This module allows including in a UM model a planar granular media, which is a set of particles (rigid polygons and circles). The particles interact with each other by contact forces. Simple models of contact forces are used in the module. Each force consists of two components. The first component is a linear viscoelastic normal force. Another one is a dry friction force with two modes: sliding and sticking. Also the particles interact with other bodies (walls, bottom of a box, sieves and so on). In term of UM any granular media is a subsystem. That is why the UM Subsystems module is necessary for working in UM Ballast. Statistics of geometrical characteristics of particles are used for granular system creating.

During simulation a set of output parameters can be obtained such as:
• porosity of a granular media (local and global);
• distribution of velocities of the particles in the volume;
• distribution of loading of the particles in the volume;
• reactions of the media on the walls and bottom;
and graphics of the whole set of variables for each particle (trajectories, velocities, accelerations and so on).

Detraining from hopper car

Filename	Size	Description
umballast.zip	19 Mb	New! Simulation of Granular Media in Universal Mechanism Software (PowerPoint presentation with animations, zip-archive)