Related Experiment Video
Updated: Apr 5, 2026
08:57
Optical Trap Loading of Dielectric Microparticles In Air
Published on: February 5, 2017
9.6K
Orbital-type trapping of elastic Lamb waves
Alexey M Lomonosov1, Shi-Ling Yan2, Bing Han2
1Faculty of Science, Nanjing University of Science and Technology, Nanjing 210094, China; General Physics Institute, Russian Academy of Sciences, 119991 Moscow, Russia.
Ultrasonics
|August 24, 2015
Summary
Researchers studied how laser-generated Lamb waves interact with conical holes. Wave energy gets trapped in the cone, offering potential for efficient acoustic damping, similar to an acoustical black hole.
Area of Science:
- Acoustics and Wave Phenomena
- Materials Science and Engineering
Background:
- Lamb waves are crucial for non-destructive testing and structural health monitoring.
- Conical structures can influence wave propagation, but their interaction with Lamb waves is not fully understood.
Purpose of the Study:
- To investigate the interaction between laser-generated Lamb waves and sharp-angle conical holes.
- To identify mechanisms of wave energy trapping within the conical region.
- To determine conditions for optimal energy conversion into trapped wave modes.
Main Methods:
- Experimental investigation using laser stroboscopic shearography for real-time acoustic field visualization.
- Numerical simulations to complement experimental findings and analyze wave dynamics.
Main Results:
- Observed two primary energy trapping mechanisms: antisymmetric Lamb wave orbiting the hole and wave localization at the acute edge.
- Identified parameters and conditions that favor efficient conversion of incident waves into trapped modes.
- Demonstrated the potential for wave energy trapping within the conical geometry.
Conclusions:
- The interaction of Lamb waves with conical holes leads to significant energy trapping.
- This trapping phenomenon can be exploited for effective acoustic damping applications.
- The findings offer insights analogous to the one-dimensional acoustical black hole effect for wave energy dissipation.
Related Concept Videos
01:28Standing Waves in a Cavity
1.6K
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:
1.6K
01:07Reflection of Waves
4.8K
When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
4.8K
01:11Atomic Nuclei: Larmor Precession Frequency
3.6K
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...
3.6K
01:18Electron Orbital Model
76.9K
Orbitals are the areas outside of the atomic nucleus where electrons are most likely to reside. They are characterized by different energy levels, shapes, and three-dimensional orientations. The location of electrons is described most generally by a shell or principal energy level, then by a subshell within each shell, and finally, by individual orbitals found within the subshells.
The first shell is closest to the nucleus, and it has only one subshell with a single spherical orbital called the...
The first shell is closest to the nucleus, and it has only one subshell with a single spherical orbital called the...
76.9K
01:04Oscillations about an Equilibrium Position
7.3K
Stability is an important concept in oscillation. If an equilibrium point is stable, a slight disturbance of an object that is initially at the stable equilibrium point will cause the object to oscillate around that point. For an unstable equilibrium point, if the object is disturbed slightly, it will not return to the equilibrium point. There are three conditions for equilibrium points—stable, unstable, and half-stable. A half-stable equilibrium point is also unstable, but is named so...
7.3K
02:32The de Broglie Wavelength
34.7K
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
34.7K