TY - JOUR A1 - Krome, Fabian A1 - Gravenkamp, Hauke ED - Every, A. T1 - Analyzing modal behavior of guided waves using high order eigenvalue derivatives N2 - This paper presents a mode-tracing approach for elastic guided waves based on analytically computed derivatives and includes a study of interesting phenomena in the dispersion curve representation. Numerical simulation is done by means of the Scaled Boundary Finite Element Method (SBFEM). Two approaches are used to identify the characteristics of the resulting wave modes: Taylor approximation and Padé approximation. Higher order differentials of the underlying eigenvalue problem are the basis for these approaches. Remarkable phenomena in potentially critical frequency regions are identified and the tracing approach is adapted to these regions. Additionally, a stabilization of the solution process is suggested. KW - Guided waves KW - Mode-tracing KW - Eigenvalue problem derivatives KW - Ultrasound KW - Scaled Boundary Finite Element Method PY - 2016 DO - https://doi.org/10.1016/j.ultras.2016.05.014 SN - 0041-624X VL - 2016 IS - 71 SP - 75 EP - 85 PB - Elsevier B.V. AN - OPUS4-38076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krome, Fabian A1 - Gravenkamp, Hauke T1 - Modenverfolgung in SBFEM-Simulationen von geführten Ultraschallwellen T2 - DACH-Jahrestagung 2015 CY - Salzburg, Österreich DA - 2015-05-11 PY - 2015 AN - OPUS4-33226 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krome, Fabian A1 - Gravenkamp, Hauke T1 - 3-D WAVEGUIDE MODELING AND SIMULATION USING SBFEM T2 - International Congress on Sound and Vibration 2015 CY - Firenze, Italy DA - 2015-07-12 PY - 2015 AN - OPUS4-33224 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krome, Fabian A1 - Gravenkamp, Hauke T1 - A novel approach to mode - tracing in SBFEM - Simulations: Higher-order Taylor- and Padeapproximation T2 - GAMM 2015 CY - Lecce, Italien DA - 2015-03-23 PY - 2015 AN - OPUS4-33225 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lugovtsova, Yevgeniya A1 - Bulling, Jannis A1 - Krome, Fabian A1 - Prager, Jens T1 - Effiziente Modellierung von geführten Wellen mit der Scaled Boundary Finite Elemente Methode und deren Anwendung für Composite-Druckbehälter N2 - Die Scaled Boundary Finite Elemente Methode (SBFEM) ist eine semi-analytische Methode, die speziell für Modellierung von geführten Wellen weiterentwickelt und optimiert wurde. Da nur den Rand der Rechendomäne diskretisiert wird, hat die SBFEM einen geringen Rechenaufwand. In diesem Beitrag wird die SBFEM benutzt, um die Ausbreitung geführter Wellen in einer Metall-Faserverbund-Werkstoffstruktur zu analysieren. Mittels der SBFEM ist es möglich, verschiede Fehlertypen, z.B. Ermüdungsrisse, Poren, Delaminationen, Korrosion, in das numerische Modell zu integrieren und damit Defekt-Mode-Wechselwirkung zu analysieren. Die Ergebnisse wurden für die Entwicklung einer Methode zur Zustandsüberwachung von Composite-Druckbehältern verwendet. T2 - DGZfP-Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Wasserstoffspeicher KW - Automobilindustrie KW - Kohlenstofffaserverstärkter Kunststoff KW - Hybrid Materialien PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-449797 SP - 1 EP - 4 AN - OPUS4-44979 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krome, Fabian A1 - Gravenkamp, H. T1 - A semi-analytical curved element for linear elasticity based on the scaled boundary finite element method N2 - This work introduces a semi-analytical formulation for the simulation and modeling of curved structures based on the Scaled Boundary Finite Element Method (SBFEM). This approach adapts the fundamental idea of the SBFEM concept to scale a boundary to describe a geometry. Until now, scaling in SBFEM has exclusively been performed along a straight coordinate which enlarges, shrinks or shifts a given boundary. In this novel approach, scaling is based on a polar or cylindrical coordinate system such that a boundary is shifted along a curved scaling direction. The derived formulations are used to compute the static and dynamic stiffness matrices of homogeneous curved structures. The resulting elements can be coupled to general SBFEM or FEM domains. For elastodynamic problems computations are performed in the frequency domain. Results of this work are validated using the Global Matrix Method and Standard Finite Element analysis. KW - Scaled boundary finite element method KW - Elasticity KW - Curved structures PY - 2017 DO - https://doi.org/10.1002/nme.5306 SN - 0029-5981 SN - 1097-0207 VL - 109 IS - 6 SP - 790 EP - 808 PB - WILEY-BLACKWELL AN - OPUS4-40170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krome, Fabian A1 - Gravenkamp, H. A1 - Birk, C. T1 - Prismatic semi-analytical elements for the simulation of linear elastic