The OSU Materials Science and Engineering department will host a colloquium on Friday, July 15 with Peter Gumbsch, one of the leaders in the computational materials science field.
MSE Special Colloquium
Friday, July 15 at 3:30 PM
395Watts Hall, 2041 College Road
New Microstructure-Based Approaches to the Plastic Deformation of Metals
Peter Gumbsch
Institute for Applied Materials IAM, Karlsruhe Institute of Technology KIT, Germany
and Fraunhofer Institute for Mechanics of Materials IWM, Freiburg, Germany
Abstract
Metal forming simulations today are based on classical constitutive descriptions of yield behavior and hardening. Microstructural materials characteristics like texture, grain size or dislocation microstructure are rarely considered and never systematically evolved. This is due to a lack of available methodology. I therefore see a need for mechanistic and physically-consistent descriptions of plastic deformation on all levels of structural complexity. I will address three levels: First, the behaviour of individual dislocations and single crystal plasticity or plastic deformation in single crystalline microcomponents are assessed using atomistic and discrete dislocation dynamics simulations. On the atomistic end I will report about recent progress in modelling magnetic bcc iron [1]. Discrete dislocation dynamics simulations are used to assess the (stochastic) response of microcomponents and to represent size effects [2]. Second, progress in the development of a dislocation density based continuum theory of plasticity is demonstrated [3]. Third, advanced homogenization techniques are used to bridge from single crystal plasticity to the deformation behavior of polycrystals. In a “virtual lab” one thereby computes texture evolution and associated changes in the yield locus [4].
[1] M. Mrovec, D. Nguyen-Manh, C. Elsässer, P. Gumbsch, »Magnetic Bond-Order Potential for Iron«, Physical Review Letters 106 (2011) 246402 1-4. [2] J. Senger, D. Weygand, C. Motz, P. Gumbsch, O. Kraft, »Aspect ratio and stochastic effects in the plasticity of uniformly loaded micrometer-sized specimens«, Acta Materialia 59 (2011) 2937-2947. [3] S. Sandfeld, T. Hochrainer, M. Zaiser P. Gumbsch, »Continuum modeling of dislocation plasticity: Theory, numerical implementation, and validation by discrete dislocation simulations«, Journal of Material Research 26 (2011) 623-632. [4] D. Helm, A. Butz, D. Raabe, P. Gumbsch , »Microstructure-based Description of the Deformation of Metals: Theory and Application«, JOM 63 (2011) 26-33.Speaker Bio
Peter Gumbsch received the diploma degree in physics in 1988 and his PhD degree in 1991 from the University of Stuttgart. After extended visits at the Sandia National Laboratories in Livermore, postdoctoral work at the Imperial College, London and the University of Oxford he returned to the Max-Planck-Institut in Stuttgart as a group leader and established the group “Modeling and Simulation of Thin Film Phenomena.” In 2001 he took his current application-oriented position at the Fraunhofer Intitute for Mechanics of Materials IWM in Freiburg and Halle and at the Karlsruhe Institute of Technology KIT.
His research activities focus on modeling and simulation of materials, in particular multiscale modelling approaches. His activities cover atomistic simulation, mesoscopic modeling as well as macroscopic materials descriptions. Central research topics are deformation and fracture processes as well as interface properties in metals and ceramics. He has recently started new activities in the area of tribology. Amongst other recognitions he was awarded the Otto Hahn Medal (1992), the Masing Memorial Award (1998), and the Gottfried Wilhelm Leibniz Prize (2007). He is member of the German Academy of Sciences Leopoldina.