Complex bridge structures assembled by utilising facetted planar elements made of carbon-reinforced ultra-high performance concrete - Graph-based modularisation and trajectory-sensitive production

目前桥梁结构的主要特点是基本工作在施工现场进行，结构是单独设计/安装的，要么作为一个整体，要么由使用传统连接技术现场连接的大型个别预制构件。这导致施工时间长，质量在很大程度上取决于天气条件和所用人员的技能，而改装、更换个别部件甚至临时使用和随后拆除是不可能的，或者只是花费高昂的费用。即使在使用预制件时，由于单个重量大、重复程度低和制造公差相对较高，也不可能进行真正的模块化设计和工业流程生产。该研究项目的基本思想是通过使用由碳纤维增强超高性能混凝土制成的刻面结构元件来始终如一地进一步发展模块化原则，用于桥梁建设。这种方法类似于将结构几何划分为有限元，其特点是将整个系统系统地划分为易于产生的基本分区(模块)。这里要遵守的边界条件一方面来自载荷和结构能力(特别是模块接头)，另一方面来自制造和组装的要求。复杂的优化问题只能通过进一步发展计算机辅助方法和有效模块的概念、它们的生产和相关的(变量)连接技术来解决。为此，本课题从理论和试验两个方面对适应内力的超高性能混凝土的连接方式和各个模块进行了研究。短碳纤维用作增强材料，可通过3D打印中的模块生产与应力路径对齐，从而实现高效的承载行为。此外，对模块化过程进行了系统的分析和进一步的开发，使分割在很大程度上是自动的。一方面要考虑模块生产和组装所产生的边界条件，另一方面要在静态方面对模块布置进行优化。模块的半自动分解是通过使用基于规则的图形替换系统或图形语法来进行的，从而基于初始几何和边界条件生成可变基本模块的不同排列可能性。概念性的和结构力学的调查以及半自动模块化的调查都可能对战略文件的总体目标作出有价值的贡献。

Bridge structures are currently mostly characterised by the fact that essential work is carried out on the construction site and the structure is designed/erected individually, either as a whole or from large-scale individual prefabricated members which are connected on site using conventional joining techniques. This results in long construction times, the quality depends largely on the weather conditions and the skills of the personnel used, and an adaptation, replacement of individual components or even temporary use and subsequent dismantling are not possible or only at great expense. Even when using prefabricated parts, no actual modular design with industrial flow production is possible due to the large individual weights, the low degree of repetition and the comparatively high manufacturing tolerances. The basic idea of the research project is to consistently further develop the modularisation principle by using facetted structural elements made of carbon-reinforced ultra-high performance concrete for bridge construction. The approach, comparable with the geometric division of structures into finite elements, is characterised by a systematic division of the overall system into basic partitions ("modules") which are easy to produce. The boundary conditions to be adhered to here result on the one hand from loads and the structural capacity (especially in module joints), on the other hand from the requirements of manufacture and assembly. The complex problem of optimisation can only be solved by a further development of computer-aided methods and the conception of efficient modules, their production and the associated (variable) joining technology. Therefore, suitable joining methods and individual modules made of ultra-high performance concrete adapted to internal stresses are developed and investigated theoretically and experimentally in the project. Short carbon fibres are used as reinforcement, which can be aligned to the stress paths by module production in 3D printing and thus enable a highly efficient load-bearing behaviour. In addition, the modularisation process is systematically analysed and further developed so that segmentation is largely automatic. On the one hand, the boundary conditions resulting from module production and assembly are to be taken into account, and on the other hand, the module arrangement is to be optimised with regard to static aspects. The semi-automated decomposition into modules is to take place by using a rule-based graph substitution system or a graph grammar, so that on the basis of the initial geometry and boundary conditions different arrangement possibilities of the variable basic modules are generated. Both the conceptual and structural-mechanical investigations as well as the investigations for semi-automated modularisation may provide valuable contributions to the overall goals of the SPP.