Representation of crushing phenomenon in DEM model of railway ballast

abstract

English

Representation of ballast behaviour in Discrete Element Models (DEM) would not be complete without including crushing of grains. Two approaches have been developed in literature. The first one represents every grain as an assembly of smaller units with cohesive contacts between them. This approach is relatively precise and universal, but it demands extreme computational resources. The other approach is exploited here. Every grain is modelled as one rigid body. The crushing occurs when some equivalent stress in the grain, here determined as von Mises stress computed from fabric stress tensor, exceeds the material strength. The grain is then replaced by several smaller bodies, pieces. These pieces must often have the same shape as the original grain (typically spherical) and their assembly therefore cannot be created in exactly the shape of the original grain. The effects of number of pieces and their properties are studied.

Discrete element method (DEM), railway ballast, crushing, abrasion, oedometric test

DUBINA, R.; ELIÁŠ, J.

3. 11. 2014

978-80-261-0429-2

30th conference with international participation Computational Mechanics 2014

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