scholarly journals Hybridized Love Waves in a Guiding Layer Supporting an Array of Plates with Decorative Endings

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1632
Author(s):  
Kim Pham ◽  
Agnès Maurel ◽  
Simon Félix ◽  
Sébastien Guenneau

This study follows from Maurel et al., Phys. Rev. B 98, 134311 (2018), where we reported on direct numerical observations of out-of-plane shear surface waves propagating along an array of plates atop a guiding layer, as a model for a forest of trees. We derived closed form dispersion relations using the homogenization procedure and investigated the effect of heterogeneities at the top of the plates (the foliage of trees). Here, we extend the study to the derivation of a homogenized model accounting for heterogeneities at both endings of the plates. The derivation is presented in the time domain, which allows for an energetic analysis of the effective problem. The effect of these heterogeneous endings on the properties of the surface waves is inspected for hard heterogeneities. It is shown that top heterogeneities affect the resonances of the plates, hence modifying the cut-off frequencies of a wave mathematically similar to the so-called Spoof Plasmon Polariton (SPP) wave, while the bottom heterogeneities affect the behavior of the layer, hence modifying the dispersion relation of the Love waves. The complete system simply mixes these two ingredients, resulting in hybrid surface waves accurately described by our model.

1966 ◽  
Vol 62 (3) ◽  
pp. 541-545 ◽  
Author(s):  
C. M. Purushothama

AbstractIt has been shown that uncoupled surface waves of SH type can be propagated without any dispersion in an electrically conducting semi-infinite elastic medium provided a uniform magnetic field acts non-aligned to the direction of wave propagation. In general, the velocity of propagation will be slightly greater than that of plane shear waves in the medium.


2013 ◽  
Vol 564 ◽  
pp. 37-40 ◽  
Author(s):  
Balázs Hajgató ◽  
Songül Güryel ◽  
Yves Dauphin ◽  
Jean-Marie Blairon ◽  
Hans E. Miltner ◽  
...  

2021 ◽  
Vol 881 ◽  
pp. 149-156
Author(s):  
Mochamad Teguh ◽  
Novi Rahmayanti ◽  
Zakki Rizal

Building material innovations in various interlocking concrete block masonry from local materials to withstand lateral earthquake forces is an exciting issue in masonry wall research. The block hook has an advantage in the interlocking system's invention to withstand loads in the in-plane and out-of-plane orientations commonly required by the masonry walls against earthquake forces. Reviews of the investigation of in-plane and out-of-plane masonry walls have rarely been found in previous studies. In this paper, the results of a series of experimental tests with different interlocking models in resisting the simultaneous in-plane shear and out-of-plane bending actions on concrete blocks are presented. This paper presents a research investigation of various interlocking concrete blocks' mechanical properties with different hook thicknesses. Discussion of the trends mentioned above and their implications towards interlocking concrete block mechanical properties is provided.


Author(s):  
Yoshimichi Kawai ◽  
Shigeaki Tohnai ◽  
Shinichiro Hashimoto ◽  
Atsushi Sato ◽  
Tetsuro Ono

<p>Steel sheet shear walls with cold formed edge stiffened burring holes are applied to low- to mid-rise housings in seismically active and typhoon- or hurricane-prone regions. A configuration with burrs on the inside and smooth on the outside enables the construction of omitting the machining of holes for equipments and thinner walls with simplified attachments of finishings. In-plane shear experiments and finite element analyses revealed that the walls allowed shear stress to concentrate in intervals between the burring holes. The walls maintained stable shear load and large deformation behavior, and the deformation areas were limited in the intervals and a large out-of-plane waveform in a sheet was effectively prevented owing to edge stiffened burring ribs. The design methods are developed for evaluating the shear load of the walls at story angle from zero to 1/100, using the idea of decreasing the band width of the inclined tension fields on the intervals with the effects of the thickness.</p>


1964 ◽  
Vol 54 (2) ◽  
pp. 627-679
Author(s):  
David G. Harkrider

ABSTRACT A matrix formulation is used to derive integral expressions for the time transformed displacement fields produced by simple sources at any depth in a multilayered elastic isotropic solid half-space. The integrals are evaluated for their residue contribution to obtain surface wave displacements in the frequency domain. The solutions are then generalized to include the effect of a surface liquid layer. The theory includes the effect of layering and source depth for the following: (1) Rayleigh waves from an explosive source, (2) Rayleigh waves from a vertical point force, (3) Rayleigh and Love waves from a vertical strike slip fault model. The latter source also includes the effect of fault dimensions and rupture velocity. From these results we are able to show certain reciprocity relations for surface waves which had been previously proved for the total displacement field. The theory presented here lays the ground work for later papers in which theoretical seismograms are compared with observations in both the time and frequency domain.


1998 ◽  
Vol 64 (618) ◽  
pp. 438-444 ◽  
Author(s):  
Kenichi HIRASHIMA ◽  
Shigerou NAKANE ◽  
Mutsumi MIYAGAWA ◽  
Shinji KIKUCHI

1991 ◽  
Vol 81 (5) ◽  
pp. 1900-1922
Author(s):  
Arthur Frankel ◽  
Susan Hough ◽  
Paul Friberg ◽  
Robert Busby

Abstract A small aperture (≈300 m), four-station array was deployed in Sunnyvale, California for 5 days to record aftershocks of the Loma Prieta earthquake of October 1989. The purpose of the array was to study the seismic response of the alluvium-filled Santa Clara Valley and the role of surface waves in the seismic shaking of sedimentary basins. Strong-motion records of the Loma Prieta mainshock indicate that surface waves produced the peak velocities and displacements at some sites in the Santa Clara Valley. We use the recordings from the dense array to determine the apparent velocity and azimuth of propagation for various arrivals in the seismograms of four aftershocks with magnitudes between 3.6 and 4.4. Apparent velocities are generally observed to decrease with increasing time after the S wave in the seismograms. Phases arriving less than about 8 sec after the S wave have apparent velocities comparable to the S wave and appear to be body waves multiply reflected under the receiver site or reflected by crustal interfaces. For times 10 to 30 sec after the direct S wave, we observe long-period (1 to 6 sec) arrivals with apparent velocities decreasing from 2.5 to 0.8 km / sec. We interpret these arrivals to be surface waves and conclude that these surface waves produce the long duration of shaking observed on the aftershock records. Much of the energy in the 40 sec after the S-wave is coming approximately from the direction of the source, although some arrivals have backazimuths as much as 60° different from the backazimuths to the epicenters. Two of the aftershocks show arrivals coming from 30 to 40° more easterly than the epicenters. This energy may have been scattered from outcrops along the southeastern edge of the basin. In contrast, the deepest aftershock studied (d = 17 km) displays later arrivals with backazimuths 30 to 40° more westerly than the epicenter. A distinct arrival for one of the aftershocks propagates from the southwest, possibly scattered from the western edge of the basin. Synthetic seismograms derived from a plane-layered crustal model do not produce the long-period Love waves observed in the waveforms of the ML 4.4 aftershock. These Love waves may be generated by the conversion of incident S waves or Rayleigh waves near the edge of the basin.


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