How do I oscillate a body in Ansys Discovery AIM?
Hello all,
I'm trying to oscillate a body in Ansys about its Z axis at a certain frequency. Is there a feature that allows for this or do I have to model a rig to mount it on and push that back and forth with a linear actuator?
I'd be very grateful for any pointers you could offer. I'm new to this fantastic software and could use a hand.
Best Answer

peteroznewman Member
I don't have AIM installed, only Workbench, so my answers are for Workbench.
Are the oscillations very small, like a vibration? If so, there is an analysis called Harmonic Response, which is specifically for vibrations of small displacements, because it is a Linear analysis. A typical example would be a cantilever beam. One end is fixed and the other end has a load, such as a force or displacement. The load in a Harmonic Response is the Amplitude of a sinusoidal function, so it goes positive and negative. In the Analysis Settings, you sweep through a range of frequencies. The results show how much displacement amplitude every node in the body has at the solution frequency. This type of analysis is fast.
If the oscillations are large, then you must use Transient Structural. You can add a Revolute Joint to Ground, then add a Joint Load of Rotation angle. You could use a formula or Tabular data and paste the sinusoidal rotation angles from Excel into the table. Make sure to have at least 20 points on one period of the sinusoid. You will need many periods to see the steady state motion and you will need to define Damping so that the transient part of the response dies out in the first few periods. This type of analysis takes a long time to solve and generates huge amounts of data that is difficult to interpret.
Answers
I don't have AIM installed, only Workbench, so my answers are for Workbench.
Are the oscillations very small, like a vibration? If so, there is an analysis called Harmonic Response, which is specifically for vibrations of small displacements, because it is a Linear analysis. A typical example would be a cantilever beam. One end is fixed and the other end has a load, such as a force or displacement. The load in a Harmonic Response is the Amplitude of a sinusoidal function, so it goes positive and negative. In the Analysis Settings, you sweep through a range of frequencies. The results show how much displacement amplitude every node in the body has at the solution frequency. This type of analysis is fast.
If the oscillations are large, then you must use Transient Structural. You can add a Revolute Joint to Ground, then add a Joint Load of Rotation angle. You could use a formula or Tabular data and paste the sinusoidal rotation angles from Excel into the table. Make sure to have at least 20 points on one period of the sinusoid. You will need many periods to see the steady state motion and you will need to define Damping so that the transient part of the response dies out in the first few periods. This type of analysis takes a long time to solve and generates huge amounts of data that is difficult to interpret.
Very helpful. Thank you, Peter.