PIEZOELECTRIC TRANSDUCERS FOR

ASSESSING AND MONITORING CIVIL INFRASTRUCTURES

ASHIF A.RS7CACLASS NO. : 13M.A.COLLEGE OF ENGINEERINGKOTHAMANGALAM

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CONTENTS

• INTRODUCTION• PIEZOELECTRIC TRANSDUCERS• BONDING• S.H.M TECHNIQUES• APPLICATIONS• CONCLUSION• REFERENCES

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INTRODUCTION

• Direct piezoelectric effect• Converse piezoelectric effect

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PIEZOELECTRIC TRANSDUCERS

• Natural Materials – Quartz(SiO2) and Rochelle salt (NaKC4H4O6–4H2O)

• Lead Zirconate Titanate (PZT) (PbZrTiO3)

• Macro-fiber composite (MFC)• Active fiber composite (AFC)• Polyvinylidene fluoride (PVDF) • Smart aggregate-Piezoceramic device

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Bonding

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SHM TECHNIQUES

• Guided wave techniques• Impedance techniques• Acoustic emission techniques• Piezoelectric transducer self-diagnosis

techniques

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Guided wave techniques

• Pulse–echo mode & Pitch–catch mode• Guided waves, defined as elastic waves

confined by the boundaries of a structure• Scattering, reflection, and mode

conversion• Sensitive to environmental and operational

variation

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Guided wave techniques

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Impedance techniques

• Electromechanical impedance signal• Applying an electric voltage to PZT and

measuring the corresponding output current

• Good for local damage detection in complex structures

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Impedance techniques

Acoustic emission techniques

• ‘Transient elastic stress waves produced by a release of energy from a localized source’

• Elastic waves propagating through the target surface

• Converted to voltage signals by an AE sensor

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Acoustic emission techniques

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Piezoelectric transducer self-diagnosis techniques

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TRP-based PZT debonding detection procedure

Applications

• Bridge Structures• Pipeline structures• Nuclear power plants

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CONCLUSION

• The nonintrusive nature, low cost, light weight, and good repeatability of the piezoelectric transducers make them attractive for SHM applications

• Future researches on miniaturization, increased flexibility, and applications under high-temperature, high-strain, and high-radiation environments.

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REFERENCES

• Journal “Sensor Technologies for Civil Infrastructures”, 2014, Page 86 - 120 Piezoelectric transducers for assessing and monitoring civil infrastructures by Y.-K. An, M.K. Kim and H. Sohn

• Journal NDT&E International, Article “Combined embedded and surface bonded piezoelectric transducer for monitoring concrete structures”

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THANK YOU