Model-based optimization of ultrasonic transducers

Heikkola, Erkki; Laitinen, M.

doi:10.1016/j.ultsonch.2004.05.009

Cited by 26 publications

(9 citation statements)

References 4 publications

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“…If the fre- quency is increased, the production of cavities in the liquid is decreased and therefore the sonochemistry effect is less effective. [28][29][30][31][32] To demonstrate the scope of the ultrasound-assisted method, several 2-chlorobenzoic acids and different primary or secondary amines were used. The results are shown in Table 1.…”

Section: Resultsmentioning

confidence: 99%

Ultrasound‐Promoted Reaction of 2‐Chlorobenzoic Acids and Aliphatic Amines

Docampo¹,

Pellón²,

Estévez‐Braun

et al. 2007

Eur J Org Chem

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An improvement to the use of DMF as a solvent for the condensation of 2‐chlorobenzoic acids with aliphatic primary or secondary amines was described. A number of alkylaminobenzoic acids and dialkylaminobenzoic acids were synthesized in acceptable‐to‐good yield. The advantages of this procedure include readily available substrates, the use of an inexpensive copper powder without taking any precautions to exclude moisture under mild conditions and experimental ease. Furthermore, this condensation could also be achieved under nonclassical conditions by using ultrasonic irradiation at room temperature. We demonstrated that ultrasound‐promoted condensation of 2‐chlorobenzoic acid with aliphatic amines with the use of DMF as the solvent, especially in the case of secondary amines, affords products in high yields and reduces the reaction time to minutes. The results proved to be highly reproducible because the relevant sonochemical parameters were rigorously controlled.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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Section: Resultsmentioning

confidence: 99%

Ultrasound‐Promoted Reaction of 2‐Chlorobenzoic Acids and Aliphatic Amines

Docampo¹,

Pellón²,

Estévez‐Braun

et al. 2007

Eur J Org Chem

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“…The objective functions have to be adequately defined depending on the characteristics of the transducer that are expected. One can define objective functions in order to optimize the bandwidth, the transmitted energy, the maximum amplitude of the transmitted acoustic wave, the input energy, the focus of the wave and so on [59][60][61][62].…”

Section: Definition Of Objective Functionsmentioning

confidence: 99%

Design optimization of embedded ultrasonic transducers for concrete structures assessment

Dumoulin

2017

Ultrasonics

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In the last decades, the field of structural health monitoring and damage detection has been intensively explored. Active vibration techniques allow to excite structures at high frequency vibrations which are sensitive to small damage. Piezoelectric PZT transducers are perfect candidates for such testing due to their small size, low cost and large bandwidth. Current ultrasonic systems are based on external piezoelectric transducers which need to be placed on two faces of the concrete specimen. The limited accessibility of in-service structures makes such an arrangement often impractical. An alternative is to embed permanently low-cost transducers inside the structure. Such types of transducers have been applied successfully for the in-situ estimation of the P-wave velocity in fresh concrete, and for crack monitoring. Up to now, the design of such transducers was essentially based on trial and error, or in a few cases, on the limitation of the acoustic impedance mismatch between the PZT and concrete. In the present study, we explore the working principles of embedded piezoelectric transducers which are found to be significantly different from external transducers. One of the major challenges concerning embedded transducers is to produce very low cost transducers. We show that a practical way to achieve this imperative is to consider the radial mode of actuation of bulk PZT elements. This is done by developing a simple finite element model of a piezoelectric transducer embedded in an infinite medium. The model is coupled with a multi-objective genetic algorithm which is used to design specific ultrasonic embedded transducers both for hard and fresh concrete monitoring. The results show the efficiency of the approach and a few designs are proposed which are optimal for hard concrete, fresh concrete, or both, in a given frequency band of interest.

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“…In general, the most widely used is the sandwich piezoelectric ceramic transducer, also known as the Langevin piezoelectric ceramic transducer. Sandwich piezoelectric transducers have the advantages of high efficiency, good heat dissipation performance, and easy changes of operating frequency and performance parameters [9,10,11,12,13]. Sandwich piezoelectric transducers are valued by researchers.…”

Section: Introductionmentioning

confidence: 99%

Analysis of a Cascaded Piezoelectric Ultrasonic Transducer with Three Sets of Piezoelectric Ceramic Stacks

Meng

Lin

2019

Sensors

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To increase the ultrasonic intensity and power of a piezoelectric transducer, a cascaded piezoelectric ultrasonic transducer with the three sets of piezoelectric ceramic stacks is analyzed. The cascaded piezoelectric ultrasonic transducer consists of four metal cylinders and three sets of piezoelectric ceramic stacks in the longitudinal direction. In analysis, the electromechanical equivalent circuit of the cascaded piezoelectric ultrasonic transducer is obtained, as well as the resonance/anti-resonance frequencies equations. By means of an analytical method, when the position of piezoelectric ceramic stacks PZT-2/PZT-3 changes, the resonance/anti-resonance frequencies and the effective electromechanical coupling coefficient of the cascaded piezoelectric ultrasonic transducer have certain characteristics. Several prototypes of the cascaded piezoelectric ultrasonic transducer are manufactured. The experimentally measured resonance frequencies are in good agreement with the theoretical and simulated results. The cascaded piezoelectric ultrasonic transducer with three sets of piezoelectric ceramic stacks presented in this paper is expected to be used in the field of high power ultrasound.

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Model-based optimization of ultrasonic transducers

Cited by 26 publications

References 4 publications

Ultrasound‐Promoted Reaction of 2‐Chlorobenzoic Acids and Aliphatic Amines

Ultrasound‐Promoted Reaction of 2‐Chlorobenzoic Acids and Aliphatic Amines

Design optimization of embedded ultrasonic transducers for concrete structures assessment

Analysis of a Cascaded Piezoelectric Ultrasonic Transducer with Three Sets of Piezoelectric Ceramic Stacks

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