Since Rayleigh waves are confined near the surface, their in-plane amplitude when generated by a point source decays only as { 1 } / { \ sqrt { r } }, where r is the radial distance.
42.
His prediction of ground vibration boom from high-speed trains travelling at speeds larger than Rayleigh wave velocity in the supporting ground has received public attention in connection with the proposed High Speed Rail system HS2 in the UK.
43.
Rayleigh waves emanating outward from the epicenter of an earthquake travel along the surface of the earth at about 10 times the speed of sound in air ( 0.340 km / s ), that is ~ 3 km / s.
44.
The transformation of the initial electric energy into mechanical energy ( in the form of SAW ) and back is usually accomplished via the use of piezoelectric materials for both generation and reception of Rayleigh waves as well as for their propagation.
45.
In seismology, Rayleigh waves ( called " ground roll " ) are the most important type of surface wave, and can be produced ( apart from earthquakes ), for example, by ocean waves, by explosions, by railway trains and ground vehicles, or by a sledgehammer impact.
46.
While much excitement rightly centres on the relatively new activity related to intersonic cracking, an old but interesting possibility remains to be incorporated in the modern work : for an interface between elastically dissimilar materials, crack propagation that is subsonic but exceeds the Rayleigh wave speed has been predicted for at least some combinations of the elastic properties of the two materials.
