Fundamental analysis of the machining process of a composite material made of concrete andCFRP with diamond grinding tools

金刚石磨具加工混凝土与CFRP复合材料的工艺基础分析

• 批准号: 391502479
• 负责人: Professor Dr.-Ing. Dirk Biermann
• 金额: --
• 依托单位: Institut für Spanende Fertigung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/391502479?language=en
• 关键词: Fundamental; analysis; machining; process; composite

Although concrete is able to bear high compressive loads, its possibility to withstand tensile loads is very low. Hence, in construction elements steel bars are embedded as reinforcement. To avoid corrosion, a thick concrete covering of the steel bars is necessary. Due to the substitution of these steel elements with elements made of carbon fibre reinforced plastic (CFRP) it is possible to reduce the amount of the concrete covering. This provides the opportunity for thinner and lighter construction elements made of reinforced concrete. Regarding recent developments in the construction industry and existing research programs it can be assumed that the amount of CFRP reinforced concrete elements will increase in the next few years and therefore efficient cutting toolsfor this kind of composite material are required. Within this research program it is planned to conduct basic analysis work regarding the machining process of the new composite material madeof CFRP and concrete. Scratch tests are a fundamental testing method to understand the fundamental mechanism of material removal. Therefore path- and force-controlled tests with single diamond grains will be carried out to analyse the fundamental interdependencies of the machining process. Diamond grains with defined shape are used to estimate the mechanical loads and the occurring wear. Further knowledge is gained by conducting tests with single diamond impregnated segments. Based on the single grain scratch tests, it is planned to carry out path- and force controlled tests.Within the investigations, the mechanical and thermal load during the cutting of CFRP reinforced concrete will be analysed. It can be assumed that high process temperatures probably lead to a thermal damage of the CFRP-matrix material as well as in clogging of the segments. Furthermore, the feasibility of alternative cooling strategies can be assessed. Additionally, investigations on the lateral wear of the segments due to fraying and uncut fibres of the CFRP are of special interest, especially how these influences may reduce the tool life. Based on the quantitative and qualitative results of single grain scratch tests and diamond impregnated segment tests single- and multi-scale process models will be generated. As an example the dependency of material and grain alignment and its influence on the material removal will be analysed. This knowledge can be used for the optimisation of the machining process of the multiphase material CFRP reinforced concrete. Due to the comprehensive analysis of single and multi-grain tests a global understanding of the specific mechanisms of material removal is reached.Hence, these investigations constitute the fundamental basis for the development of efficient diamond tools for the machining of CFRP reinforced concrete.

尽管混凝土能够承受高压缩载荷，但其承受拉伸负荷的可能性非常低。因此，在建筑要素中，钢筋嵌入为加固。为了避免腐蚀，需要厚厚的混凝土覆盖钢棒。由于用碳纤维增强塑料（CFRP）制成的元素取代了这些钢元素，因此可以减少混凝土覆盖物的量。这为钢筋混凝土制成的较薄和较轻的建筑元素提供了机会。关于建筑行业和现有研究计划的最新发展，可以假设CFRP增强混凝土元素的数量将在未来几年内增加，因此需要这种复合材料的有效切割工具。在该研究计划中，计划进行有关CFRP和混凝土制成的新复合材料的加工过程的基本分析工作。刮擦测试是了解材料去除的基本机制的基本测试方法。因此，将进行单个钻石晶粒的路径和力对照测试，以分析加工过程的基本相互依赖性。具有定义形状的钻石颗粒用于估计机械载荷和发生的磨损。通过使用单钻石浸渍段进行测试来获得进一步的知识。基于单粒刮擦测试，计划进行路径和力控制测试。在研究中，将分析切割CFRP钢筋混凝土期间的机械和热负载。可以假设高过程温度可能导致CFRP-Matrix材料以及片段堵塞的热损伤。此外，可以评估替代冷却策略的可行性。此外，对CFRP的磨损和未切割的纤维引起的细分市场的横向磨损的调查是特别感兴趣的，尤其是这些影响如何降低工具寿命。将基于单粒刮擦测试的定量和定性结果，以及钻石浸渍段测试单个和多尺度工艺模型。例如，将分析材料和谷物对齐的依赖性及其对材料去除的影响。这些知识可用于优化多相材料CFRP钢筋混凝土的加工过程。由于对单个和多粒测试的全面分析，全球对材料去除的特定机制的了解。因此，这些研究构成了开发有效的钻石工具来加工CFRP加固混凝土的基本基础。