Joining and design principles for two- and three-dimensional filigree trusses constructed of form-optimized UHPC rod members and corrosion-free CFRP-reinforcement

由形状优化的 UHPC 杆件和防腐蚀 CFRP 加固构成的二维和三维花丝桁架的连接和设计原理

• 批准号: 257612823
• 负责人: Professor Dr.-Ing. Oliver Fischer
• 金额: --
• 依托单位: Lehrstuhl für Massivbau
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/257612823?language=en
• 关键词: Joining; design; principles; two; three

So far concrete load-bearing systems are mostly characterized by an unbalanced utilization of material. Besides decisively raising costs for formwork and scaffolding of geometrically more effective structures this above all results from missing general optimization strategies and the related design principles. By substitution of conventional concrete structures by slender trusses governed by the form-follows-force approach distinct enhancements are possible in terms of weight reduction and resource efficiency as well as structural transparency and aesthetic aspects are concerned. The use of innovative materials (e.g. UHPC) and erection methods for smart structures both on system level (overall arrangement of struts and ties) and regarding the individual components (optimized rods and connection elements) concrete trusses already may be an alternative to other solutions leading to decisively reduced corrosion effects and hence to highly durable structural members requiring minimum maintenance. Therefore, the main goal of the research project is to derive general mechanical models as well as optimized joining and design principles for two- and three-dimensiona filigree concrete trusses. In doing so, a modular construction concept with variable arrangement of rods and connection elements - depending on the governing loads and the overall geometric boundary conditions - will be developed being characterized by prefabricated form-optimized struts, ties and connection elements assembled to the overall load-bearing system on site. Within the first funding period of the DFG priority program (2011 - 2014; individual project (form-optimized filigree rods utilizing UHPC and corrosions-free CFRP-reinforcement for variable three-dimensional rod structures) appropriate mechanical models and design principles have been derived for material-optimized compression struts and prestressed tension members constructed of ultra-high performance concrete and non-metallic CFRP reinforcement and prestressing, only. Based on the results gained from the first period the research activities within the second funding period (2014 - 2017) will concentrate on the development of an effective joining concept (nodes) and particularly on the derivation of general and design principles on system level (i.e. overall arrangement of rods and nodes). Following the completion of the project scientifically proven principles will be provided enabling the conception of light and transparent two- and three-dimensional concrete rod structures requiring minimum resources. In order to verify both effectiveness and practicability it is planned to finally build a full-scale demonstrator taking into account all relevant results and findings gained in the two funding periods. This exemplary structure will also be used to demonstrate and check the overall ductility of the system by experimental testing.

迄今为止，混凝土承重系统的主要特点是材料利用不平衡。除了决定性地提高几何上更有效的结构的模板和脚手架的成本之外，这首先是由于缺少一般优化策略和相关设计原则造成的。通过用形式跟随力方法控制的细长桁架代替传统的混凝土结构，可以在减轻重量和资源效率以及结构透明度和美观方面得到明显的增强。在系统层面（支柱和拉杆的整体布置）和单个组件（优化的杆和连接元件）混凝土桁架上使用创新材料（例如UHPC）和智能结构的安装方法可能已经成为其他领先解决方案的替代方案显着减少腐蚀影响，从而实现需要最少维护的高度耐用的结构构件。因此，该研究项目的主要目标是导出二维和三维花丝混凝土桁架的通用力学模型以及优化的连接和设计原理。在此过程中，将开发出一种模块化结构概念，该概念具有杆和连接元件的可变布置（取决于控制载荷和总体几何边界条件），其特点是预制形式优化的支柱、拉杆和连接元件组装到总体载荷-现场轴承系统。在 DFG 优先计划的第一个资助期内（2011 - 2014 年；单个项目（利用 UHPC 和无腐蚀 CFRP 加固的可变三维杆结构的形状优化花丝杆），已经导出了适当的机械模型和设计原理仅基于第一阶段获得的结果，由超高性能混凝土和非金属 CFRP 加固和预应力构造的材料优化压缩支柱和预应力受拉构件。第二资助期（2014-2017）的研究活动将集中于开发有效的连接概念（节点），特别是系统层面的一般和设计原则的推导（即杆和节点的总体布置）。该项目的完成将提供经过科学验证的原则，从而能够实现需要最少资源的轻型透明的二维和三维混凝土杆结构的概念。为了验证有效性和实用性，计划最终建立一个全面的演示器，考虑到两个资助期间获得的所有相关结果和发现。该示例性结构还将用于通过实验测试来演示和检查系统的整体延展性。