We congratulate Moritz Zistl on his PhD
28 July 2022
Moritz Zistl, a former research assistant at our institute (Structural Mechanics), successfully defended his PhD thesis on July 28, 2022. We congratulate him most sincerely!
The title of his thesis:
"Modellbildung und experimentell-numerische Untersuchungen zur Schädigung und zum Versagen duktiler Metalle unter nichtproportionaler Belastung"
("Modeling and experimental-numerical investigations on the damage and failure of ductile metals under non-proportional loading")
Univ.-Prof. Dr.-Ing. habil. Michael Brünig (University of the Bundeswehr Munich) Univ.-Prof. Dr.-Ing. habil. Stefanie Reese (RWTH Aachen University) and Univ.-Prof. Dr.-Ing. Stefan Hartmann (Clausthal University of Technology) acted as reviewers for this PhD thesis.
The thesis deals with the continuum-mechanical modeling of the damage behavior of metals under large deformations, its consideration within the framework of the finite element method, the execution of special experiments, and the parameter identification of the material parameters occurring in the material model.
This involves considering non-proportional load paths and tension-compression asymmetries. It is precisely at this point that the capabilities of an anisotropic damage model become apparent, a topic being thoroughly investigated by Mr. Zistl. A major challenge lies in identifying the material parameters, which, in a model for ductile behavior, can be subdivided into parameters for elastic, plastic, and damage behavior.
In addition to standard and newly developed biaxial experiments with various non-proportional load paths, corresponding numerical simulations are used to elucidate and predict damage and failure mechanisms under different loading conditions. This makes it possible to reduce costly experiments to the necessary minimum and largely replace them with numerical simulations and parameter studies. Furthermore, systematic analyses enable the development of new specimens for biaxial experiments with diverse load paths to cover a wide range of critical stress states.
