures, and how to calculate and interpret results for different rock property tests.
This presentation is mainly about the study of slope failure using FLAC 3D software. The authors believe that it will surely help especially 4th b tech guys who are interested in project related to slope stability. Thanks
Stress is a concept fundamental to Rock Mechanics principles and applications. There is a pre-existing state in the rock mass and we need to understand it, both directly, and as a stress state applies to analysis and design.
This document provides an overview of geomechanics concepts for petroleum engineers. It discusses stress and strain theory, elasticity, homogeneous and heterogeneous stress fields, principal stresses, and the Mohr circle construction. It also covers rock deformation mechanisms including cataclasis and intracrystalline plasticity. Key concepts are defined such as normal and shear stress, elastic moduli like Young's modulus and Poisson's ratio, elastic stress-strain equations, and strain measures including conventional, quadratic, and natural strain.
The document discusses several failure criteria for rocks, including:
1) The Mohr-Coulomb criterion, which defines shear strength as a function of cohesion and friction angle.
2) The Hoek-Brown criterion, which models the non-linear relationship between principal stresses and incorporates rock mass quality.
3) The Griffith failure criterion, which postulates that stress concentrations at flaws like cracks cause propagation and failure.
It also briefly mentions the Drucker-Prager yield criterion and that empirical criteria tailored to a specific rock type may provide the most precise failure prediction.
This document provides an overview of laboratory and field testing methods for rocks. It discusses index property tests such as unit weight, porosity, permeability, electrical resistivity, and sonic velocity that are used to characterize and classify rocks. It also describes mechanical property tests like unconfined compressive strength testing, triaxial testing, point load strength testing, and beam bending tests. Common field testing methods mentioned include pressuremeter testing, in-situ direct shear testing, and hydraulic fracturing. The document provides details on sample preparation, equipment used, procedures, and how to calculate and interpret results for different rock property tests.
Rock mechanics for engineering geology part 3Jyoti Khatiwada
Hydraulic fracturing is a method to estimate initial stresses by pressurizing a sealed borehole section until it fractures. The fracture orientation indicates the minimum stress direction. This provides the orientation of the maximum horizontal stress for vertical boreholes. The breakdown pressure estimates the minimum principal stress, while the reopening pressure estimates the maximum principal stress. This allows estimating the 2D stress field in the horizontal plane, making it suitable for deep measurements where no underground access exists. However, it requires space for equipment and is best suited to vertical boreholes.
This document discusses the importance of geomechanics in understanding unconventional reservoirs. It covers topics such as natural fractures, mechanical rock properties, stress regimes, and how they impact horizontal drilling, hydraulic fracturing, and reservoir productivity. Natural fractures are especially important in tight formations as they can provide permeability and introduce anisotropy. The document also provides classifications of fractured reservoirs and naturally occurring fractures.
The Mohr Coulomb failure criterion describes the relationship between normal and shear stresses at failure through a linear equation. It represents the peak shear strength of a material as a function of the applied normal stress and the angle of internal friction. The criterion is commonly used in geotechnical analysis but has limitations as it assumes shear failure and does not account for non-linear failure envelopes or the intermediate principal stress.
The document discusses various drilling methods used for extracting samples from the ground including percussion drilling, auger drilling, rotary drilling, cable tool drilling, and air core drilling. Percussion drilling involves repeatedly lifting and dropping a heavy bit attached to rope to break up the earth. Auger drilling uses a helical screw that is rotated into the ground to lift cuttings up the borehole. Rotary drilling applies high-speed rotation and downward thrust to drilling rods with a cutting bit to drill through rock and soil. Cable tool drilling also involves repeated lifting and dropping but of a drill stem to force a bit into the ground. Air core drilling uses compressed air to remove cuttings made drilling unconsolidated ground with steel or tungsten
This document discusses the applicability of hydraulic mining in India. It analyzes trials of hydraulic mining conducted at the Gopalichak mine in BCCL. In the first two trials using an 80 bar hydraulic monitor, recovery rates remained low at 40% and below 20% respectively due to high convergence and support loads. In the third trial where the panel was developed into four pillars, convergence and support loads decreased to within 12 mm and 14 tons, resulting in an improved recovery rate of 65%. In conclusion, the document examines using hydraulic mining techniques like high-pressure water jets in Indian mines as an eco-friendly alternative to traditional mining.
The document discusses underground mining methods. It begins by explaining that the choice of mining method depends on characteristics of the orebody like thickness and dip, as well as the competency of surrounding rock. It then provides details on various hard rock and soft rock underground mining methods. These include longwall mining, room-and-pillar, blast mining, shortwall mining, and coal skimming for soft rocks. For hard rocks, methods include various stoping techniques, longwall mining, and caving methods. Stoping is defined as the process of extracting ore by leaving behind an open space called a stope.
The document discusses stresses around underground openings such as tunnels. It describes how underground openings alter the initial stress state of rocks and how determining stresses is important for design. Different types of tunnels and excavation methods are also outlined. The document then focuses on analyzing stresses around circular underground openings using transformations between rectangular and polar coordinate systems. It presents solutions for circular openings under hydrostatic stress fields and discusses elastic-plastic behavior, including Bray's model for analyzing squeezing tunnels.
