Mechanical interactions of micrometer-sized particles based on calibrated contact models

研究和模拟单个粒子之间的接触行为是前两个工作阶段的主要目标。在PiKo的最后阶段，重点将放在使用单粒子相互作用模型的体实验和实验校准的DEM模拟之间的比较。研究小组Zetzener博士（iPAT，不伦瑞克）和Auernhammer博士（MPI聚合物研究，美因茨）之间的合作将被安装。与Guido Grundmeier教授、Hans-Joachim Schmid教授（德国帕德博恩大学）和Volker Schmidt教授（德国乌尔姆大学）进行科学交流。使用现有的测量设备（X射线显微断层扫描，布伦瑞克；共聚焦激光扫描显微镜，美因茨）和新的测量工具（混合器模型，比肯菲尔德）收集的数据将在所有小组之间共享。这些实验将使用TiO2团块（来源：PiKo服务项目和Paderborn）和麦芽糊精进行。基于来自美因茨、比肯菲尔德、布伦瑞克和乌尔姆的常用分析工具，实验数据将与TUHH开发的dem模拟进行比较。由于这个工作组网络，将实现对散装材料颗粒间接触的更深刻的科学理解。本研究的目的是利用实验确定的不规则形状颗粒在散装固体中的颗粒轨迹来验证具有最高精度的模拟。粒子在小法向力作用下的相互作用将根据第一周期的知识进行测量和描述。这些相互作用将在一个新的实验装置中进行检验，该装置将在比肯菲尔德实现，以便使用x射线微断层扫描对混合过程进行3D测量。以及DEM模拟，这些数据将用于验证目的。Zetzener博士，iPAT和s博士也将进行与不同加载模式下的体性能相关的实验。Aman， OVGU，通过实验确定了材料的性能。基于这些材料特性的DEM模拟将生成速度、力和接触分布，并结合单个粒子的粒子轨迹。此外，设备壁和工具上的应力由大量接触将被考虑。将进行涉及不规则形状粒子的碰撞的支持DEM/ fem模拟。这些粒子的形状将通过x射线微断层扫描（IMiP, iPAT）收集。碰撞本身将由高速摄像机（TUHH）进行分析。从而可以研究颗粒形态对接触性能的影响。此外，dem软件MUSEN将通过安装新的软件模块（压痕测试、压缩测试、休止角）、多球体方法的实施和团块中颗粒间结合力的建模，进一步发展和增强。

Research and modelling of the contact behaviour between individual particles was the main objective in the first two working periods. In the final period of PiKo, the focus will be on the comparison between bulk experiments and experimentally calibrated DEM simulations using single particle interaction models. A cooperation between the research groups Dr. Zetzener (iPAT, Braunschweig) and Dr. Auernhammer (MPI for Polymer Research, Mainz) will be installed. Also a scientific exchange with Prof. Guido Grundmeier, Prof. Hans-Joachim Schmid (University of Paderborn) and Prof. Volker Schmidt (University of Ulm) is intended. Data gathered using available measurement equipment (X Ray micro-tomography, Braunschweig; confocal laser scanning microscope, Mainz) and new measuring tools (mixer model, Birkenfeld) will be shared between all groups. These experiments will be run using TiO2 agglomerates (Source: PiKo service project and Paderborn) and Maltodextrin. Based on common analysing tools from Mainz, Birkenfeld, Braunschweig and Ulm, the experimental data will be compared with DEM-simulations developed by TUHH. Due to this network of working groups, a more profound scientific understanding of interparticulate contacts in bulk materials will be achieved. Objective of this research is to use experimentally determined particle trajectories of irregularly shaped particles within bulk solids to validate simulations with highest accuracy. The interaction of particles under small normal forces will be measured and described based on the knowledge of the first periods. These interactions will be examined in a new experimental set-up, which will be realised in Birkenfeld in order to allow 3D measurement of mixing processes using X-Ray micro-tomography. As well as for DEM simulations these data will be used for validation purposes. Experiments related to the bulk behaviour with different modes of loading will also be carried out by Dr. Zetzener, iPAT and Dr.S. Aman, OVGU, resulting in experimentally determined material properties. DEM simulations based on these material properties will generate speed, force and contact distributions in combination with particle trajectories of individual particles. Additionally the stress on equipment walls and tools resulting from the bulk contact will be considered. Supporting DEM/FEM-simulations of collisions involving irregularly shaped particles will be carried out. The shape of these particles will be gathered by X-Ray micro-tomography (IMiP, iPAT). The collisions themselves will be analysed by high-speed cameras (TUHH). As a result the effect of particle morphology on contact properties can be studied. Also the DEM-software MUSEN will be further developed and enhanced by installing new software modules (indentation test, compression test, angle of repose), the implementation of multi-sphere-methods and the modelling of interparticulate binding forces in agglomerates.