Modelling Fragmentation in Large Scale DEM Simulations

Topic:

Development of techniques for the physically correct handling of particle fragmentation in numerical DEM simulations of granular material.

Motivation/Aim:

During the past decade, Discrete Element Simulation (DEM) made great progress and is by now generally acknowledged as a reliable tool for the description of bulk solids in a variety of applications. Comminution and wear belong to the most important technological processes in particle engineering. To simulate such processes, DEM has to be extended to take into account the fragmentation of particles. The fracture of a particle is a highly complicated problem by its own, therefore, in order to simulate a relevant amount of granular material comprising a large number of grains, simplifying assumptions are needed which, however, represent the essential features of fragmentation processes sufficiently well. Currently, the predictive power of DEM simulations is still poor when dealing with fragmentation probabilities and fragment size distributions. Despite the fact that common granular particles reveal a variety of characteristic shapes, current approaches use purely spherical models. Other important effects like wear of the material and generation of heat due to fragmentation and plastic deformation are neglected as well by current models, impeding a reliable description of material behavior including failure. The aim of the research project is to close this gap and to develop a particle model which allows for both, realistic modelling of fragmentation in DEM simulations and at the same time highly efficient large scale simulations.

Your tasks:

In your work you will enable large scale DEM simulations with realistic modelling of fragmentation. To that you will

develop and implement non-spherical particle models using a multi-sphere approach,
derive and implement statistically correct load dependent fragmentation probabilities and fragment size distribution in agreement with empirical laws,
model secondary effects such as plastic deformation, heat transfer and wear (ageing),
validate and apply your models by optimizing milling processes on the industrial scale.

The derived particle models shall be incorporated to a HPC suited DEM environment like e.g. LIGGGHTS. You will present and publish your results on conferences and in journals.

Your Profile/Qualification:

You are highly motivated and you are deeply committed to research. You are able to work independently and as part of a team. You are equipped with an analytical and critical mind-set and you communicate clearly and concisely.

master’s degree in physics, computational engineering, mechanical engineering or related
programming skills (preferably C++, Python)
experience in particle simulations (e.g. DEM) is a plus
good speaking and writing skills in English

Environment:

You will work at the Institute for Multiscale Simulation (MSS, www.mss.tf.fau.de) of the Friedrich Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany. At MSS, we investigate the multiscale physics of particulate systems. The international research team offers an interdisciplinary environment, working numerically, theoretically and experimentally. The project is part of the interdisciplinary research training group Fracture across Scales (FRASCAL, GRK 2423, www.frascal.research.fau.eu). FRASCAL comprises 11 doctoral projects and 1 postdoctoral project The overall aim of FRASCAL is to train the next generation of scientists and engineers to become experts in fracture who successfully bridge scales, materials, and disciplines.

Our offer:

We offer a fully funded PhD position according to German salary level TV-L E13. The position is available immediately and limited to three years.

Your application:

Send questions and your application (single pdf including reference number MSS-2025-FR, motivation letter, CV and, if applicable, a list of your publications) to PD Dr. Patric Müller, mss-recruitment@fau.de
Review of applications begins on February 20th, 2025.