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Lamb wave

mohammad hassannezhad

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How do you simulate the pure A0 mode of the lamb wave in a composite laminate in Comsol Multiphysics


4 Replies Last Post May 12, 2023, 12:58 p.m. EDT
Henrik Sönnerlind COMSOL Employee

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Posted: 12 months ago May 11, 2023, 4:33 a.m. EDT

If you have the Composite Materials Module, it should be fairly straightforward to model Lamb waves using the Layered Shell interface. The formulation there is essentially 3D, so not just A0 waves, but also S waves and higher order A waves can be captured.

An A0 mode for a thin plate can also be modeled using the Shell interface, using the Layered Linear Elastic Material. In this case, classical laminate theory is used, so the other type of modes are not present. If you are able to supply aggregated cross section data (essentially ABD form), then no other license than the Structural Mechanics Module is needed.

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Henrik Sönnerlind
COMSOL
If you have the Composite Materials Module, it should be fairly straightforward to model Lamb waves using the Layered Shell interface. The formulation there is essentially 3D, so not just A0 waves, but also S waves and higher order A waves can be captured. An A0 mode for a thin plate can also be modeled using the Shell interface, using the Layered Linear Elastic Material. In this case, classical laminate theory is used, so the other type of modes are not present. If you are able to supply aggregated cross section data (essentially ABD form), then no other license than the Structural Mechanics Module is needed.

Edgar J. Kaiser Certified Consultant

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Posted: 12 months ago May 11, 2023, 5:25 a.m. EDT

Hi Henrik,

that is interesting. Do you have an example or reference for the application of aggregated cross section data?

Cheers Edgar

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Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Hi Henrik, that is interesting. Do you have an example or reference for the application of aggregated cross section data? Cheers Edgar

Henrik Sönnerlind COMSOL Employee

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Posted: 12 months ago May 11, 2023, 7:23 a.m. EDT

Edgar,

The key here is the Section Stiffness material model in the Shell interface. So, if you can compute the extensional, bending, coupling, and shear stiffness matrices one way or another (maybe Excel), you can enter them there. For dynamics, you would also need the various mass/inertia matrices.

This material model can be applied for linear problems, as long as you are not interested in the per layer stresses.

See the attached screenshot showing the settings pane.

I cannot think about a sutable example right now, but in https://www.comsol.com/model/material-characteristics-of-laminated-composite-shell-67691 the ABD matrices are extracted from a full layered model. Such matrices could be directly entered into another non-layered model with preserved stiffness properties.

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Henrik Sönnerlind
COMSOL
Edgar, The key here is the *Section Stiffness* material model in the Shell interface. So, if you can compute the extensional, bending, coupling, and shear stiffness matrices one way or another (maybe Excel), you can enter them there. For dynamics, you would also need the various mass/inertia matrices. This material model can be applied for linear problems, as long as you are not interested in the per layer stresses. See the attached screenshot showing the settings pane. I cannot think about a sutable example right now, but in the ABD matrices are extracted from a full layered model. Such matrices could be directly entered into another non-layered model with preserved stiffness properties.


Edgar J. Kaiser Certified Consultant

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Posted: 12 months ago May 12, 2023, 12:58 p.m. EDT

Thanks Henrik, will have a look into that.

Cheers Edgar

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Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Thanks Henrik, will have a look into that. Cheers Edgar

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