scholarly journals Influence of the Spatial Dimensions of Ultrasonic Transducers on the Frequency Spectrum of Guided Waves

Sensors ◽  
2017 ◽  
Vol 17 (8) ◽  
pp. 1825 ◽  
Author(s):  
◽  
Keyword(s):  
Frequency Spectrum ◽  
Guided Waves ◽  
Ultrasonic Transducers ◽  
Spatial Dimensions

Inspection of Concrete-Metal Rod Interface Using Guided Waves

2000 ◽  
Author(s):  
Won-Bae Na ◽  
Tribikram Kundu ◽  
Mohammad R. Ehsani
Keyword(s):  
Lamb Wave ◽  
Guided Waves ◽  
Lamb Waves ◽  
Guided Wave ◽  
Ultrasonic Transducers ◽  
Interface Debonding ◽  
Long Distance ◽  
Steel Rebar ◽  
Steel Bars ◽  
Steel Rebars

Abstract The feasibility of detecting interface degradation and separation of steel rebars in concrete beams using Lamb waves is investigated in this paper. It is shown that Lamb waves can easily detect these defects. A special coupler between the steel rebar and ultrasonic transducers has been used to launch non-axisymmetric guided waves in the steel rebar. This investigation shows that the Lamb wave inspection technique is an efficient and effective tool for health monitoring of reinforced concrete structures because the Lamb wave can propagate a long distance along the reinforcing steel bars embedded in concrete as the guided wave and is sensitive to the interface debonding between the steel rebar and concrete.

Development of Circuits for Excitation and Reception in Ultrasonic Transducers for Generation of Guided Waves in Hollow Cylinders for Fouling Detection

2008 ◽  
Vol 57 (6) ◽  
pp. 1149-1153 ◽  
Author(s):  
Jaidilson JÓ da Silva ◽  
Miguel GonÇalves Wanzeller ◽  
Paulo de Almeida Farias ◽  
JosÉ SÉrgio da Rocha Neto
Keyword(s):  
Guided Waves ◽  
Ultrasonic Transducers ◽  
Hollow Cylinders

scholarly journals Rayleigh Wave Calibration of Acoustic Emission Sensors and Ultrasonic Transducers

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3129 ◽  
Author(s):  
Kanji Ono
Keyword(s):  
Acoustic Emission ◽  
Rayleigh Waves ◽  
Guided Waves ◽  
Laser Interferometer ◽  
Ultrasonic Transducers ◽  
Glass Capillary ◽  
Small Aperture ◽  
Transfer Block ◽  
Acoustic Emission Sensors ◽  
Incident Waves

Acoustic emission (AE) sensors and ultrasonic transducers were characterized for the detection of Rayleigh waves (RW). Small aperture reference sensors were characterized first using the fracture of glass capillary tubes in combination with a theoretical displacement calculation, which utilized finite element method (FEM) and was verified by laser interferometer. For the calibration of 18 commercial sensors and two piezoceramic disks, a 90° angle beam transducer was used to generate RW pulses on an aluminum transfer block. By a substitution method, RW receiving sensitivity of a sensor under test was determined over the range of frequency from 22 kHz to 2 MHz. Results were compared to the sensitivities to normally incident waves (NW) and to other guided waves (GW). It was found that (1) NW sensitivities are always higher than RW sensitivities, (2) differences between NW and RW receiving sensitivities are dependent on frequency and sensor size, (3) most sensors show comparable RW and GW receiving sensitivities, especially those of commonly used AE sensors, and (4) the receiving sensitivities of small aperture (1 mm diameter) sensors behave differently from larger sensors.

Analysis of Cement Hydration Monitoring Using Embedded and External Ultrasonic Transducers

2011 ◽  
Vol 306-307 ◽  
pp. 514-518
Author(s):  
Qian Qian Zhong ◽  
Lei Qin ◽  
Shi Feng Huang ◽  
Xin Cheng
Keyword(s):  
Frequency Spectrum ◽  
Cement Paste ◽  
Health Monitoring ◽  
Cement Hydration ◽  
Piezoelectric Transducers ◽  
Ultrasonic Transducers ◽  
Hydration Process ◽  
Ultrasonic Monitoring ◽  
Early Hydration ◽  
Coupling Problem

This study adopted home-made embedded piezoelectric transducers and external commercial ultrasonic transducers respectively to monitor early hydration processes of cement. This paper discussed the development of ultrasonic amplitude and frequency spectrum during the hydration process. It is proved that the method is effective for monitoring the hydration of cement paste. The embedded transducer could resolve the coupling problem of ultrasonic monitoring and it could be used for the whole life health monitoring of concrete.

Analysis of Ultrasonic Guided Waves Propagation in Complex Composite Structures

2014 ◽  
Vol 14 (08) ◽  
pp. 1440024 ◽  
Author(s):  
Renaldas Raišutis ◽  
Egidijus Žukauskas ◽  
Vykintas Samaitis ◽  
Audrius Jankauskas ◽  
Lina Draudvilienė ◽  
...  
Keyword(s):  
Composite Structures ◽  
Guided Waves ◽  
Experimental Testing ◽  
Low Energy ◽  
Ultrasonic Transducers ◽  
Ultrasonic Guided Waves ◽  
Cylindrical Shape ◽  
Self Healing ◽  
Storage Tanks ◽  
Liquid Storage

The object of the investigation is a honeycomb structure of composite sandwich made of glass-epoxy laminating layers and a honeycomb core of epoxy impregnated paper. Large composite tanks possessing cylindrical shape are produced using the winding process. Therefore, the final products have uneven thickness and fibre orientation lamina layers, and also an unevenly impregnated honeycomb layer. The aim of this research is to develop an economically attractive embedded ultrasonic measurement technique for on-field diagnostics of complex composite structures used for production of large liquid storage tanks. Development of the relatively cheap and easy to operate embedded diagnostic/monitoring technique is important aiming to assure safety of liquid storage tanks (monitoring structural integrity against overpressure, etc.) and detection of accidental defects that may appear during transportation, installation and exploitation of those structures. Typical defects that are aimed to be detected are relatively large delaminations/disbonds (area having diameter of 150–200 mm) of skin layers caused by low energy impacts that cannot be detected visually and show severe influence on the structural strength and safety of liquid tanks. This work presents results of numerical modeling and experimental research in low frequency (50 kHz) ultrasonic guided waves (UGW) propagation in large honeycomb composite structures. Finite element (FE) simulation of UGW propagation has been made aiming to reduce quantity of ultrasonic transducers and optimize their placement on composite structure. The possibilities to place ultrasonic transducers and receivers on both sides (internal or external) of composite structures and to use such a proposed technique for detection of delamination/debonding areas caused by low energy impacts or alternating semi static loads (e.g. filling and draining of liquid from storage tank) and monitoring of partial self-healing of relatively rigid composite structures were proved by experimental testing.

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