Block Format Keyword Defines a cyclic boundary condition on a structure in a fixed cylindrical coordinate system.


(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
skew_ID grnd_ID1 grnd_ID2


Field Contents SI Unit Example
bcs_ID Boundary conditions block identifier.

(Integer, maximum 10 digits)

bcs_cyclic_title Cyclic boundary conditions block title.

(Character, maximum 100 characters)

skew_ID Skew identifier for the boundary conditions.
= 0 (Default)
Global coordinate system is used.
Local coordinate system is used.


grnd_ID1 Node group of the first section.


grnd_ID2 Node group of the second section.



  1. The node set grnd_ID1 and grnd_ID2 input are mandatory.
  2. Each node of the second section must have a corresponding node on the first section with the same cylindrical longitudinal and radial coordinates.
  3. The node group grnd_ID2 must have the same number of nodes of as the node group grnd_ID1.
  4. The directions X, Y, and Z of the fixed local coordinate system skew_ID refer to translations along the radial direction (r), azimuthal angular direction ( θ ), and longitudinal direction (Z).

    Figure 1.