The document discusses mineral beneficiation and comminution. It defines mineral beneficiation as the separation of valuable minerals from gangue in ore. Comminution, or size reduction, is the primary operation in mineral dressing and involves crushing and grinding the raw ore to liberate valuable minerals. The key steps in comminution are primary crushing, secondary crushing, coarse grinding, and fine grinding. Jaw crushers and gyratory crushers are used for primary crushing and reduce ore sizes from about 1 meter to 100 mm.
subsidence, upsidence, subsidence limits, components of subsidence, prediction of subsidence, analysis of subsidence, coal mines, control of subsidence, subsidence trough, harmonic extraction, abandoned mines subsidence prevention, subsidence prevention in working coal mines, factors affecting subsidence
This document discusses in situ rock stresses and induced stresses from excavation. It describes how vertical stress increases with depth and horizontal stress varies with a coefficient and can be modeled. Numerical methods like boundary element and finite element are presented to model stresses around openings. Examples show applying these methods to analyze stresses induced around tunnels.
This document discusses the Hoek-Brown failure criterion for estimating the strength and deformation properties of rock masses. It provides details on:
1) Estimating the intact rock strength (ciσ) and Hoek-Brown constant (mi) from triaxial test data on rock cores.
2) Methods for estimating ciσ and mi when direct testing is not possible.
3) Factors that influence rock mass strength estimates such as rock type, discontinuity spacing, and scale of the structure being analyzed.
The document discusses numerical methods for solving structural mechanics problems, specifically the Rayleigh Ritz method. It provides an overview of the Rayleigh Ritz method, indicating that it is an integral approach that is useful for solving structural mechanics problems. The document then provides a step-by-step example of using the Rayleigh Ritz method to determine the bending moment and deflection at the mid-span of a simply supported beam subjected to a uniformly distributed load over the entire span.
The document discusses mine opening and development, focusing on box cuts. It defines a box cut as the initial cut made to physically develop a mine. Box cuts can be internal, located partially or fully within the mineralized zone, or external, located completely outside the mineralized zone. The key parameters of a box cut are its maximum level difference or height, which is usually equal to the proposed bench height, and its floor width, which must allow smooth machinery movement. Methods for opening a box cut include drilling and blasting or excavation by machinery like shovels. Factors in selecting a box cut location include site accessibility, excavation needs, dumping space, and the overall mine plan.
This document discusses various methods for classifying rock masses, including the Geomechanics Classification (RMR) method developed by Bieniawski, the Norwegian Q-System, and the RMi method. It provides details on how each system determines classification based on parameters such as rock quality, discontinuity spacing and condition, groundwater conditions, and orientation. The classifications are then used to determine appropriate excavation dimensions and support requirements for tunnels based on the rock mass quality.
The document provides an overview of the key steps and considerations in designing an openpit mining operation, including:
1) Preliminary evaluation of the deposit to assess resources, mining technology options, and economic viability.
2) Conceptual mine planning including pit layout, equipment selection, and modifications or optimization.
3) Detailed steps in the design process such as studying exploration data, setting final pit limits, developing production sequences, and designing access ramps and haul roads.
4) Additional design elements like pit dimensions and slope angles, production capacity based on reserves and equipment, and optimizing stripping ratios.
Mohr's circle is a graphical representation that illustrates the relationships between normal and shear stresses or strains at a point. It shows the two principal stresses or strains and the maximum shear stress or strain. The circle is centered at the average stress or strain and has a radius equal to the maximum shear value. Mohr's circle can be used to determine principal stresses/strains and directions, transform between stress/strain systems, and visualize how stresses/strains change with rotation. It remains a useful tool for engineers despite the availability of calculators.
This document discusses concepts of failure in materials including tensile failure, shear failure, and failure criteria. It specifically examines the Mohr-Coulomb failure criterion, which states that failure depends on the material's cohesion and internal friction angle. The criterion can be represented on a Mohr's circle diagram, where failure occurs if the circle contacts the linear failure envelope line. Pore fluid pressure is also accounted for using effective stress. Triaxial tests are described that apply different confining pressures to measure failure properties over a range of stress conditions.
This document discusses principles of comminution and crushing in mineral processing. It describes the key theories of comminution including Kick's law, Rittinger's theory, and Bond's theory. It then focuses on primary crushers, describing the main types of jaw and gyratory crushers. Details are provided on jaw crusher construction and the differences between single toggle and double toggle jaw crushers. The document also discusses secondary and tertiary crushing operations.
This document discusses computational fluid dynamics (CFD). CFD uses numerical analysis and algorithms to solve and analyze fluid flow problems. It can be used at various stages of engineering to study designs, develop products, optimize designs, troubleshoot issues, and aid redesign. CFD complements experimental testing by reducing costs and effort required for data acquisition. It involves discretizing the fluid domain, applying boundary conditions, solving equations for conservation of properties, and interpolating results. Turbulence models and discretization methods like finite volume are discussed. The CFD process involves pre-processing the problem, solving it, and post-processing the results.
