Novel approach to helicopter brownout based on vortex and discrete element methods

In this paper, we present a novel approach to modeling and analysis of Vacuum Packed Particle dampers (VPP dampers) with the use of Discrete Element Method (DEM). VPP dampers are composed of loose granular medium encapsulated in a hermetic envelope, with controlled pressure inside the envelope. By changing the level of underpressure inside the envelope, one can control mechanical properties of the system. The main novelty of the DEM model proposed in this paper is the method to treat special (pressure) boundary conditions at the envelope. The model has been implemented within the open-source Yade DEM software. Preliminary results are presented and discussed in the paper. The qualitative agreement with experimental results has been achieved.

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Application of discrete-element methods to approximate sea-ice dynamics

10.31223/osf.io/j6vpn ◽

2018 ◽

Author(s):

Anders Damsgaard ◽

Alistair Adcroft ◽

Olga Sergienko

Keyword(s):

Sea Ice ◽

Discrete Element ◽

Ice Dynamics ◽

Sea Ice Dynamics ◽

Discrete Element Methods

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SIMULATION OF FRACTURE USING A MESH-DEPENDENT FRACTURE CRITERION IN THE DISCRETE ELEMENT METHOD

Facta Universitatis Series Mechanical Engineering ◽

10.22190/fume171229010d ◽

2018 ◽

Vol 16 (1) ◽

pp. 41 ◽

Cited By ~ 6

Author(s):

Andrey Dimaki ◽

Evgeny Shilko ◽

Sergey Psakhie ◽

Valentin Popov

Keyword(s):

Particle Size ◽

Discrete Element Method ◽

Mechanical Behavior ◽

Fracture Criterion ◽

Discrete Element ◽

Macroscopic Behavior ◽

Detachment Criterion ◽

Discrete Element Methods ◽

Adhesive Contacts ◽

Fracture Processes

Recently, Pohrt and Popov have shown that for simulation of adhesive contacts a mesh dependent detachment criterion must be used to obtain the mesh-independent macroscopic behavior of the system. The same principle should be also applicable for the simulation of fracture processes in any method using finite discretization. In particular, in the Discrete Element Methods (DEM) the detachment criterion of particles should depend on the particle size. In the present paper, we analyze how the mesh dependent detachment criterion has to be introduced to guarantee the macroscopic invariance of mechanical behavior of a material. We find that it is possible to formulate the criterion which describes fracture both in tensile and shear experiments correctly.

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