Workshop: Introducción a los Métodos de Elementos Discretos con Altair EDEM - Primer día

Welcome to the Workshop on Discrete Element Method with Altair

Introduction and Overview

• The workshop is introduced by Marco Antonio Castro, who welcomes participants to the first session focused on discrete element simulations using Altair software.

• The session aims to familiarize attendees with basic simulations and the software interface, starting with installation and authorization processes.

• Participants are encouraged to confirm their software download status via chat; assistance will be provided for those who have not yet installed it.

Software Installation Guidance

• A brief overview of the tutorial manual for downloading the software is presented, addressing potential version discrepancies among users.

• Marco shares his background in mechanical engineering and experience in computational mechanics, particularly in discrete elements.

Workshop Structure and Content

• The workshop spans four hours divided into two classes, with a focus on installation during the initial part. If most participants complete this quickly, subsequent theoretical content will follow sooner.

• After one hour of instruction, there will be a break around 8:30 PM for refreshments.

Interaction and Questions

• Attendees are encouraged to ask questions either verbally or through chat; public questions are preferred for collective learning benefits.

Simulation Basics Using Altair Eden

Initial Simulations

• Basic simulations will utilize available elements within Eden without requiring additional files initially; practical cases involving real-world applications will be addressed later.

Licensing Information

• The license provided by Altair is strictly for personal academic use during the workshop; participants must adhere to these guidelines.

Workshop Content Outline

Overview of Topics Covered

• The workshop includes an introduction to Altair as a leading company in computational calculations and artificial intelligence.

• An explanation of discrete element method (DEM), its significance, models used, and algorithms followed by the software will be discussed briefly due to time constraints.

Practical Applications

• Participants will engage in basic simulations today while more complex scenarios related to mining equipment like conveyors and ball mills will be explored tomorrow.

About Knowledge Without Limits

Educational Offerings

• Knowledge Without Limits offers various virtual courses led by qualified professionals; details can be found on their website.

Course Benefits

• Additional weekly advisory sessions complement course lectures, allowing students direct access for queries throughout their learning journey.

Introduction to Altair Engineering

Company Background

• Altair Engineering specializes in computational analysis tools across multiple domains including finite element methods (FEM), CFD simulations, etc., providing extensive resources online.

Key Features of Eden Software

Capabilities of Eden

• Eden allows simulation of particle movement using various shapes through multi-sphere approximation techniques which enhance accuracy without excessive computational costs.

Examples of Simulations

• Demonstrations include simulating particle flow through transfer chutes and analyzing wear patterns under different conditions.

Advanced Simulation Techniques

Eden supports advanced studies such as estimating particle size distribution post-breakage using specific algorithms that ensure mass conservation during simulations.

Introduction to Simulations in Eden Software

Overview of Simulation Capabilities

• The process of learning to use simulations can seem straightforward, but challenges arise when specific issues occur or when reviewing detailed simulations.

• Eden software allows for direct and easy integration with complex multi-body dynamics programs like Altair's MotionSolve, enhancing simulation capabilities.

• MotionSolve enables the creation of complex movements that can be sent to Eden for particle simulation, showcasing a significant advantage over other discrete element software.

• Eden supports multifaceted simulations including finite element analysis (FEA), computational fluid dynamics (CFD), and does not require mesh, allowing for faster simulations than conventional FEA tools.

Understanding Discrete Element Simulations

• Discrete element method (DEM) refers to numerical techniques used to study particle movement and interactions within systems, simplifying terminology by using "den" as shorthand.

• DEM allows users to analyze particle velocity, position, acceleration, and their effects on equipment such as chutes and deflectors during operation.

Particle Dynamics in Simulations

Mechanics of Particle Movement

• Particles are influenced by gravity and collisions; their interactions can be modeled to understand wear on equipment due to friction between particles and surfaces.

• By calculating wear accurately through external software like SinSolid, one can estimate lifespan based on mass loss related to volume reduction.

Interaction Between Particles

• In a simulation setup, particles move under gravitational influence until they collide; slight overlaps are intentionally allowed in calculations for accuracy.

• Upon collision, particles rebound according to the coefficient of restitution—a critical parameter influencing post-collision velocities.

Types of Elements in DEM

Distinction Between Particles and Geometries

• Two main elements exist: particles (individual solid entities affected by gravity and collisions), and geometries (static representations of equipment).

• Particles move freely while geometries remain fixed unless programmed otherwise; this distinction is crucial for accurate modeling in simulations.

Geometry Characteristics

• Geometries are created using 3D design software saved as STL files; they do not respond dynamically like particles but serve as boundaries or containers within the simulation environment.