Introduction to CAE and Element Properties.pptxDrDineshDhande
INTRODUCTION
USE OF CAE IN PRODUCT DEVELOPMENT
CONTENTS:
(1) DISCRETIZATION METHODS : FEM,FDM AND FVM
(2) CAE TOOLS
(3) ELEMET SHAPES
(4) SHAPE FUNCTIONS
Rock mechanics for engineering geology part 3Jyoti Khatiwada
Hydraulic fracturing is a method to estimate initial stresses by pressurizing a sealed borehole section until it fractures. The fracture orientation indicates the minimum stress direction. This provides the orientation of the maximum horizontal stress for vertical boreholes. The breakdown pressure estimates the minimum principal stress, while the reopening pressure estimates the maximum principal stress. This allows estimating the 2D stress field in the horizontal plane, making it suitable for deep measurements where no underground access exists. However, it requires space for equipment and is best suited to vertical boreholes.
This document discusses the importance of geomechanics in understanding unconventional reservoirs. It covers topics such as natural fractures, mechanical rock properties, stress regimes, and how they impact horizontal drilling, hydraulic fracturing, and reservoir productivity. Natural fractures are especially important in tight formations as they can provide permeability and introduce anisotropy. The document also provides classifications of fractured reservoirs and naturally occurring fractures.
The Mohr Coulomb failure criterion describes the relationship between normal and shear stresses at failure through a linear equation. It represents the peak shear strength of a material as a function of the applied normal stress and the angle of internal friction. The criterion is commonly used in geotechnical analysis but has limitations as it assumes shear failure and does not account for non-linear failure envelopes or the intermediate principal stress.
The document discusses various drilling methods used for extracting samples from the ground including percussion drilling, auger drilling, rotary drilling, cable tool drilling, and air core drilling. Percussion drilling involves repeatedly lifting and dropping a heavy bit attached to rope to break up the earth. Auger drilling uses a helical screw that is rotated into the ground to lift cuttings up the borehole. Rotary drilling applies high-speed rotation and downward thrust to drilling rods with a cutting bit to drill through rock and soil. Cable tool drilling also involves repeated lifting and dropping but of a drill stem to force a bit into the ground. Air core drilling uses compressed air to remove cuttings made drilling unconsolidated ground with steel or tungsten
This document discusses the applicability of hydraulic mining in India. It analyzes trials of hydraulic mining conducted at the Gopalichak mine in BCCL. In the first two trials using an 80 bar hydraulic monitor, recovery rates remained low at 40% and below 20% respectively due to high convergence and support loads. In the third trial where the panel was developed into four pillars, convergence and support loads decreased to within 12 mm and 14 tons, resulting in an improved recovery rate of 65%. In conclusion, the document examines using hydraulic mining techniques like high-pressure water jets in Indian mines as an eco-friendly alternative to traditional mining.
The document discusses underground mining methods. It begins by explaining that the choice of mining method depends on characteristics of the orebody like thickness and dip, as well as the competency of surrounding rock. It then provides details on various hard rock and soft rock underground mining methods. These include longwall mining, room-and-pillar, blast mining, shortwall mining, and coal skimming for soft rocks. For hard rocks, methods include various stoping techniques, longwall mining, and caving methods. Stoping is defined as the process of extracting ore by leaving behind an open space called a stope.
The document discusses stresses around underground openings such as tunnels. It describes how underground openings alter the initial stress state of rocks and how determining stresses is important for design. Different types of tunnels and excavation methods are also outlined. The document then focuses on analyzing stresses around circular underground openings using transformations between rectangular and polar coordinate systems. It presents solutions for circular openings under hydrostatic stress fields and discusses elastic-plastic behavior, including Bray's model for analyzing squeezing tunnels.
The document discusses mineral beneficiation and comminution. It defines mineral beneficiation as the separation of valuable minerals from gangue in ore. Comminution, or size reduction, is the primary operation in mineral dressing and involves crushing and grinding the raw ore to liberate valuable minerals. The key steps in comminution are primary crushing, secondary crushing, coarse grinding, and fine grinding. Jaw crushers and gyratory crushers are used for primary crushing and reduce ore sizes from about 1 meter to 100 mm.
subsidence, upsidence, subsidence limits, components of subsidence, prediction of subsidence, analysis of subsidence, coal mines, control of subsidence, subsidence trough, harmonic extraction, abandoned mines subsidence prevention, subsidence prevention in working coal mines, factors affecting subsidence
This document discusses in situ rock stresses and induced stresses from excavation. It describes how vertical stress increases with depth and horizontal stress varies with a coefficient and can be modeled. Numerical methods like boundary element and finite element are presented to model stresses around openings. Examples show applying these methods to analyze stresses induced around tunnels.
This document discusses the Hoek-Brown failure criterion for estimating the strength and deformation properties of rock masses. It provides details on:
1) Estimating the intact rock strength (ciσ) and Hoek-Brown constant (mi) from triaxial test data on rock cores.
2) Methods for estimating ciσ and mi when direct testing is not possible.
3) Factors that influence rock mass strength estimates such as rock type, discontinuity spacing, and scale of the structure being analyzed.
The document discusses numerical methods for solving structural mechanics problems, specifically the Rayleigh Ritz method. It provides an overview of the Rayleigh Ritz method, indicating that it is an integral approach that is useful for solving structural mechanics problems. The document then provides a step-by-step example of using the Rayleigh Ritz method to determine the bending moment and deflection at the mid-span of a simply supported beam subjected to a uniformly distributed load over the entire span.
