TY - CONF A1 - Rahman, Mehbub-Ur A1 - Prager, Jens T1 - Simulation of lamb wave propagation with elastodynamic finite integration technique (EFIT) T2 - DAGA 2012 - 38. Jahrestagung für Akustik - Fortschritte der Akustik N2 - 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. T2 - DAGA 2012 - 38. Jahrestagung für Akustik - Fortschritte der Akustik CY - Darmstadt, Deutschland DA - 2012-03-19 PY - 2012 SP - 953 EP - 954 PB - Deutsche Gesellschaft für Akustik e.V. AN - OPUS4-25999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rahman, Mehbub-Ur A1 - Prager, Jens ED - Linde, B. B. J. ED - Paczkowski, J. ED - Ponikwicki, N. T1 - Modeling of lamb wave propagation with elastodynamic finite integration technique T2 - International congress on ultrasonics N2 - This paper presents the numerical modeling of the Lamb wave propagation in thin plates 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 such as the finite integration technique (FIT), the finite element method (FEM) and the boundary element method (BEM) can be used to model this NDT situation. The elastodynamic finite integration technique (EFIT) is an effective tool to model Lamb wave propagation in plates over long distances in an efficient way. With the help of the simulation results obtained from the EFIT tool the propagation of different symmetric and anti-symmetric 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 analytical results is also presented. T2 - International congress on ultrasonics CY - Gdansk, Poland DA - 2011-09-05 KW - NDT KW - EFIT KW - Lamb wave KW - Symmetric and anti-symmetric modes PY - 2012 SN - 978-0-7354-1019-0 DO - https://doi.org/10.1063/1.3703226 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1433 SP - 455 EP - 458 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolkoori, Sanjeevareddy A1 - Rahman, Mehbub-Ur A1 - Prager, Jens T1 - 3D ray tracing model for ultrasound field evaluation in inhomogeneous anisotropic materials: model and experimental validation T2 - DAGA 2012 - 38. Jahrestagung für Akustik - Fortschritte der Akustik N2 - 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 Lamb’s 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. T2 - DAGA 2012 - 38. Jahrestagung für Akustik - Fortschritte der Akustik CY - Darmstadt, Deutschland DA - 2012-03-19 KW - Ultrasonic field KW - 3D ray tracing KW - Inhomogeneous KW - Austenitic weld PY - 2012 SP - 959 EP - 960 PB - Deutsche Gesellschaft für Akustik e.V. AN - OPUS4-26204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolkoori, Sanjeevareddy A1 - Rahman, Mehbub-Ur A1 - Chinta, P.K. A1 - Kreutzbruck, Marc A1 - Prager, Jens ED - Thompson, D. O. ED - Chimenti, D. E. T1 - Quantitative evaluation of ultrasonic sound fields in anisotropic austenitic welds using 2D ray tracing model T2 - Review of progress in quantitative nondestructive evaluation, volume 31 N2 - Ultrasonic investigation of inhomogeneous anisotropic materials such as austenitic welds is complicated because its columnar grain structure leads to curved energy paths, beam splitting and asymmetrical beam profiles. A ray tracing model has potential advantage in analyzing the ultrasonic sound field propagation and there with optimizing the inspection parameters. In this contribution we present a 2D ray tracing model to predict energy ray paths, ray amplitudes and travel times for the three wave modes quasi longitudinal, quasi shear vertical, and shear horizontal waves in austenitic weld materials. Inhomogenity in the austenitic weld material is represented by discretizing the inhomogeneous region into several homogeneous layers. At each interface between the layers the reflection and transmission problem is computed and yields energy direction, amplitude and energy coefficients. The ray amplitudes are computed accurately by taking into account directivity, divergence and density of rays, phase relations as well as transmission coefficients. Ultrasonic sound fields obtained from the ray tracing model are compared quantitatively with the 2D Elastodynamic Finite Integration Technique (EFIT). The excellent agreement between both models confirms the validity of the presented ray tracing results. Experiments are conducted on austenitic weld samples with longitudinal beam transducer as transmitting probe and amplitudes at the rear surface are scanned by means of electrodynamical probes. Finally, the ray tracing model results are also validated through the experiments. T2 - 38th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Burlington, VT, USA DA - 2011-07-17 KW - Ultrasonic sound field KW - Ray tracing KW - Ray