Elastic wave propagation and scattering in austenitic steel
- Fraunhofer Inst. for Nondestructive Testing, Saarbrucken (Germany)
- Univ. of Kassel (Germany)
Ultrasonic nondestructive testing of austenitic steel welds is very difficult because fundamental wave propagation and scattering effects in such complicated, anisotropic environments are only hardly understood. Therefore, a step-by-step evaluation of elastic wave propagation in transversely isotropic media has been initiated starting with two quasi-homogeneous specimens of different austenitic grain orientation. Under the assumption of transverse isotropy the modeling codes EFIT (Elastodynamic Finite Integration Technique) and GPSS (Generalized Point Source Synthesis), developed as basic tools to model NDE problems, were extended to anisotropic homogeneous media. These codes allow 3D computation of quasi-pressure and quasi-shear, as well as surface waves (EFIT), modeling finite size transducers as radiating apertures on otherwise stress-free surfaces. Time-domain wavefront snapshots clearly illustrate the strange behavior of, for instance, quasi-pressure waves being released orthogonally into the specimens and exhibiting a skewing-angle dependent on the grain orientation; up to now, this skewing angle could only be computed for plane waves. The transmitted C-scan-like sound field distribution on the specimens` backwall, as evaluated with the EFIT- or GPSS-code, agrees very well with measurements, even for the case of grain inclinations in 3D, thus confirming the appropriateness of the model. Based on this confidence, crack scattering is investigated in detail with the EFIT and GPSS-code and discussed in terms of time wavefronts, amplitude dynamics and A-scans.
- OSTI ID:
- 86116
- Report Number(s):
- CONF-9505104-; ISBN 0-87170-548-6; TRN: IM9534%%188
- Resource Relation:
- Conference: 13. international conference on nondestructive evaluation in the nuclear and pressure vessel industries, Kyoto (Japan), 22-25 May 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the 13. international conference on NDE in the nuclear and pressure vessel industries; Iida, Kunihiro [ed.] [Shibaura Inst. of Technology, Tokyo (Japan)]; Light, G.M [ed.] [Southwest Research Inst., San Antonio, TX (United States)]; Whittle, M.J. [ed.] [John Whittle and Associates, Cheshire (United Kingdom)]; PB: 503 p.
- Country of Publication:
- United States
- Language:
- English
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