SYNCHRO, RATIO, Cname
Specifies whether the excitation frequency is synchronous
or asynchronous with the rotational velocity of a structure.
RATIOThe ratio between the frequency of excitation and
the frequency of the rotational velocity of the structure. This value
must be greater than 0. The default is an unbalance excitation (RATIO = 1.0).
CnameThe name of the rotating component on which to apply the harmonic excitation.
The SYNCHRO command specifies whether the excitation frequency is synchronous or asynchronous with the rotational velocity of a structure in a harmonic analysis. Use the command to take into account rotating harmonic forces on rotating structures.
Mechanical APDL calculates the rotational velocity Ω of the structure from the excitation
frequency f, defined (via the HARFRQ
command) as Ω = 2πf /
RATIO. The rotational velocity is applied along the direction cosines
of the rotation axis (specified via an OMEGA or CMOMEGA
command).
Specifying any value for RATIO causes
a general rotational force excitation and not an unbalance force.
To define an unbalance excitation force (F = Ω2 * Unb), RATIO should be left blank (the
nodal unbalance Unb is specified via the F command).
The SYNCHRO command
is valid only for a full-solution harmonic analysis (HROPT,Method = FULL) and the Variational Technology
method (HROPT,Method = VT) involving a rotating structure (OMEGA or CMOMEGA) with Coriolis enabled in a stationary reference frame (CORIOLIS,,,,RefFrame = ON).