A Numerical Model for Simulation and Design of Particle-Bed 3D-Printing Process

用于颗粒床 3D 打印过程模拟和设计的数值模型

• 批准号: 417019981
• 负责人: Professor Dr.-Ing. Dirk Lowke
• 金额: --
• 依托单位: IFSTTAR - Institut français des Sciences et Technologies des Transports, de lAménagement et des Réseaux
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/417019981?language=en
• 关键词: Numerical; Model; Simulation; Design; Particle

The present project addresses the emerging subject of Particle-bed 3D printing (PB3DP) and suggests an innovative numerical approach to simulate and predict the printing process. One of the most promising Particle-Bed 3D-Printing techniques is the selective paste intrusion method. It is based on a localised intrusion of a fluid (cement paste) into a bed of particles (aggregate), and the subsequent hardening. The main advantage of this technique is that the printed elements have a high resolution and almost no restrictions in freedom of form. Up to now, this method is applied successfully to print small and medium scale objects with compressive strength up to 70 MPa, but there is still lack of large scale implementation. To realise application in construction industry, fundamental questions need to be answered. These are related to the optimisation of the process as well as the material and granulate properties (such as rheological properties of the paste or permeability of the aggregate layer). Appropriate computational models, to describe and predict the printing process, are essential for a successful implementation. The aim of the present project is to study the process of the PB3DP numerically and to predict the propagation of the fluid through the particle bed. Based on experimentally determined input parameters such as the rheological properties of the propagating fluid and the permeability of the aggregate layer, the goal is to predict the final penetration depth, which determines the overall quality of the produced component (mechanical properties, durability and shape accuracy). The outcome of the project is a numerical tool, capable to predict the printing process. The tool will be able to deal with the flow prediction within the process as well as with its optimization. The originality and innovation of the proposed approach lies in two main attributes: (I) description of the particle bed as a porous medium and (II) consideration of structural build up caused by thixotropy. To achieve the above mentioned objectives, basic research regarding (a) the specific characterisation and control of the rheological properties of cement pastes for PB3DP, (b) the packing and permeability properties of the particle bed and (c) the numerical methods for the simulation and prediction of the printing process is necessary.

本项目介绍了粒子床3D打印（PB3DP）的新兴主题，并提出了一种创新的数值方法来模拟和预测打印过程。最有希望的粒子床3D打印技术之一是选择性糊状入侵方法。它基于将液体（水泥糊）局部侵入到颗粒床中（聚集体）的床和随后的硬化。该技术的主要优点是印刷元素具有很高的分辨率，几乎没有形式自由的限制。到目前为止，该方法已成功地应用于以高达70 MPa的抗压强度打印中小型物体，但仍然缺乏大规模实施。要实现建筑行业的应用，需要回答基本问题。这些与该过程的优化以及材料和颗粒状特性有关（例如糊的流变特性或聚集层的渗透性）。适当的计算模型以描述和预测打印过程，对于成功实施至关重要。本项目的目的是在数值上研究PB3DP的过程，并预测流体通过粒子床的传播。基于实验确定的输入参数，例如传播流体的流变特性和聚集层的渗透性，目标是预测最终的穿透深度，这决定了生产成分的总体质量（机械性能，耐用性，耐用性和形状精度）。该项目的结果是一个数值工具，能够预测打印过程。该工具将能够处理流程中的流程预测以及其优化。所提出的方法的独创性和创新在于两个主要属性：（i）将粒子床描述为多孔介质，以及（ii）考虑由触变的构建。为了实现上述目标，有关PB3DP水泥糊的流变特性的特定表征和控制，（b）粒子床的包装和渗透率特性以及（c）打印过程的仿真和预测的数值方法是必要的。