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Coupling Interface Programming Guide
The Coupling Interface Programming Guide provides an overview of how to use the EDEM Coupling Interface to couple with a generic CFD code and/or Multi Body dynamics codes.
The Multi Body Dynamics Coupling Interface
The Multi Body Dynamics (MBD) Coupling Interface is a subset of features in the EDEM Coupling Interface specifically designed for coupling EDEM to Multi Body Dynamics packages.
Set Point of Action on a Geometry
The point of action of a Geometry is set to the same value as its center of mass.

Welcome
What's New
New features and enhancements available in EDEM.
Release Notes
This document contains information about the EDEM release, such as key features and enhancements, bug fixes, and known issues.
About EDEM
EDEM is a high-performance simulation software for bulk and granular materials.
Get Started with EDEM
The EDEM user interface comprises three icons for each simulation component - Creator, Simulator, and Analyst.
EDEM Creator
EDEM Creator is the pre-processor for creating an EDEM simulation model, including setting up equipment and defining the generation of bulk materials.
EDEM Simulator
EDEM Simulator is a powerful solver used for fast and efficient simulations.
EDEM Analyst
EDEM Analyst is the post-processor used to analyze and visualize the results of your simulation.
EDEM Contact Models
A Contact Model describes how elements behave when they come into contact with each other.
EDEM Cal Utility
EDEM Cal is a utility which works with EDEM and is designed to assist in performing calibration.
GPU CUDA Guide
The EDEM CUDA GPU module uses the latest General Purpose Computing on Graphical Processing Units (GPU) technology.
Programming Guide
The EDEM Programming Guide describes the EDEM API.
Coupling Interface Programming Guide
The Coupling Interface Programming Guide provides an overview of how to use the EDEM Coupling Interface to couple with a generic CFD code and/or Multi Body dynamics codes.
- Enable and Run the Coupling Server
  The EDEM Coupling Server options are accessible from the top-right corner of the EDEM window.
- Start and Stop the Coupling Server
  By default, EDEM will launch with the Coupling Server stopped and requires you to start the server before a coupled simulation can proceed.
- Run a Compiled Application
  When running your compiled application, you must ensure that the EDEM libraries can be correctly picked up, You must add the location of the EDEM libraries to theLD_LIBRARY_PATH environment variable.
- Coupled EDEM-CFD Simulation
  EDEM integrates fluid drag forces and torques into the particle simulation on an individual particle level.
- The Multi Body Dynamics Coupling Interface
  The Multi Body Dynamics (MBD) Coupling Interface is a subset of features in the EDEM Coupling Interface specifically designed for coupling EDEM to Multi Body Dynamics packages.
  - Register Geometries for Motion
    Geometries in EDEM are easily identifiable by their readable names. However, to maintain computational performance during simulation using the Multi Body Dynamics Coupling Interface, Geometries are identified by an unique integer ID. The method also registers the coupling for control using the Coupling Interface.
  - Retrieve the Position of a Geometry
    You can retrieve the position of a Geometry from EDEM at any point in a coupled code when EDEM is not executing a simulation using the getGeometryPosition method.
  - Set Geometry Motion
    Three groups of parameters related to setting a Geometry motion using the setGeometryMotion method are available.
  - Deform Geometries
    The EDEM Coupling Interface can deform a Geometry by setting or offsetting the Geometry nodes' local or global positions.
  - Retrieve Material Forces Acting on Geometries
    You can retrieve the summed material force and torque acting on the specified Geometry using the getGeometryForces method.
  - Set Point of Action on a Geometry
    The point of action of a Geometry is set to the same value as its center of mass.
  - Perform Multi-step Simulation
    The EDEM Coupling Interface supports multiple Time Steps. You can simulate multiple Time Steps in EDEM between data exchanges when using the Multi Body Dynamics Coupling Interface.
  - Interpolate Geometry Motion
    You can implement Geometry motion over multiple Time Steps using the setGeometryMotion method.
  - Change the size of Geometry Velocity Vectors
    The Geometry Velocity vectors widget in the Analyst's Model to enable you to increase or decrease the size of the vectors.
  - Force Averaging
    The average force is updated in the custom property at every EDEM Time Step.
- Design of Experiment-style Studies
  Design-Of-Experiment (DOE) style programs or parametric CAD packages allows equipment designs to evolve through co-simulation. This capability in the EDEM Coupling Interface also allows you to automatically create many simulations containing variations on Geometry or Geometry dynamics for running in batch mode.
- Compile Coupling Interface Code to an Executable
  You can compile simple user-written code into a stand-alone executable to work with the coupling interface.
EDEMpy
EDEMpy is a Python library for accessing EDEM data from .h5 files (the underlying EDEM file format). EDEMpy does not require prior knowledge of advanced programming.
EDEM Solver Capabilities
EDEM contains four solver engines.
Appendix
This section provides additional information about how to estimate simulation time, supported EDEM File types, attribute definitions, and so on.
EDEM Terminology
Definitions of terms used in EDEM.
References and Bibliography
This section cites the contributions made by various authors and sources that have been used as reference material for EDEM, and the specifics of how they have been applied can be found in the individual contact model sections.

Set Point of Action on a Geometry

The point of action of a Geometry is set to the same value as its center of mass.

To set the point of action on a Geometry:

Change the value of the center of mass if rotations of a Geometry occur from any other point using the setGeometryPointOfAction method.

Note:

This operation should be performed at the beginning of a simulation in the majority of cases.
The point of action of a Geometry is relevant to two of the methods provided by the Multi Body Dynamics Coupling Interface. It determines the position of the center of rotation for a change in a Geometry’s orientation when setting the motion and the point about which torque acting on the Geometry is calculated.
It is not recommended to regularly update of the point of action. Doing so introduces small positional errors into the simulation that can result in motion instability. Allowing the Multi Body Dynamics Interface to move the point of action, if required, is the preferred option. If the point of action of a Geometry does not change during the course of the simulation, disable the motion of the point of action when using the setGeometryMotion method to eliminate the introduction of position error.