Basic investigations on the robot-aided magnetic distribution and alignment of microsteel fibers in thin-walled UHPFRC components

该研究项目的目的是通过超高性能纤维增强混凝土(UHPFRC)中钢纤维的受控、基于机器人的磁场分布和取向，探索制造资源节约型部件的基础。拟议的研究项目一方面基于数字化和机器人支持的部件制造提供的可能性，另一方面基于纤维对准提高超高性能混凝土材料效率的潜力。超高性能钢纤维混凝土中钢纤维的分布和取向方法是基于物理磁学现象。由于钢纤维具有铁磁性，磁场可以选择性地改变其在新混凝土中的位置。本课题的研究目的是在混凝土生产过程中，按照力的流动规律和“形随力”的原则，对钢纤维在混凝土中的位置进行调整。纤维在部件中的这种限定布置旨在显著提高所使用的纤维部件的有效性，并且除了改进的可加工性之外，还导致所使用的纤维的显著减少，从而提供了在生态和经济资源方面的巨大节约潜力。通过使用机器人生产领域的最新发展来确保对过程的可重复控制，对于该方法的经济、建筑-实际应用将是决定性的。如有可能，第一批工作包的成果应纳入DFG优先方案1542“混凝土轻质施工”的子项目，该项目将在国际技术教育研究所和IBMB持续到2017年底。特别是，该方法可用于生产模块化结构的杆和表面元件(板)以及高应力连接部位(齿连接)，目的是实现这些高性能部件性能的明显提高。纤维对准表示用于在预期的数字制造链中生产部件的几个对准处理步骤之一。这种磁性纤维对准方法的实际应用是多方面的，并且对于不同的组件组是可以想象的。因此，在大面积组件的情况下，例如工业地板，可以通过限定的纤维取向显著降低纤维含量。此外，该方法可用于提高局部高应力区域的抗拉强度，例如在部件连接区域，或用于跨结构厚度的材料特性的分级。此外，研究项目还针对传统钢筋的特定区域替代，如双T梁或UHPFRC空心梁的推力加固。

The aim of the proposed research project is to explore the basis for the manufacturing process of resource-efficient components by means of the controlled, robot-based magnetic distribution and orientation of steel fibers in UHPFRC (Ultra-High Performance Fibre-Reinforced Concrete). The proposed research project is based on the possibilities offered by digital and robot-supported component manufacturing on the one hand and the potential of fiber alignment to increase the material efficiency of UHPFRC on the other. The method of distributing and orienting steel fibers in UHPFRC is based on the physical phenomenon of magnetism. Since steel fibers are ferromagnetic, magnetic fields can selectively modify their position in fresh concrete. The aim of the research project is to align the position of the steel fibers in the concrete matrix during the production process according to the force flow and the maxim “form follows force”. This defined arrangement of the fibers in a component is intended to significantly increase the effectiveness of the fiber component used and, in addition to improved workability, lead to a considerable reduction in the fibers used, as a result of which a great potential for savings in ecological and economic resources is provided. The reproducible control of the process, which is ensured by the use of the latest developments in the field of robotic production, will be decisive for an economic, building-practical application of the method. The results of the first work packages should, if possible, be integrated into the sub-project of the DFG's Priority Program 1542 "Light Construction with Concrete", which runs until the end of 2017 at the ITE and iBMB. In particular, the method could be used in the production of modularly constructed rod and surface elements (plates) as well as in the highly stressed joint sites (tooth connections) with the aim of achieving a clear increase in performance of these high-performance components. The fiber alignment represents one of several aligned processing steps for the production of a component in a prospective digital manufacturing chain. The practical applications for this method of magnetic fiber alignment are manifold and conceivable for different component groups. Thus, the fiber content in the case of large-area components, e.g. industrial flooring, can be significantly reduced by a defined fiber orientation. Further, the method can be used to increase the tensile strength in locally highly stressed areas, e.g. in the component joining areas or for the gradation of material properties across the structural thickness. In addition, the research project aims at the area-specific replacement of conventional reinforcement, such as the thrust reinforcement in double T-beams or hollow beams made of UHPFRC.