Mean rotation MPC. next up previous contents
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Mean rotation MPC.

This MPC is used to apply a rotation to a set of nodes. The rotation is characterized by its size (angle in radians) and its axis (normal vector). All nodes participating in the rotation should be listed three times (once for each DOF). The user must define an extra node at the end in order to define the size and axis of rotation: the coordinates of the extra node are the components of a vector on the rotation axis, the first DOF of the node is interpreted as the size of the rotation. This size can be defined using a *BOUNDARY card. Applying a mean rotation implies that the mean of the rotation of all participating nodes amounts to a given value, but not the individual rotations per se. The complement of the mean rotation is the torque needed for the rotation. By selecting RF on a *NODE PRINT or *NODE FILE card this torque can be saved in the .dat or .frd file. Conversely, instead of specifying the mean rotation one can also specify the torque (specify a force with *CLOAD on the first DOF of the extra node) and calculate the resulting mean rotation.

Example:

*NODE
162,0.,1.,0.
*MPC
MEANROT,3,3,3,2,2,2,14,14,14,39,39,39,42,42,42,
50,50,50,48,48,48,162
..
*STEP
*STATIC
*BOUNDARY
162,1,1,.9
..
*END STEP

specifies a mean rotation MPC. Its size is 0.9 radians = $ 51.56
^\circ$ and the global y-axis is the rotation axis. The participating nodes are 3,2,14,39,42,50 and 48.


Example files: beammr, beammrco.


next up previous contents
Next: Maximum distance MPC. Up: User-defined nonlinear equations Previous: User-defined nonlinear equations   Contents
guido dhondt 2012-10-06