The document discusses mine opening and development, focusing on box cuts. It defines a box cut as the initial cut made to physically develop a mine. Box cuts can be internal, located partially or fully within the mineralized zone, or external, located completely outside the mineralized zone. The key parameters of a box cut are its maximum level difference or height, which is usually equal to the proposed bench height, and its floor width, which must allow smooth machinery movement. Methods for opening a box cut include drilling and blasting or excavation by machinery like shovels. Factors in selecting a box cut location include site accessibility, excavation needs, dumping space, and the overall mine plan.
This document discusses various methods for classifying rock masses, including the Geomechanics Classification (RMR) method developed by Bieniawski, the Norwegian Q-System, and the RMi method. It provides details on how each system determines classification based on parameters such as rock quality, discontinuity spacing and condition, groundwater conditions, and orientation. The classifications are then used to determine appropriate excavation dimensions and support requirements for tunnels based on the rock mass quality.
The document provides an overview of the key steps and considerations in designing an openpit mining operation, including:
1) Preliminary evaluation of the deposit to assess resources, mining technology options, and economic viability.
2) Conceptual mine planning including pit layout, equipment selection, and modifications or optimization.
3) Detailed steps in the design process such as studying exploration data, setting final pit limits, developing production sequences, and designing access ramps and haul roads.
4) Additional design elements like pit dimensions and slope angles, production capacity based on reserves and equipment, and optimizing stripping ratios.
Mohr's circle is a graphical representation that illustrates the relationships between normal and shear stresses or strains at a point. It shows the two principal stresses or strains and the maximum shear stress or strain. The circle is centered at the average stress or strain and has a radius equal to the maximum shear value. Mohr's circle can be used to determine principal stresses/strains and directions, transform between stress/strain systems, and visualize how stresses/strains change with rotation. It remains a useful tool for engineers despite the availability of calculators.
This document discusses concepts of failure in materials including tensile failure, shear failure, and failure criteria. It specifically examines the Mohr-Coulomb failure criterion, which states that failure depends on the material's cohesion and internal friction angle. The criterion can be represented on a Mohr's circle diagram, where failure occurs if the circle contacts the linear failure envelope line. Pore fluid pressure is also accounted for using effective stress. Triaxial tests are described that apply different confining pressures to measure failure properties over a range of stress conditions.
This document discusses principles of comminution and crushing in mineral processing. It describes the key theories of comminution including Kick's law, Rittinger's theory, and Bond's theory. It then focuses on primary crushers, describing the main types of jaw and gyratory crushers. Details are provided on jaw crusher construction and the differences between single toggle and double toggle jaw crushers. The document also discusses secondary and tertiary crushing operations.
This document discusses computational fluid dynamics (CFD). CFD uses numerical analysis and algorithms to solve and analyze fluid flow problems. It can be used at various stages of engineering to study designs, develop products, optimize designs, troubleshoot issues, and aid redesign. CFD complements experimental testing by reducing costs and effort required for data acquisition. It involves discretizing the fluid domain, applying boundary conditions, solving equations for conservation of properties, and interpolating results. Turbulence models and discretization methods like finite volume are discussed. The CFD process involves pre-processing the problem, solving it, and post-processing the results.
Introduction to CAE and Element Properties.pptxDrDineshDhande
INTRODUCTION
USE OF CAE IN PRODUCT DEVELOPMENT
CONTENTS:
(1) DISCRETIZATION METHODS : FEM,FDM AND FVM
(2) CAE TOOLS
(3) ELEMET SHAPES
(4) SHAPE FUNCTIONS
This document proposes using subdivision surfaces within an isogeometric boundary element method for Helmholtz analysis. Subdivision surfaces can overcome limitations of NURBS used in CAD and allow local refinement. The boundary element method requires only boundary discretization. An example problem models acoustic scattering from a subdivision surface sphere mesh, achieving higher accuracy than a Lagrangian discretization of the same order. Future work includes coupling with finite elements for structural-acoustic analysis and electromagnetic scattering problems.
This document discusses unstructured grid generation and flow simulation for discrete fractured models (DFMs). It describes:
- Generating unstructured meshes using Delaunay tessellation for 2D and 3D DFMs in MATLAB and TetGen.
- Simulating single-phase flow on the meshes using the two-point flux approximation (TPFA) scheme, accounting for matrix-matrix, matrix-fracture, and fracture-fracture connections.
- Evaluating different solvers like LSOR and SIP for solving the pressure equation, showing SIP converges faster.
- Discussing permeability upscaling using pressure solver methods in programs like flowsim, and how upscaling results are affected
Lecture on Introduction to finite element methods & its contentsMesayAlemuTolcha1
The document provides an overview of the Finite Element Method (FEM) course being taught. It discusses:
1. What FEM is and its common application areas like structural analysis, heat transfer, fluid flow.
2. The main steps in FEM including discretization, selecting interpolation functions, developing element matrices, assembling the global matrix, imposing boundary conditions, and solving equations.
3. Different element types like 1D, 2D, and 3D elements and the use of isoparametric formulations.
4. The history of FEM and how it has evolved from being used on mainframe computers to PCs.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The document provides an overview of good practices in finite element analysis (FEA). It discusses various aspects of the FEA process including analysis types, element types, mesh quality, validation techniques, and quality assurance requirements. An example engineering problem is also presented on using FEA to analyze stress in a monopile offshore structure and identify stress concentration factors to inform fatigue assessments. The document aims to provide guidance on best practices across the full FEA workflow.
