Curriculum Vitae

Since 02/2020	PhD Student / Research Assistant, Institute of Engineering Mechanics, Chair for Continuum Mechanics, in cooperation with the Institute of Fluid Mechanics, Karlsruhe Institute of Technology (KIT)
05/2019–11/2019	Master thesis: "Direct Numerical Simulation of the Anisotropic Flow of Fiber-Suspensions" Institute of Fluid Mechanics in cooperation with the Institute of Engineering Mechanics, Chair for Continuum Mechanics, Karlsruhe Institute of Technology (KIT)
04/2017–11/2019	Studies of Mechanical Engineering (Master) with the specialization "Theoretical Mechanical Engineering",Karlsruhe Institute of Technology (KIT) Major Field: "Applied Mechanics" and "Fluid Mechanics", Master´s degree with distinction
01/2017–03/2017	Bachelor thesis: "Comparison and Evaluation of the Application of Multi-Layer-Models for the Simulation of Short-Fiber Reinforced Polymers in Combination with Organo Sheets", Institute of Engineering Mechanics, Chair for Continuum Mechanics, Karlsruhe Institute of Technology (KIT), in cooperation with Schaeffler Technologies AG & Co. KG, Herzogenaurach
09/2016–12/2016	Internship in modeling and simulation of fiber reinforced polymers, department "Advanced Materials", Schaeffler Technologies AG & Co KG, Herzogenaurach
10/2013–03/2017	Studies of Mechanical Engineering (Bachelor), Karlsruhe Institute of Technology (KIT), Major Field: "Continuum Mechanics and Strength of Materials"

Field of Research

Fluid Mechanics and Homogenization of Anisotropic Flow Processes

During the processing of fiber-reinforced polymer materials by injection molding, the orientation of the fibers is determined by the flow field in the polymer melt. Since the orientation of the fibers significantly influences the anisotropic elastic properties of the manufactured part, a precise prediction of the orientation state at the end of mold filling is of great interest. The fibers induce an anisotropic viscous behavior of the fiber suspension that influences the flow field already during mold filling. One aim of the project is to investigate this so-called flow-fiber coupling with regard to the related effects on the predicted mechanical properties. The focus here is on micromechanical approaches for both the fiber-polymer melt and the composite.

In engineering practice, tensors are used to describe the orientation state, which are obtained by solving a suitable evolution equation. Since these equations are not closed, suitable approaches are required to close them. Another aim of the project is to develop closure methods that are both numerically efficient and accurately predict the evolution of the fiber orientation. In addition, closures are also used to predict the anisotropic viscous and elastic properties. The suitability of the developed closures in this context represents a further research objective.

Publications

Fiber orientation tensor approximations based on an implicitly defined closure approach
Karl, T.; Schneider, M.; Böhlke, T.
2023. 23rd International Conference on Composite Materials, ICCM 2023, Belfast 30th July-4th August 2023, Queen’s University Belfast

On fully symmetric implicit closure approximations for fiber orientation tensors
Karl, T.; Schneider, M.; Böhlke, T.
2023. Journal of Non-Newtonian Fluid Mechanics, 318, 105049. doi:10.1016/j.jnnfm.2023.105049

Influence of flow–fiber coupling during mold-filling on the stress field in short-fiber reinforced composites
Karl, T.; Zartmann, J.; Dalpke, S.; Gatti, D.; Frohnapfel, B.; Böhlke, T.
2023. Computational Mechanics, 71 (5), 991–1013. doi:10.1007/s00466-023-02277-z

Unified mean-field modeling of viscous short-fiber suspensions and solid short-fiber reinforced composites
Karl, T.; Böhlke, T.
2022. Archive of Applied Mechanics, 92 (12), 3695–3727. doi:10.1007/s00419-022-02257-4

Asymptotic fiber orientation states of the quadratically closed Folgar-Tucker equation and a subsequent closure improvement
Karl, T.; Gatti, D.; Frohnapfel, B.; Böhlke, T.
2021. Journal of Rheology, 65 (5), 999–1022. doi:10.1122/8.0000245

