@inproceedings{MayerMayerMayeretal.,
  author    = {Mayer, Andreas and Mayer, Elena and Mayer, Markus and J{\"a}ger, Philipp M. and Ruile, Werner and Bleyl, Ingo and Wagner, Karl},
  title     = {Full 2D-FEM calculations of third-order intermodulations in SAW devices},
  series = {Ultrasonic Symposium},
  organization    = {IEEE},
  doi       = {10.1109/ULTSYM.2016.7728469},
  pages     = {4},
  abstract  = {In a recent paper it has been shown that the effective nonlinear constant which is used in a P-Matrix approach to describe third-order intermodulation (IMD3) in surface acoustic wave (SAW) devices can be obtained from finite element (FEM) calculations of a periodic cell using nonlinear tensor data [1]. In this paper we extend this FEM calculation and show that the IMD3 of an infinite periodic array of electrodes on a piezoelectric substrate can be directly simulated in the sagittal plane. This direct approach opens the way for a FEM based simulation of nonlinearities for finite and generalized structures avoiding the simplifications of phenomenological approaches.},
  language  = {en}
}
@inproceedings{MayerRuileJohnsonetal.,
  author    = {Mayer, Markus and Ruile, Werner and Johnson, John and Kiwitt, J{\"u}rgen and San Jose, Romeo and Schmidhammer, Edgar and Bleyl, Ingo and Wagner, Karl and Mayer, Andreas and Mayer, Elena},
  title     = {Application of a rigorous nonlinear P-matrix method to the simulation of third order intermodulation in test devices and duplexers},
  series = {Proceedings of the 2014 IEEE Ultrasonics Symposium},
  issn      = {1051-0117},
  doi       = {10.1109/ULTSYM.2014.0193},
  pages     = {787 -- 790},
  language  = {en}
}
@inproceedings{RogallFeilDingetal.,
  author    = {Rogall, Olga and Feil, Niclas M. and Ding, Anli and Mayer, Elena and Pupyrev, Pavel Dmitrievich and Lomonosov, Alexey M. and Žukauskaitė, Agnė and Ambacher, Oliver and Mayer, Andreas},
  title     = {Determining Elastic Constants of AlScN Films on Silicon Substrates by Laser Ultrasonics},
  series = {2020 Symposium Proceedings},
  organization    = {IEEE},
  isbn      = {978-1-7281-5448-0 (digital)},
  issn      = {1948-5727 (digital)},
  doi       = {10.1109/IUS46767.2020.9251632},
  pages     = {4},
  abstract  = {Laser ultrasound was used to determine dispersion curves of surface acoustic waves on a Si (001) surface covered by AlScN films with a scandium content between 0 and 41\%. By including off-symmetry directions for wavevectors, all five independent elastic constants of the film were extracted from the measurements. Results for their dependence on the Sc content are presented and compared to corresponding data in the literature, obtained by alternative experimental methods or by ab-initio calculations.},
  language  = {en}
}
@inproceedings{MayerDaenekasRohjansetal.,
  author    = {Mayer, Christoph and D{\"a}nekas, Christian and Rohjans, Sebastian and Breuer, Andreas and Theisen, Thomas and Drzisga, Torsten and K{\"o}nig, Andreas and Luhmann, Till and Stadler, Michael and M{\"a}rten, Matthias and Terzidis, Orestis and Weidlich, Anke},
  title     = {Technologische Migrationspfade in das Smart Grid},
  series = {Tagungsband: VDE-Kongress 2012},
  publisher = {VDE-Verlag},
  address   = {Berlin},
  organization    = {Verband der Elektrotechnik, Elektronik, Informationstechnik},
  isbn      = {978-3-8007-3446-7},
  pages     = {6},
  abstract  = {Die Ver{\"a}nderungen in der Energieversorgung f{\"u}hren zu einer neuen Systemarchitektur der Stromversorgung, die nur durch einen massiven Einsatz von Informations- und Kommunikationstechnologien (IKT) bew{\"a}ltigt werden kann und meist als „Smart Grid" bezeichnet wird. W{\"a}hrend es bereits umfangreiche Forschungsarbeiten und Demonstrationsprojekte zu einzelnen technologischen Komponenten gibt, existieren noch wenige {\"U}berlegungen, in welchen technologischen Schritten eine Migration hin zu Smart Grids durchgef{\"u}hrt werden sollte, die sowohl betriebstechnisch zukunftssicher ist, als auch marktgetriebene Innovationen beg{\"u}nstigt. Der Beitrag veranschaulicht die Herleitung solcher Migrationspfade im Rahmen eines schrittweisen Vorgehens. Zun{\"a}chst werden Zukunftsszenarien f{\"u}r das Jahr 2030 konstruiert, um die maßgeblichen, oft auch nichttechnischen Einflussfaktoren auf das Smart Grid zu identifizieren. Darauf aufbauend werden die wesentlichen IKT-bezogenen Technologiefelder und ihre Zuordnung