Mechanical modeling of microstructures in elasto-plastically deformed crystalline solids [Elektronische Ressource] / von Dennis Michael Kochmann

MechanicalModelingofMicrostructuresinElasto-PlasticallyDeformedCrystallineSolidsDissertationzurErlangung des GradesDoktor-IngenieurderFakultat¨ fur¨ Maschinenbauder Ruhr-Universitat¨ BochumvonDennis Michael Kochmannaus BottropBochum 2009Dissertation eingereicht am: 29. April 2009Tag der mundlichen¨ Prufung:¨ 29. Juni 2009Erster Referent: Prof. Dr. rer. nat Klaus HacklZweiter Prof. Dr. rer. nat. Khanh Chau LeVorsitzender: Prof. Dr. rer. nat. Alexander HartmaierDie Neigung der Menschen, kleine Dinge fur¨ wichtig zu halten,hat sehr viel Großes hervorgebracht.Georg Christoph LichtenbergHerausgeber:Institut fur¨ Mechanik— Schriftenreihe —Ruhr-Universitat¨ BochumD-44780 Bochumc ¨ ¨ 2009 Dennis M. Kochmann, Institut fur Mechanik, Ruhr-Universitat BochumPrinted in GermanyvSummaryThis thesis reports research progress on several fields of modeling microstructures in crystal-line solids under elasto-plastic deformations. Based on thermodynamic minimum principles,the origin and subsequent evolution of microstructures is analyzed and computational tech-niques for their determination are presented. The present work decomposes into two majorparts which emphasize different modeling aspects in this context.In the first part, microstructures as minimizers of non-convex energy potentials in fini-te plasticity are investigated, following the thermodynamic principles of minimum potentialenergy and of minimum dissipation potential.