This document provides an overview of good practices in finite element analysis (FEA). It discusses various topics including the FEA process, analysis types, element types, mesh quality, and validation. The modern design process utilizes optimization and virtual testing with FEA earlier in the process compared to the traditional design-build-test approach. A variety of linear and nonlinear analysis types are described such as static, dynamic, and buckling analyses. The document emphasizes the importance of validation, quality assurance, and maintaining proper documentation of the FEA process.
The document discusses different types of mesh generation schemes used in computational fluid dynamics (CFD) simulations. It describes structured, unstructured, and hybrid meshes based on connectivity and also element-based classifications including quadrilaterals, triangles, hexahedra, tetrahedra, and other elements. Surface meshes are also discussed as important for applying boundary conditions in 3D simulations. Proper mesh generation is presented as crucial for the success of CFD modeling efforts.
Object-oriented Modeling of Mechatronics Systems in Modelica Using Wrapped Bo...MariaMarque
This document discusses object-oriented modeling of mechatronic systems using bond graphs and Modelica. It presents bond graphs and multi-bond graphs as graphical modeling tools to represent physical systems in a modular way. Bond graphs keep component models simple and maintainable. Model wrapping is used to provide intuitive interfaces for different domains like mechanics, electronics, while internally using bond graph representations. The document demonstrates modeling of various physical examples from different domains using bond graphs in Dymola libraries.
This document provides an overview of simulation software for modeling multibody systems. It discusses different modeling approaches, such as using Cartesian or relative coordinates, and different solution methods in dynamics simulation, including Lagrange multipliers and velocity transformations. Examples of computer implementation for kinematics and dynamics simulation are presented. The document also briefly discusses using web technologies for simulation and collaboration.
This document summarizes the use of numerical modeling techniques for strata control in coal mines. It discusses various numerical modeling approaches including continuum methods like finite difference and finite element methods, and discontinuum methods like discrete element modeling. It provides examples of applying these techniques to model longwall mining. Specifically, it presents a case study using finite element analysis to model shield-strata interaction in a longwall panel of a project in India.
This document provides guidelines for modeling fluid flow simulations using ANSYS Fluent. It discusses defining modeling goals, pre-processing steps like geometry simplification and meshing, setting up the solver by selecting physical models and boundary conditions, computing the solution, and examining results. Guidelines are provided for choosing pressure-based vs density-based solvers, spatial and temporal discretization, and modeling turbulence. The document aims to help users optimize their workflow and achieve accurate results efficiently.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document discusses the chimera grid method for computational fluid dynamics simulations of complex geometries. It has two main elements: (1) decomposition of the computational domain into sub-domains that are each gridded independently, and (2) communication of solution data between sub-domains through interpolation. Overlapping grids allow each sub-domain to be gridded with structured grids while handling interfaces through hole and outer boundaries. The chimera grid method makes it possible to model problems with complex geometries using easier-to-generate body-fitted grids. It has been used successfully for simulations of configurations like the integrated space shuttle.
This document compares three popular discretization approaches in computational fluid dynamics (CFD): finite difference method (FDM), finite volume method (FVM), and finite element method (FEM). It explains that FDM replaces derivatives with difference formulas on a grid, FVM is based on integral forms of partial differential equations solved over finite volumes, and FEM uses piecewise basis functions over finite elements. While each method has advantages and disadvantages, FVM generally provides better conservation properties and can handle complex domains, though all three approaches make the modeling of fluid flows and related phenomena possible through computer-based simulation.
1) The document discusses the basics of the finite element method (FEM), which involves dividing a structure into simple subdomains called finite elements connected at nodes.
2) FEM allows for the analysis of complex problems by replacing differential equations with algebraic equations at nodes. This is done using shape functions to interpolate values within an element.
3) The document compares FEM to other numerical methods like the finite difference method, noting advantages of FEM include better accuracy with fewer elements and the ability to model curved boundaries and nonlinear problems.
Review of Diverse Techniques Used for Effective Fractal Image CompressionIRJET Journal
This document reviews different techniques for fractal image compression to enhance compression ratio while maintaining image quality. It discusses algorithms like quadtree partitioning with Huffman coding (QPHC), discrete cosine transform based fractal image compression (DCT-FIC), discrete wavelet transform based fractal image compression (DWTFIC), and Grover's quantum search algorithm based fractal image compression (QAFIC). The document also analyzes works applying these techniques and concludes that combining QAFIC with the tiny block size processing algorithm may further improve compression ratio with minimal quality loss.
Similar to Numerical Modeling & FLAC3D Introduction.pptx (20)
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELijaia
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
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Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Home security is of paramount importance in today's world, where we rely more on technology, home
security is crucial. Using technology to make homes safer and easier to control from anywhere is
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AI based model home security system. The system has a user-friendly interface, allowing users to start
model training and face detection with simple keyboard commands. Our goal is to introduce an innovative
home security system using facial recognition technology. Unlike traditional systems, this system trains
and saves images of friends and family members. The system scans this folder to recognize familiar faces
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Build the Next Generation of Apps with the Einstein 1 Platform.
Rejoignez Philippe Ozil pour une session de workshops qui vous guidera à travers les détails de la plateforme Einstein 1, l'importance des données pour la création d'applications d'intelligence artificielle et les différents outils et technologies que Salesforce propose pour vous apporter tous les bénéfices de l'IA.
