The MOTION function returns component comp of a force due to MOTION/id as calculated in the coordinate system of marker rm. If jflag is set to zero, the value returned is the force/torque acting on the I marker of the MOTION. If jflag is set to one, the value returned is that acting on the J marker. rm may be specified as zero if the results are desired in the global coordinate system.
Format
MOTION (id, jflag, comp, rm)
Arguments
id | An integer specifying the identification number of the motion. |
jflag | An integer flag specifying the motion connectivity marker at which the forces and torques are computed.
0 = forces and moments at the I marker
1 = forces and moments at the J marker |
comp | An integer value that specifies the component of the motion force to be returned.
1 = Magnitude of the force
2 = x component of the force
3 = y component of the force
4 = z component of the force
5 = Magnitude of the torque
6 = x component of the torque
7 = y component of the torque
8 = z component of the torque |
rm | The coordinate system in which the results are expressed. To return the results in the global coordinate system, set rm = 0. |
Examples
JOINT/34, REVOLUTE, I=21, J=11
MOTION/1, ROTATIONAL, JOINT=34, FUNCTION=TIME**2
DIFF/1, IC=0
, FUNCTION=WZ(21,11)*MOTION(1,0,8,11)
This DIFF statement defines a user defined state. Its derivative is the instantaneous power required to effect the displacement specified by MOTION/1. Therefore, the value of the state is the total work done by MOTION/1 during a simulation.