Practical surface acoustic wave devices

Holland, M. G.; Claiborne, L.T.

doi:10.1109/proc.1974.9483

Cited by 54 publications

(6 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Subscripts 'a' and 'b' in Eqs. (21) and (23) refer to the sensors design previously described, and denoted as 'sensor ðaÞ' and 'sensor ðbÞ.' One note, is the fact that while the practical implementation of sensor ðaÞ is not feasible, the evaluation of its performance through the considered approach and Eq.…”

Section: B Sampling Of Measurement Grid and Evaluation Of The Spiralmentioning

confidence: 99%

“…This basic idea has been widely exploited for the design of interdigitated transducers (IDTs) used as part of surface acoustic wave (SAW) devices. 21 While linear IDT configurations are commonly employed for selective generation and detection of surface waves, other alternative configuration, such as the slanted IDT described for example in Ref. 22, and the annular IDTs proposed in Ref.…”

mentioning

confidence: 99%

See 1 more Smart Citation

A frequency selective acoustic transducer for directional Lamb wave Sensing

Senesi

Ruzzene

2011

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

A frequency selective acoustic transducer (FSAT) is proposed for directional sensing of guided waves. The considered FSAT design is characterized by a spiral configuration in wavenumber domain, which leads to a spatial arrangement of the sensing material producing output signals whose dominant frequency component is uniquely associated with the direction of incoming waves. The resulting spiral FSAT can be employed both for directional sensing and generation of guided waves, without relying on phasing and control of a large number of channels. The analytical expression of the shape of the spiral FSAT is obtained through the theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. Testing is performed by forming a discrete array through the points of the measurement grid of a scanning laser Doppler vibrometer. The discrete array approximates the continuous spiral FSAT geometry, and provides the flexibility to test several configurations. The experimental results demonstrate the strong frequency dependent directionality of the spiral FSAT and suggest its application for frequency selective acoustic sensors, to be employed for the localization of broadband acoustic events, or for the directional generation of Lamb waves for active interrogation of structural health.

show abstract

Section: B Sampling Of Measurement Grid and Evaluation Of The Spiralmentioning

confidence: 99%

mentioning

confidence: 99%

A frequency selective acoustic transducer for directional Lamb wave Sensing

Senesi

Ruzzene

2011

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…For curved surfaces, however, the generation of surface waves with these methods is less practical. An interdigital transduction (IDT) method commonly used in telecommunication filtering devices was adapted for the current application [3][4][5] . Based on the same transduction principles, a narrow band IDT sensor with a resonance frequency in the range of 3 MHz was designed and fabricated.…”

Section: Idt Sensorsmentioning

confidence: 99%

Detection of surface breaking fatigue crack on a complex aircraft structure with Rayleigh surface waves

Blackshire

Kuhr

2009

SPIE Proceedings

View full text Add to dashboard Cite

As part of an on-going, multi-year effort focused on developing a practical structural health monitoring (SHM) sensor for critical structural components in aircraft, a miniature Rayleigh surface wave sensor has been developed and tested. The sensor was specifically designed to detect localized, deterministic cracking in targeted locations in critical locations where fatigue cracking is prevalent. A representative aircraft component was used in the present investigation. Miniature interdigital transducers (IDTs) operating in the low megahertz frequency range were designed, fabricated, and tested on compact tension (CT) fatigue specimens in the laboratory before they were strategically placed on the structure, where surface wave signals were monitored in both pitch-catch and pulse-echo detection modes simultaneously. Under a high-cycle fatigue loading to the structure, the IDT sensors performed well with three of the sensors successfully detecting the existence of a critical fatigue crack. Visual and eddy current inspection methods subsequently verified the presence of the crack and its location. In this paper, the entire effort from the design and characterization of the IDT sensors to the final fatigue test on an actual aircraft part is discussed.

show abstract

“…The observed changes wrn qualitatively and jdantieatlvely veil characterized In t*rnw of the tima changing tim^ei'ature of the vibratin;; quartz and its effect on frequency. Tliercnl transient inJuccd frequency chancer, in AT cut resonator* were observed as early fo 1939 5 And described empirically as a function of the tine changing *1hts work was supported by the U.S. Oopartwent of Energy, ambient.'' Holland's' work on thermal gradi ent effects in thickness 3hear resonators led to the TTC cut, which is approximately rquivalent to EcrNiase's stress compou-.Jted, SC, cut.° Holland's calculations d(;al with thermal gradi ents in the chicVncns direction while, in the present work, the thermal modelling of the reso nator structure ia concerned with radial heat flow and relates the inst.nnrar.oou9 frequency change linearly to the rr.te of change of tem perature -t the oscillating boundary.…”

Section: Introductionmentioning

confidence: 99%

Radiation-Induced Frequency Transients in AT, BT and SC Cut Quartz Resonators

Koehler¹

1979

33rd Annual Symposium on Frequency Control

View full text Add to dashboard Cite

Earlier studies of transient frequency changes in high-purity swept AT quartz resona tor* led to the conclusion that impurity induced effects were, if present, small! while the observed changes were qualitatively and quanti tatively well characterized in tarns of the time changing temperature of the vibrating quartz and its effect on frequency.In the present work, we have prepared 5 MHz, AT cut fifth overtone, and BT a.id SC cut third overtone resonators Iron a single stone of Sawyer fwept Premum-Q quarts. The resonators were operated in precision ovenised oscillators at or near their turnover temperatures. Pulsed irra diation, at dose levels of the order of rads (Si) per pulse, wa4 accomplished at the Sandia Labs' Hermes II facility operating in the Brcms-itrahlung node.The cxperiaentfll data, display negative fre quency transients for the AT cut resonators, positive frequency transients for the 3T cut resonators, and vary small transient effects for the SC cut resonators. Frota those experimental results wc conclude that I) no measurable impurity-inducod frequency changes (elaitic ondulus changes) are being observed in this high purity swept-quarts and thac 2) the frequency tran sients nvc accurately saddled in torms of tran sient temperature offects ateaming from the thermal characteristics of the resonator •tructuro.

show abstract

Practical surface acoustic wave devices

Cited by 54 publications

References 68 publications

A frequency selective acoustic transducer for directional Lamb wave Sensing

A frequency selective acoustic transducer for directional Lamb wave Sensing

Detection of surface breaking fatigue crack on a complex aircraft structure with Rayleigh surface waves

Radiation-Induced Frequency Transients in AT, BT and SC Cut Quartz Resonators

Contact Info

Product

Resources

About