Fraunhofer-Gesellschaft

Publica

Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Theoretical description of ultrasonic propagation and scattering phenomena in polycrystalline structures aiming for simulations on nondestructive materials characterization

 
: Hirsekorn, Sigrun

:
Volltext urn:nbn:de:0011-n-3134033 (725 KByte PDF)
MD5 Fingerprint: 6c1e5b2258dbc502c32e83faa46731f5
Erstellt am: 19.11.2014


Prevorovsky, Zdenek ; European Federation for Non-Destructive Testing -EFNDT-:
11th European Conference on Nondestructive Testing, ECNDT 2014. CD-ROM : October 6-10, 2014, Prague, Czech Republic; Conference proceedings
Brno: Brno University of Technology, 2014
ISBN: 978-80-214-5018-9
Beitrag 331
European Conference on Nondestructive Testing (ECNDT) <11, 2014, Prague>
Bundesministerium für Umwelt, Naturschutz, Bau und Reaktorsicherheit BMUB
032531OC; String Control
Englisch
Konferenzbeitrag, Elektronische Publikation
Fraunhofer IZFP ()
non-destructive testing; microstructure; polycrystal; scattering; structural noise; theory; ultrasound

Abstract
In microscopically inhomogeneous media ultrasonic scattering at grain and/or phase boundaries causes sound velocity dispersion and attenuation. These effects as well as the amplitudes of the scattering waves can be used for materials characterization. Concomitant, scattering at the microstructure of materials hampers defect detection and evaluation because the so-called structural noise superposes defect signals, and velocity dispersion corrupts defect positioning. Hence, the simulation of ultrasonic propagation and nondestructive testing procedures must contain microstructural scattering phenomena. In a general approach, the scattering wave energy flux densities in microscopically inhomogeneous materials are derived from the formal infinite Born series presentation of ultrasonic displacement vectors, the solutions of the elasto dynamic equation of motion. The energy flux densities are ensemble averaged respective the microscopic inhomogeneity and evaluated for single phase polycrystals in lowest non-zero order. The resultant directional and frequency dependent scattering wave amplitudes are dis-cussed in the context of results from the literature.

: http://publica.fraunhofer.de/dokumente/N-313403.html