The Powders Database

The EDEM Powders database is a collection of pre-calibrated EDEM material models for powders.

These material models capture the complex bulk behaviour of powder materials while using up-scaled numerical particles. This ensures practical solution times when simulating full scale industrial processes described in the works of Thakur, S. C., Morrissey, J. P., Sun, J., Chen, J. F., & Ooi, J. Y. (2014).

Models that capture the poured bulk density, static angle of repose described in Standard Test Method for Bulk Solids Characterization by Carr Indices, ASTM International, West Conshohocken, PA, 2021, steady state shear stress measured in direct shear described in Standard Test Method for Shear Testing of Bulk Solids Using the Jenike Shear Tester, ASTM International, West Conshohocken, PA, 2016 and the works of R. Freeman FT4 Basic Flowability Energy (BFE) described in Measuring the flow properties of consolidated, conditioned and aerated powders - A comparative study using a powder rheometer and a rotational shear cell, Powder Technol. 174 (2007) 25–33 are included in the database.

The EDEM models used to derive the results are shown in Figure 1. Direct shear data is provided for 1 kPa and 5 kPa normal stresses and BFE data is provided for the standard test performed in a 160 ml cell at 100 mm/s blade velocity. The database for the BFE is expanded using an Artificial Intelligence model generated in Altair romAI and varies from the true results by 5% on average.
Figure 1. a) Angle of repose test via the lifting cylinder method and b) direct shear test under constant normal stress, Freeman FT4 rheometer BFE test in a 160ml cell


The two-sphere particle shape shown in Figure 2 and the normal relative particle size distribution described in the tables are adopted in order to capture shear dilation effects and avoid non-physical packing states described in the works of Härtl, J.Y. Ooi. The standard particle diameter D50 in the database is 1.5 mm, but the values between 0.2 and 5 mm are available for the direct shear response where particle size and density scaling laws are applied to maintain the behaviour constant over a range of sizes described in the works of Thakur, S. C., Ooi, J. Y., & Ahmadian, H. (2016).

The interaction forces at the meso-contact scale are described in the Edinburgh Elastic-Plastic-Adhesive (EEPA) and Type C Rolling Friction models.
Figure 2. Numerical particle shape


The following tables contain information about the material model parameter space.
Particle Size Distribution
Type Dmin/D50 Dmax/D50 ơ/D50
Normal 0.85 1.15 0.15
Fixed Parameter Space
Particle Poisson’s ratio v 0.25
Particle Shear Modulus G (Pa) 1e+7
Particle solid density ρs (kg/m3) 1000
Particle coefficient of restitution e 0.1
Particle – Geometry coefficient of static friction μg 0.5
Particle – Geometry coefficient of rolling friction μrg 0.1
EEPA tangential stiffness multiplier ktan 0.667
EEPA loading exponent n 1
EEPA tensile exponent kadh 3
Variable Parameter Space
Particle – particle coefficient of static friction μs
Particle – particle coefficient of rolling friction μr
EEPA constant pull-off force f0
EEPA surface energy γ (J/m2)
EEPA contact plasticity ratio λ
The database containing thousands of material models and the probability density distributions for different responses are shown in Figure 3.
Figure 3. Probability density distributions for a) the static angle of repose, b) the shear stress at 5 kPa normal stress, the shear stress at 1 kPa normal stress , and c) the FT4 rheometer Basic Flowability Energy


The database can be searched per response, and the results are sorted based on the relative error between the requested response values and the database results.

The required inputs for the search are:
  • The bulk cohesion and compressibility, which are qualitatively categorized using the bond number and the EEPA contact plasticity ratio respectively.


  • The bulk density, which is captured via particle solid density and Bond number scaling of the baseline values, and has variable ranges for the different bulk cohesion levels.
  • The mean particle diameter (direct shear response only).
  • The target value of the response of interest.