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".

本项目的目的是进一步开发和验证一种新的弹塑性多接触模型，用于压实和压片的离散元法模拟（DEM），例如压片。药粉，以便更好地预测微观和宏观机械特性。到目前为止，高塑性颗粒变形和低孔隙率是挑战，这使得 DEM 无法用作压片和压实工艺和配方设计的标准工具。申请人已经建立了 DEM 的多接触接触模型，并成功测试了主要是弹性变形和中等压实度。然而，为了能够对粉末压实和压片等工业相关过程进行建模，必须在现有模型中额外记录和实现高压缩应力下材料的塑性变形和接触表面的变化。目的是基于机械依赖性对多接触接触模型进行建模，并用实验数据对其进行校准和验证。为了实现这一点，在初始阶段将在微型计算机断层扫描仪（μCT）中压缩少量粒子。随后，将对实验进行结构参数分析。结合有限元法（FEM）和离散元法（DEM）模拟方法，系统地研究微观结构参数的变化及其对接触力的影响。此外，通过自动部分模型评估、模型开发和使用遗传算法的参数化，将识别更多复杂的物理依赖性并将其集成到新的接触模型中。然后，将通过在装备齐全的“压实模拟器”中使用的模型系统的压实模拟和实验研究来进行多接触模型的验证和最终调整。