Location

La Jolla, CA

Start Date

1-1-1991 12:00 AM

Description

It is well known that the interatomic anharmonicity of the propagation medium gives rise to the generation of harmonics of an initially sinusoidal acoustic waveform. It is, perhaps, less well appreciated that the anharmonicity also gives rise to the generation of a static or “dc” component of the propagating waveform. We have previously shown [1,2] that the static component is intrinsically linked to the acoustic (Boussinesq) radiation stress in the material. For nondispersive solids theory predicts that a propagating gated continuous waveform (acoustic toneburst) generates a static displacement pulse having the shape of a right-angled triangle, the slope of which is linearly proportional to the magnitude and sign of the acoustic nonlinearity parameter of the propagation medium. Such static displacement pulses have been experimentally verified in single crystal silicon [3] and germanium [4].

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

10B

Chapter

Chapter 7: Characterization of Materials

Section

Non-Linear Acoustic Properties

Pages

1805-1811

DOI

10.1007/978-1-4615-3742-7_87

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Acoustic Nonlinearity in Dispersive Solids

La Jolla, CA

It is well known that the interatomic anharmonicity of the propagation medium gives rise to the generation of harmonics of an initially sinusoidal acoustic waveform. It is, perhaps, less well appreciated that the anharmonicity also gives rise to the generation of a static or “dc” component of the propagating waveform. We have previously shown [1,2] that the static component is intrinsically linked to the acoustic (Boussinesq) radiation stress in the material. For nondispersive solids theory predicts that a propagating gated continuous waveform (acoustic toneburst) generates a static displacement pulse having the shape of a right-angled triangle, the slope of which is linearly proportional to the magnitude and sign of the acoustic nonlinearity parameter of the propagation medium. Such static displacement pulses have been experimentally verified in single crystal silicon [3] and germanium [4].