Related Experiment Video
Updated: Jul 31, 2026
10:39
Fabrication and Characterization of Thickness Mode Piezoelectric Devices for Atomization and Acoustofluidics
Published on: August 5, 2020
On ultrasonic guided waves in a thin anisotropic layer lying between two isotropic layers
1University of Colorado, Department of Mechanical Engineering, Boulder 80309-0427, USA.
The Journal of the Acoustical Society of America
|December 7, 2000
Summary
This study introduces an approximate method for analyzing guided wave dispersion in anisotropic sandwich plates, useful for superconducting tapes. The findings aid in ultrasonic measurements of thin layer elastic properties.
Area of Science:
- Solid Mechanics
- Materials Science
- Wave Propagation
Background:
- Guided wave dispersion analysis is crucial for understanding wave propagation in layered structures.
- Sandwich plates with anisotropic cores, like superconducting tapes, present unique challenges due to material properties.
- Accurate modeling is needed for material characterization and non-destructive testing.
Purpose of the Study:
- To develop and validate an approximate dispersion relation for guided waves in a three-layered anisotropic sandwich plate.
- To investigate the low-frequency characteristics of wave propagation in such structures.
- To assess the applicability of the derived approximation for material property measurements.
Main Methods:
- Derivation of an approximate dispersion relation using a Taylor expansion of the field within the thin anisotropic layer (correct to O(h)).
- Numerical analysis of guided wave dispersion for specific superconducting tape configurations.
- Comparison of approximate dispersion relations with exact solutions to evaluate accuracy.
Main Results:
- An approximate dispersion relation was successfully derived and validated against exact solutions.
- The approximation demonstrates good accuracy within the frequency range of interest.
- Distinctive low-frequency wave propagation features were identified and investigated.
Conclusions:
- The developed approximate method provides an efficient tool for analyzing guided waves in anisotropic sandwich plates.
- The identified characteristic features can be leveraged for ultrasonic-based characterization of anisotropic elastic constants in thin layers.
- This research offers potential for improved non-destructive evaluation techniques for advanced materials.
Related Concept Videos
01:04Travelling Waves
A wave is a disturbance that propagates from its source, repeating itself periodically, and is typically associated with simple harmonic motion. Mechanical waves are governed by Newton's laws and require a medium to travel. A medium is a substance in which a mechanical wave propagates, and the medium produces an elastic restoring force when it is deformed.
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is water;...
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is water;...
01:07Interference and Superposition of Waves
When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect of the waves is the sum of the individual waves' effects. However, it does not imply that the individual waves affect the propagation of other waves.
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
01:07Propagation of Waves
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
00:53Sound Waves: Interference
Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When two identical waves from the same source superimpose on each other, the combination of two crests or two troughs results in amplitude reinforcement known as constructive interference. If two identical waves, that are initially in phase, become out of phase because of different path lengths, the combination of crests with troughs...
01:17Ultrasonography
Ultrasonography is an imaging technique that uses high-frequency sound waves to visualize the body's internal structures. It is a non-invasive and safe procedure that does not involve the use of ionizing radiation, making it widely used in various medical fields. Ultrasonography is used to study heart function, blood flow in the neck or extremities, certain conditions such as gallbladder disease, and fetal growth and development.
During an ultrasonography procedure, a handheld device called a...
During an ultrasonography procedure, a handheld device called a...
01:28Standing Waves in a Cavity
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by: