Mechanism-based development and validation of a structural health monitoring for climate adaptive architectural Cottonid elements

棉花是一种以纤维素为基础、可持续利用的材料，由于化石资源的有限性质，它在当今显示出新的应用潜力。由于其材料的硬度，棉花可以用作可持续的、气候适应的功能材料以及尺寸稳定的建筑材料。这些特性使该材料成为生产用于传统结构应用和创新仿生建筑的建筑构件的有效候选材料。在联合项目的第一阶段，推导了单一制造以及环境参数对棉质材料行为的基本关系。此外，还对制备工艺进行了优化，以提高材料的吸湿性。所获得的结果使人们对棉属植物与其环境的相互作用有了一个基本的了解。关于将棉花作为建筑构件的应用，在后续项目中，将探索在结构健康监测(SHM)材料中实施传感器和传感元件(组件)。单层纸层叠层的棉质材料制造原理在结构健康监测传感器的集成方面具有很大潜力。关于集成光纤温度和应变传感器(FBG)的一个基本问题是，它们是否通过保持其功能来经受住羊皮纸过程。应首先用物理化学方法验证这一点，然后在作为材料厚度函数的驱动和疲劳实验中进行研究。在这里，还将考虑并进一步发展用于评估材料水分含量的电阻测量。已建立的SHM方法将进一步与一种用于本征应变测量的创新方法进行对比，在该方法中，棉形试件将被压电氧化锌修饰。同时，不同棉花变种的气候特定应变谱应分别通过长期实验获得和研究。最后，对材料的生物降解行为进行了表征。在后续项目中，将在后续项目中进一步开发资金阶段1的优化制造工艺，以实现气候适应性建筑棉状构件的SHM传感器的面向应用的实施。仪表化的Cottonid元件的功能和性能将通过分析研究以及驱动和疲劳实验进行验证，以得出关于材料行为和真实天气条件下的长期行为的基本结论。通过SHM传感器的实施和该领域创新仿生方法的探索，后续项目代表着预期的棉花元素在建筑和土木工程中的应用的桥梁。

Cottonid is a cellulose-based, sustainably available material, which exhibits new application potential nowadays due to the finite nature of fossil resources. As a function of its material tickness, Cottonid can be used as sustainable, climate adaptive functional material as well as dimensionally stable construction material. These properties define the material as an efficient candidate for the production of architectural elements for conventional structural applications as well as for innovative biomimetic architecture. In the first phase of the joint project, basic relationships between single manufacturing as well as environmental parameters on the material behavior of Cottonid were derived. Further, the manufacturing process was optimized with the aim to increase the hygroscopicity the material. Obtained results allowed to build up a basic understanding of Cottonid‘s interaction with its environment. With regard to the application of Cottonid as architectural element, in the follow-up project the implementation of sensors and sensory elements (assemblies) in the material for a structural health monitoring (SHM) will be explored. The manufacturing principle of Cottonid by layering single paper layers on top of each other has great potential for the integration of SHM sensors. One fundamental question concerning the integration of e.g. fiber optic sensors for temperature and strain measurements (FBG) is, if they withstand the parchmentizing process by maintaining their function. This shall be verified first with physicochemical methods and subsequently investigated in actuation and fatigue experiments as a function of the material thickness. Here, also electrical resistance measurement for assessment of materials‘ moisture content will be considered and further developed. Established SHM methods will further be contrasted with an innovative apporach for intrinsic strain measurement, where Cottonid specimens will be modified with piezoelectric zinc oxide. Accompanying, climate specific strain spectra of different Cottonid variants shall be derived and investigated via long-term experiments, repectively. Finally, the biological degradation behavior of the material is characterized. The optimized manufacturing process from funding phase 1 will be further developed in the follow-up project to realize an application-oriented implementation of SHM sensors for climate adaptive architectural Cottonid elements. Functionality and performance of the instrumented Cottonid elements will be verified via analytical investigations as well as actuation and fatigue experiments to derive essential findings concerning the material behavior and ist long-term behavior under real weather conditions. By the implementation of SHM sensors and the exploration of innovative biomimetic approaches in this field, the follow up project represents a brigde to the intended application of Cottonid elements in architecture and civil engineering.