Mechatronics is a multidisciplinary field that refers to the skill sets needed in the contemporary, advanced automated manufacturing industry. At the intersection of mechanics, electronics, and computing, mechatronics specialists create simpler, smarter systems. Mechatronics is an essential foundation for the expected growth in automation and manufacturing.
Mechatronics deals with robotics, control systems, and electro-mechanical systems.
Supermarket Management System Project Report.pdfKamal Acharya
Supermarket management is a stand-alone J2EE using Eclipse Juno program.
This project contains all the necessary required information about maintaining
the supermarket billing system.
The core idea of this project to minimize the paper work and centralize the
data. Here all the communication is taken in secure manner. That is, in this
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Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
2. Outline
• Numerical Modeling and its types
• Finite Volume Method and its comparison
• How to decide a Modeling Technique
• 2D vs 3D Modeling
• FLAC3D Introduction and its features
• Mesh, Types of Meshes and Mesh Quality
• Mesh Generation Tools
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 2
3. Why Numerical Modeling is used
?
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 3
4. Why Numerical Modeling ?
• The best way to solve a physical problem governed by differential equations is to
obtain a closed form analytical solution.
• Unfortunately there are many practical situations where the analytical solution is
difficult to obtain or analytical solution does not exist.
• This is because in order to obtain analytical solution, the shape of the physical
domain must be known in the mathematical form. If the shape of the domain is
irregular, so that no mathematical representation can be made. Then it is
impossible to solve the problem using analytical method.
• Even if the shape of the domain is regular, many a times the governing equations
of the problem may be nonlinear and makes the problem more complex to solve.
• There are several procedures to obtain an approximate numerical solution to a
partial differential equation.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 4
5. Different Numerical Methods
• In broad sense, numerical methods can be classified into continuum and discontinuum.
The concept of continuum and discontinuum are not absolute but relative and problem
specific depending specially on geometric configuration.
• A continuum model is a representation of a structure or a process of gradual and
uninterrupted change in its elements between two distinctive points defined by a
particular measure.
• There are several procedures to obtain an approximate numerical solution to a partial
differential equation.
• Some of the popular methods are:-
Finite Element Method (FEM)
Finite Difference Method (FDM)
Finite Volume Method (FVM)
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 5
6. Flow chart depicting the procedure followed
to solve a problem by FVM, FDM & FEM
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 6
Fig: The most commonly used numerical methods and their essential differences
7. Finite Volume Discretization Approaches
• The FVM divides a geometrically arbitrary domain
into a finite number of elements (a structured or
unstructured mesh), subsequently used to build finite or
control volumes (a dual mesh).
• The discretization of the domain into control volumes
can be performed by adopting a vertex-centred
approach (where each node of the mesh is the centre
of a finite volume, whose boundaries are obtained by
connecting the centroids of each element and
the midpoints of each element edge), or by a cell-
centred approach (where control volumes coincide
with elements), as depicted in Figure for the two-
dimensional case.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 7
Fig: Mesh and dual mesh in vertex-centred FVM (a, b) and cell-centred
FVM (c, d). Control volumes are defined by the grey-coloured areas [4]
8. FDM vs FVM
Finite Difference Method (FDM)
• Differential form of governing
equations
• Domain is discretized into finite
discrete points
• Defined on a regular/structured grid
• Regular grids are suitable for very
large scale simulations
• Solution will be obtained on nodal
points
Finite Volume Method (FVM)
FLAC3D (Explicit Continuum Modeling of Non-linear Material
Behavior in 3D) Presentation by Maharshi (DT21MIN001)
8
• Integral form of governing equations
• Domain is discretized into finite
volumes or cells
• Defined on any irregular/unstructured
mesh
• Irregular grids are suitable for
complex geometries
• Solution will be obtained on centre of
each cell
9. How to decide Modeling Technique ?
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 9
Method Scheme Time for
Convergence
Applicability Error Geometry
FDM Difference
Equations and
uses Taylor’s
Expansion
Fast Very good for
Higher order
PDE’s
more Regular and
Large-scale
Problems
FVM Integral form
and uses
Divergence
Theorem
Slow Good (up to
second order
PDE’s)
less Regular/
Irregular and
Complex
geometries
FEM stiffness
matrices and
Uses basic
functions
Slow Good (up to
second order
PDE’s)
less Regular/
Irregular and
Complex
geometries
10. Lagrangian vs Eulerian Approach
• The choice of either a Lagrangian or an Eulerian viewpoint depends on the
physical problem under investigation.
• Normally, the Eulerian description is used in fluid mechanics because particles
have very large, complicated motions relative to each other and, in most cases, the
interest is concentrated in the condition of flow in a fixed region of space.
• While in solid mechanics, the Lagrangian system is normally employed because it
provides an easier method of identifying paths of particles which is important in
problems involving deformations of boundaries which are often not known before.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 10
11. 2D vs 3D Modeling
• All real-world stress and strain states are three-dimensional. In many cases,
however, we can make assumptions that greatly simplify the analysis, without
greatly affecting the result.
• 2D approaches can used only if the problem fulfils the plain strain criteria i.e. if
the out-of-plain strain resulting from the model perturbation is zero or uniform.