zu den Dom{\"a}nen der Energiewirtschaft beschrieben. F{\"u}r jedes Technologiefeld werden die in den n{\"a}chsten zwei Jahrzehnten denkbaren Entwicklungsstufen ermittelt und deren Abh{\"a}ngigkeit untereinander analysiert. Die gemeinsame Betrachtung von Szenarien, der Entwicklungsstufen der Technologiefelder und deren Interdependenzen f{\"u}hren schließlich zu einer Roadmap, welche die Migrationspfade in das Smart Grid beschreiben. Es lassen sich drei Entwicklungsphasen erkennen: Die Konzeptionsphase, die Integrationsphase und die Fusionsphase. Die pr{\"a}sentierten Ergebnisse entstammen dem Projekt „Future Energy Grid - Migrationspfade ins Internet", welches vom Bundesministerium f{\"u}r Wirtschaft und Technologie im Rahmen des E-Energy-Programms (F{\"o}rderkennzeichen 01ME10012A und 01ME10013) gef{\"o}rdert wurde.},
  language  = {de}
}
@inproceedings{RjelkaKoehlerMayer,
  author    = {Rjelka, Marek and K{\"o}hler, Bernd and Mayer, Andreas},
  title     = {M{\"o}glichkeiten zur Extraktion akustoelastischer Konstanten aus dem Nichtlinearit{\"a}tsparameter akustischer Oberfl{\"a}chenwellen in metallischen Werkstoffen},
  series = {DGZfP Jahrestagung 2017, 22-24 May, Koblenz, Germany},
  pages     = {1 -- 6},
  abstract  = {Zerst{\"o}rungsfreie Verfahren zur Messung von Eigenspannungen erfordern, abh{\"a}ngig vom gew{\"a}hlten Verfahren, die Kenntnis gewisser Kopplungskonstanten. Im Falle von Ultraschallmessverfahren sind das neben den elastischen Konstanten zweiter Ordnung (SOEC) vor allem die Konstanten dritter Ordnung (TOEC). Elastische Konstanten fester, metallischer Bauteile werden in der Regel in Zugversuchen bestimmt. Zur Ermittlung der TOEC werden diese mit Ultraschallmessmethoden kombiniert. Durch {\"a}ußere Einfl{\"u}sse, wie etwa mechanische Nachbehandlungen der zu untersuchenden Bauteile k{\"o}nnen sich diese Konstanten jedoch {\"a}ndern und m{\"u}ssen folglich direkt am ver{\"a}nderten Material bestimmt werden. Mithilfe von Simulationen wird die Ausbreitung der zweiten Harmonischen und der nichtlinear erzeugten Oberfl{\"a}chenwellen in Wellenmischexperimenten analysiert und der akustische Nichtlinearit{\"a}tsparameter (ANP) bzw. der Kopplungsparameter aus der Amplitudenentwicklung berechnet. Insbesondere wird untersucht, welchen Einfluss ein gegebenes Tiefenprofil der TOEC auf den ANP hat (Vorw{\"a}rtsproblem) und inwiefern sich aus den Messungen des ANP auf ein vorliegendes Tiefenprofil der TOEC schließen l{\"a}sst (inverses Problem). Außerdem wird diskutiert, welchen Einfluss lokale {\"A}nderungen der SOEC auf den ANP haben k{\"o}nnen und wie groß diese {\"A}nderungen sein d{\"u}rfen, um die TOEC dennoch bestimmen zu k{\"o}nnen. Die Untersuchungen hierzu wurden auf der Basis eines 3D-FEM Modells mit zuf{\"a}llig orientierten Mikrorissen durchgef{\"u}hrt. Die numerischen Rechnungen zeigen dabei auch eine gute {\"U}bereinstimmung mit einem aus der Literatur bekannten und f{\"u}r dieses Problem erweiterten, analytischen Modell. Neben der rissinduzierten Nichtlinearit{\"a}t kann bei diesem auch die Gitternichtlinearit{\"a}t ber{\"u}cksichtigt werden.},
  language  = {de}
}
@inproceedings{RjelkaKoehlerMayer,
  author    = {Rjelka, Marek and K{\"o}hler, Bernd and Mayer, Andreas},
  title     = {Extraction of Depth Profiles of Third-Order Elastic Constants in Cracked Media},
  series = {AIP Conference Proceedings 1806},
  doi       = {10.1063/1.4974610},
  pages     = {060001-1 -- 060001-9},
  abstract  = {Elastic constants of components are usually determined by tensile tests in combination with ultrasonic experiments. However, these properties may change due to e.g. mechanical treatments or service conditions during their lifetime. Knowledge of the actual material parameters is key to the determination of quantities like residual stresses present in the medium. In this work the acoustic nonlinearity parameter (ANP) for surface acoustic waves is examined through the derivation of an evolution equation for the amplitude of the second harmonic. Given a certain depth profile of the third-order elastic constants, the dependence of the ANP with respect to the input frequency is determined and on the basis of these results, an appropriate inversion method is developed. This method is intended for the extraction of the depth dependence of the third-order elastic constants of the material from second-harmonic generation and guided wave mixing experiments, assuming that the change in the linear Rayleigh wave velocity is small. The latter assumption is supported by a 3D-FEM model study of a medium with randomly distributed microcracks as well as theoretical works on this topic in the literature.},
