icrotate#

MiscLoads.icrotate(node='', omega='', x1='', y1='', z1='', x2='', y2='', z2='', vx='', vy='', vz='', accel='', **kwargs)#

Specifies initial velocity at nodes as a sum of rotation about an axis and translation.

Mechanical APDL Command: ICROTATE

Parameters:
nodestr

Node at which the initial velocity is to be specified. If ALL, apply to all selected nodes ( nsel ). A component name may be input for NODE.

omegastr

Scalar rotational velocity about the rotational axis.

x1str

Coordinates (in the global Cartesian coordinate system) of the beginning point of the rotational axis vector.

y1str

Coordinates (in the global Cartesian coordinate system) of the beginning point of the rotational axis vector.

z1str

Coordinates (in the global Cartesian coordinate system) of the beginning point of the rotational axis vector.

x2str

Coordinates (in the global Cartesian coordinate system) of the end point of the rotational axis vector.

y2str

Coordinates (in the global Cartesian coordinate system) of the end point of the rotational axis vector.

z2str

Coordinates (in the global Cartesian coordinate system) of the end point of the rotational axis vector.

vxstr

Initial translational velocity in direction x of the nodal coordinate system.

vystr

Initial translational velocity in direction y of the nodal coordinate system.

vzstr

Initial translational velocity in direction z of the nodal coordinate system.

accelstr

Key to initialize acceleration due to centrifugal effects:

  • (blank) - Do not initialize acceleration (default).

  • CENT - Initialize acceleration due to centrifugal effects along with the initial velocity.

Notes

The icrotate command specifies initial velocity for all translational degrees of freedom of the specified nodes. The velocity value is a combination of velocity due to rotation about an axis and translation. The velocity at the node is calculated as:

\(equation not available\)

where

  • v N = velocity of node N in the nodal coordinate system

  • v trans = translational velocity input as [ Vx, Vy, Vz ]

  • ω = scalar angular velocity input as OMEGA

  • x 1 and x 2 denote the coordinates of points prescribing the beginning [ X1, Y1, Z1 ] and end [ X2, Y2, Z2 ] of the rotation axis

  • x N denotes the coordinates of node N

All coordinates are input in the global Cartesian coordinate system, and the velocity due to rotation is then converted to the nodal coordinate system and added to the prescribed translation.

If ACCEL = CENT is specified, acceleration due to centrifugal effects is initialized as well. The acceleration at node a N is initialized as:

\(equation not available\)

The icrotate command is valid only for static analysis and full method transient analysis ( timint,ON with trnopt,FULL). The initial value is specified at the beginning of the first load step; that is, at time = 0.0.

The command calculates the nodal velocities and saves them in the database as if the ic command had been used to calculate these velocities. Thus, when the Jobname.CDB or Jobname.DB file is written, the velocities prescribed by the icrotate command appear as ic commands. All assumptions, recommendations, and restrictions for the ic command are also true for the icrotate command.

This command is also valid in PREP7.