!BOUNDARY¶

Definition of displacement boundary conditions

Parameters¶

GRPID      = group ID
AMP        = time function name (specified by !AMPLITUDE, valid in dynamic analysis)
ROT_CENTER = center node number or node group name for rotational displacement constraint.
             When specified, this !BOUNDARY is recognized as a rotational displacement constraint.
TOTAL        When specified, displacement is treated as the total amount from the initial configuration (default: relative amount from the configuration at the start of the step)

** 2nd line and later **

(2nd line) NODE_ID, DOF_idS, DOF_idE, Value

Variable	Attribute	Description
NODE_ID	I/C	Node number or node group name
DOF_idS	I	Start number of constrained degree of freedom
DOF_idE	I	End number of constrained degree of freedom
Value	R	Prescribed value (default: 0)

Example¶

!BOUNDARY, GRPID=1
  1, 1, 3, 0.0
  ALL, 3, 3,

Note: The prescribed value is 0.0

!BOUDARY, ROT_CENTER=7, GRPID=1
  ROT_NODES, 1, 1, 3.141
  ROT_NODES, 2, 2, -4.188

Apply a rotation to ROT_NODES about node 7, with magnitude \(||(3.141, -4.188)|| = 5.233[rad]\) and rotation axis \((3/5, -4/5, 0)\).

Rotation specified by ROT_CENTER is a displacement constraint on the three translational degrees of freedom and differs from constraints on degrees of freedom 4, 5, and 6 for shell elements.

When ROT_CENTER is specified:

The node group specified by ROT_CENTER must contain exactly one node.
Within one !BOUNDARY data block, all NODE_ID values must be identical.
All unspecified degrees of freedom are constrained to 0.