Reduction in resonance magnitude for a motor/drive-axle model

[siddy88]

Hi all,

I am conducting some tests on a simulated physical model of a motor/drive axle system. The goal of the experimentation is to come up with some suggestions to reduce the peak magnitude at the resonant frequency by 30%.

Based on the analysis done, a few proposed changes are 1) increasing the motor resistance, 2) increasing the motor constant and 3) modifying the inertia of the flywheels that the axle is attached to.

I am having some difficulty in figuring out why these would lead to a reducing peak magnitude at the resonant frequency and I was wondering if anyone could help out.

For example, my understanding is that motor resistance has a direct correlation to motor efficiency- ie if I have a motor with a lower motor resistance my motor will be more efficient and thereby be able to supply more power. However what does this really have to do with the resonant frequency.

I would greatly appreciate if anyone could give me some tips on how those above listed factors are related to resonance/ resonant frequency.

Thanks for your time and I hope i have explained myself clearly enough.

 

[Achy47]

Hi there,

I am a scientist with expertise in mechanical engineering and vibrations. From my understanding, the proposed changes that you have mentioned can indeed help in reducing the peak magnitude at the resonant frequency. Let me explain how each of these changes can affect the resonant frequency.

1) Increasing the motor resistance: As you correctly mentioned, a lower motor resistance can result in a more efficient motor. In the context of your experiment, this means that the motor will be able to supply more power to the system without drawing excessive current. This can help in reducing the peak magnitude at the resonant frequency because the motor will be able to counteract the vibrations caused by the system more effectively.

2) Increasing the motor constant: The motor constant is a measure of the motor's ability to convert electrical energy into mechanical energy. By increasing the motor constant, the motor will be able to supply more torque to the system, which can help in reducing the vibrations at the resonant frequency. This is because a higher torque can counteract the forces causing the vibrations more effectively.

3) Modifying the inertia of the flywheels: The inertia of the flywheels is directly related to the system's natural frequency, which is the frequency at which the system will vibrate the most. By modifying the inertia of the flywheels, you can change the natural frequency of the system and potentially shift it away from the resonant frequency. This can result in a reduction of the peak magnitude at the resonant frequency.

In summary, all of the proposed changes can have a direct or indirect effect on the resonant frequency of the system. By optimizing these factors, you can reduce the peak magnitude at the resonant frequency and improve the overall performance of the system. I hope this helps in your experimentation and feel free to reach out if you have any further questions. Good luck with your research!