Location

Seattle, WA

Start Date

1-1-1996 12:00 AM

Description

The motivation for this research is our ongoing effort in the development of ultrasonic, waveform-based, materials characterization techniques. Having developed a three-dimensional representation of the elastodynamic Green’s Function for anisotropic plates [1], we now seek to verify the applicability of this representation. With elastic properties measurement as our end goal, we also seek a transducer for measurement of theoretically predicted waveforms. Our waveforms typically exhibit a large range in both amplitude (40 to 60 dB) and frequency (20 kHz to 2 MHz). The transducer used must exhibit both high-sensitivity and high-fidelity so that multiple reflections can be detected and identified. In a companion paper we describe a transducer developed at NIST for acoustic emission (AE) studies [2]. In that paper we determine that this transducer has a displacement sensitivity of approximately 5×10−17mHz√ in the 250 kHz to 1 MHz frequency region on aluminum. This transducer appears to be a good candidate for waveform-based materials characterization. In this paper we evaluate this transducer’s fidelity by comparing it with both theoretical results and measurements from a path-stabilized, Michelson interferometer. We conclude that the current transducer design does not have sufficient fidelity for waveform-based materials characterization and discuss the reasons for its shortcomings and potential solutions to these problems.

Volume

15A

Chapter

Chapter 4: NDE Sensors

Section

Ultrasonic Transducers (Liquid Coupled)

Pages

971-978

DOI

10.1007/978-1-4613-0383-1_127

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Fidelity of Michelson Interferometric and Conical Piezoelectric Ultrasonic Transducers

Seattle, WA

The motivation for this research is our ongoing effort in the development of ultrasonic, waveform-based, materials characterization techniques. Having developed a three-dimensional representation of the elastodynamic Green’s Function for anisotropic plates [1], we now seek to verify the applicability of this representation. With elastic properties measurement as our end goal, we also seek a transducer for measurement of theoretically predicted waveforms. Our waveforms typically exhibit a large range in both amplitude (40 to 60 dB) and frequency (20 kHz to 2 MHz). The transducer used must exhibit both high-sensitivity and high-fidelity so that multiple reflections can be detected and identified. In a companion paper we describe a transducer developed at NIST for acoustic emission (AE) studies [2]. In that paper we determine that this transducer has a displacement sensitivity of approximately 5×10−17mHz√ in the 250 kHz to 1 MHz frequency region on aluminum. This transducer appears to be a good candidate for waveform-based materials characterization. In this paper we evaluate this transducer’s fidelity by comparing it with both theoretical results and measurements from a path-stabilized, Michelson interferometer. We conclude that the current transducer design does not have sufficient fidelity for waveform-based materials characterization and discuss the reasons for its shortcomings and potential solutions to these problems.