A model fitting approach to the broad band measurement of ultrasonic wave velocities in thin samples of engineering material
| Autor: | R. J. Freemantle, R. E. Challis, T. Alper |
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| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Measurement Science and Technology. 4:1129-1137 |
| ISSN: | 1361-6501 0957-0233 |
| DOI: | 10.1088/0957-0233/4/10/017 |
| Popis: | This paper presents a novel broad band short-pulse ultrasonic system for the simultaneous measurement of compression and shear acoustic wave velocities in thin solid slabs. Using a goniometer stage a test sample is immersed in a water cell between two axially aligned thick ultrasonic transducers. Compression and shear wave reverberations are generated in the test material and the resulting compression waves in the water on the receiver side are received and digitized. Each wave reverberation can be separately time resolved and time-of-flight (TOF) measurements can be made. A time domain model of the wave system in the solid is presented with comparisons with existing frequency domain models. The measured arrival times of the successive reverberations are input to a computer algorithm derived from the time domain model which, using a parameter fitting routine, calculates the acoustic wave velocity for both the compression and shear reverberations in the sample. The problem of interference between successive reverberations in the time domain is greatly reduced due to the wide bandwidth/short pulse operating mode possible with acoustically thick transducers. |
| Databáze: | OpenAIRE |
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