During the last decade Railways have become one of the most advanced and fast developing branches of transportation technology. The reason is very high speeds achievable by the most advanced modern trains (French TGV, German ICE, Italian Pendolino, Swedish X2000, Spanish AVE, Belgium Thalys, the Eurostar) and very low air pollution per passenger compared with road vehicles. Unfortunately, the i...

Surface wave method can be used to determine the properties of the component materials of a pavement structure. The measurements are made of the differences in the phase of a wave of the Rayleigh type, received at two points at known radial spacing from the source of the wave. Pavements for highways or airport runways are usually constructed of cement concrete. Such pavements are treated as a s...

[1] We estimate crustal structure and thickness of South America north of roughly 40°S. To this end, we analyzed receiver functions from 20 relatively new temporary broadband seismic stations deployed across eastern Brazil. In the analysis we include teleseismic and some regional events, particularly for stations that recorded few suitable earthquakes. We first estimate crustal thickness and av...

A new transducer beam model is developed for the generation of Rayleigh surface wave and Lamb plate waves by an angle beam transducer, which is one of the configurations commonly used for the generation of these wave types. The beam model is a fully 3-D model that takes into account the fields generated by the transducer acting on the surface of a wedge. The model also accounts for the leaky wa...

The noncontact and wide-band characteristics of the ultrasonic signal excited by laser make it widely used in nondestructive detection. In this paper, finite element method is to simulate multiple modes responses them metal defects. simulation shows that changes Rayleigh-wave (RW) shear-wave (SW) can be research surface crack internal defect sample respectively. By analyzing reflected wave RW S...

We present a theoretical and experimental study on the phonon dynamics of the low-temperature Sn/Ge(1 1 1)-(3 3) structure. High-resolution helium atom scattering (HAS) data show that, besides the Rayleigh wave, there are three surface phonon branches with low dispersion related to the (3 3) surface phase. Their energies are approximately 6.5, 4, and 3 meVat the G point. In addition, we detect ...

Constraints on upper crustal seismic anisotropy provide insight into the local stress orientation and structural fabric, but such constraints are scarce except in areas with dense recordings of local seismicity. We investigate directionally dependent Rayleigh wave ellipticity, or Rayleigh wave H/V (horizontal to vertical) amplitude ratios, between 8 and 20 s period across USArray to infer azimu...

An original method is presented to determine the complex Lamb wave spectrum by using a numerical spectral method applied to the elasticity equations. This method presents the advantage to directly determine complex wave numbers for a given frequency via a classical matricial eigenvalue problem, and allows the wave numbers to be determined at relatively high frequencies (i.e., corresponding to m...

The elastic wave transparency phenomenon of a solid sphere coated with metamaterials is investigated in a solid host medium having nonzero shear modulus. The first three scattering coefficients of the coated sphere are derived in the Rayleigh limit and expressed in terms of the effective parameters of the coated sphere assemblage. It is found that the effective bulk modulus, mass density, and s...