N2 - This work addresses the computation of stiffness matrices for general prismatic structures with an arbitrary cross section. The presented approach is based on the scaled boundary finite element method (SBFEM), a semi-analytical method, which can be used to model structures by only discretizing the boundary of a domain. For prismatic structures, the process is further simplified, as only the cross section of the structure has to be discretized. Thus, a particular semi-analytical finite element is constructed for bounded and unbounded domains. The proposed approach leads to a frequency-dependent stiffness matrix. This stiffness matrix can easily be coupled to other prismatic SBFEM domains or general SBFEM domains. Necessary modifications to include forces along the scaling direction, such as body loads, are addressed. The results of the proposed approach are compared to those of traditional FEM models obtained using commercially available software. KW - Scaled boundary finite element method KW - Elasticity KW - Prismatic structures KW - Body-loads PY - 2017 DO - https://doi.org/10.1016/j.compstruc.2017.06.015 VL - 192 SP - 83 EP - 95 PB - Elsevier Ltd. AN - OPUS4-43415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krome, Fabian A1 - Gravenkamp, Hauke T1 - 3-D Waveguide modeling and simulation using SBFEM N2 - The modeling of waveguides by means of the Scaled Boundary Finite Element Method (SBFEM) has recently been addressed and is considered an effective procedure for the simulation of ultrasonic guided waves in plates and uniform structures, as well as their interaction with defects. This work presents the extension of the known applications like uniform concrete foundation cylinders to structures with more complex shapes and defects. The main focus is the required modeling of 3-D structures in SBFEM to solve these efficiently. Furthermore the coupling of different models is discussed. This involves models like a mainly uniform foundation cylinder with varying material behavior or geometry in certain areas which has to be modeled in 3-D SBFEM. With the presentation of numerical examples the accuracy and performance of the modeling is discussed and the advantages in improving numerical stability are shown. T2 - ICSV22 CY - Florence, Italy DA - 12.07.2015 KW - Scaled boundary finite element method PY - 2015 SP - 2805 EP - 2810 AN - OPUS4-43416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wasmer, Paul A1 - Krome, Fabian A1 - Bulling, Jannis A1 - Prager, Jens T1 - A fluid model for the simulation of fluid‐structure interaction in the Scaled Boundary Finite Element Method for prismatic structures N2 - The Scaled Boundary Finite Element Method is known as an efficient method for the simulation of ultrasonic wave propagation. As to investigate acoustic wave behavior in case of fluid‐structure interaction, a fluid model is implemented in the SBFEM for prismatic structures. To omit coupling terms a displacement‐based formulation is used. Spurious modes, which occur in the solution, are suppressed using a penalty parameter. To verify this formulation dispersion curves obtained with Comsol Multiphysics are compared to results of SBFEM. The results of both methods are in very good agreement T2 - GAMM 2018 CY - Munich, Germany DA - 19.03.2018 KW - Scaled Boundary Finite Element Method KW - Penalty Parameter KW - Fluid-Structure Interaction KW - Guided Waves PY - 2018 DO - https://doi.org/10.1002/pamm.201800139 VL - 18 IS - 1 SP - e201800139 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-47063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bulling, Jannis A1 - Prager, Jens A1 - Krome, Fabian T1 - Application of the scaled boundary finite element method (SBFEM) for a numerical simulation of ultrasonic guided waves N2 - This paper addresses the computation of dispersion curves, mode shapes and propagation of elastic guided waves. It summarizes the approaches based on the Scaled Boundary Finite Element Method. Descriptions for plates, rods, pipelines and waveguides with an arbitrary cross section are included. The important steps for the approximation of the displacement in bounded and unbounded domains are stated. The grid generation process is explained. It is highlighted that the Scaled Boundary Finite Element Method is very efficient, if large portions of the domain are either straight or with a constant curvature. The computation of dispersion curves for layered structures is presented. T2 - Sensor + Test CY - Nürnberg, Germany DA - 30.05.2017 KW - Ultrasonic guided waves KW - Non-destructive testing KW - Scaled boundary finite element method (SBFEM) PY - 2017 SN - 978-3-9816876-4-4 VL - 2017 SP - C5.4, 376 EP - 381 AN - OPUS4-41876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -