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- 2012 (2) (entfernen)
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- Englisch (2)
Referierte Publikation
- nein (2) (entfernen)
Schlagworte
- 3D ray tracing (1)
- Austenitic weld (1)
- Inhomogeneous (1)
- Ultrasonic field (1)
This paper presents the numerical modeling of the Lamb
wave propagation in plate like structures with the
Elastodynamic Finite Integration Technique (EFIT) and its
validation with the measured results. In general, Lamb
waves offer an attractive method to detect the defects inside
long plate like structures efficiently. However, such a nondestructive
testing (NDT) requires profound understanding
of the Lamb wave propagation in the plates, generation of
the symmetric and anti-symmetric modes of different orders
and their interaction with the defects of the materials.
Modern simulation tools based on numerical methods can be
used to model this complex NDT situation. EFIT is an
effective tool to model such problems in an efficient way.
With the help of the simulation results obtained from the
EFIT tool the propagation of different symmetric and antisymmetric
Lamb wave modes is analyzed and thus a proper
technique is developed to excite different modes and to
separate them from each other precisely. A validation of the
numerical results with the measured results is also presented.
In this contribution a 3D ray tracing model for ultrasonic
field evaluation in inhomogeneous anisotropic materials
such as austenitic welds is presented. The inhomogenity of
austenitic weld material is represented as several
homogeneous layers. The general problem of energy
reflection and transmission at the boundaries of the layers
are solved resulting 3D amplitude and energy reflection and
transmission coefficients. The directivity factor for the ray in
general arbitrary oriented austenitic weld material (including
lay back orientation) is determined based on Lambs
reciprocity theorem. The transducer excited ultrasonic fields
are accurately evaluated by employing ray directivity factor,
transmission coefficients, divergence of the ray bundle and
density of rays. Finally, the comparison between theoretical
and experimental results will be described.