TCHG
TCHG, ENAME1, ENAME2, ETYPE2
Converts 20-node degenerate tetrahedral elements to their
10-node non-degenerate counterparts.
ENAME1Name (or the number) of the 20-node tetrahedron element that you want to convert. This argument is required.
ENAME2Name (or the number) of the 10-node tetrahedron element to which you want to convert the
ENAMEelements. This argument is required.ETYPE2Element TYPE reference number for
ENAME2. IfETYPE2is 0 or is not specified, the program selects the element TYPE reference number forENAME2. See the "Notes" section for details. This argument is optional.
Notes
The TCHG command allows you to specify conversion of any selected 20-node brick that is degenerated into a tetrahedron to a 10-node tetrahedron.
The TCHG command is useful when used in with the MOPT,PYRA command. Twenty-node pyramid shaped elements may be used in the same volume with 10-node tetrahedra.
Performing a conversion is likely to create circumstances in which more than one element type is defined for a single volume.
If specified, ETYPE2 will usually
be the same as the local element TYPE number (ET,ITYPE) that was assigned to ENAME2 with the ET command. You
can specify a unique number for ETYPE2 if
you prefer. Although ETYPE2 is optional,
it may be useful when two or more ITYPEs have been assigned to the same element (for example, if two SOLID187 elements have been established in the element
attribute tables for the current model, use the ETYPE2 argument to distinguish between them). If ETYPE2 is nonzero and it has not already
been assigned to an element via ET, the program
assigns the ETYPE2 value to ENAME2 as its element TYPE reference number.
If ETYPE2 is 0 or is not specified,
the program determines the element TYPE reference number for ENAME2 in one of these ways:
If
ETYPE2is 0 or is not specified, andENAME2does not appear in the element attribute tables, the program uses the next available (unused) location in the element attribute tables to determine the element TYPE reference number forENAME2.If
ETYPE2is 0 or is not specified, andENAME2appears in the element attribute tables, the program usesENAME2's existing element TYPE reference number forETYPE2. (If there is more than one occurrence ofENAME2in the element attribute tables (each with its own TYPE reference number), the program uses the firstENAME2reference number forETYPE2.)
You cannot use element conversion if boundary conditions or loads are applied directly to any selected elements.
For more information about converting degenerate tetrahedral elements, see Meshing Your Solid Model in the Modeling and Meshing Guide