HIGH RESOLUTION DIFFERENTIAL TECHNIQUE FOR PHASE VELOCITY AND ATTENUATION MEASUREMENTS OF ULTRASONIC INTERFACE WAVES

1985 ◽  
Vol 46 (C10) ◽  
pp. C10-805-C10-808
Author(s):  
S. I. ROKHLIN
2010 ◽  
Vol 127 (3) ◽  
pp. 2006-2006
Author(s):  
Christian C. Anderson ◽  
Michal Pakula ◽  
Pascal Laugier ◽  
G. Larry Bretthorst ◽  
Mark R. Holland ◽  
...  

2020 ◽  
Vol 37 (9) ◽  
pp. 3407-3429
Author(s):  
Manisha Maity ◽  
Santimoy Kundu ◽  
Raju Kumhar ◽  
Shishir Gupta

Purpose This mathematical analysis has been accomplished for the purpose of understanding the propagation behaviour like phase velocity and attenuation of Love-type waves through visco-micropolar composite Earth’s structure. Design/methodology/approach The considered geometry of this problem involves a micropolar Voigt-type viscoelastic stratum imperfectly bonded to a heterogeneous Voigt-type viscoelastic substratum. With the aid of governing equations of motion of each individual medium and method of separation of variable, the components of micro-rotation and displacement have been obtained. Findings The boundary conditions of the presumed geometry at the free surface and at the interface, together with the obtained components of micro-rotation, displacement and mechanical stresses give rise to the determinant form of the dispersion relation. Moreover, some noteworthy cases have also been extrapolated in detail. Graphical interpretation irradiating the impact of viscoelasticity, micropolarity, heterogeneity and imperfectness on the phase velocity and attenuation of Love-type waves is the principal highlight of the present study. Practical implications In this study, the influence of the considered parameters such as micropolarity, viscoelasticity, heterogeneity, and imperfectness has been elucidated graphically on the phase velocity and attenuation of Love-type waves. It has been noticed from the graphs that with the rising magnitude of micropolarity and heterogeneity, the attenuation curves shift upwards, that is the loss of energy of these waves takes place in a rapid way. Hence, from the outcomes of the present analysis, it can be concluded that heterogeneous micropolar stratified media can serve as a helpful tool in increasing the attenuation or in other words, loss of energy of Love-type waves, thus reducing the devastating behaviour of these waves. Originality/value Till date, the mathematical modelling as well as vibrational analysis of Love-type waves in a viscoelastic substrate overloaded by visco-micropolar composite Earth’s structure with mechanical interfacial imperfection remain unattempted by researchers round the globe. The current analysis is an approach for studying the traversal traits of surface waves (here, Love-type waves) in a realistic stratified model of the Earth’s crust and may thus, serves as a dynamic paraphernalia in various domains like earthquake and geotechnical engineering; exploration geology and soil mechanics and many more, both in a conceptual as well as pragmatic manner.


1990 ◽  
Vol 142 ◽  
pp. 262-263
Author(s):  
K. Somasundaram ◽  
S. Manthiramoorthi ◽  
A. Sathya Narayanan

The conditions under which the hydromagnetic interface waves can exist at a magnetic interface is deduced. Using these conditons, it is shown that a slow interface wave with a phase velocity about 5Km/s and a fast interface wave with a phase velocity 6.5 to 8km/s at the photospheric level can exist.


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