DEM Simulation

    What is DEM?

    In recent years, simulations have become increasingly prevalent in various fields. In this series, we will delve into the simulation of powders to provide detailed insights.
    Among the methods for simulating powder behavior, the Discrete Element Method (DEM) is one widely used approach worldwide. The concept behind DEM is straightforward: it involves simulating the motion of individual particles to represent the collective behavior of the entire powder assembly. Consequently, calculations are performed for the movement of each individual particle.
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    With that in mind, this time we’ll focus on explaining the movement of a single particle as considered in DEM.

    Movement of particles

    Movement of particles in DEM can be categorized into “translation” and “rotation.” Conversely, the motion of particles can be described solely by the combination of these two types of movement.
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    • Translation motion
    Translation motion is expressed as follows:
    The forces involved include various types of forces such as “gravity,” “contact forces” between particles, “adhesive forces,” and when considering fluid, “fluid resistance.” Even when dealing with an increased variety of forces, these forces are simply added to the right-hand side of the equation, and the overall equation structure does not change significantly.
    • Rotational motion
    Rotational motion is expressed as follows:
    The acting forces include considerations for “contact torque,” “rotational resistance torque,” and others, but similar to translational motion, these forces are added on the right-hand side without significantly altering the overall equation structure.

    Is it really just translational and rotational motion?

    In actual powder processes, particle “deformation” is also involved. This occurs in processes like compaction and grinding, where particle movement is essential. However, in DEM, particles are assumed to be “rigid” and do not deform. Therefore, DEM considers only translational and rotational motion. This fundamental concept of DEM involves calculating the translational and rotational motion of individual particles using simple equations.
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