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Version: 3.4.20 (unreleased)

Discrete Element Model

Right-click commands for the Discrete Element Model branch of the Interpretation Tree — the branch header, each model under it, and each model's Attributes row.

Source resources: IDR_IT_DEMGROUP, IDR_IT_DEM, IDR_IT_DEM_ATTRIBUTES.

"DEM" here means Discrete Element Model

This branch is the particle-based Discrete Element Model, not a digital elevation model. It only appears when your licence includes the DFN feature.

Item Context Menu​

Right-click a discrete element model. While the simulation runs, most of these are disabled or refused: stop it first.

Actions​

  • Navigate To — Navigate to the item in the 3D view (ID_POPUP_ITEM_GOTO)
  • Make Active — Make this the active DE volume, so the ribbon tab appears and the test chart follows it. Choose it again to clear it. (ID_DEMODEL_MAKEACTIVE)
  • Fit To Active Outcrop — Resize and position the DE volume to match the active mesh or point cloud. This empties the model: use Reset to fill the new box. (ID_DEMODEL_FITTOACTIVE)
  • Clip Pack To Outcrop — Confine the pack to the rock of the active mesh: remove every element outside it, and refill only the rock on Reset. See Clipping the pack to the rock. (ID_DEMODEL_CLIPTOOUTCROP)
  • Set Marker Horizons... — Record every element's current position as its reference and band the model into marker horizons, so throw, folds and offset show as displacement from where the rock started. Asks for the layer thickness. See Marker horizons and displacement. (ID_DEMODEL_SETMARKERHORIZONS)
  • Convert to Voxel Model... — Put the model on a voxel grid: solid fraction, broken-bond density and, with marker horizons, displacement. Asks for the cell size. See Converting to a voxel model. (ID_DEMODEL_CONVERTTOVOXELMODEL)
  • Group — Group the selected items into a single project tree entry. (ID_PROJEXP_GROUP)
  • Delete — Delete this model from the project. (ID_POPUP_ITEM_DELETE)

Simulation submenu​

  • Start/Stop — Start the simulation on the selected models, or stop it. (ID_DEMODEL_START)
  • Step Forward — Advance the model by one physics step. (ID_DEMODEL_STEPSIMULATION)
  • Reset — Rebuild the particle pack from scratch. (ID_DEMODEL_RESETSIMULATION)
  • Show Test Chart — Show the stress-strain chart of this model's loading test (ID_DEMODEL_SHOWCHART)
  • Export Test History... — Export the stress-strain history of the last test as CSV (ID_DEMODEL_EXPORTHISTORY)

Elements submenu​

  • Add Elements — Add particles until Target Porosity is reached or placement saturates. (ID_DEMODEL_ADDELEMENTS)
  • Prepare Pack — Fill to Target Porosity in the model box: deposit, relax, add particles after sustained low kinetic energy, and repeat. See Prepare Pack. (ID_DEMODEL_PREPAREPACK)
  • Cement Model — Bond the packed particles into rock, so the assembly has strength to break. (ID_DEMODEL_CEMENTMODEL)
  • Seed From DFN — Pre-break or weaken every bond crossed by a fracture of the active DFN. See Seeding a model from a DFN. (ID_DEMODEL_SEEDFROMDFN)
  • Export Fractures to DFN — Turn the failed bonds into a discrete fracture network. (ID_DEMODEL_EXPORTTODFN)
  • Grow Elements — Grow the particles to close the porosity of the pack. (ID_DEMODEL_GROWELEMENTS)

Material Sets submenu​

See Material sets.

  • Add Set — Add a material set: another bulk material and cement for one layer of a mechanical stratigraphy. (ID_DEMODEL_ADDMATERIALSET)
  • Remove Set... — Remove a material set; its elements return to the base material. (ID_DEMODEL_REMOVEMATERIALSET)
  • Assign Material Set... — Put the elements of a depth band, or of one side of a mapped surface, into a material set. (ID_DEMODEL_ASSIGNMATERIALSET)

Add Section submenu​

  • XZ Plane — Add a section in the xz plane (ID_ADDSECTION_XZ)
  • YZ Plane — Add a section in the yz plane (ID_ADDSECTION_YZ)
  • XY Plane — Add a section in the xy plane (ID_ADDSECTION_XY)

Attributes Row Context Menu​

Right-click the Attributes row under a model. See Element attributes. The layers under the row, and any section rows under the model, show the standard item menu.

Add Attribute submenu​

  • Radius — Add each element's radius as an attribute (ID_DEMATTRIB_RADIUS)
  • Volume — Add each element's volume as an attribute (ID_DEMATTRIB_VOLUME)
  • Mass — Add each element's mass as an attribute (ID_DEMATTRIB_MASS)
  • Speed — Add each element's current speed as an attribute (ID_DEMATTRIB_SPEED)
  • Contacts — Add how many elements touch each element (coordination number) (ID_DEMATTRIB_CONTACTS)
  • Intact Bonds — Add each element's count of intact bonds (ID_DEMATTRIB_INTACT_BONDS)
  • Broken Bonds — Add each element's count of broken bonds (ID_DEMATTRIB_BROKEN_BONDS)
  • Bond Damage — Add the fraction of each element's bonds that have broken (ID_DEMATTRIB_BOND_DAMAGE)
  • Tensile Breaks — Add each element's count of bonds broken in tension (ID_DEMATTRIB_TENSILE_BREAKS)
  • Shear Breaks — Add each element's count of bonds broken in shear (ID_DEMATTRIB_SHEAR_BREAKS)
  • Material Set — Add each element's material set as an attribute, to colour the layers (ID_DEMATTRIB_MATERIAL_SET)
  • Marker Band — Add the marker horizon each element started in (needs Set Marker Horizons) (ID_DEMATTRIB_MARKER_BAND)
  • Displacement — Add how far each element has moved from its marked position (needs Set Marker Horizons) (ID_DEMATTRIB_DISPLACEMENT)
  • Vertical Displacement — Add each element's vertical movement from its marked position, positive up (needs Set Marker Horizons) (ID_DEMATTRIB_VERTICAL_DISPLACEMENT)
  • All — Add every element attribute, leaving out the three that need marker horizons if none are set. (ID_DEMATTRIB_ALL)

Group Context Menu​

Right-click the Discrete Element Model branch header. A group made with Group shows the standard group menu instead, with Delete Group at the end.

Actions​

  • New — Create a new model and fill it with the default pack. (ID_DEMODEL_NEW)
  • Import — Read a model from a text file of elements (*.txt). (ID_GROUPPOPUP_IMPORT)
  • Use Own Display Properties — Let this group carry its own display settings instead of inheriting the parent's. (ID_GROUP_USE_OWN_DISPLAY_PROPS)

New from Template submenu​

Each builds a model set up for a test, leaving Mode at Off. See Starting from a template.

  • Sandstone Core - UCS — A 5-inch core of medium-grained sandstone for an unconfined compression test. (ID_DEMTEMPLATE_FIRST)
  • Sandstone Core - Triaxial 10 MPa — The same core for a triaxial test at 10 MPa. (ID_DEMTEMPLATE_FIRST + 1)
  • Loose Sand - Settling Box — A box of loose sand that settles under gravity. (ID_DEMTEMPLATE_FIRST + 2)

See also​