Observations of nonlinear elastic wave behavior in sandstone

Journal Article · Wed Dec 01 00:00:00 EST 1993 · Journal of the Acoustical Society of America; (United States)

DOI:https://doi.org/10.1121/1.407191· OSTI ID:5020385

Meegan, Jr, G D; Johnson, P A; Guyer, R A; McCall, K R ^[1]

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1. Los Alamos National Lab., NM (United States)

An experimental investigation of nonlinear elastic wave behavior was conducted using a 2-m-long cylindrical rod of Berea sandstone in order to study the strong elastic nonlinearity that is characteristic of microcracked materials. Measurements of the displacement field at distance [chi] from the source show rich harmonic content with harmonic amplitudes depending on [chi], source frequency, and source amplitude. The amplitude of the 2[omega] harmonic is found to grow linearly with [chi] and as the square of both the source frequency [omega] and the source amplitude U. This behavior is in agreement with the predictions of nonlinear elasticity theory for a system with cubic anharmonicity. From the measured amplitude of the 2[omega] harmonic the parameter [vert bar][beta][vert bar], a measure of the strength of the cubic anharmonicity, is found to be of order 10[sup 4] (7.0 x 10[sup 3] [+-] 25%). This value is orders of magnitudes greater than that found in ordinary uncracked materials. These results suggest that wave distortion effects due to nonlinear elasticity can be large in seismic wave propagation and significantly influence the relationship of seismic signal to seismic source. 22 refs., 7 figs.

• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5020385
• Journal Information: Journal of the Acoustical Society of America; (United States), Vol. 94:6; ISSN 0001-4966
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
36 MATERIALS SCIENCE
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
SANDSTONES
PHYSICAL PROPERTIES
SOUND WAVES
MATHEMATICAL MODELS
ELASTICITY
FRACTURES
SEISMIC WAVES
TRANSDUCERS
FAILURES
MECHANICAL PROPERTIES
ROCKS
SEDIMENTARY ROCKS
TENSILE PROPERTIES
661300* - Other Aspects of Physical Science- (1992-)
360606 - Other Materials- Physical Properties- (1992-)
990200 - Mathematics & Computers