  language  = {en}
}
@inproceedings{MayerKrylovLomonosov,
  author    = {Mayer, Andreas and Krylov, Victor V. and Lomonosov, Alexey M.},
  title     = {Guided Acoustic Waves Propagating at Surfaces, Interfaces and Edges},
  series = {2011 IEEE International Ultrasonics Symposium Proceedings},
  address   = {Piscataway, NJ},
  organization    = {IEEE},
  isbn      = {978-1-4577-1252-4 (Online)},
  issn      = {1948-5727 (Online)},
  doi       = {10.1109/ULTSYM.2011.0508},
  pages     = {2046 -- 2052},
  abstract  = {Surface and interface acoustic waves are two-dimensionally guided waves, as their displacement field is plane-wave like regarding its dependence on the spatial coordinates parallel to the guiding plane, while it decays exponentially along the axis normal to that plane. When propagating at the planar surface or interface of homogeneous media, they are non-dispersive. Another type of non-dispersive acoustic waves which is, however, one-dimensionally guided, has displacement fields localized near the apex of a wedge made of an elastic material. In this short review, their propagation properties are described as well as theoretical and experimental methods which have been used for their analysis. Experimental findings are discussed in comparison with corresponding theoretical work and potential applications of this fascinating type of acoustic waves are presented.},
  language  = {en}
}
@inproceedings{GartsevRjelkaKoehleretal.,
  author    = {Gartsev, Sergey and Rjelka, Marek and K{\"o}hler, Bernd and Mayer, Andreas},
  title     = {Determination of the nonlinear elastic constants in a surface treated layer for aero-engine disk residual stress measurement},
  series = {10th International Symposium on NDT in Aerospace, 24-26 October 2018, Dresden/Germany},
  pages     = {8},
  abstract  = {Existing ultrasonic stress evaluation methods utilize the acoustoelastic effect for bulk waves propagating in volume, which is unsuitable for a surface treated material, possessing a significant variation in material properties with depth. With knowledge of nonlinear elastic parameters - third-order elastic constants (TOEC) close to the surface of the sample, the acoustoelastic effect might be used with surface acoustic waves. This work is focused on the development of an independent method of TOEC measurement using the effect of nonlinear surface acoustic waves scattering - i.e. the effect of elastic waves interaction in a nonlinear medium. In this paper, the possible three wave interactions of surface guided waves and bulk waves are described and formulae for the efficiency of harmonic generation and mode mixing are derived. A comparison of the efficiency of surface waves scattering in an isotropic medium for different interaction types is carried out with the help of nonlinear perturbation theory. First results for surface and bulk wave mixing with known second- and third-order elastic constants are shown.},
  language  = {en}
}
@inproceedings{Mayer,
  author    = {Mayer, Andreas},
  title     = {Nonlinear surface acoustic waves: Theory},
  series = {Ultrasonics : Selected Papers from ICU 2007},
  volume    = {48},
  number    = {6/7},
  publisher = {Elsevier},
  issn      = {0041-624X},
  doi       = {10.1016/j.ultras.2008.06.009},
  pages     = {478 -- 481},
  abstract  = {A theoretical description is given for the propagation of surface acoustic wave pulses in anisotropic elastic media subject to the influence of nonlinearity. On the basis of nonlinear elasticity theory, an evolution equation is presented for the surface slope or the longitudinal surface velocity associated with an acoustic pulse. It contains a non-local nonlinearity, characterized by a kernel that strongly varies from one propagation geometry to another due to the anisotropy of the substrate. It governs pulse shape evolution in homogeneous halfspaces and the shapes of solitary surface pulses that exist in coated substrates. The theory describing nonlinear Rayleigh-type surface acoustic waves is extended in a straightforward way to surface waves that are localized at a one-dimensional acoustic waveguide like elastic wedges.},
  language  = {en}
}