Location

Snowmass Village, CO

Start Date

1-1-1995 12:00 AM

Description

In ultrasonic nondestructive testing use is made of the physical properties of elastic waves in solids in order to detect defects and material inhomogeneities. Difficulties in testing anisotropic materials are due to the direction dependence of the ultrasonic velocities and to the inherent effects of beam divergence and beam distortion. Based on a theory of elastic wave propagation in transversely isotropic media [1], the Generalized Point-Source-Synthesis-method (GPSS) has been developed to model the radiation, propagation and scattering of elastic waves as generated by ultrasonic transducers in these media [2]. The method accounts for the three-dimensionality and the vectorial character of anisotropic wave phenomena and is particularly useful in view of application-directed modeling at low computation times. A specifically interesting outcome is OPoSSM (‘Optimization by Point-Source-Synthesis-Modeling’), which allows optimized dimensioning and build-up of complex transducers according to their selected field of application. In this contribution, results are presented for austenitic weld material and fiber composites, covering echo dynamic curves — in comparison with experimental results — for commercial transducers. Furthermore, OPoSSM-results on optimized TR-array-probes are presented as well as snapshots of transducer-generated wavefronts, impressively illustrating the modeling of time-dependent rf-signals.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

14A

Chapter

Chapter 4: Transducers, Sensors, and Process Control

Section

Ultrasonic Transducer Fields and Ray Tracing

Pages

1013-1020

DOI

10.1007/978-1-4615-1987-4_128

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Application-Directed Modeling of Radiation and Prpagation of Elastic Waves in Anisotropic Media: GPSS and OPOSSM

Snowmass Village, CO

In ultrasonic nondestructive testing use is made of the physical properties of elastic waves in solids in order to detect defects and material inhomogeneities. Difficulties in testing anisotropic materials are due to the direction dependence of the ultrasonic velocities and to the inherent effects of beam divergence and beam distortion. Based on a theory of elastic wave propagation in transversely isotropic media [1], the Generalized Point-Source-Synthesis-method (GPSS) has been developed to model the radiation, propagation and scattering of elastic waves as generated by ultrasonic transducers in these media [2]. The method accounts for the three-dimensionality and the vectorial character of anisotropic wave phenomena and is particularly useful in view of application-directed modeling at low computation times. A specifically interesting outcome is OPoSSM (‘Optimization by Point-Source-Synthesis-Modeling’), which allows optimized dimensioning and build-up of complex transducers according to their selected field of application. In this contribution, results are presented for austenitic weld material and fiber composites, covering echo dynamic curves — in comparison with experimental results — for commercial transducers. Furthermore, OPoSSM-results on optimized TR-array-probes are presented as well as snapshots of transducer-generated wavefronts, impressively illustrating the modeling of time-dependent rf-signals.