Multi-contact elastoplastic contact model for DEM-simulations of high load compaction derived from realistic microstructure

多接触弹塑性接触模型，用于源自真实微观结构的高负载压实 DEM 模拟

• 批准号: 461773986
• 负责人: Professor Dr.-Ing. Carsten Schilde
• 金额: --
• 依托单位: Institut für Partikeltechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/461773986?language=en
• 关键词: Multi; contact; elastoplastic; model; DEM

The aim of the present project is the further development and validation of a new elastic-plastic multi-contact model for the Discrete Element Method Simulation (DEM) of compaction and tabletting, e.g. of pharmaceutical powders, for better prediction of micro- and macromechanical properties. The high plastic particle deformations as well as the low porosities are challenges so far, which prevent the DEM from being used as a standard tool for process and formulation design in tabletting, respectively compacting. A multi-contact contact model for the DEM has already been established and successfully tested by the applicant for predominantly elastic deformation and medium degrees of compaction. However, in order to be able to model industrially relevant processes such as powder compaction and tabletting, the plastic deformation of the material and the change in the contact surfaces under high compressive stress must be additionally recorded and implemented in the existing model. The aim is to model the multi-contact contact model on the basis of mechanistic dependencies and to calibrate and validate it with experimental data.To realize this, a small number of particles will be compressed in a microcomputer tomograph (µCT) in the initial phase. Subsequently, the experiments will be analyzed with respect to structural parameters. In combination with the simulation methods Finite-Element-Method (FEM) and Discrete-Element-Method (DEM), the change of microstructural parameters and their influence on contact forces will then be systematically investigated. In addition, further complex physical dependencies are to be identified and integrated into the new contact model by means of automatic partial model evaluation, model development and parameterization using a genetic algorithm. The validation and final adaptation of the multi-contact model will then be carried out by means of simulation and experimental investigation of the compaction of the model systems used in a fully equipped "Compaction Simulator".

本项目的目的是针对压实和片剂的离散元素方法模拟（DEM）的新弹性塑性多接触模型的进一步开发和验证，例如用于更好地预测微力和宏观力学特性的药物粉末。到目前为止，高塑料颗粒变形以及低孔隙度是挑战，这阻止了DEM作为过程和制定片剂设计的标准工具，分别是紧凑的。 DEM的多接触接触模型已经通过主要弹性变形和中等程度的压实程度的应用已建立并成功测试。但是，为了能够对工业相关的过程进行建模，例如粉末压实和片剂，必须在现有模型中记录并实现了材料的塑性变形以及在高压缩应力下的接触表面变化。目的是根据机械依赖性对多接触接触模型进行建模，并使用实验数据对其进行校准和验证。要意识到这一点，在初始阶段将在微型计算机层压仪（µCT）中压缩少数颗粒。随后，将针对结构参数分析实验。结合仿真方法有限元元素方法（FEM）和离散元素方法（DEM），将系统地研究微结构参数的变化及其对接触力的影响。此外，使用遗传算法的自动部分模型评估，模型开发和参数化，将确定进一步的复杂物理依赖性并将其集成到新的接触模型中。然后，将通过模拟和实验投资对完全设备的“压实模拟器”中使用的模型系统的压实进行验证和最终改编。