• The simplest example of this is a straight tunnel in a homogenous rock mass
• If the plain strain criteria is not fulfilled (i.e. for a tunnel intersection or curve) a
3D model is required.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 11
12. What is FLAC3D ?
• FLAC3D is a three-dimensional explicit Lagrangian finite-volume program.
• It is a continuum numerical modeling software for geotechnical analyses of
soil, rock, ground water and ground supports.
• It is used mainly in civil, mining, geotechnical and petroleum engineering
applications.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 12
13. Audio Clip from ITASCA
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 13
Youtube Link: https://www.youtube.com/watch?v=dCkmGbQhwVI&t=40s
14. Features of FLAC3D
• FLAC3D is mostly a command driven program (i.e., FISH and Python scripting
languages) which makes it more powerful.
Parametric Studies
Automating model sequences
Modification of Physics
• FLAC3D features accelerated 3D graphics that allow for rapid model
visualization.
• Extensive plotting capabilities including easy mechanisms for constructing
animations (videos) are available to facilitate pre and post processing.
• Dynamic Modeling and Thermal Analysis.
• 26 Mechanical and 9 Creep Constitutive Models built-in.
• Can create your own constitutive model.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 14
15. Features of FLAC3D
• Model Building: Extrusion Pane, Building Blocks and Imported geometric surfaces.
• Densification of zones close to imported surfaces or interfaces or at a desired
location.
• Import the geometric meshes of a physical domain from third-party CAD softwares
like Rhino, AutoCAD, etc.
• Can create structural elements like Beams, Cables, Piles, Shells, Liners & Geogrids.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 15
• Can create interfaces like Faults, Joints.
• Can create water table.
• Time varying loads can be applied.
• Can view results as calculation progresses.
16. Numerical Formulation of FLAC3D
The method of solution in FLAC3D is characterized by the following three approaches:
• Finite volume approach (First-order space and time derivatives of a variable are
approximated by finite volumes assuming linear variations of the variable over finite
space and time intervals, respectively);
• Discrete-model approach (The continuous medium is replaced by a discrete equivalent
one in which all forces involved (applied and interactive) are concentrated at the nodes of
a three-dimensional mesh used in the medium representation); and
• Dynamic-solution approach (The inertial terms in the equations of motion are used as
numerical means to reach the equilibrium state of the system under consideration).
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 16
17. Sign Conventions used in FLAC3D
Itasca software follows mechanical engineering practices:
• Direct Stress: Positive stresses indicate tension; negative stresses indicate compression
• Shear Stress: Positive shear stress points in the positive direction of the coordinate axis
• Direct Strain: Positive strain indicates extension; negative strain indicates compression
• Shear Strain: Follows the convention of shear stress
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 17
18. What is a Mesh ?
• The finite volume grid is an assemblage of one or more finite volume zones across
the physical region that is being analysed. Another term for grid is mesh.
• Gridpoints are associated with the corners of the finite volume zones. There are
four, five, six, seven, or eight gridpoints associated with each polyhedral zone,
depending on the zone shape.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 18
19. Mesh Types
Meshes are often categorized as: structured, unstructured,
or hybrid meshes.
• Structured Mesh: Structured meshes are identified by
regular connectivity.
• For example, a quadrilateral mesh in 2D is structured if
each internal node is joined to 4 neighbouring
quadrilaterals, forming a regular array of elements.
• In 3D, a structured hexahedral grid has each internal
node connected to 8 elements. Structured meshes
typically have well-shaped elements.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 19
Fig: Structured Mesh of a domain [2].
20. Mesh Types
• Unstructured Mesh: An unstructured grid is
identified by irregular connectivity.
• Hybrid mesh: usually refers to a mesh that
contains a combination of structured and
unstructured meshes.
• In general, structured meshes offer
simplicity and easy data access, while
unstructured meshes offer more convenient
mesh adaptivity and a better fit to
complicated domains.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 20
Fig: Unstructured Mesh of a domain [2].
21. Mesh Types
• Meshes are also categorized as: conformal
and non-conformal meshes.
• Conformal: A conformal mesh is a mesh
where each zone in the mesh, completely
shares a face with the neighbour (it should
also share the edges and nodes of that face as
well).
• In conformal mesh, the nodes at the contact
region are exactly one-one match, such as the
red nodes and green nodes in the conform
mesh plot.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 21
Fig: Conformal Mesh of a 2D domain [5].
22. Mesh Types
• Non-Conformal: A non-conformal mesh includes
a hexahedral element sharing one of its
quadrilateral faces with more than one face of
adjoining element/zone.
• Another example includes the case where two
meshes might be laterally offset from each other,
where some of the nodes and edges do not match
at element boundaries (sometimes referred to as
"hanging nodes").
• FLAC3D is capable of handling both of these grid
types.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 22
Fig: Non-conformal Mesh of a 2D domain [5].
23. What is a Octree Mesh ?
• Consider an initial structured
hexahedral grid. If we refine this grid
by subdividing hexahedrons (a hex is
subdivided into eight smaller
hexahedrons) in areas of interest.
• We continue subdividing the smaller
hexahedrons in our areas of interest up
to a certain level of refinement.
• If we then enforce the rule that an
element’s neighbour must be either ½,
1, or 2 times its size (by subdividing
further), we obtain a balanced octree
mesh.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 23
24. What is a Octree Mesh ?
• With this method, the user initially creates a regular structured hexahedral grid
independent of the geometry and densifies this grid close to the features that need
to be modeled and analyzed.
