Materials with an optimal load-carrying behavior are often composed of different material phases, arranged in a certain material microstructure, in order to combine the advantageous properties of each phase. Whilst optimal arrangements for the respective types of loading have evolved naturally for biological materials, the development of many man-made materials is still governed by intuition and trial-and-error approaches.
This research project has been working on the optimal performance of materials with respect to dynamic and even impact loading, allowing for the performance-based development of energy-absorbing materials. The problem has been tackled from two directions:
· in order to specify the mechanical behavior of materials showing time-dependent and highly dissipative behavior, the multiscale approach of material description, so far restricted to a homogenous deformation pattern within a representative volume element, has been extended to localized deformation situations as observed in the case of impact loading.
· the relations between impact loading, macroscopic material properties, and objective functions related to energy dissipation in composite materials have been expressed by general master curves allowing for the direct optimization depending on the respective load characteristics. The performance of the developed optimization procedure is assessed by experimental validations of the impact of spherical bodies with prescribed velocity on material samples characterized by varying microstructures.
Consequently, the project team originally consisted of two teams: The group at DCAMM/DTU (Danish Center for Applied Mathematics and Mechanics / Danmarks Tekniske Universitet), responsible for the micro-scale description and the upscaling procedure by topology optimization, and the group for the optimization procedures on the structural scale (i.e. macroscale) at TUM. During the project phase, PI Roman Lackner successfully applied for a professorship at the Unit of Material Technology Innsbruck and accepted the subsequent call. By this extension of the research team, we have gained new opportunities by the access to the specialized laboratories at the Unit of Material Technology Innsbruck.