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Rayleigh damping for approximating Lamb wave attenuation in finite element simulations
Mattie Green1, Fadhel Alsaffar1, Ajit Mal1
1Mechanical and Aerospace Engineering Department, University of California, 420 Westwood Plaza, Los Angeles, 90095, CA, USA.
Ultrasonics
|July 1, 2026
Summary
Rayleigh damping effectively models Lamb wave attenuation in viscoelastic materials within finite element simulations. This method accurately predicts wave behavior across specific frequency ranges for fundamental modes, especially when attenuation varies consistently with frequency.
Area of Science:
- Materials Science
- Mechanical Engineering
- Computational Mechanics
Background:
- Numerical modeling of Lamb waves aids experiment design and prediction of complex behaviors.
- Modeling Lamb wave propagation in viscoelastic materials requires accounting for material damping.
- Lamb wave attenuation in frequency domain uses complex stiffness, but spatial domain definition is needed for finite element models.
Purpose of the Study:
- To investigate the feasibility of using Rayleigh damping for modeling Lamb wave attenuation in finite element simulations.
- To evaluate the accuracy and limitations of Rayleigh damping for Lamb wave attenuation.
- To improve numerical models by comparing simulation results with experimental measurements.
Main Methods:
- Finite element simulations were performed on a polyetherimide (PEI) plate using previously measured experimental properties.
- Rayleigh damping was implemented to model Lamb wave attenuation in the spatial domain.
- Simulations examined both A0 and S0 fundamental Lamb wave modes.
- Experimental measurements were conducted over an extended frequency range for model validation and improvement.
Main Results:
- Rayleigh damping can accurately implement Lamb wave attenuation in time-domain finite element simulations for specific frequency ranges of fundamental modes.
- The model's accuracy is maximized when the rate of attenuation variation with frequency is constant or nearly constant.
- The study discusses the limitations of the Rayleigh damping model for Lamb wave attenuation.
Conclusions:
- Rayleigh damping is a viable method for simulating Lamb wave attenuation in viscoelastic materials within finite element analysis.
- The accuracy of Rayleigh damping is dependent on the frequency-dependent characteristics of the material's attenuation.
- This approach enhances the predictive capability of numerical models for wave propagation in polymers and composites.
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