A Methodical approach for additively manufactured heat-generating structures – linkage between material development, manufacturing process and geometry

增材制造如材料挤压（MEX），由于其逐层沉积材料的原理，为设计提供了新的自由度。在其他好处中，这允许在一个零件中组合多种材料，而不需要额外的组装和连接过程。因此，材料特定功能的集成，如热产生的导电性，提供了高成本功能性聚合物的非常有效的开发。发热结构的集成允许使用热激活形状记忆聚合物制造个性化焦耳加热系统（几何形状和表面温度）或执行器。目前有两个主要挑战限制了这种潜力的开发。一个是功能复合材料在电导率方面的性能非常有限，并且在工艺温度下具有极高的粘度。另一个挑战是缺乏对工艺参数和几何形状的选择与电气部件性能之间固有依赖关系的深入了解。这是由于制造过程中产生的各向异性引起的材料特性的变化。由此可见，目前在材料开发、制造工艺和几何结构方面对增材制造产热结构的系统设计受到很大限制。本研究项目旨在为增材制造发热结构的设计开发一种方法学方法。过程工程和工程设计领域之间紧密联系的合作是阐明材料系统、工艺参数和几何设计之间复杂相互作用的先决条件。这包括研究功能性聚合物的生产过程，这些聚合物具有用于MEX的特定电学和工艺相关特性，以及达到特定表面温度的工艺和几何相关杠杆。通过水平分辨热像分析，评估了所有影响因素的影响，并考虑了设计知识的提供。材料性能、制造工艺和几何定义之间明确的依赖关系将用于建立模型，该模型最大限度地基于物理。并将其应用于有限元数值模型的参数化。对方法方法和有限元模型的评估将通过有针对性的设计和制造具有初步定义的特性（表面温度和几何形状）的集成发热结构来完成。

Additive Manufacturing like Material Extrusion (MEX), offers new freedom in design, due to its principle of layer-by-layer material deposition. Among other benefits, this allows a combination of multiple materials within one part, without additional assembly and joining processes are needed. Thus, an integration of material-specific functions as electrical conductivity for heat generation is enabled which provides a very efficient exploitation of high-cost functional polymers.The integration of heat-generating structures allows manufacturing individualized Joule heating systems (geometry and surface temperature) or actuators by using thermally activated shape-memory polymers. Two central challenges currently limit the exploitation of such potentials. One is the very limited performance of functional composites in terms of electrical conductivity accompanied by an extremely high viscosity at process temperature. The other challenge is the lacking in-depth knowledge about the inherent dependencies between the choice of process parameters and geometry and the resulting electrical part properties. This is due to a change in the material properties caused by anisotropies that originates from the manufacturing process. From this follows, that a systematic design of additively manufactured structures for heat generation with respect to aspects regarding material development, manufacturing process and geometry is strongly limited at present.This research project aims to develop a methodological approach for the design of additively manufactured heat-generating structures. The closely linked cooperation between the fields of process engineering and engineering design is the prerequisite for elucidating the complex interactions of the material system, process parameters and the design of geometry. This includes investigating the production process of functional polymers with defined electrical and process-relevant properties for MEX, as well as process and geometry related levers for reaching defined surface temperatures. By means of strand-level resolved thermographic analysis, the effect of all influencing factors is assessed and regarded for the provision of design-knowledge. The clarified dependencies between material properties, manufacturing process and geometry definition will be employed to establish a model, which is physically based to the greatest extend. It is also applied to parameterize a numerical model by means of the Finite Element Method (FEM). The evaluation of the methodological approach and the FEM-Model will be done by the targeted design and manufacturing of integrated heat-generating structures with preliminarily defined properties (surface temperature and geometry).