ESYM, --, NINC, IEL1, IEL2, IEINC
Generates elements from a pattern by a symmetry reflection.
--Unused field.
NINCIncrement nodes in the given pattern by NINC.
IEL1, IEL2, IEINCReflect elements from pattern beginning with IEL1 to IEL2 (defaults
to IEL1) in steps of IEINC (defaults
to 1). If IEL1 = ALL, IEL2 and IEINC are
ignored and pattern is all selected elements [ESEL]. If IEL1 =
P, graphical picking is enabled and all remaining command fields are ignored
(valid only in the GUI). A component name may also be substituted for IEL1 (IEL2 and IEINC are ignored).
Generates additional elements from a given pattern (similar to EGEN) except with a "symmetry" reflection. The operation generates a new element by incrementing the nodes on the original element, and reversing and shifting the node connectivity pattern. For example, for a 4-node 2-D element, the nodes in positions I, J, K, and L of the original element are placed in positions J, I, L, and K of the reflected element.
Similar permutations occur for all other element types. For line elements, the nodes in positions I and J of the original element are placed in positions J and I of the reflected element. In releases prior to ANSYS 5.5, no node pattern reversing and shifting occurred for line elements generated by ESYM. To achieve the same results with ANSYS 5.5 as you did in prior releases, use the EGEN command instead.
It is recommended that symmetry elements be displayed and graphically reviewed.
If the nodes are also reflected (as with the NSYM command) this pattern is such that the orientation of the symmetry element remains similar to the original element (i.e., clockwise elements are generated from clockwise elements).
For a non-reflected node pattern, the reversed orientation has the effect of reversing the outward normal direction (clockwise elements are generated from counterclockwise elements).
Note: Since nodes may be defined anywhere in the model independently of this command, any orientation of the "symmetry" elements is possible. See also the ENSYM command for modifying existing elements.