Location

La Jolla, CA

Start Date

1-1-1993 12:00 AM

Description

We are interested in the nonlinear interaction of frequency components in large amplitude acoustic waves in rocks. As compared to other, more ordered solids, rocks are elastically highly nonlinear. The ratio of third order elastic constants to second order elastic constants in a typical rock is orders of magnitude greater than in solids such as iron [1]. This high degree of nonlinearity means that frequency components mix and elastic energy is transferred from the fundamentals to sum and difference frequencies. There are at least three reasons for our interest in these effects in rocks. 1) Accurate models of explosion and earthquake sources may depend on understanding nonlinear elastic effects. 2) Efficient frequency mixing in a highly nonlinear elastic material could lead to a low frequency seismic source generated from two high frequency input waves. 3) Accurate measurement of nonlinear coefficients in rock would provide a sensitive probe of physical characteristics such as consolidation and saturation.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

12B

Chapter

Chapter 7: Nonlinearity, Deformation and Fracture

Section

Nonlinear Effects

Pages

2105-2112

DOI

10.1007/978-1-4615-2848-7_268

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Nonlinear Waves in Rocks

La Jolla, CA

We are interested in the nonlinear interaction of frequency components in large amplitude acoustic waves in rocks. As compared to other, more ordered solids, rocks are elastically highly nonlinear. The ratio of third order elastic constants to second order elastic constants in a typical rock is orders of magnitude greater than in solids such as iron [1]. This high degree of nonlinearity means that frequency components mix and elastic energy is transferred from the fundamentals to sum and difference frequencies. There are at least three reasons for our interest in these effects in rocks. 1) Accurate models of explosion and earthquake sources may depend on understanding nonlinear elastic effects. 2) Efficient frequency mixing in a highly nonlinear elastic material could lead to a low frequency seismic source generated from two high frequency input waves. 3) Accurate measurement of nonlinear coefficients in rock would provide a sensitive probe of physical characteristics such as consolidation and saturation.