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I am attempting to model the acoustic behaviors of a circular membrane (drum head). I know that software like ANSYS will give me the modes of vibration pretty easy from a simulation.

But what if I also want the Q (quality factors) ie. decay properties of the various modes? Is there any way to determine that? Can ANSYS do this? If so, how? If not, which software can provide it and any basic starter tips on how to get it?

Please excuse me if this is a very basic question. I am not an engineer of course but I am doing my best to figure out things as I go for my goal. Thanks.

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There are at least 3 factors that influence the damping

  1. Internal material damping within the membrane. For a single ply drum head, this is probably small, but if you are using a multi-ply head (e.g. the batter head on a typical snare drum), it will be larger and could get pretty complicated to model
  2. Friction at the interface of the drum head to the drum. Friction is very hard to model in general, and its hard to predict ahead of time.
  3. Energy radiated to the surrounding air as sound. From the point of view of the membrane, the energy carried away by the sound decreases the energy of the membrane and thus its damping energy. This is an acoustics / fluid structure interaction problem. It should be possible to model this and calculate the values. I used to do similar calculations for beams and the theory should be similar for membranes. However, it might involve fairly advanced math.

Which of these three is dominant probably depends on what modes you are talking about. For some modes and some drums, you might be able to neglect one of these mechanisms. However, they can all get pretty complicated. If you are not an engineer, its probably easiest to just run an experiment and measure the decay rates experimentally.

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