ansys.mapdl.core.Mapdl.tchg#

Mapdl.tchg(ename1='', ename2='', etype2='', **kwargs)#

Converts 20-node degenerate tetrahedral elements to their 10-node non-degenerate counterparts.

Mechanical APDL Command: TCHG

Parameters:
ename1str

Name (or the number) of the 20-node tetrahedron element that you want to convert. This argument is required.

ename2str

Name (or the number) of the 10-node tetrahedron element to which you want to convert the ENAME elements. This argument is required.

etype2str

Element TYPE reference number for ENAME2. If ETYPE2 is 0 or is not specified, the program selects the element TYPE reference number for ENAME2. See the TCHG_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 ITYPE s 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 ETYPE2 is 0 or is not specified, and ENAME2 does 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 for ENAME2.

  • If ETYPE2 is 0 or is not specified, and ENAME2 appears in the element attribute tables, the program uses ENAME2 ‘s existing element TYPE reference number for ETYPE2. (If there is more than one occurrence of ENAME2 in the element attribute tables (each with its own TYPE reference number), the program uses the first ENAME2 reference number for ETYPE2.)

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