Cornelius Strackeljan
Dr.-Ing. Cornelius Strackeljan
Mehrkörperdynamik (IWTM)
Current projects
Simulating the implantation process of endoprostheses to determine mechanical load in the bones during operation
Duration: 01.01.2022 bis 30.06.2025
Modern, shoulder arthroplasties with stemless implants (figure a) help to preserve larger parts of the original bone substance and to reduce potential risks of conventional implants. Their shape allows newly formed bone structures to grow directly through the implant. However, it is not fully explained how an optimal fixation of the implant can be achieved or stimulated.
In this context, the project aims to simulate the mechanical loading in the humerus during the operation using the finite element method. The results are used to investigate whether one or more mechanical parameter, e.g. stresses or elastic/plastic strains, can be correlated with measurement data of cell activity in the bone, which is available in the form of SPECT/CT data.
The derived workflow consists of the following steps:
- Derive the relevant bone geometries as well as the exact location of the implant from SPECT/CT data (figure b) .
- Transform the geometries as well as the measurement data to a reference position for the simulation.
- Generate a finite element model from the data (3D point cloud and corresponding intensity from the CT measurement (figure a) .
- Conduct FEM-Simulation with suitable material models and material data (figure d) .
- Evaluation of the simulation results and correlation with measured cell activity in vicintiy of the implant.
Completed projects
Thermo-hydrodynamic bearing models with increased accuracy
Duration: 01.07.2023 bis 31.03.2024
This project builds on two previous publicly founded projects, which focused on detailed models for hyrodynamic bearings to calculate the complex dynamic behaviour of rotors, which are supported by hydrodynamic bearings. In this context, it is essential to simulate the non-linear behaviour of the bearings as accurately as possible. This non-linear bearing behaviour is characterised by non-linear stiffness and damping properties, cavitation processes and a non-linear dependence of the lubricant viscosity on the operating temperature. This modelling is done by transient solving the differential equations, which describe the lubricating film: the Reynolds PDE and the energy equation.
Three aspects are analysed in more detail in the current project:
- Precise calculation of the fluid flow in gap height direction. The velocity of this flow is usually very small because of the small gap heights (order of magnitude: <100 µm), but it can still have a big impact on heat transfer mechanisms in the lubricating film. This is especially true for thrust bearings at high rotational speeds and loads (figure 1). Because there is more heat transfer in gap height direction, more heat is carried over the segment, which means an increased temperature niveau in the lubricating film
- Investigation of the centrifugal term in the Reynolds PDE for thrust bearings, which is often not implemented completely, but only up to the order h³. At high rotational speeds, this can also lead to inaccuracies. In the analysed load cases, the inertial influence is overestimated by up to 15% due to the simplified implementation.
- Investigation of suitable temperature boundary conditions at the segment inlet of hydrodynamic bearings.
Dynamics of exhaust gas turbocharger rotors with coupled radial and axial bearings
Duration: 01.10.2019 bis 31.03.2022
The aim of the research project is to improve the existing calculation methodology for high-speed exhaust gas turbochargers (ATL) with hydrodynamic bearings. While the previous project focused on radial bearings in the form of floating bush bearings (shown in blue), the current project addresses the modeling of axial bearings (shown in red; simple and floating disk bearings). The influences of the thrust bearings on the rotor dynamics as a result of their non-linear tilting rigidity and the coupling of the thrust bearings to the radial bearings are to be investigated. This also includes practically relevant counter-rotation excitations, e.g. due to engine vibrations.
The movement of the shaft results in dynamic misalignment of the track disk and, if applicable, the floating disk. The resulting small gaps lead to high shear stresses and thus to a significant heat input into the system. At the same time, there are interactions between the temperatures and the hydrodynamic properties (thermal expansion, viscosity), which is why the transient temperature development of the bearing partners and the oil must be modeled. In addition, radial and axial bearings are connected to each other via the oil supply lines, the influence of which must be recorded thermodynamically and hydrodynamically.
The individual aspects are mapped in a holistic simulation model, which includes rotor, hydrodynamics and thermodynamics, and the underlying differential equations are solved numerically within the framework of time integration, whereby the results of the previous project are consistently developed further.
Ultimately, the reliable simulation of subharmonic vibrations in frequency and amplitude should be made possible, as these cause safety-relevant issues (rubbing processes) as well as having drastic effects on the power loss and service life of the bearings
This text was translated with DeepL
2024
Peer-reviewed journal article
Identifying a suitable material model to simulate the mechanical load transfer into the humeral bone in stemless shoulder endoprostheses
Strackeljan, Cornelius; Duvigneau, Fabian; Borgolte, Melissa; Lohmann, Christoph H.; Döring, Joachim; Berth, Alexander; Woschke, Elmar
In: Proceedings in applied mathematics and mechanics - Weinheim : Wiley-VCH, Bd. 24 (2024), Heft 3, Artikel e202400100, insges. 10 S.
