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!VELOCITY

Definition of velocity boundary conditions

Parameters

TYPE = INITIAL (initial velocity boundary condition)
     = TRANSIT (time-history velocity boundary condition specified with !AMPLITUDE; default)
GRPID = group ID
AMP  = time function name (specified with !AMPLITUDE)
       !AMPLITUDE defines the relationship between time t and coefficient f(t).
       The value obtained by multiplying Value below by coefficient f(t) becomes the prescribed value at that time
       (if omitted: the time-coefficient relationship is f(t) = 1.0).

** 2nd line and later **

(2nd line) NODE_ID, DOF_idS, DOF_idE, Value
Variable name Attribute Description
NODE_ID I/C Node number or node group name
DOF_idS I First constrained degree of freedom number
DOF_idE I Last constrained degree of freedom number
Value R Prescribed value (default: 0)

Example

!VELOCITY, TYPE=TRANSIT, AMP=AMP1
  1, 1, 1, 0.0
  ALL, 3, 3
  ※ prescribed value is 0.0
!VELOCITY, TYPE=INITIAL
  1, 3, 3, 1.0
  2, 3, 3, 1.0
  3, 3, 3, 1.0
  • For velocity boundary conditions, unlike displacement boundary conditions, multiple degrees of freedom cannot be defined together, so DOF_idS and DOF_idE must have the same number.
  • When TYPE is INITIAL, AMP is disabled.
  • GRPID is referenced from the !STEP line of BOUNDARY and is used to enable velocity boundary conditions for each step.