@phdthesis{,
    author = {Schmidt, Marco},
    title = {Biaxiale Experimente und numerische Simulationen mit neu entwickelten Probekörpern zur Vorhersage der Schädigung und des Versagens duktiler Metalle},
    editor = {},
    booktitle = {},
    series = {},
    journal = {},
    address = {},
    publisher = {},
    edition = {},
    year = {2020},
    isbn = {},
    volume = {},
    number =  {},
    pages = {},
    url = {},
    doi = {},
    keywords = {biaxial experiments, ductil metals, numerical simulations, damage and crack behavior, digital image correlation, Ansys},
    abstract = {The predictability of damage and failure processes in ductile metals, which are dependent on the stress state, are experimentally and numerically examined throughout this work. Various load cases are tested on biaxial test specimens made of aluminum and steel alloy until the material fails. They are then compared with corresponding elastic-plastic-damaging simulations. A commercial finite element program with its own material routine that is based on a phenomenological, micromechanically motivated continuum damage model with stress-dependent damage development is used for the simulations. Because the various damage mechanisms depend on the stress state, the biaxial test specimens are examined under different load cases in order to determine the maximum possible range of stress triaxiality and lode parameter. These different representations of the stress state denoted throughout the text play an important role in damage and failure modeling. In this context, two new types of biaxials and one other previously used biaxial test specimen were assessed with regard to their geometry, the occurring stress states, as well as suitability for the investigation of ductile damage and failure processes. The damage observed in experiments, which includes among other things the softening behavior and the damage mechanisms that occur, is compared with numerically determined stress and strain values in order to show relationships. With the investigation of strongly pressure-dominant load cases, the limit value of the negative stress triaxiality is also determined and a novel stress-dependent function for this is suggested. Furthermore, a crack criterion that is based on invariants of the numerically determined damage strain tensor is formulated and thus, both isotropic and anisotropic damage mechanisms are also considered. The material parameters required for the crack criterion are analyzed depending on the stress state and then formulated.},
    note = {},
    
    school = {Universität der Bundeswehr München},
    
}