B3/II Mesomechanical modelling of hybrid reinforced concrete structures at impact loading

Doctoral Researcher
Julien Stöcker

Principal Investigator
Michael Kaliske

in cooperation with 
Stefan Löhnert
Chokri Cherif

Project poster
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The hybrid reinforcement of concrete composite structures made of textile reinforcement embedded in a short fiber reinforced concrete matrix (SHCC) combines the advantageous properties of both types of reinforcements with regard to impact loading. For an optimal design of the composite structure, it is necessary to characterize the interactions of the base materials as well as the resulting mesomechanical properties. Numerical simulation methods are an ideal tool for this purpose. The knowledge gained enables the development of effective material models for the analysis of a structural component. Furthermore, the influence of the inherent scattering of structural and material parameters can be numerically quantified by a polymorphic uncertainty analysis.

FE-model of a representative volume element (RVE)

FE-model of a representative volume element (RVE)   

For the multi-scale analysis of textile reinforced concrete, an FE-model of the mesostructure in form of a representative volume element (RVE, see figure) was developed in the PhD project B3 of the first cohort. Besides the geometric representation, suitable constitutive formulations of the base materials and their interactions were formulated. The derived numerical models in GRK 2250/1 should be extended for the representation of hybrid reinforcement. For this purpose, a suitable description of the SHCC matrix on the meso-level, which represents the relevant properties, should be developed. A micromorphic damage approach should be implemented to model degradation. The mechanical behavior of the RVE shall be investigated at static and dynamic loads. Here, suitable boundary conditions for dynamic load cases are to be selected. The effective composite behavior is derived by means of virtual material tests and validated by experimental results. The focus is on the development of efficient and reliable metamodels for the description of the effective RVE behavior and their application in structural simulations. The developed approaches form the basis for a scale bridging uncertainty analyses.