Study on an Ultrasonic Method for Detecting Micro-defects by Using the Leaky Rayleigh Wave

2015 ◽  
Vol 65 (2) ◽  
pp. 199-204 ◽  
Author(s):  
Yun-Taek YEOM ◽  
Hak-Joon KIM ◽  
Sung-Jin SONG ◽  
Sung-Sik KANG ◽  
Sung-Duk KWON*
Keyword(s):  
Rayleigh Wave ◽  
Ultrasonic Method ◽  
Leaky Rayleigh Wave

scholarly journals MULTI-WAVE ULTRASONIC CONTROL OF CONCRETE

2017 ◽  
Vol 16 (4) ◽  
pp. 289-297
Author(s):  
D. Yu. Snezgkov ◽  
S. N. Leonovich
Keyword(s):  
Rayleigh Wave ◽  
Pulse Propagation ◽  
Ultrasonic Method ◽  
Physical And Mechanical Properties ◽  
Pulse Velocity ◽  
Energy Localization ◽  
Near Surface ◽  
In Situ Conditions ◽  
Selection Of

The existing non-destructive testing system of structure concrete is actually orientated on the usage of longitudinal acoustical waves. This is due to simplicity of technical realization for measuring velocity (time) of acoustical pulse propagation in bulk concrete. But a reverse side of simple measuring procedure is a loss of additional information on concrete which is contained in the accepted acoustical signal. Therefore usage of an ultrasonic concrete testing method is limited by assessment of its strength. Joint usage of several wave types, so-called multi-wave testing, allows to refine metrology parameters of the ultrasonic method and to gain more information while determining physical and mechanical properties of concrete in laboratory and in situ conditions. The paper considers testing of elongated concrete elements and structures by an ultrasonic pulsing method on the basis of longitudinal subsurface and Rayleigh waves. It has been proposed to use methodology for time selection of wave components according to amplitude parameter and it has been applied for standard acoustical transformers with considerable reverberation time and not possessing spatial selectivity Basic principle of the proposed methodology is visual (according to oscillogram of the received signal) determination of characteristic time moments which are used for calculation of differential value of a propagation velocity in the Rayleigh wave impulse. The paper presents results pertaining to simulation of acoustical pulse propagation on the basis of 0.15 m and data of concrete ultrasonic in situ testing on measuring bases from 0.25 to 1.75 m. Advantage of large baseline for sonic test is a possibility for execution of a hundred percent inspection for surface of large-sized elements and structures, and so there is no need to make a selective inspection in some control areas as it is stipulated by provided by existing regulations. Responsivity of the Rayleigh wave parameters to near surface concrete defects permits quickly and efficiently to detect crack areas in a reinforced structure. Energy localization of a surface wave in a layer having width λ/2–λ provides a possibility to ignore reinforcement availability under appropriate selection of oscillation frequency. In addition to this, large measuring baseline makes it possible to lower effect of concrete structural inhomogeneity on statistical stability for pulse velocity assessment that ultimately reveals a possibility to register an appearance of concrete acoustical elasticity effect under in situ conditions.

Attenuation of Leaky Rayleigh Wave: Experiment and Numerical

1999 ◽  
pp. 175-181
Author(s):  
Koichiro Kawashima ◽  
Toshihiro Ito ◽  
Ikuya Fujii ◽  
Naoki Takenouchi ◽  
Ryuuji Omote
Keyword(s):  
Rayleigh Wave ◽  
Wave Experiment ◽  
Leaky Rayleigh Wave

scholarly journals Leaky Rayleigh wave reflection from anisotropic wedges

1986 ◽  
Vol 80 (S1) ◽  
pp. S120-S121 ◽  
Author(s):  
Michel de Billy ◽  
Peter B. Nagy ◽  
Gerard Quentin ◽  
Laszlo Adler
Keyword(s):  
Rayleigh Wave ◽  
Wave Reflection ◽  
Leaky Rayleigh Wave
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