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，但其承受拉伸载荷的可能性非常低。因此，在建筑元件中嵌入钢筋作为钢筋。为了避免腐蚀，必须在钢筋上覆盖厚厚的混凝土。由于用碳纤维增强塑料 (CFRP) 制成的元件替代这些钢元件，可以减少混凝土覆盖层的数量。这为采用钢筋混凝土制成的更薄、更轻的建筑元件提供了机会。根据建筑行业的最新发展和现有的研究计划，可以假设未来几年 CFRP 钢筋混凝土构件的数量将会增加，因此需要针对这种复合材料的高效切削工具。在该研究计划中，计划对由碳纤维增强塑料和混凝土制成的新型复合材料的加工过程进行基础分析工作。划痕测试是了解材料去除基本机制的基本测试方法。因此，将使用单个金刚石晶粒进行路径和力控制测试，以分析加工过程的基本相互依赖性。具有确定形状的金刚石颗粒用于估计机械载荷和发生的磨损。通过使用单个金刚石孕镶刀头进行测试可以获得更多知识。在单晶划痕测试的基础上，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载荷。可以假设，高工艺温度可能会导致 CFRP 基体材料的热损坏以及节段的堵塞。此外，还可以评估替代冷却策略的可行性。此外，对 CFRP 纤维磨损和未切割导致的刀头横向磨损的研究也特别令人感兴趣，特别是这些影响如何缩短刀具寿命。基于单晶粒划痕测试和金刚石孕镶段测试的定量和定性结果，将生成单尺度和多尺度过程模型。作为示例，将分析材料和晶粒排列的依赖性及其对材料去除的影响。该知识可用于优化多相材料 CFRP 钢筋混凝土的加工工艺。通过对单晶粒和多晶粒测试的综合分析，我们对材料去除的具体机制有了全面的了解。因此，这些研究构成了开发用于加工 CFRP 钢筋混凝土的高效金刚石刀具的根本基础。