Light, microreinforced UHPC shell structures optimised to deformations using the example of parabolic trough collectors in concentrating solar power plants

以聚光太阳能发电厂中的抛物面槽式集热器为例，针对变形进行了优化的轻质微强化 UHPC 外壳结构

• 批准号: 198176582
• 负责人: Professor Dr.-Ing. Peter Mark
• 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: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/198176582?language=en
• 关键词: Light; microreinforced; UHPC; shell; structures

Shell structures made from UHPC and micro-reinforcement or GRP meshes acc. to the guiding principle "form follows forces", have been confirmed to be extremely slender, deflection-resistant and producible with striking surface accuracy during the first period. Focus has purposely been laid on parabolic shell-troughs of solar power plants concentrating insolation to gain green energy. These structures are predestinated for fundamental and detailed research due to its very complex demands for deflection-restrained sun tracking, environmental exposure in deserts and quality assured serial production. The approach taken is interactive, interdisciplinary and multileveled, including conceptual and component design as well as detailing provisions. Scientific analyses accompanied by experimental verifications and iterative optimizations are performed involving a bunch of engineering disciplines, e.g. concrete design, structural mechanics and dynamics, wind as well as solar and materials engineering. In the currently running period boundary conditions are explored, specific impact conditions investigated, precision demands assessed and numerical models developed. Algorithms for multi-criteria optimization have been adapted and tested as well as checks on the rigidity and vibration safety features of the structure have been performed. In experiments adequate concrete mixtures have been designed and a geometric surveying procedure - able to approve the shell's shape-accuracy - has been established. Finally, the interactive research activities merged into an innovative full-scale prototype of a parabolic trough collector made from UHPC. With respect to recent developments of parabolic troughs aside, that enable notably increased lengths and widths, here the essential innovations of a second period aim at the realisation of hollow instead of single-walled shells introducing pre-stressing. This way structural weight should be significantly decreased while its stiffness against deformation can be maintained or even amplified. Furthermore, the performance ratio of UHPC in compression can be efficiently improved. Stochastic uncertainties in geometry, material and wind loads and also due to structural degradation during service shall be captured by simulation based optimisation techniques on response surfaces to ensure structural robustness. Wind tunnel tests will deliver quasi-static but also multi-criteria, transient wind pressure data for fully transient modal analyses. The experimental part comprises the general but specific nodal design required by a hollow shell structure in accordance to formwork, manufacturing process and reinforcing techniques. Finally, a full-size prototype collector with photogrammetric proven surface accuracy and conform to all theoretical design requirements laid out above is envisaged.

根据“力决定形状”的指导原则，由UHPC和微钢筋或GRP网制成的壳体结构已被证实非常细长，抗挠曲，并且在第一阶段可生产出惊人的表面精度。人们的注意力被有意地放在太阳能发电厂的抛物面壳槽上，这些壳槽集中太阳能以获得绿色能源。这些结构是预定的基础和详细的研究，由于其非常复杂的要求，偏转约束太阳跟踪，环境暴露在沙漠和质量保证的批量生产。所采取的方法是互动的，跨学科的和多层次的，包括概念和组件设计以及详细的规定。科学分析伴随着实验验证和迭代优化，涉及一系列工程学科，例如混凝土设计，结构力学和动力学，风以及太阳能和材料工程。在当前运行期间，探索边界条件，调查具体的影响条件，评估精度要求和开发数值模型。多准则优化算法已被改编和测试，以及对结构的刚度和振动安全特性的检查已被执行。在实验中，设计了足够的混凝土混合物，并建立了几何测量程序-能够批准壳的形状精度。最后，互动研究活动合并成一个由UHPC制成的抛物槽集热器的创新全尺寸原型。除了抛物线槽的最新发展，这使得长度和宽度显着增加，这里的第二个时期的基本创新旨在实现中空而不是单壁壳体引入预应力。这样，结构重量应显著降低，同时其抵抗变形的刚度可以保持或甚至放大。此外，UHPC的压缩性能比可以有效地提高。几何形状、材料和风荷载的随机不确定性，以及由于使用期间结构退化引起的随机不确定性，应通过响应面上基于模拟的优化技术进行捕获，以确保结构鲁棒性。风洞试验将提供准静态以及多标准瞬态风压数据，用于完全瞬态模态分析。试验部分根据模板、制作工艺和加固技术，对空心壳结构所需的节点进行了一般而又具体的设计。最后，一个全尺寸的原型收集器与摄影测量证明表面精度，并符合所有理论设计要求，上述设想。