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.

虽然混凝土能够承受很高的压缩载荷，但其承受拉伸载荷的可能性很低。因此，在建筑构件中，钢筋被嵌入作为钢筋。为了避免腐蚀，需要在钢筋上覆盖一层厚的混凝土。由于用碳纤维增强塑料（CFRP）制成的元件替代这些钢元件，因此可以减少混凝土覆盖物的量。这为由钢筋混凝土制成的更薄、更轻的建筑元件提供了机会。考虑到建筑行业的最新发展和现有的研究计划，可以假设CFRP加固混凝土构件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.在本研究计划中，计划对CFRP和混凝土制成的新型复合材料的加工过程进行基本分析工作.划痕试验是了解材料去除基本机理的基本测试方法。因此，将对单个金刚石颗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。通过对单个金刚石孕镶段进行测试，获得了进一步的知识。在单颗粒划痕试验的基础上，计划进行路径控制和力控制试验，在研究中，将分析CFRP加固混凝土切割过程中的机械载荷和热载荷。可以假设，高的工艺温度可能导致CFRP基体材料的热损伤以及段的堵塞。此外，可以评估替代冷却策略的可行性。此外，对由于CFRP纤维磨损和未切割而导致的片段横向磨损的研究也特别有趣，特别是这些影响如何可能缩短工具寿命。基于单颗粒划痕试验和金刚石浸渍段试验的定量和定性结果，将生成单尺度和多尺度过程模型。作为一个例子，材料和晶粒取向的依赖性及其对材料去除的影响将进行分析。这些知识可用于优化多相材料CFRP增强混凝土的加工过程。通过对单颗粒和多颗粒试验的全面分析，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加固混凝土的高效金刚石工具的基础。