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Acoustic emissions in bearings

    • Magnus Norstenes
      Subscriber

      In my master's project, I aim to investigate the propagation of acoustic emissions through lubrication, transitioning from the inner ring to the outer ring. While I'm still in the preliminary stages and haven't initiated the research, I'm considering utilizing "Explicit Dynamics" in Ansys Workbench for this study. Given that I'm unfamiliar with Ansys, I'd appreciate insights on whether this approach is applicable. If so, what should be my primary objectives, and how might I best commence and proceed with the project?

    • Ashish Kumar
      Forum Moderator

      Hi Magnus,

       

      Are you interested in modeling Fluid Solid Interaction (FSI)? Following are the analysis system using Mechanical:

      Regards,

      Ashish Kumar

    • Magnus Norstenes
      Subscriber

      I am going to use something called AE sensors. The waves measured is a bit different than normal sound waves:

      "Acoustic emission (AE) is the phenomenon of radiation of acoustic (elastic) waves in solids that occurs when a material undergoes irreversible changes in its internal structure, for example as a result of crack formation or plastic deformation due to aging, temperature gradients, or external mechanical forces."

      Not sure if those tools are sufficient for the waves to be simulated. The waves are much more like shear waves, and not pressure waves

    • Bill Bulat
      Ansys Employee

      Hi Magnus,

      An explicit solver may well be best suited for your objectives. Just so you know, we often do use implicit structural elements to simulate wave propagation in solids - for example, in SAW and BAW (surface and bulk acoustic wave) filters.

      We cannot attach files to forum posts, but the image below is a single frame of an animation of stress waves propagating from left to right (in the +x direction) in the piezoelectric material beneath a pair of output electrodes.

      In these devices, the wavelength of the frequency of the wave that is not to be filtered (passed) equals the electrode spacing.

      In the image above, the stress waves are absorbed without reflection in the "PML" (perfectly matched layers) region to the right of the output electrodes.

      Nonlinear material laws can be used to account for material yield and damage in full transient analyses, which would of course affect stress wave propagation.

      But explicit dynamics is almost certainly more often used for simulations such as what you described.

    • Magnus Norstenes
      Subscriber

      Thank you for your answers Kumar and Bulat!

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