日本語フィールド
著者：Kenbu Teramoto, Akito Uekihara題名：Time reversal imaging for gradient sensor networks over the Lamb-wave field発表情報：Proceedings of SICE2009 CD-ROMキーワード：Spatio-temporal gradient analysis, Time reversal mirror, Non-destructive evaluation概要：抄録：Combining the time reversal mirror (TRM) with the spatio-temporal
gradient analysis has an ability to localize a scatterer
such as a defect in a thin plate.
Time-reversed signals propagate backwards through
the time-independent medium and go through all the multiple
scattering, reflections, and refraction.
As a result, the TRM provides the means for
converging wave front narrowly in time and space.
If the focal point coincides with a point-like,
the converging cylindrical wave provides
the orthogonal pair of out-of-plane-surface shear strains
to be linearly independent.
The proposed imaging method utilizes the determinant of the
covariance matrix defined over the shear strain field.
The determinant denotes the Distributions of Correlated Intensity Modulation (DCIM) of two or more converging wave fronts. The DCIM increases significantly in the near-field of the focal point. In this paper, we explore analytically and numerically the defect imaging by time reversal method based on the spatio-temporal gradient analysis.英語フィールド
Author：Kenbu Teramoto, Akito UekiharaTitle：Time reversal imaging for gradient sensor networks over the Lamb-wave fieldAnnouncement information:Proceedings of SICE2009 CD-ROMKeyword：Spatio-temporal gradient analysis, Time reversal mirror, Non-destructive evaluationAn abstract：Combining the time reversal mirror (TRM) with the spatio-temporal
gradient analysis has an ability to localize a scatterer
such as a defect in a thin plate.
Time-reversed signals propagate backwards through
the time-independent medium and go through all the multiple
scattering, reflections, and refraction.
As a result, the TRM provides the means for
converging wave front narrowly in time and space.
If the focal point coincides with a point-like,
the converging cylindrical wave provides
the orthogonal pair of out-of-plane-surface shear strains
to be linearly independent.
The proposed imaging method utilizes the determinant of the
covariance matrix defined over the shear strain field.
The determinant denotes the Distributions of Correlated Intensity Modulation (DCIM) of two or more converging wave fronts. The DCIM increases significantly in the near-field of the focal point. In this paper, we explore analytically and numerically the defect imaging by time reversal method based on the spatio-temporal gradient analysis.