Creating Movements Within Simulations

Programming Movements

• Geometries do not move under gravity but can be animated through specific movements defined within the Eden software—essential for simulating conveyor belts or similar mechanisms.

Questions About Model Integration

Importing 3D Models into Eden

• Users can export 3D models from various commercial design programs into Eden as long as they are saved in STL format; both solids and surfaces are acceptable.

Forces During Collisions

Collision Dynamics

• Collisions between particles involve contact forces calculated via contact models that determine new velocities after impacts based on restitution coefficients.

• There are two types of collisions: particle-to-particle and particle-to-geometric surface; each type has distinct implications for how forces act upon them during interactions.

Contact Force Calculations

Models Used in Calculating Forces

• Contact forces arise from collisions between particles or with geometrical boundaries; these forces are computed using mathematical models tailored for different scenarios.

Advanced Modeling Techniques

Elastic vs Plastic Collision Models

Eden provides multiple models depending on whether elastic or plastic behavior is required during collisions. For elastic impacts involving cohesive materials, specific equations govern force calculations.

Cohesive Materials Modeling

• Cohesive materials exhibit unique behaviors during impacts due to moisture content affecting adhesion between particles; specialized models account for these interactions effectively.

Additional Optional Models

• Beyond basic collision models, additional options include those addressing rolling resistance or wear calculations which enhance simulation fidelity based on user needs.

Overview of Particle Simulation Models

Introduction to Spray Coating and Bonding Models

• The discussion begins with the concept of a particle disappearing in simulations, indicating it is integrated into a model. This involves spray coating and bonding models.

• The bonding model allows for the simulation of "metaparticles," which are particles composed of other particles, enabling flexible element representation.

• An example is given where metaparticles can simulate grass, demonstrating how they can move and interact like real-world materials when modeled correctly.

Heat Conduction and Additional Models

• The heat conduction model is introduced, emphasizing its role in simulating heat transfer between particles.

• Additional models for electric charge simulation are mentioned but noted as less critical compared to the primary models discussed.

Choosing Contact Models for Simulations

Recommendations Based on Particle Properties

• A participant asks about modeling a hard inner particle with a soft outer layer; recommendations include cohesive or plastic contact models based on particle interaction.

• It’s emphasized that selecting an appropriate contact model requires understanding the physical behavior being simulated, necessitating calibration against real experimental data.

Calibration Process Importance

• Calibration is crucial to ensure that simulation results align with real-world behaviors, allowing adjustments to be made for accurate representations.

Metaparticle Configuration Challenges

Mixing Different Particle Types

• Questions arise regarding mixing different shapes in metaparticles; it’s suggested that typically only identical shapes can be used due to configuration constraints.

• Clarification indicates that while metaparticles must consist of similar components, linking different shapes through bonding models may be possible.

Practical Considerations in Modeling

• When creating metaparticles, all components must share characteristics such as shape and size; this limits flexibility but ensures consistency within simulations.

Advanced Features in Eden Software

New Functionalities in Version 2023

• The recent release of Eden version 2023 introduces new functionalities that may allow more complex configurations for metaparticles than previously possible.

User Queries on Custom Configurations

• Users inquire about creating multiser or composite particles; discussions highlight potential methods for achieving desired configurations using various particle types.

Understanding Collision Dynamics

Key Concepts in Particle Interactions

• A review of collision dynamics emphasizes the importance of understanding forces involved during interactions between particles.

Summary of Contact Forces

• Discussion includes calculating normal and tangential forces during collisions using established contact models tailored to specific material properties.

Steps for Configuring Simulations

Initial Setup Requirements

• Essential steps include configuring materials by defining properties such as density and mechanical characteristics relevant to each particle type.

Interaction Parameters

• Important parameters like friction coefficients need careful consideration as they significantly affect simulation outcomes during particle interactions.

Time Management in Simulations

Understanding Time Steps

• The concept of discrete time steps is likened to frames in a video; each step represents calculations performed at specific intervals throughout the simulation process.

Computational Implications

• As simulations progress through time steps, computational demands increase with the number of particles involved due to additional calculations required for interactions.

Transitioning from Theory to Practice

Practical Application Session Overview

• After theoretical discussions conclude, participants prepare for hands-on experience with Eden software focusing on practical applications rather than further theory.

Simulation Configuration in Eden

Setting Up the Simulation Time and Components

• The simulation duration can be configured, for example, to simulate a system for 20 seconds. Users can select which component of their computer to simulate, such as the graphics card or processor.

• The software allows the use of NVIDIA graphics cards with CUDA cores, providing flexibility in simulation configurations.

Post-Processing Analysis Options

• After running simulations, users can perform post-processing analysis to visualize particles and geometries based on various properties like color and speed.

• The interface changes depending on whether the user is in the creator, simulator, or analyzer mode; each mode offers different options under the 'File' menu.