Coupled simulation of flow-induced viscous and elastic anisotropy of short-fiber reinforced composites
Karl, T.; Gatti, D.; Böhlke, T.; Frohnapfel, B.
2021. Acta mechanica, 232 (6), 2249–2268. doi:10.1007/s00707-020-02897-z

Conferences

Talks

2023

Karl, T., Schneider, M., Böhlke, T.:
Implicit fiber orientation tensor closures
MathSEE Symposium on Applications of Mathematical Sciences, 27.-29.09.2023, Karlsruhe, Germany

Karl, T., Schneider, M., Böhlke, T.:
Fiber orientation tensor approximations based on an implicitly defined closure approach
International Conference on Composite Materials, 30.07.-04.08.2023, Belfast, Northern Ireland

Karl, T., Zartmann, J., Dalpke, S., Gatti, D., Frohnapfel, B., Böhlke, T.:
Mean-field based modeling of anisotropic viscosity and flow-fiber coupled mold-filling simulation of short-fiber suspensions
16th International Conference on Advanced Computational Engineering and Experimenting, 03.-07.07.2023, Heraklion, Crete

Karl, T., Böhlke, T.:
Flow-fiber coupling of mold-filling fiber suspension simulations based on anisotropic viscosity and mean-field modeling
IRTG/ICRG Summer School 2023, 20.06.2023, WissenschaftsForum Berlin, Germany

Böhlke, T., Karl, T., Sterr, B., Krause, M., Gajek, S.:
Skalenübergreifende kontinuumsmechanische Modellierung von Kompositen und Polykristallen
Abschiedskolloquium H. Altenbach, 12.05.2023, Otto-von-Guericke-Universität Magdeburg, Germany

Karl, T., Böhlke, T.:
Mean-Field basierte Fließsimulationen von Fasersuspensionen unter Berücksichtigung anisotroper Viskosität
Kolloquium der Materialwissenschaft und Werkstofftechnik, 31.01.2023, Universität des Saarlandes, Saarbrücken, Germany

2022

Karl, T., Gatti, D., Frohnapfel, B., Böhlke, T.:
Asymptotic fiber orientation states of the quadratically closed Folgar-Tucker equation and a subsequent closure improvement,
8th ECCOMAS Congress 2022, 05.-09.06.2022, Oslo, Norway

2021

Karl, T., Gatti, D., Frohnapfel, B., Böhlke, T.:
Coupled simulation of flow-induced viscous and elastic anisotropy of short-fiber reinforced composites,
91st GAMM Annual Meeting 2020@21, 15.-19.03.2021, Kassel, Germany

Academic Teaching

Courses

Winter Semester 2023/2024

Übungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)
Rechnerübungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)

Summer Semester 2023

Vertretung ausgewählter Vorlesungen in Mathematische Methoden der Mikromechanik (MMM)
Übungen zu Mathematische Methoden der Mikromechanik (MMM)
Übungen zu Nonlinear Continuum Mechanics (NCM)

Winter Semester 2022/2023

Übungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)
Rechnerübungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)

Summer Semester 2022

Übungen zu Mathematische Methoden der Mikromechanik (MMM)
Übungen zu Nonlinear Continuum Mechanics (NCM)

Winter Semester 2021/2022

Übungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)
Rechnerübungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)

Summer Semester 2021

Übungen zu Mathematische Methoden der Mikromechanik (MMM)
Übungen zu Nonlinear Continuum Mechanics (NCM)

Winter Semester 2020/2021

Übungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)
Rechnerübungen zu Kontinuumsmechanik der Festkörper und Fluide (KMFF)

Summer Semester 2020

Rechnerübungen zu Einführung in die Finite-Elemente-Methode (FEM)
Übungen zu Mathematische Methoden der Mikromechanik (MMM)