Non-peer-reviewed journal article
Measurement data of the compressive strength in the trabecular region of humeral heads taken from shoulder surgeries
Strackeljan, Cornelius; Borgolte, Melissa; Döring, Joachim; Berth, Alexander; Woschke, Elmar
In: Magdeburg: Otto-von-Guericke Universität, 2024, 1 Online-Ressource [2 Dateien im zip und xlsx-Format; Vollständiger Messdatensatz zu Strackeljan, Duvigneau, Borgolte, Lohmann, Döring, Berth und Woschke – "Identifying a suitable material model to simulate the mechanical load transfer into the humeral bone in stemless shoulder endoprostheses", DOI:10.1002/pamm.202400100]
2023
Peer-reviewed journal article
Nonlinear vibration phenomena in hydrodynamically supported rotor systems
Nitzschke, Steffen; Woschke, Elmar; Strackeljan, Cornelius
In: GAMM-Mitteilungen / Gesellschaft für Angewandte Mathematik und Mechanik - Weinheim : Wiley-VCH . - 2023, insges. 21 S. [Online first]
Dissertation
Thermo-hydrodynamische Gleitlagermodelle für die instationäre Simulation von Rotorschwingungen
Strackeljan, Cornelius; Woschke, Elmar
In: Magdeburg: Universitätsbibliothek, Dissertation Otto-von-Guericke-Universität Magdeburg, Fakultät für Maschinenbau 2023, 1 Online-Ressource (XI, 143 Seiten, 11,91 MB) [Literaturverzeichnis: Seite 135-143][Literaturverzeichnis: Seite 135-143]
2022
Peer-reviewed journal article
Influence of lubricant film cavitation on the vibration behaviour of a semi-floating ring supported turbocharger rotor with thrust bearing
Ziese, Christian; Strackeljan, Cornelius; Nitzschke, Steffen; Daniel, Christian; Woschke, Elmar; Klimpel, Thomas
In: Journal of engineering for gas turbines and power - New York, NY : ASME, Bd. 144 (2022), insges. 19 S.
Article in conference proceedings
Dynamics of TC rotors with coupled bearings FVV no. 1373 - final report (AB)
Strackeljan, Cornelius; Ziese, Christian
In: The FVV Transfer + Networking Event , 2022 - Frankfurt am Main : FVV, S. 826-857 [The FVV Transfer + Networking Event, Würzburg, October 2022]
Scientific monograph
Dynamik von ATL-Rotoren mit gekoppelter Lagerung - transiente Simulation der nichtlinearen Dynamik von Abgasturbolader-Rotoren unter Berücksichtigung der Wechselwirkungen von Radial- und Axialgleitlagern über das Ölversorgungssystem : Abschlussbericht zum FVV-Vorhaben 1373
Strackeljan, Cornelius; Ziese, Christian
In: Frankfurt am Main: FVV, 2022, 1 Online-Ressource
2021
Book chapter
Run-up simulation of a floating ring supported turbocharger rotor with thrust bearing considering mass-conserving cavitation
Ziese, Christian; Strackeljan, Cornelius; Nitzschke, Steffen; Woschke, Elmar
In: The 14th International Conference on Dynamics of Rotating Machines , 2021 - Gdańsk : Wydawnictwo IMP PAN, S. 134-144 [Konferenz: 14th International Conference on Dynamics of Rotating Machines, SIRM 2021, Gdańsk, Poland, February 17-19, 2021]
Run-up simulation of an automotive turbocharger rotor using an extensive thermo-hydrodynamic bearing model
Strackeljan, Cornelius; Ziese, Christian; Kreschel, Martin; Woschke, Elmar
In: The 14th International Conference on Dynamics of Rotating Machines , 2021 - Gdańsk : Wydawnictwo IMP PAN, S. 145-155 [Konferenz: 14th International Conference on Dynamics of Rotating Machines, SIRM 2021, Gdańsk, Poland, February 17-19, 2021]
Peer-reviewed journal article
Influence of thermally induced changes in lubricating gap clearance and oil viscosity on nonlinear oscillations of hydrodynamically supported rotors
Strackeljan, Cornelius; Ziese, Christian; Woschke, Elmar
In: Proceedings in applied mathematics and mechanics - Weinheim : Wiley-VCH, Bd. 21 (2021), Heft 1, Artikel e202100167, insges. 2 S.
Influence of lubricant film cavitation on the rotor dynamic system behaviour of an exhaust gas turbocharger rotor
Ziese, Christian; Strackeljan, Cornelius; Woschke, Elmar
In: Proceedings in applied mathematics and mechanics - Weinheim : Wiley-VCH, Bd. 20 (2021), Heft 1, Artikel e202000053, insges. 2 S. [Special Issue: 91st Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM)]
Run-up simulation of a semi-floating ring supported turbocharger rotor considering thrust bearing and mass-conserving cavitation
Ziese, Christian; Strackeljan, Cornelius; Nitzschke, Steffen; Daniel, Christian; Woschke, Elmar
In: Lubricants - Basel : MDPI, Bd. 9 (2021), Heft 4, Artikel 44, insges. 23 S.
