Acoustic dispersion and attenuation relations in bubbly mixture

We used the Green’s function summation method together with the randomly perturbed asperity sources to sum up broadband statistical Green’s functions of a moderate-size source and predict strong ground motions due to the expected M8.1 to 8.7 Nankai-Trough earthquakes along the southern coast of western Japan. We successfully simulated seismic intensity distributions similar to the past earthquakes and strong ground motions similar to the empirical attenuation relations of peak ground acceleration and velocity. Using these results, we predicted building damage by non-linear response analyses and find that at the regions close to the source, as well as regions with relatively thick, soft sediments such as the shoreline and alluvium valleys along the rivers, there is a possibility of severe damage regardless of the types of buildings. Moreover, the predicted damage ratios for buildings built before 1981 are much higher than those built after because of the significant code modifications in 1981. We also find that the damage ratio is highest for steel buildings, followed by wooden houses, and then reinforced concrete buildings.

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Dispersion and attenuation of shear wave in couple stress stratum due to point source

Journal of Vibration and Control ◽

10.1177/1077546321998880 ◽

2021 ◽

pp. 107754632199888

Author(s):

Richa Kumari ◽

Abhishek K Singh

Keyword(s):

Point Source ◽

Shear Wave ◽

Couple Stress ◽

Imperfect Interface ◽

Layered Composite ◽

Functionally Graded ◽

Function Technique ◽

Dispersive Wave ◽

Attenuation Profiles ◽

Dispersion And Attenuation

This study discusses the propagation of a horizontally polarised shear wave in a layered composite structure consisting of couple stress stratum over a functionally graded orthotropic viscoelastic substrate due to point source existing at an imperfect interface of the stratum and substrate. Because of the CS effect in the stratum, the existence of the second kind of dispersive (shear) wave is established along with conventional first kind of a shear wave. The closed-form dispersion equations and damping equations of the first and second kind of a dispersive wave are derived by adopting non-traditional boundary conditions and Green’s function technique. The effect of characteristic length of microstructure, imperfect bonding parameter and functional gradient parameters on velocity profiles and attenuation profiles of the first and second kind of dispersive wave has been computed numerically and delineated graphically. For validation, established results are matched with the classical one.

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Wave Dispersion and Attenuation on Human Femur Tissue

Sensors ◽

10.3390/s140815067 ◽

2014 ◽

Vol 14 (8) ◽

pp. 15067-15083 ◽

Cited By ~ 8

Author(s):

Maria Strantza ◽

Olivia Louis ◽

Demosthenes Polyzos ◽

Frans Boulpaep ◽

Danny van Hemelrijck ◽

...

Keyword(s):

Wave Dispersion ◽

Human Femur ◽

Dispersion And Attenuation

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