Learning Forum

[Samuele Luigetti]

Hello, 

is there a way to apply 2 rotating force with different direction on a single structure? 

[dlooman]

Yes.  A rotating force doesn't have to be defined with the "Rotating Force" in Mechanical.  It can just be defined with a complex "Force" as shown below.  You can define as many complex forces as you want.  Note that to define a force rotating about Z in a positive sense (right hand rule) you have make the imaginary component negative.  You would think that a positive rotation would be positive X into positive Y, but it's not.

[Samuele Luigetti]

Ok thanks so it's like a trick to fix the issue, it's not possible to use directly the properly rotating force

[dlooman]

No, you can specify multiple Rotating Forces also.  See below.  You can use the Phase Angle input to change the direction.

[Samuele Luigetti]

ok so you suggest to shift 180 degree to change the direction?

Another thing, i do not understand how it's calculated the rotating force...i mean on the help there is F=m*r*w^2, where w is the rotational velocity of the structure but which? since i can't define a rotational velocity in the full harmonic response 

[dlooman]

Yes.  In a harmonic, the frequency you define is the rotational velocity.  That's one advantage of the Rotating Force load.  If you solve for a frequency range, the unbalanced force will be computed for each frequency automatically.

[Samuele Luigetti]

yes right i understand thank you very much for the support