directivity KW - Austenitic weld PY - 2012 SN - 978-0-7354-1013-8 DO - https://doi.org/10.1063/1.4716359 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1430 SP - 1227 EP - 1234 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26205 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolkoori, Sanjeevareddy A1 - Rahman, Mehbub-Ur A1 - Chinta, P.K. A1 - Boehm, Rainer A1 - Prager, Jens ED - Linde, B. B. J. ED - Paczkowski, J. ED - Ponikwicki, N. T1 - Simulation of ultrasonic fields in anisotropic materials using 2D ray tracing method T2 - International congress on ultrasonics N2 - Ultrasound propagation in inhomogeneous anisotropic materials is difficult to examine because of the directional dependency of elastic properties. Simulation tools play an important role in developing advanced reliable ultrasonic testing techniques for the inspection of anisotropic materials particularly austenitic cladded materials and dissimilar welds. A 2-D Ray tracing method is developed for evaluating ray path, amplitude and travel time for three wave modes namely quasi longitudinal wave (qP), quasi shear vertical wave (qSV) and shear horizontal waves (SH) in anisotropic materials such as austenitic cladded materials. The inhomogenity in the anisotropic material is represented by discretizing the anisotropic region into several homogeneous layers. The ray paths are traced during its propagation through the various interfaces between those layers. At each interface the problem of reflection and refraction is solved. The ray amplitudes are computed by taking into account the directivity and phase relations. Ray divergence variation and ray transmission coefficients at each refraction boundary are considered. The Ray tracing results for ultrasonic field profiles in austenitic cladded materials are validated quantitatively by 2-D Elastodynamic Finite Integration Technique (EFIT) results and by the experiments. T2 - International congress on ultrasonics CY - Gdansk, Poland DA - 2011-09-05 KW - Ray path KW - Energy vector KW - Austenitic cladded material KW - Ultrasonic beam profile PY - 2012 SN - 978-0-7354-1019-0 DO - https://doi.org/10.1063/1.3703288 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1433 SP - 743 EP - 746 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kolkoori, Sanjeevareddy A1 - Rahman, Mehbub-Ur A1 - Prager, Jens T1 - Effect of columnar grain orientation on ultrasonic plane wave energy reflection and transmission behaviour in anisotropic austenitic weld materials JF - Journal of nondestructive evaluation N2 - This article describes a comprehensive quantitative analysis on effect of columnar grain orientation on ultrasonic plane wave energy reflection and transmission behaviour in acoustically anisotropic austenitic weld materials. The quantitative results are presented for following general interfaces (a) Isotropic-Anisotropic, (b) Anisotropic-Isotropic, (c) Fluid-Anisotropic, (d) Anisotropic-Fluid, (e) Anisotropic-Anisotropic, (f) Anisotropic-Free surface occur during the ultrasonic non destructive evaluation of austenitic weld materials. Explicit analytical expressions are presented for energy reflection and transmission coefficients at an interface between two arbitrarily oriented transversely isotropic materials. By applying explicit analytical expressions for energy reflection and transmission coefficients, numerical results are presented for several columnar grain orientations of the transverse isotropic austenitic weld material including both real and complex domain of the reflected and transmitted normal component of slowness vectors. Valid domains of incident wave vector angles, angular dependency of energy reflection and transmission coefficients and critical angles for reflected and transmitted waves are discussed. The existence of a reflected (or) transmitted second branch of quasi shear vertical waves and its consequence to the ultrasonic non destructive testing of austenitic weld materials are investigated. The presented comprehensive quantitative evaluation provides an overview on the effect of anisotropic properties on energy reflection and transmission coefficients in columnar grained austenitic weld materials. KW - Anisotropy KW - Inhomogeneous waves KW - Austenitic weld material KW - Polarization vector KW - Energy skewing KW - Critical angle KW - Energy flux vector KW - Evanescent waves PY - 2012 DO - https://doi.org/10.1007/s10921-012-0140-1 SN - 0195-9298 SN - 1573-4862 VL - 31 IS - 3 SP - 253 EP - 269 PB - Plenum Press CY - New York, NY AN - OPUS4-27792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -