Project Details
Projekt
Stochastic spatiotemporal analysis of 3D particle systems under shear and statistical validation of numerical DEM simulations
Applicant
Professor Dr. Volker Schmidt
Subject Area
Mechanical Process Engineering
Term
from 2014 to 2016
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 258662145
The main task of the DFG priority programme 1486 is to understand the physicochemical (micro-) processes during approach, contact and detachment of cohesive particles, and to implement this knowledge for product design in solids process engineering. By knowledge of contact mechanics it is possible to numerically determine spatial positions, velocities and accelerations of all particles in a system. Therefore, an important step during the third and last funding period of the priority programme 1486 is the analysis of experimental data and the identification of relationships between properties on the micro- and macro-scale. By comparison of data obtained from real and simulated experiments, numerical DEM simulations and their contact models can be validated. Such a validation then allows systematic variation of particle properties with the purpose to detect relationships between the micro- and macro-scale. In the proposed research project of the group of Prof. Schmidt, these validation tasks will be investigated with help of statistical approaches based on spatiotemporal models. Stochastic analyses and models help to essentially reduce the complexity of experimental (and time-resolved) 3D image data and permit an efficient quantitative description and evaluation of experimental image data as well as statistical comparisons with numerically obtained results. Real experiments and numerical simulations are performed by partner groups within the priority programme, particularly by the groups of Prof. Kwade, Prof. Wolf and Dr. Auernhammer. 3D image data of shear tests is available for various time steps (angles of shear, respectively). Particles, tracks of particles and contact networks will be extracted from such experimental image data, in particular also for non-spherical particles. Using automatic algorithms, homogeneous regions (with respect to particle behavior) will be identified in the inhomogeneous and anisotropic (dynamic) contact network. For each of these regions, the experimental contact network will be described quantitatively using stochastic analyses. Numerically obtained contact networks will be validated by statistical tests for equality. To make this possible, we will describe the "typical" behavior of particles in dependence of the currently considered region and the particle's properties like particle size, shape and adhesion. Furthermore, contact networks will be modeled by random graphs, which enables us to implement statistical tests on the level of particle systems.
DFG Programme
Priority Programmes
