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Reflection of flexural waves in a structure

Neal Connor Acoustics

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I am trying to model the propation of flexural waves in a 2D rectangular beam with decreasing thickness and the effect that different profiles of thickness have on the reflection of these waves, for my university project. So far, I have been able to design the structure using the geometry tools and apply boundary conditions and the size and type of mesh, but as I am only a beginner at using COMSOL I am finiding it rather tricky to model the propagation of these waves and to calculate the reflection, I am currently using version 6.0 for my simulations. I have tried introducing a point of excitation to the model to try to include a source of the flexural waves but I am unsure whether this is correct.

Physics Selected: * Acoustics > Elastic Waves > Solid Mechanics (Elastic Waves)

Study: * Frequency Domain

Frequency: * 10Hz to 10kHz

I have uploaded the geometry of one of my plates with the boundary conditions and the mesh parameters already chosen. I would be grateful for any suggestions to what I should do to model the propagation and to find the reflection of these flexural waves.

Thank you.



3 Replies Last Post 14.02.2023, 11:21 GMT-5
Edgar J. Kaiser Certified Consultant

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Posted: 1 year ago 13.02.2023, 15:42 GMT-5

Neal,

the setup looks good and you can add e.g. a boundary load or a prescribed displacement somewhere to excite the structure. The frequency domain study shows you the vibration pattern in the dynamic steady state, i.e. after a long time of excitation. If you want to see the propagation and reflection of a certain disturbance you would need to run a time dependent study.

Cheers Edgar

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Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Neal, the setup looks good and you can add e.g. a boundary load or a prescribed displacement somewhere to excite the structure. The frequency domain study shows you the vibration pattern in the dynamic steady state, i.e. after a long time of excitation. If you want to see the propagation and reflection of a certain disturbance you would need to run a time dependent study. Cheers Edgar

Neal Connor Acoustics

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Posted: 1 year ago 14.02.2023, 07:27 GMT-5

Hi Edgar,

Thank you for your response, how would the reflection of a disturbance be done in a time dependent study. Would I have to use point probes at either end.

Hi Edgar, Thank you for your response, how would the reflection of a disturbance be done in a time dependent study. Would I have to use point probes at either end.

Edgar J. Kaiser Certified Consultant

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Posted: 1 year ago 14.02.2023, 11:21 GMT-5

Sure, point probes may be an option. It depends on the question you have to the model.

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Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Sure, point probes may be an option. It depends on the question you have to the model.

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