Autonomous research for exploring structure-property linkages and optimizing microstructures

• Applicants: Professor Dr.-Ing. Markus Kästner; Professor Dr. Daniel Peterseim
• Subject Area: Mechanics ; Mathematics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 496984632

Developing novel materials plays an important role in technological innovations. Especially the relationship between the process parameters, the local material structure and the resulting properties is of great interest. Since the local structure of the materials essentially dictates its properties, the generation and understanding of structure-property (SP) linkages is of utmost importance. The envisioned project aims to establish reliable SP linkages fast and cheaply, thereby identifying realistic, manufacturable material structures with optimal properties.The experimental exploration of SP linkages requires considerable technological effort, which is associated with high costs. The achievable limited data basis is a major obstacle for the application of modern machine learning methods. To this end, model-based numerical simulations can provide a remedy in the form of synthetic data to reduce the number of complex and expensive experiments. Furthermore, a practically relevant algorithm requires the automated generation of synthetic microstructures and numerical simulations on selected samples in order to systematically extend the experimental data base. This procedure, referred to as autonomous research, is developed in four steps: 1) Stationary, translation-invariant microstructure descriptors are developed that are rich in morphological information and allow for a fast reconstruction. 2) Efficiently reconstructing a microstructure from such a description is a current research topic. Based on first preliminary results, a fast and universally applicable algorithm is developed. 3) The numerical simulations for the determination of effective properties are rendered efficiently through a hierarchy of models and numerical resolutions and are supplemented by uncertainty quantification. 4) Taking the previously calculated microstructure-property pairs calculated into account, an SP linkage is established and its optimum is estimated. Based on this estimate, the next sample is selected and the autonomous loop is closed.These four steps are developed and implemented in a material-independent manner and validated using two exemplary microstructures. The effective property as the objective of SP linkages and optimization is equally generic. In this project, beyond the prediction of elastic properties, damage tolerance is considered in terms of an effective critical energy release rate.Altogether, the synthesis of model-based numerical simulation and data-driven algorithms promises to provide a deeper understanding of the mechanisms of action underlying SP linkages, as well as to accelerate materials development.

• DFG Programme: Research Grants