SYMM,<no>,[<type>],[<node1>],[<node2>],[<node3>]

sets the parameters for symmetry/anti-symmetry plane/line number <no> (maximum 2), where: <type> = 0 - symmetry, <type> = 1 - anti-symmetry, and <node1>, <node 2>, and <node3> define the line / plane. The three nodes defining a plane must not lie on a straight line. To reset the plane / line, set <node1> to 0. To list the active planes/lines, use the STATUS command.

Any combination of a maximum of two structural planes / lines of symmetry which are symmetric or anti-symmetric relative to the loading can be considered. In case of a 3D analysis, the planes of symmetry or anti-symmetry must be parallel to the xz or yz planes. In case of 1D or 2D analysis, the line of symmetry / anti-symmetry must be parallel to the z-axis. Also note that the name symmetry or anti-symmetry is used in relation to the loading.