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Propagate Command

The Propagate command sets the criterion used for crack propagation in MPM calculations and optionally sets a crack propagation direction method and traction law material to use on new crack surfaces.

Propagate (crit),<(dir)>,<(tract)>

where (crit) and optionally (dir) are the crack propagation criterion and the method to select the crack propagation direction. The setting in (crit) is one of the following options (by number or name):

Each criterion above has a default method for determination of the crack propagation direction. The optional crack propagation direction setting in (dir) can override the default method with one of the following methods (by number or name):

See the OSUPDocs wiki for more details about the above crack propagation criteria and on the crack propagation direction.

The optional parameter (tract) can define a material ID for a previously defined traction law material. When this parameter is used, new crack surfaces created by crack propagation will be initialized with the provided traction law material. To set (tract) without specifying a direction rule in (dir), set (dir) to the default value (or 0). Note that any crack that propagates into a traction law material must use a frictionless contact law. If any initial crack particles have a traction law material, the crack will automatically be converted to a frictionless contact crack. If the initial crack, however, has no traction laws, you must be sure to create that crack as a frictionless crack.

Notes

  1. Crack propagation and direction criteria are based on material properties that must be set in the analysis.
  2. Crack propagation occurs in the material defined by the tip material parameter when defining cracks.
  3. The Propagate command defines the default propagation, direction, and traction law material for all materials. If desired, a specific material can override these defaults using the criterion, direction, and traction material property settings. In addition, a specific crack can override the traction setting by using a CrackTractionProp command.
  4. The Propagate command is only allowed for MPM analyses.