The use of data-driven approaches for exploring synergies between experiment and simulation

　　Professor Stefan Sandfeld

　　Micromechanical Materials Modelling | IMFD/MiMM

　　TU Bergakademie Freiberg, Lampadiusstr. 4, room 125,

　　09599 Freiberg, Germany

　　Experimental observations and simulation data should – in principle – help to shed light on the “inner workings” of a physical system, say, a material or specimen. There, the “inner workings” would be the interaction of microstructural features (such as dislocations) among themselves, with the surfaces of the specimen, or with phase boundaries, to name but a few. Both experiment and simulation, however, suffer from particular problems which in many situations makes it difficult to directly compare them or to use results from one as input or support for the other. We will give an overview over current attempts for integrating experiment and simulation in the context of data driven approaches. We will then demonstrate, on the one hand, how data science approaches might be used to access data from experiments that would be otherwise inaccessible and, on the other hand, how data science also might help to reduce the high level of abstraction inherent to most simulations. We will show that with those methods, a real bridge between experiment and simulation might finally emerge.

 

　　Thermally-activated dislocation plasticity in BCC Cr characterized by high-temperature nanoindentation

　　Professor Ruth Schwaiger

　　Institute for Applied Materials - Materials and Biomechanics

　　Karlsruhe Institute of Technology

　　Hermann-von-Helmholtz-Platz 1,

　　76344 Eggenstein-Leopoldshafen, Karlsruhe Germany

    The application of body centered cubic (BCC) refractory metals is usually limited by the low temperature brittleness, which is intrinsically linked to the limited screw dislocation mobility. In this study, high-temperature nanoindentation experiments were conducted to determine the dislocation mobility regimes with and without interstitial impurities in pure Cr. Samples having different levels of impurities were tested from room temperature to 600 K and the temperature-dependent hardness, activation volume and apparent activation enthalpy determined. The signatures of the underlying plastic deformation mechanisms are compared to the mobility from theory. A detailed quantitative analysis of the experimental data revealed the solute-drag and kink-pair nucleation-limited dislocation mobility regimes. The latter is subdivided into elastic interaction and line-tension regimes showing characteristic changes of slip system signatures with increasing temperature.

 

时　 间：8月15日（周四）14：00-16：30

地　 点：李薰楼249会议室