Location

Williamsburg, VA

Start Date

1-1-1986 12:00 AM

Description

To exploit theoretical advances in elastic wave inverse scattering, an automated multiviewing ultrasonic transducer system and associated signal processing algorithms have recently been developed for the characterization of flaws in solids. The reliability of the model-based reconstruction method depends on the extent of the flaw surface illuminated by the interrogating ultrasonic field within a finite viewing aperture and is therefore sensitive to the orientation of the flaw. In this paper, the reconstruction of arbitrarily oriented flaws using the multiviewing system is addressed. The effects of aperture size on the reconstruction reliability is investigated by computer simulation and experimental results are presented for the reconstruction of tilted oblate and prolate spheroid-like flaws. The multiviewing capability of the system is used to predetermine a spatial data acquisition pattern which improves the reconstruction reliability by increasing the signal-to-noise ratio and the surface area of the flaw illuminated by the multiviewing transducer.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

5A

Chapter

Chapter 2: Inversion, Imaging and Reconstruction

Section

Imaging and Reconstruction

Pages

529-539

DOI

10.1007/978-1-4615-7763-8_55

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

The Effects of Flaw Orientation and Finite Aperture on Model Based Reconstruction Using Multiprobe Transducers

Williamsburg, VA

To exploit theoretical advances in elastic wave inverse scattering, an automated multiviewing ultrasonic transducer system and associated signal processing algorithms have recently been developed for the characterization of flaws in solids. The reliability of the model-based reconstruction method depends on the extent of the flaw surface illuminated by the interrogating ultrasonic field within a finite viewing aperture and is therefore sensitive to the orientation of the flaw. In this paper, the reconstruction of arbitrarily oriented flaws using the multiviewing system is addressed. The effects of aperture size on the reconstruction reliability is investigated by computer simulation and experimental results are presented for the reconstruction of tilted oblate and prolate spheroid-like flaws. The multiviewing capability of the system is used to predetermine a spatial data acquisition pattern which improves the reconstruction reliability by increasing the signal-to-noise ratio and the surface area of the flaw illuminated by the multiviewing transducer.