grpa

   'grpa' <nr> <set> ['dyna']
This command allows to assign elements to a group. The group number is an element attribute. One element can only belong to one group. This command assigns a group number to certain elements stored in a given set. An ls-dyna *PART command is written to a file if the parameter dyna is given. The group number is used as a property ID in an eventually written mesh file in ls-dyna format. See “Remarks Concerning ls-dyna” and “Element Definition Block” how this applies to the result format (frd).