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ExtrapolateRigid Command

The ExtrapolateRigid command activates a mode where rigid particles for setting boundary conditions extrapolate to the nodes before setting boundary conditions:

ExtrapolateRigid <(option)>

where (option) is "yes" to activate the mode or anything else to not activate the mode. If (option) is omitted, it is assumed to be "yes".

When this option is activated, all rigid material particles that set boundary conditions for velocity, temperature, concentration, or pore pressure, will extrapolate to the grid first and then set boundary conditions on those extrapolated values. It is normally used when the rigid particle values vary with position, such as loading in shear.

Notes

  1. When this mode is activated, all rigid particles use the extrapolation approach and the boundary conditions they create are assigned ID = -40 (which can be used when archiving reaction forces.)
  2. The ExtrapolateRigid command is only allowed for MPM analyses.