@inproceedings{StaatHeitzerReindersetal.2001,
  author    = {Staat, Manfred and Heitzer, Michael and Reinders, H. and Schubert, F.},
  title     = {Einspielen und Ratchetting bei Zug- und Torsionsbelastung: Analyse und Experimente},
  year      = {2001},
  abstract  = {Traglast- und Einspielanalysen sind vereinfachte doch exakte Verfahren der klassischen Plastizit{\"a}tstheorie, die neben ausreichender Verformbarkeit keine einschr{\"a}nkenden Voraussetzungen beinhalten. Die Vereinfachungen betreffen die Beschaffung der Daten und Modelle f{\"u}r Details der Lastgeschichte und des Stoffverhaltens. Eine FEM-basierte Traglast- und Einspielanalyse f{\"u}r ideal plastisches Material wurde auf ein kinematisch verfestigendes Materialgesetz erweitert und in das Finite Element Programm PERMAS implementiert. In einem einfachen Zug-Torsionsexperiment wurde eine Hohlprobe mit konstanter Torsion und zyklischer Zugbelastung beansprucht, um die neue Implementierung zu verifizieren. Es konnte gezeigt werden, dass die Einspielanalyse gut mit den experimentellen Ergebnissen {\"u}bereinstimmt. Bei Verfestigung lassen sich wesentlich gr{\"o}ßere Sicherheiten nachweisen. Dieses Potential bedarf weiterer experimenteller Absicherung. Parallel dazu ist die Eisnpieltheorie auf fortschrittliche Verfestigungsans{\"a}tze zu erweitern.},
  subject      = {Zug-Druck-Beanspruchung},
  language  = {de}
}
@article{Staat2000,
  author    = {Staat, Manfred},
  title     = {Direct FEM Limit and Shakedown Analysis with Uncertain Data},
  year      = {2000},
  abstract  = {The structural reliability with respect to plastic collapse or to inadaptation is formulated on the basis of the lower bound limit and shakedown theorems. A direct definition of the limit state function is achieved which permits the use of the highly effective first order reliability methods (FORM) is achieved. The theorems are implemented into a general purpose FEM program in a way capable of large-scale analysis. The limit state function and its gradient are obtained from a mathematical optimization problem. This direct approach reduces considerably the necessary knowledge of uncertain technological input data, the computing time, and the numerical error, leading to highly effective and precise reliability analyses.},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}
@article{Staat2003,
  author    = {Staat, Manfred},
  title     = {Shakedown and ratchetting under tension-torsion loadings: analysis and experiments},
  year      = {2003},
  abstract  = {Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis.},
  subject      = {Einspielen <Werkstoff>},
  language  = {en}
}
@inproceedings{StaatHeitzer2002,
  author    = {Staat, Manfred and Heitzer, Michael},
  title     = {The restricted influence of kinematic hardening on shakedown loads},
  year      = {2002},
  abstract  = {Structural design analyses are conducted with the aim of verifying the exclusion of ratcheting. To this end it is important to make a clear distinction between the shakedown range and the ratcheting range. In cyclic plasticity more sophisticated hardening models have been suggested in order to model the strain evolution observed in ratcheting experiments. The hardening models used in shakedown analysis are comparatively simple. It is shown that shakedown analysis can make quite stable predictions of admissible load ranges despite the simplicity of the underlying hardening models. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis. Both give identical or similar shakedown ranges. Structural shakedown analyses show that the loading may have a more pronounced effect than the hardening model.},
  subject      = {Biomedizinische Technik},
  language  = {en}
}