The overarching goal of this research project is to develop a mechanistically informed model incorporating microstructural length-scale effects into scaling laws to describe the mechanical behaviour of nanoporous gold (np-Au) and nanoporous silicon (np-Si) at different hierarchical scales.
The approach taken incorporates micromechanical experiments, microstructural characterization and multiscale-modelling approaches with which the influences of salient structural characteristics will be identified and carried over to coarsened models. To this end, neural network modelling will be used to identify a critical subset of structural parameters needed to describe experimentally observed mechanical response. Unlike traditional materials, it is unclear a priori what the influence of size and hierarchical level is on the mechanisms of deformation; size-dependent and hierarchy-dependent deformation mechanisms must be explicitly identified through targeted micromechanical experiments to investigate structural influences of np-AU and np-Si over two or even three levels of hierarchy.
The model development is based on outcomes from both experiments and modeling from the previous funding phases. Describing the mechanical behavior of np-Au is makes use of beam models for achieving relevant deformation modes with increased computational efficiency, as a function of structural parameters such as solid fraction, ligament size distribution, and structural disorder. The latter includes various levels ranging from the connectivity of the ligament network and the distortion of the ligament axis down to the variation of the cross-section of the ligaments. The effective mechanical behavior will be translated to the next hierarchy level by surrogate models that are based on machine learning. The computational modeling of np-Si without and with polymer infiltration uses FE-voxel models generated from TEM tomography data. This allows for comparing the macroscopic mechanical behavior of the material under electromechanical actuation in an experimental in-situ setup and provides complementary information about the mechanisms on the micro and nanoscale.
In the end, a key challenge will be to find appropriate homogenization schemes in order to understand and predict the mechanical behavior over several hierarchical levels in the material system for such complex, multiscale material systems.
|Dr. rer. nat. Jürgen Markmann,
|Prof. Dr. Norbert Huber,
interfaces & interphases
scaling laws composites
1. Brinker, M.; Dittrich, G.; Richert, C.; Lakner, P.; Krekeler, T.; Keller, T.F.; Huber, N.; Huber, P. Giant electrochemical actuation in a nanoporous silicon-polypyrrole hybrid material. Science Advances 2020, 6, doi:10.1126/sciadv.aba1483.
2. Huber, N. A Strategy for Dimensionality Reduction and Data Analysis Applied to Microstructure–Property Relationships of Nanoporous Metals. Materials 2021, 14, 1822, doi:10.3390/ma14081822.
3. Brinker, M.; Dittrich, G.; Richert, C.; Lakner, P.; Krekeler, T.; Keller, T.F.; Huber, N.; Huber, P. Giant electrochemical actuation in a nanoporous silicon-polypyrrole hybrid material. Science Advances 2020, 6, doi:10.1126/sciadv.aba1483.
... and more on the list of publications.