Understanding Software Navigation

• It's crucial to know your current location within the software (creator, simulator, or analyzer), as available options vary significantly between these modes.

• Users should familiarize themselves with where specific features are located to avoid confusion when navigating through different functionalities.

Steps for Configuring a Simulation

• The procedure in Eden is structured into three main steps: starting from the creator for configuration, moving to the simulator for solving equations, and finally using the analyzer for post-processing.

• Initially, users will see limited options until they start creating elements like materials and particles; more options become available as they progress.

Creating Materials and Particles

• Users begin by naming their project and optionally adding descriptions that serve as documentation for future reference.

• Material creation starts with bulk material settings where users define properties relevant to particles; this includes selecting appropriate materials based on intended simulations.

Adding Particles

• Once materials are created, users can add particles by right-clicking on their chosen material. Options include adding multi-sphere or polyhedral shapes directly from libraries.

• Different particle shapes are categorized; basic shapes like spheres are recommended initially before advancing to more complex forms in later sessions.

Configuring Particle Properties

• Newly created particles inherit properties from their associated materials. Users can rename them for better identification during simulations.

• Particle shape modifications are possible after creation; users can switch between different geometric forms easily within the software interface.

Defining Interaction Parameters

• To configure interactions between materials (e.g., coefficient of restitution), users must specify parameters that govern how two distinct materials interact during collisions.

• Calibration of interaction parameters is essential since accurate simulation results depend on realistic values derived from experimental data or established databases.

Finalizing Material Interactions

• After setting up interactions between similar materials (material one against itself), users must also establish interactions involving different material types (material one against material two).

Geometry Creation

• Following particle setup, geometry needs configuration. This involves defining physical characteristics that will interact with simulated particles during experiments.

Building Geometries Within Eden

• Users have options to create simple geometries directly within Eden or import complex designs from external software using STL files.

Factory Setup for Particle Ingress

• Factories must be created within geometries to allow particle entry into simulations. A new geometry may be designated specifically as a factory while keeping other geometries separate for storage purposes.

Configuring Virtual Geometry in Simulation

Introduction to Virtual Geometry

• The speaker discusses the benefits of converting physical geometry into virtual geometry for simulations, indicating that it will not participate in particle interactions.

• A demonstration is provided on how to adjust the position of a virtual square along the Z-axis, showcasing its flexibility in simulation setup.

Creating Geometries and Factories

• The speaker explains how to create geometries with different shapes (e.g., hexagons), emphasizing size adjustments for effective simulation.

• Instructions are given on creating a particle entry factory within the virtual geometry, highlighting its role as an input for particles.

Particle Configuration Options

• Various options for configuring particle entries are discussed, including setting limits on particle numbers and mass flow rates.

• The importance of selecting specific types of particles is emphasized, suggesting duplication methods to manage different materials effectively.

Managing Multiple Factories

Setting Up Multiple Particle Inputs

• The creation of multiple factories within the same geometry allows for distinct material inputs; one factory can handle larger particles while another manages smaller ones.

• Configuration details such as mass flow rates are specified for each factory to ensure proper material handling during simulations.

Adjusting Units and Parameters

Customizing Simulation Units

• The speaker addresses unit customization within the software, allowing users to switch from standard units (SI units) to industry-specific measurements like tons per hour.

Interaction Models in Simulations

Understanding Physical Interactions

• Different interaction models between particles and geometries are introduced, focusing on elastic collisions and drag forces.

• Specific models like Hertz-Mindlin are highlighted as foundational for simulating particle behavior under various conditions.

Environment Setup in Simulations

Defining Simulation Domains

• The concept of defining a simulation domain is explained; it restrictively bounds where particles can exist during simulations.

Gravity Settings and Boundary Conditions

• Gravity settings are configured along with boundary conditions necessary for periodic domains or dynamic simulations.

Solver Configuration

Time Step Management

• Recommendations regarding time step percentages are provided; keeping below 20% is advised unless simulating breakage scenarios which require lower percentages.

Result Storage Frequency

• Users must decide how frequently results should be saved during simulations, balancing detail with computational efficiency.

Running Simulations

Initiating Simulation Process

• Instructions on starting the simulation process using a designated button are shared, alongside tips on monitoring progress without overloading resources.

Analyzing Results

Post-Simulation Analysis Techniques

• After completing simulations, techniques such as coloring particles based on velocity provide insights into their behavior during tests.

Visualization Tools

The use of legends helps interpret speed data visually; additional features allow users to generate images or videos from simulation results.

Future Learning Opportunities

Upcoming Classes Overview

• A preview of future classes indicates a shift towards more complex simulations involving real-world applications like conveyor belts and ball mills.