Nonlinear elastic wave interactions in rock

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6972297

Johnson, P A; Shankland, T J

We are exploiting the nonlinear elastic properties of rocks to generate low-frequency, long-wavelength elastic wave beams. The appeal of rocks for nonlinear studies arises from their numerous microcracks that compress readily under applied stress. The result is large changes of elastic moduli and wave velocities with pressure in comparison with crystals, glasses, or liquids. In laboratory studies, we established that nonlinear elastic wave interactions take place in rock by verifying selection rules derived from the nonlinear elastic wave equation. The definitive work came from continuous-wave (CW) mode observations of the general case where two driving signals, intersecting at a prescribed angle, produced a difference frequency ({Delta}f) beam at a different angle. Further, with pulsed drivers we measured {Delta}f beam travel times that agreed with predicted times. Most recently, we obtained propagation path lengths using a CW-mode interference method. 7 refs., 4 figs.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6972297
• Report Number(s): LA-UR-90-1348; CONF-900893-1; ON: DE90010601
• Resource Relation: Conference: 12. international symposium on nonlinear acoustics, Austin, TX (USA), 26-31 Aug 1990
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
58 GEOSCIENCES
NONLINEAR PROBLEMS
BENCH-SCALE EXPERIMENTS
ROCKS
ELASTICITY
ATTENUATION
ENERGY CONSERVATION
GEOPHYSICS
MEASURING METHODS
SANDSTONES
SEISMIC P WAVES
SEISMIC S WAVES
SEISMIC SURFACE WAVES
WAVE EQUATIONS
WAVE PROPAGATION
DIFFERENTIAL EQUATIONS
EQUATIONS
MECHANICAL PROPERTIES
PARTIAL DIFFERENTIAL EQUATIONS
SEDIMENTARY ROCKS
SEISMIC WAVES
TENSILE PROPERTIES
360603* - Materials- Properties
580000 - Geosciences