Home
EDEM Physics Models
A Contact Model describes how elements behave when they come into contact with each other.
Additional Models
You can also add additional models to a simulation.
Oka Wear Model
The Oka or Impact Wear contact model extends any Base Model to give an estimation of erosion depth for Geometry surfaces due to particle impacts.

Welcome
What's New
This section describes the key features in EDEM version 2025.1.
About EDEM
EDEM is a high-performance simulation software for bulk and granular materials.
Hardware Requirements
This section details the minimum system requirements and requisites for running EDEM.
Release Notes EDEM 2025.1.1
This section contains information about the EDEM 2025.1.1 release, such as bug fixes.
Release Notes EDEM 2025.1
This section contains information about the EDEM 2025.1 release, such as key features, enhancements, and bug fixes.
Tutorials
Start using EDEM with our interactive tutorials.
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 Physics Models
A Contact Model describes how elements behave when they come into contact with each other.
- Base Contact Models
  Base Contact models define the physical collision between particle materials or particles and geometries.
- Friction Models
  Rolling Friction is the resistive force that slows down the motion of a rolling object.
- Additional Models
  You can also add additional models to a simulation.
  - Archard Wear Model
    The Archard Wear contact model extends any Base Model to provide an estimation of wear depth for geometry surfaces.
  - Bonding V2 Model
    The Bonding V2 contact model is used to bond particles with a finite-sized 'glue' bond.
  - Collisional Energy Tracking Model
    The Collisional Energy Tracking Model is a contact model that allows tracking of the energy dissipated in collisions during a simulation.
  - Electrostatics Model
    The Electrostatics contact model allows you to add electrostatic forces to the existing kinematic forces in the Particle Body Force section.
  - Fibers Bonding Model
    The Fibers Bonding Model keeps particles bonded in order to simulate long structures like fibers, stems, branches, or strings.
  - Heat Conduction Model
    The Heat Conduction contact model calculates the heat flux based on the relative temperatures and the particle overlap.
  - Hydrodynamic Lubrication Model
    The Hydrodynamic Lubrication contact model simulates the effect of short-range hydrodynamic forces on particles as though they were saturated in a fluid.
  - Linear Cohesion V2 Model
    The Linear Cohesion V2 contact model is an enhancement of the Linear Cohesion model and was made accessible for the first time in EDEM version 2017.2) owing to its improved performance for non-uniform particle size distributions.
  - Liquid Bridge and Exchange Model
    The Liquid Bridge and Exchange Model introduces a cohesive force between two particles (or between one particle and a Geometry) when the particles are wet.
  - Oka Wear Model
    The Oka or Impact Wear contact model extends any Base Model to give an estimation of erosion depth for Geometry surfaces due to particle impacts.
  - Relative Wear Model
    The Relative Wear contact model is used to identify regions of high impact (normal) and abrasive (tangential) wear on the equipment within a simulation.
  - Residence Time in Geometries Models
    The Residence Time in Geometries contact models allow you to track the total time spent by specific particle types inside the boundaries of one or more predefined geometries: a sphere, a box (cuboid), or cylinder.
  - Spray Coating Model
    The Spray Coating contact model adds the mass of one type of particle to another upon contact.
  - Tavares UFRJ Breakage Model
    The Tavares UFRJ Breakage contact model captures the various body breakage mechanisms that occur during particle collisions.
  - Tribocharging Model
    The Tribocharging contact model allows you to simulate a change in the charge of particles within a material after they come into contact with a different material.
  - Wet Mixing Model
    The Wet Mixing contact model allows you to add particles with moisture content (defined in the factory settings) to a simulation.
- Particle Body Force Models
  You can define a particle body force to act on particles when a specified condition is met, when particles are in certain positions, or are traveling at a specified velocity.
- Field Data Manager
  Field Data Manager allows you to import and manage field data for use in a Custom model (typically, a Particle Body Force).
- Physics Models and GPU Device Compatibility
  The EDEM Solver can run on both CPU and GPU(CUDA) hardware platforms.
EDEM Cal Utility
EDEM Cal is a utility which works with EDEM and is designed to assist in performing calibration.
EDEM Calibration Kits
The EDEM Calibration kits are a collection of EDEM models of standard bulk solids characterization tests commonly used for EDEM material model 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.
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.

Oka Wear Model

The Oka or Impact Wear contact model extends any Base Model to give an estimation of erosion depth for Geometry surfaces due to particle impacts.

This model originates from the work by Oka and Yoshida (Oka and Yoshida, 2005). and is an erosion model that computes the volume of material removed from a surface due to high-velocity particle impacts according to equations 1-3.

V_{ω} = g (α) E_{90} m_{p}

g (α) = \sin {(α)}^{n_{1}} (1 + H_{υ} {(1 - \sin (α))}^{n_{2}}

E_{90} = K {(α H_{υ})}^{k_{1} b} {(\frac{υ}{υ'})}^{k_{2}} {(\frac{D}{D'})}^{k_{3}}

Where V_w is the removed volume, α is the particle impact angle, H_v is the Vicker’s hardness of the worn material, D is the particle diameter, v is the impact velocity, D' and v' are the corresponding reference values in Oka and Yoshida’s experiments (Oka and Yoshida, 2005), and n₁, n₂, k₁, k₂, k₃, and b are empirical constants of arbitrary units.

The term (αH_v)^-b is lumped into a wear constant W of arbitrary units resulting in the following equation (the change in the sign of k₁ is due to the definition of W).

E_{90} = K W^{- k_{1}} {(\frac{υ}{υ'})}^{k_{2}} {(\frac{D}{D'})}^{k_{3}}

The worn volume is converted into a uniform wear depth on Geometry elements according to equation 5.

D_{w} = \frac{V_{w}}{A}

where D_w is the wear depth and A is the Geometry element area.

The following table summarizes the values reported by Oka and Yoshida (Oka and Yoshida, 2005) that are taken for the empirical constants of the model.

Table 1. Values for the empirical model constants reported by Oka and Yoshida for SiO₂ particles.
K	n₁	n₂	k₁	k₂	k₃	v' (ms^-1)	D' (μm)
65	0.71 H_v^-0.94	2.4 H_v^-0.94	-0.12	2.3 H_v^0.038	0.19	104	326

The inputs of the model then reduce to the wear constant W and the Vicker’s hardness H_v of the worn material. The following table summarizes the values for some common metals reported by Oka and Yoshida (Oka and Yoshida, 2005).

Table 2. Values for the wear constant and Vicker’s hardness of some common materials as reported by Oka and Yoshida
Material	W	H_v (GPa)
Carbon Steel	3	0.54-1.18
Stainless Steel	10	1.770
Aluminium	1000	0.36

EDEM also provides the option to deform the Geometry according to the wear depth.

In the Oka Wear Model Parameter Values dialog box:

Select the Enable Deformation check box to enable Geometry deformation.
If you select Enable Deformation, you must specify the Scaling Factor which allows the deformation results to be linearly scaled as desired.