Article in conference proceedings
Dynamics of TC rotors with coupled bearings - FVV no. 1373 : interim report - Dynamik von ATL-Rotoren mit gekoppelter Lagerung - FVV Nr. 1373 : Zwischenbericht (ZB)
Strackeljan, Cornelius; Ziese, Christian
In: Herbsttagung 2021 / Forschungsvereinigung Verbrennungskraftmaschinen , 2021 - Frankfurt am Main : Forschungsvereinigung Verbrennungskraftmaschinen e.V., S. 547-578 [Tagung: FVV Herbsttagung 2021, Nürnberg, 08. - 09. November 2021]
2020
Article in conference proceedings
Thermally extended rotordynamics of turbochargers FVV no. 1258 final report
Irmscher, Cornelius; Ziese, Christian
In: FVV Autumn Conference - Frankfurt am Main : Forschungsvereinigung Verbrennungskraftmaschinen e.V. . - 2020, S. 509-556 [Konferenz: FVV 2020 Autumn Conference, digital conference, 21 - 25 September 2020]
2019
Book chapter
Transient thermo-hydrodynamic analysis of a laval rotor supported by journal bearings with respect to calculation times
Irmscher, Cornelius; Nitzschke, Steffen; Woschke, Elmar
In: Proceedings of 13th SIRM, the 13th International Conference on Dynamics of Rotating Machinery - Lyngby, Denmark : Department of Mechanical Engineering, Technical University of Denmark ; Santos, Ilmar Ferreira . - 2019, S. 162-173 [Konferenz: 13th International Conference on Dynamics of Rotating Machinery, Lyngby, Copenhagen, 13-15 February 2019]
2018
Peer-reviewed journal article
Design, optimisation and testing of a compact, inexpensive elastic element for series elastic actuators
Irmscher, Cornelius; Woschke, Elmar; May, Erik; Daniel, Christian
In: Medical engineering & physics - Amsterdam [u.a.] : Elsevier Science, Bd. 52 (2018), S. 84-89
Influence of friction-induced heating on the dynamic behaviour of rotors supported by journal bearings
Irmscher, Cornelius; Nitzschke, Steffen; Daniel, Christian; Woschke, Elmar
In: Proceedings in applied mathematics and mechanics - Weinheim : Wiley-VCH - Vol. 18.2018, 1, Art. e201800412 [Special Issue: 89th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM), December 2018]
Article in conference proceedings
Thermisch erweiterte Rotordynamik von Turboladern - Erweiterte thermische Modellierung für die transiente, hydrodynamisch gekoppelte Simulation der nichtlinearen Rotordynamik von Turboladern - Zwischenbericht über das Vorhaben Nr. 1258 (IGF-Nr. 18760)
Ziese, Christian; Irmscher, Cornelius
In: Abschluss- und Zwischenberichte der Forschungsstellen Turbomaschinen / Forschungsvereinigung Verbrennungskraftmaschinen , 2018 - Frankfurt am Main : Forschungsvereinigung Verbrennungskraftmaschinen e.V, S. 145-181 [Tagung: FVV-Herbsttagung 2018, Würzburg, 27.-28. September 2018]
2017
Book chapter
Entwicklung und Erprobung eines flexiblen Messverfahrens mithilfe FEMgestützter Positionierung von Dehnungsmessstreifen
Koch, Sebastian; Irmscher, Cornelius; Daniel, Christian; Woschke, Elmar
In: 13. Magdeburger Maschinenbau-Tage 2017 , 2017 - Magdeburg : Universitätsbibliothek, S. 171-179 [Konferenz: MMT2017]
Radlastmessung an einem Elektrofahrzeug bei verschiedenen Fahrbahnbelägen inklusive Sonder- und Missbrauchsereignissen
Irmscher, Cornelius; Koch, Sebastian; Daniel, Christian; Woschke, Elmar
In: 13. Magdeburger Maschinenbau-Tage 2017 , 2017 - Magdeburg : Universitätsbibliothek, S. 94-104 [Konferenz: MMT2017]
2010-2013 | Bachelorstudium Maschinenbau Vertiefungsrichtung Mechanik und Produktentwicklung an der Otto-von-Guericke-Universität Magdeburg |
2013-2014 | Praktikant bei der MAN Diesel&Turbo SE, Augsburg |
2014-2016 | Masterstudium Maschinenbau Vertiefungsrichtung Produktentwicklung und Berechnung an der Otto-von-Guericke-Universität Magdeburg |
2014-2016 | Hilfswissenschaftlicher Mitarbeiter am Institut für Mechanik (IFME) bzw. am Institut für Maschinenkonstruktion (IMK) der Otto-von-Guericke-Universität Magdeburg |
seit 2016 | Wissenschaftlicher Mitarbeiter am IFME, Lehrstuhl JP Fluid-Struktur-Kopplung in Mehrkörpersystemen, Otto-von-Guericke-Universität Magdeburg |
- Dynamics of Motion (exercises) ( Link zur LV im LSF )
- Technische Mechanik 3 - Übung - MB ( Link zur LV im LSF )