Location

Brunswick, ME

Start Date

1-1-1997 12:00 AM

Description

Piezoelectric transducers are the basic tool for ultrasonic NDE applications and are commercially available in a variety of sizes. shapes and frequencies. However. the information that is typically provided for these transducers by vendors is of limited value. This is especially true when it comes to testing anisotropic materials. The wave propagation effects such as beam skewing. splitting and distortion. when taken into experimental consideration for anisotropic media. requires knowledge of the spatial radiation field distribution of the transmitting transducer. In this paper, a previously developed methodology to map the radiation fields for piezoelectric transducers [ 1 ] is applied to imaging (mapping) three dimensional radiation fields generated by transducers of various shapes and frequencies placed in contact with anisotropic propagation media. The processed data files are calculated for transversely isotropic materials via the Generalized-Point-Source-Synthesis (GPSS) method [2,3]. The material is regarded to be homogeneous since the ultrasonic wavelength is larger than the grain dimensions. A computationally efficient version of GPSS is used for modeling the quasi-longitudinal (quasi-pressure) wave [4]. Emphasis is placed on these waves, since they are of particular interest in nondestructive ultrasonic testing of austenitic weldments. The synthetic data is transferred to an imaging workstation. where the 3-D transducer fields are displayed using commercially available graphic packages. The fields of circular transducers of various frequencies are shown for different austenitic weld material configurations. For reference purposes, fields in an isotropic base material are also shown using the same transducers. In closing, the implications of such 3-D mappings are discussed.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

16A

Chapter

Chapter 4: NDE Sensors

Section

UT Fields and Probes

Pages

837-844

DOI

10.1007/978-1-4615-5947-4_109

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Numerical Modeling and Imaging of Three-Dimensional Transducer Fields in Anisotropic Materials

Brunswick, ME

Piezoelectric transducers are the basic tool for ultrasonic NDE applications and are commercially available in a variety of sizes. shapes and frequencies. However. the information that is typically provided for these transducers by vendors is of limited value. This is especially true when it comes to testing anisotropic materials. The wave propagation effects such as beam skewing. splitting and distortion. when taken into experimental consideration for anisotropic media. requires knowledge of the spatial radiation field distribution of the transmitting transducer. In this paper, a previously developed methodology to map the radiation fields for piezoelectric transducers [ 1 ] is applied to imaging (mapping) three dimensional radiation fields generated by transducers of various shapes and frequencies placed in contact with anisotropic propagation media. The processed data files are calculated for transversely isotropic materials via the Generalized-Point-Source-Synthesis (GPSS) method [2,3]. The material is regarded to be homogeneous since the ultrasonic wavelength is larger than the grain dimensions. A computationally efficient version of GPSS is used for modeling the quasi-longitudinal (quasi-pressure) wave [4]. Emphasis is placed on these waves, since they are of particular interest in nondestructive ultrasonic testing of austenitic weldments. The synthetic data is transferred to an imaging workstation. where the 3-D transducer fields are displayed using commercially available graphic packages. The fields of circular transducers of various frequencies are shown for different austenitic weld material configurations. For reference purposes, fields in an isotropic base material are also shown using the same transducers. In closing, the implications of such 3-D mappings are discussed.