Search results for "Shear waves"
showing 7 items of 7 documents
Shaping Brillouin Light in Specialty Optical Fibers
2017
Effective hydrostatic limits of pressure media for high‐pressure crystallographic studies
2007
The behavior of a number of commonly used pressure media, including nitrogen, argon, 2-propanol, a 4:1 methanol–ethanol mixture, glycerol and various grades of silicone oil, has been examined by measuring the X-ray diffraction maxima from quartz single crystals loaded in a diamond-anvil cell with each of these pressure media in turn. In all cases, the onset of non-hydrostatic stresses within the medium is detectable as the broadening of the rocking curves of X-ray diffraction peaks from the single crystals. The onset of broadening of the rocking curves of quartz is detected at ∼9.8 GPa in a 4:1 mixture of methanol and ethanol and at ∼4.2 GPa in 2-propanol, essentially at the same pressures …
Adapting available finite element structural programs to solve three-dimensional high frequency electromagnetic problems
1991
The adaptation of available structural mechanics software to solve microwave problems is possible by the analogy between the differential equations. A brief review of the analogy between transverse or shear waves in elasticity and electromagnetic waves is presented, followed by a more detailed discussion of the adaptation of a program to obtain the resonant frequencies of a rectangular resonant cavity, doing a three-dimensional analysis. The geometry of the electric field is also obtained for the resonant modes.
On the effect of damping on dispersion curves in plates
2013
AbstractThis paper presents a study on quantitative prediction and understanding of time-harmonic wave characteristics in damped plates. Material dissipation is modelled by using complex-valued velocities of free dilatation and shear waves in an unbounded volume. As a numerical example, solution of the classical Rayleigh–Lamb problem for a viscoelastic plate is presented to illustrate and discuss the role of dissipation in the cut-off phenomenon and in the phenomenon of veering for dispersion curves. These phenomena are explained in more detail considering a simple model, which allows accurate asymptotic analysis of the perturbation of dispersion curves in the regions of cut-off and veering.
Cloaking In-Plane Elastic Waves with Swiss Rolls
2020
We propose a design of cylindrical cloak for coupled in-plane shear waves consisting of concentric layers of sub-wavelength resonant stress-free inclusions shaped as Swiss rolls. The scaling factor between inclusions&rsquo
Spatial response spectra and site amplification effects
2002
A simplified analysis of local site amplification effects on the seismic response of multi-support structures is presented. The site effects are modeled by considering reflections and transmission of vertically propagating shear waves from bedrock to the surface through a soil layer. A random vibration-based response spectrum of a simple oscillator on two supports, one of which is founded on rock outcrop and the other on soil layer, is formulated in order to study the influence of non-uniform excitations on multi-support structures. Joint inertial and pseudo-static effects in the overall response are studied in detail. The resulting response spectra are formulated as displacement and force …
Integration of constrained electrical and seismic tomographies to study the landslide affecting the cathedral of Agrigento
2014
The Cathedral of Saint Gerland, located on the top of the hill of Agrigento, is an important historical church, which dates back to the Arab–Norman period (XI century). Unfortunately throughout its history the Cathedral and the adjacent famous Archaeological Park of the 'Valley of the Temples' have been affected by landslides. In this area the interleaving of calcarenites, silt, sand and clay is complicated by the presence of dislocated rock blocks and cavities and by a system of fractures partly filled with clay or water. Integrated geophysical surveys were carried out on the north side of the hill, on which the Cathedral of Agrigento is founded, to define lithological structures involved …