Rayleigh Wave


Also found in: Dictionary, Wikipedia.
Related to Rayleigh Wave: primary wave, Surface wave

Rayleigh wave

[′rā·lē ‚wāv]
(geophysics)
In seismology, a surface wave with a retrograde, elliptical motion at the free surface. Also known as R wave.
(mechanics)
A wave which propagates on the surface of a solid; particle trajectories are ellipses in planes normal to the surface and parallel to the direction of propagation. Also known as surface wave.

Rayleigh Wave

 

an elastic disturbance that propagates along the free boundary of a solid body and is attenuated with depth. The existence of such waves was predicted by Lord Rayleigh in 1885.

Rayleigh waves occur on the earth’s surface during earthquakes. Ultrasonic waves used to check the surface layer of various device components and specimens are another example of Rayleigh waves. The thickness of the layer where the waves are localized is (1–2)λ, where λ is the wavelength. At a depth λ the energy density in a wave is ~0.05 of the density at the surface. Particles in Rayleigh waves move in elliptical trajectories whose semimajor axis is perpendicular to the surface of the body and whose semiminor axis is parallel to the direction of wave propagation. The phase velocity of Rayleigh waves is less than the phase velocities of longitudinal and shear waves and is equal to the group velocity.

In anisotropic media the structure and properties of Rayleigh waves depend on the type of anisotropy and the direction of wave propagation. There exist media, such as triclinic crystals, in which Rayleigh waves cannot exist at all. Sometimes, the term “Rayleigh waves” is applied to surface waves of a more general type that arise at the interface between a solid and a liquid or at the boundary of a system of solid or liquid layers with a solid half space.

REFERENCES

Kol’skii, G. Volny napriazheniia v tverdykh telakh. Moscow, 1955. (Translated from English.)
Landau, L. D., and E. M. Lifshits. Teoriia uprugosti, 3rd ed. Moscow, 1965. (Teoreticheskaia fizika, vol. 7.)
Viktorov, I. A. Fizicheskie osnovy primeneniia ul’trazvukovykh voln Releia i Lemba v tekhnike. Moscow, 1966.
References in periodicals archive ?
In general, across the entire frequency range, the modal energy values of the fundamental toroidal and spheroidal modes (Love and Rayleigh wave equivalently) are larger than those of the overtones.
Good agreement between these parameters suggests that [f.sub.1] = 2.19 Hz corresponds to the Rayleigh wave fundamental mode.
Qu, "Experimental study of nonlinear Rayleigh wave propagation in shot-peened aluminum plates--Feasibility of measuring residual stress," NDTE and Int, vol.
8.1 Rayleigh Wave. Figure 7 shows the variations of phase velocity of Rayleigh wave verses wave number for FTTIWIS, FTTIIS, FTIWIS, and FTIIS.
Figures 23, 24, and 25 show the variations of the Rayleigh wave velocity and attenuation coefficient with respect to phase velocity c, it has oscillatorybehavior in the whole range of c for different values of relaxation times [[tau].sub.0], [[theta].sub.O], and [n.sup.*], respectively, for L-S theory, G-L theory, and G-N theory, which changes from the positive to the negative gradually.
Moreover, the motion orbits calculated from the three-dimensional analyses indicate that the Rayleigh wave is the dominating wave type outside the embankment [44].
In the paper, the influence of gravity and non-homogeneity on the propagation of surface waves (Rayleigh wave type) in a granular half space supporting a different granular layer is studied.
The generated Rayleigh wave data are recorded at all shot points.
The arrivals include all the regular reflected rays and all possible head waves and Rayleigh wave; each has an associated pair of number [k.sub.1] and [k.sub.2], denoting the group of the ray paths.
Another option is to inspect the bolt in place by using cylindrical guided ultrasonic waves, which involves either placing a transducer on the exposed bolt end, or positioning a transducer so that a Rayleigh wave front a crack would be detected behind the thread root.