Set Geometry Motion

Three groups of parameters related to setting a Geometry motion using the setGeometryMotion method are available.

To set Geometry motion:
  1. Select one of the following options:
    • Total translation & Orientation

      A Geometry controlled using the Multi Body Dynamics Coupling Interface can have two components of motion, a linear displacement and a rotational displacement about a point of action. The linear displacement is set as the total translated distance the Geometry has undergone from its starting position in EDEM. The motion/position of a Geometry is set using the total translation value from the starting position to avoid the accumulation of a positional error between EDEM and the Dynamics Code.

      Rotational displacement is expressed as an orientation using a 3x3 rotational matrix, acting about a point of action, defined for the Geometry. By default, a Geometry’s point of action is set the same as its center of mass. This can be changed using the setGeometryPointOfAction method.

    • Velocity & Angular Velocity

      The Geometry’s linear and angular velocity are not used to determine the position of the Geometry in the EDEM simulation. They are used in the resolution of particle to Geometry contacts in the contact model and therefore have an outcome on the collision force resolution and overall behavior of the EDEM Physics. User-defined velocity and angular velocity are stored in custom properties that are created when a Geometry is registered for control by the dynamics coupling using the getGeometryID method.

    • Time & Motion of Point of Action

      These parameters determine the final options that are required for implementing the Geometry motion. These are the time over which the action should be and a variable telling EDEM whether the point of action of rotation is moved with any translation applied to the Geometry, or not.

    Note: An optional parameter allows you to determine whether the point of action of their Geometry will move with the translation of the Geometry, or not. In the vast majority of simulations, this will be the case, and, this option is selected by default. However, if you want to control the point of action independently of motion, you can set the option to false.
  2. Set the motions to act over multiple EDEM Time Steps to reduce the communication overhead on the coupling.
    For more information about how this is achieved, see Interpolate Geometry Motion.