DEM Rayleigh time & contact overlap

Back to Utilities

For a spherical particle, this tool computes the Rayleigh critical time — commonly used to select a stable Discrete Element Method (DEM) time step — from the particle diameter, density, Young's modulus and Poisson's ratio. Given a typical impact velocity, it also estimates the maximum Hertzian contact overlap during a collision between two identical particles, in metres and as a percentage of the particle diameter.

Particle diameterd_p [m]

Particle densityρ_p [kg/m³]

Young's modulusE [Pa]

Poisson ratioν [–]

Impact velocityv [m/s]

–

s

Rayleigh critical time

–

m

Max contact overlap

–

% of diameter

Overlap / diameter