NairnFEAMPM Icon

GridRect Command

For 2D and axisymmetric MPM, the GridRect command sets up a rectangle to define the background grid:

GridRect (xmin),(xmax),(ymin),(ymax)

where the parameters give the x minimum, x maximum, y minimum, and y maximum of the rectangular mesh (where x and y refer to R and Z if axisymmetric) in length units.

For 3D MPM, the GridRect command sets up a box to define the background grid:

GridRect (xmin),(xmax),(ymin),(ymax),(zmin),(zmax)

where the parameters give the x minimum, x maximum, y minimum, y maximum, z minimum, and z maximum of the orthogonal mesh in length units.

Before using a GridRect command, you should use the GridHoriz, GridVert, and GridDepth commands to set the number of cells in the horizontal (x), vertical (y) directions, and depth (z) directions. In 2D grids, you should use the GridThickness command to set the thickness, and it must be set before the GridRect command.

Notes

  1. When using a GIMP method (uGIMP, lCPDI, or qCPDI), a particle is considered to have left the grid if it moves into any element on the edge of the analysis. Thus, the use of a GIMP method will cause this command to automatically add an extra boundary of elements.
  2. The GridRect command is only allowed for MPM analyses.