P3H-3 Thin Film Stack Transducer for Simultaneous Generation of Longitudinal and Shear Waves at Same Frequency

2007 ◽  
Author(s):  
T. Yanagitani ◽  
T. Matsuo ◽  
M. Matsukawa ◽  
Y. Watanabe
Keyword(s):  
Thin Film ◽  
Shear Waves ◽  
Simultaneous Generation ◽  
Longitudinal And Shear Waves

The Horizontally Polarized Shear Waves in Multilayered Piezo-Composites with 2-2 Connectivity

2004 ◽  
Vol 261-263 ◽  
pp. 465-470
Author(s):  
Zheng Hua Qian ◽  
Feng Jin ◽  
Zi Kun Wang ◽  
Kikuo Kishimoto
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Velocity ◽  
Polymer Composites ◽  
Piezoelectric Ceramic ◽  
Shear Waves ◽  
Electrical Performance ◽  
Sh Waves ◽  
Structural Applications ◽  
Waves Propagation

Following the advances in structural applications, composite structures are being used commonly in transducer applications to improve acoustic, mechanical and electrical performance of piezoelectric devices. Functional composite transducers for sensors and actuators generally consist of ceramics and polymers, the disadvantage of the brittleness nature of the piezoelectric ceramics can be overcome and the structures especially good for sensing can be allowed for building up. Propagation behavior of horizontally polarized shear waves (SH-waves) in piezoelectric ceramic-polymer composites with 2-2 connectivity is taken into account. The multilayer structures are consisted of piezoelectric thin films bonded perfectly with polymeric thin films alternately. The phase velocity equations of SH-waves propagation in the piezoelectric ceramic-polymer composites with 2-2 connectivity are obtained for the cases of wave propagation in the direction perpendicular to the layering and along the layering, respectively. Filter effect of this kind of structure and the effect of volume fraction and shear modulus ratio of piezoelectric layer to polymer layer on the phase velocity are discussed in detail, respectively. One practical combination of piezoelectric thin film-polymer thin film multilayer system is chosen to carry out the numerical simulation, some basic properties of SH-waves propagation in above multilayered structures are revealed.

Preliminary results of an investigation of crustal structure in Southeastern Europe

1966 ◽  
Vol 56 (6) ◽  
pp. 1241-1268
Author(s):  
Basil C. Papazachos ◽  
Peter E. Comninakis ◽  
John C. Drakopoulos
Keyword(s):  
Travel Time ◽  
Crustal Structure ◽  
Lower Layer ◽  
Shear Waves ◽  
Middle Layer ◽  
Average Thickness ◽  
Southeastern Europe ◽  
Preliminary Results ◽  
Longitudinal And Shear Waves ◽  
Layered Crust

Abstract Travel-time curves for the most prominent phases of the longitudinal and shear waves for epicentral distances between zero and 140 km and between 200 km and 1000 km have been constructed for Southeastern Europe. Both refraction and reflection methods indicate a three-layered crust. The average thickness is approximately 16 km for the top layer, 15 for the middle layer and 11 for the lower layer. The crustal thickness varies from about 47 to 32 km from place to place. The extremely low value 0.21 for Poisson's ratio was found in the top as well as in the middle layer.

The free shock wave as a seismic source

1995 ◽  
Vol 450 (1939) ◽  
pp. 351-370
Keyword(s):  
Shock Wave ◽  
Mode Conversion ◽  
Shear Waves ◽  
Incident Shock ◽  
Seismic Survey ◽  
Physical Parameters ◽  
Wave System ◽  
Wave Source ◽  
Simultaneous Generation ◽  
Free Shock

The free shock wave has particular advantages as a source for seismic survey. Its physical parameters can be precisely defined and its interaction with the rock environment predicted. In particular, the wave mode conversion which occurs leads to the simultaneous generation of both strong compression and shear waves in the rock matrix. The first part of the present study outlines the basic principles of design for a source that will generate, repetitively, free shock waves with associated pressure fields that range over two orders of magnitude (measured in bars). The second part of the paper describes the wave system which develops when shocks, generated by such a source, interact with water in, for example, a water-filled surface bore-hole. The multiplication of incident shock pressure in water, which is characteristic of the operational performance of the shock-wave source, is shown to be a consequence of the complex interactions that take place between wave systems transmitted and reflected at the gas-water interface and those that are reflected at the water-solid interface. The third part of the paper illustrates the behaviour of compressional and shear waves generated by the shock-wave source in both sedimentary rock and granite. It is shown that the mode conversion to compressional and shear waves in granite leads to near-ideal behaviour in terms of the ratio of velocities of propagation for the two types of wave in the rock.

Estimation of Local Elastic Moduli of Carbon-Containing Materials by Laser Ultrasound

2018 ◽  
Vol 769 ◽  
pp. 96-101 ◽  
Author(s):  
Ivan A. Shibaev ◽  
Dmitry V. Morozov ◽  
Oleg L. Dudchenko ◽  
Ilya A. Pavlov
Keyword(s):  
Chemical Composition ◽  
Shear Modulus ◽  
Elastic Properties ◽  
Precision Measurement ◽  
Elastic Moduli ◽  
Pyrolytic Graphite ◽  
Shear Waves ◽  
Laser Ultrasound ◽  
Longitudinal And Shear Waves ◽  
Ultrasonic Techniques

The elastic properties of two carbon-containing materials are investigated. Shungite rock is a natural nanocomposite; isotropic pyrolytic graphite is an artificial material. Precision measurement of the local velocities of longitudinal and shear waves propagating in shungite and isotropic pyrographite samples was performed by laser ultrasonic techniques. Young's modulus, the shear modulus and Poisson's ratio are calculated, and the chemical composition of the samples is given.

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