Location

Williamsburg, VA

Start Date

1-1-1986 12:00 AM

Description

The widespread application of ultrasonics to the characterization of material flaws has met with success in nearly all systems of research or commercial interest. Composite materials, however, represent a real challenge for quantitative analysis complicated by the material inhomogeneity, anisotropy, and laminated construction. Although through transmission C-scan results can find delaminations, other techniques are troubled by the complexity of the returning waveform. Distributed porosity, microcracks, and geometrical scatterers further complicate the analysis. Therefore, it is especially important to work with as sharp an analysis tool for NDE imaging when working in such complex solids. In this paper we identify a signal processing tool that can significantly enhance the sharpness of ultrasonic waveforms and provide clearer pictures of the nature of the material flaw. The technique artificially improves the resolution of the system to discrete events by pulse shaping the measured waveform based on the signal from a reference. The optimum pulse shape operator is determined from a least-squares method in the z-domain.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

5A

Chapter

Chapter 3: Sensors and Signal Processing

Section

Signal Processing

Pages

781-787

DOI

10.1007/978-1-4615-7763-8_83

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Application of Digital Pulse Shaping by Least Squares Method to Ultrasonic Signals in Composites

Williamsburg, VA

The widespread application of ultrasonics to the characterization of material flaws has met with success in nearly all systems of research or commercial interest. Composite materials, however, represent a real challenge for quantitative analysis complicated by the material inhomogeneity, anisotropy, and laminated construction. Although through transmission C-scan results can find delaminations, other techniques are troubled by the complexity of the returning waveform. Distributed porosity, microcracks, and geometrical scatterers further complicate the analysis. Therefore, it is especially important to work with as sharp an analysis tool for NDE imaging when working in such complex solids. In this paper we identify a signal processing tool that can significantly enhance the sharpness of ultrasonic waveforms and provide clearer pictures of the nature of the material flaw. The technique artificially improves the resolution of the system to discrete events by pulse shaping the measured waveform based on the signal from a reference. The optimum pulse shape operator is determined from a least-squares method in the z-domain.