Numerical simulations of multiaxial damage behaviour of concrete using the method of discrete elements

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The aim of the project is to explore the potential of the discrete element method with regard to the quasi-static and dynamic material behaviour of concrete and to obtain insights into crack evolution and damage mechanisms. The aim includes, in particular, the investigation of material behaviour under different loading conditions using one and the same basic model approach and the principally same simulation code. DEM simulations allow to use the same virtual specimens under different loading conditions and loading velocities. The underlying contact approach which is used for the calculation of the contact forces of interacting particles and the parameters of the contact approach are the only a priori assumptions. No assumptions or elements regarding potential cracks and no damage model are included. Effects based on fragmentation and mesostructural rearrangement are the result of the simulation instead.Furthermore, discrete element simulations are suited for the analysis of the material behaviour under high loading velocities as they occur in impact situations. Due to the particle-based character and due the usage of Newtons second law the DEM simulations allow the qualitative and quantitative study of the complex dynamic phenomena related to the shock wave propagation in concrete. As part of the project, discrete element simulations are to be developed further with a numerical tool for conception and design of laboratory experiments in view. The interpretation and extrapolation of experimental results are further applications of numerical simulations using discrete elements. Investigations under quasi-static load and under impact load using virtual homogeneous specimens and specimens with mesostructure as well as investigations of the strain rate effect are planned within the proposed project phase.