• The level of densification will depend on the precision that is required.
• The densification process consists of dividing a hexahedron into eight
hexahedrons and repeating this until the desired zone size is achieved.
• The main advantage of the octree method is its ability to generate a mesh for
complex geometries very quickly.
• The main disadvantage is that the resulting mesh does not conform to the
geometry, but rather results in “stair step” boundaries that approximate the
modeled features, which is not acceptable for all types of problems.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 24
25. Mesh Quality
• A good mesh is a mesh that allows you to solve your problem at the expected level
of accuracy within the time available for the project.
• Mesh quality is crucial for the stability, accuracy, and fast convergence of a
numerical simulation.
• There are numerous measures of mesh or element quality, such as element aspect
ratio, Jacobian, planarity of element faces, maximum and minimum angles at
corners, etc.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 25
26. Mesh Metrics
• “Mesh Metrics” is one of the most useful features in
determining the correct shape and size of the elements.
• You can find a range of criteria for quality check of
your mesh like Aspect Ratio, Jacobian Ratio and
Skewness, etc.
Aspect Ratio
• The Aspect Ratio quantifies the quality of the
elements, where 1 is a perfectly shaped tetrahedral
element and the element shape is worse with a
higher Aspect Ratio.
• The aspect ratio is defined as the ratio of the shortest
length of the element to the longest length of the
element.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 26
Fig: Showing different Aspect Ratio Elements
27. Mesh Metrics
Jacobian
• Jacobian Ratio is a measure of the deviation of a
given element from an ideally shaped element.
• The Jacobian value ranges from -1.0 to 1.0,
where 1.0 represents a perfectly shaped element.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 27
Fig: Showing different Jacobian Ratio Elements
28. Mesh Metrics
Skewness
• Skewness is the Angular Measure of
Element quality with respect to the Angles
of Ideal Element Types.
• It is one of the Primary Qualities Measures
of FE Mesh. Skewness determines how
close to ideal (i.e., equilateral or equi-
angular) a face or cell is.
• The acceptable range of skewness is “0 to
0.5”.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 28
Fig: Showing different Triangular and quad Elements
29. Important Aspect in Numerical Modeling
Convergence Analysis
• The most fundamental and accurate method for evaluating mesh quality is to
refine the mesh until a critical result, such as the maximum stress in a specific
location converges (i.e. it doesn’t change significantly with each refinement).
• Basically, the convergence tool increases the mesh density and checks the results
between each step. You can easily see how your results change depending on the
element quantity.
• The problem with this method is that it requires multiple remeshing and re-solving
operations. While this method is fine for simple models, it can be very time-
consuming for complex models. However, in Ansys you can easily perform this
operation automatically by using Convergence tool option.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 29
30. Important Aspect in Numerical Modeling
Convergence Analysis
• An example is shown in Figure 1, where a 2D
bracket model is constrained at its top end and
subjected to a shear load at the edge on the lower
right. This generates a peak stress in the fillet, as
shown.
• The curve shows that as the mesh density increases,
the peak stress in the fillet increases.
• Ultimately, increasing the mesh density further
produces only minor increases in peak stress.
• In this case, an increase from 1134 elements per
unit area to 4483 elements per unit area yields only
a 1.5% increase in stress.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 30
31. Mesh Generation Tools
• Mesh or Grid generation with FLAC3D involves adjusting and shaping the mesh
to fit the shape of the physical domain.
• Itasca offers a number of mesh generation tools. They may be divided into two
categories.
1. Using built-in meshing capabilities that are standard features with FLAC3D or
3DEC.
2. Using Rhino, CAD-based capabilities offered by Griddle or BlockRanger. Itasca
introduced a new powerful and easy-to-use automatic mesher called Griddle.
Griddle is accessible from the Rhino CAD-system and can output both all-
tetrahedral and hex-dominant meshes.
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 31
32. FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 32
Introduction to FLAC3D Software?
33. FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 33
Introduction to FLAC3D Software?
34. FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 34
Introduction to FLAC3D Software?
35. References
[1] http://docs.itascacg.com/flac3d700/flac3d/docproject/source/flac3dhome.html
[2] Aissa, M., 2017. GPU-accelerated CFD simulations for turbomachinery design optimization (Doctoral
dissertation, Doctoral thesis, Delft University of Technology).
[3] Maneeratana, K., and A. Ivankovic. "Finite volume method for large deformation with linear hypoelastic
materials." In second international symposium on finite volumes for complex applications (FVCA II) for
complex applications II: problems and perspectives. Hermes Science Publication, University Duisburg,
Germany, pp. 459-466. 1999.
[4] Aleksendric, Dragan, and Pierpaolo Carlone. Soft Computing in the Design and Manufacturing of Composite
Materials: Applications to Brake Friction and Thermoset Matrix Composites. Woodhead Publishing, 2015.
[5] Chen, Lu, Xiaowei Zhou, Zhigao Huang, and Huamin Zhou. "Three-Dimensional Transient Finite Element
Cooling Simulation For Injection Molding Tools." (2021).
[6] https://www.youtube.com/watch?v=dCkmGbQhwVI&t=40s
FLAC3D (Explicit Continuum Modeling of Non-linear Material Behavior in 3D) Presentation by Maharshi (DT21MIN001) 35