Location

La Jolla, CA

Start Date

1-1-1993 12:00 PM

Description

Acoustic emission (AE) is the phenomenon in which elastic or stress waves are emitted from a rapid, localized change of strain energy in a material[1]. AE sensors generate electric signals when they are stimulated by an acoustic wave. They are used for safety control of a structure and evaluation of elastic source event and material. Most of them are piezoelectric sensors employing piezoelectric elements which transform elastic signals into electric signals. AE sensors need to be chracterized before using them and the characteristics of them have been usually examined using the mechanical calibration system composed of a known elastic source and a large transmission medium. Well-defined elastic sources include small steel ball impact[2], electric spark[3], and high power laser[4] that generate delta function forces and glass capillary break[5], pencil lead break[6,7] and capacitive Coulomb force[8] that generate step function forces. Glass capillary break is known to generate step force of relatively high power and short rise time. As theoretical approach, a Green’s function for an ideal elastic medium with simple geometry was studied through the utilization of the generalized ray method[9] and numerically calculated through a Fourier inversion method[10].

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

12A

Chapter

Chapter 4: Sensors and New Techniques

Section

Ultrasonic and Acoustic Sensors

Pages

981-988

DOI

10.1007/978-1-4615-2848-7_125

Language

en

File Format

application/pdf

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Jan 1st, 12:00 PM

Predetermination of characteristics of acoustic emission sensors by electrical response analysis

La Jolla, CA

Acoustic emission (AE) is the phenomenon in which elastic or stress waves are emitted from a rapid, localized change of strain energy in a material[1]. AE sensors generate electric signals when they are stimulated by an acoustic wave. They are used for safety control of a structure and evaluation of elastic source event and material. Most of them are piezoelectric sensors employing piezoelectric elements which transform elastic signals into electric signals. AE sensors need to be chracterized before using them and the characteristics of them have been usually examined using the mechanical calibration system composed of a known elastic source and a large transmission medium. Well-defined elastic sources include small steel ball impact[2], electric spark[3], and high power laser[4] that generate delta function forces and glass capillary break[5], pencil lead break[6,7] and capacitive Coulomb force[8] that generate step function forces. Glass capillary break is known to generate step force of relatively high power and short rise time. As theoretical approach, a Green’s function for an ideal elastic medium with simple geometry was studied through the utilization of the generalized ray method[9] and numerically calculated through a Fourier inversion method[10].