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

• Applicants: Professor Dr.-Ing. Frank Walther; Professor Dr. Cordt Zollfrank
• Subject Area: Polymeric and Biogenic Materials and Derived Composites ; Synthesis and Properties of Functional Materials
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 325009350

• Final Report Year: 2025

Final Report Abstract

Cottonid is a cellulose-based material produced by layering and chemical-physical bonding of unsized papers via the parchmenting process. Cottonid has great technical potential, partly due to the scarcity of fossil resources, as cellulose is the most available raw material on earth. As a function of material thickness, Cottonid can be used as a sustainable, climate-adaptive functional material or as a dimensionally stable construction material. These properties make the material ideal for the production of architectural elements for conventional structural applications as well as for innovative biomimetic architecture. In the research project, the material was further developed using a laboratory-scale production line and optimized in terms of its hygroscopic adaptability and structural anisotropy. The fundamental influence of individual manufacturing and environmental parameters on the material behavior was investigated. With regard to the application of Cottonid as a climate-adaptive architectural element, the introduction of sensors for structural health monitoring (SHM) was then researched. One of the central scientific questions was to what extent the functionality of fiber optic sensors (FBG) as a conventional SHM technique is maintained during parchmenting. In addition, the electrical resistance measurement for assessing the material moisture was examined. The established SHM methods were further compared with an innovative method in which the Cottonid samples are modified with piezoelectric zinc oxide for intrinsic strain measurement. Accompanying longterm experiments were used to characterize environmental and weather-specific ageing mechanisms of Cottonid. Finally, the biodegradability of the material was investigated with a view to environmentally friendly recycling at the end of the product life cycle.

Publications

• Experimental study on the actuation and fatigue behavior of the biopolymeric material Cottonid. Materials Today: Proceedings, 7, 476-483.
  Scholz, Ronja; Langhansl, Matthias; Zollfrank, Cordt & Walther, Frank
  
• Humidity-Sensing Material Cottonid – Microstructural Tuning for Improved Actuation and Fatigue Performance. Frontiers in Materials, 7.
  Scholz, Ronja; Langhansl, Matthias; Zollfrank, Cordt & Walther, Frank
  
• In Situ Characterization of Damage Development in Cottonid Due to Quasi-Static Tensile Loading. Materials, 13(9), 2180.
  Scholz, Ronja; Delp, Alexander & Walther, Frank
  
• Impact of solar radiation on chemical structure and micromechanical properties of cellulose-based humidity-sensing material Cottonid. Functional Composite Materials, 2(1).
  Scholz, R.; Langhansl, M.; Hemmerich, M.; Meyer, J.; Zollfrank, C. & Walther, F.
  
• In Situ Characterization of the Damage Initiation and Evolution in Sustainable Cellulose-Based Cottonid. The Minerals, Metals & Materials Series, 867-878. Springer International Publishing.
  Scholz, R.; Delp, A. & Walther, F.
  
• Mechanism-based assessment of cellulose-based biocomposite Cottonid for sustainable construction. ECCM20, Proceedings of the 20th European Conference on Composite Materials 3, (2022) 616–623
  Scholz, R. & Walther, F.
  
• Mechanism-Based Assessment of Structural and Functional Behavior of Sustainable Cottonid. Werkstofftechnische Berichte │ Reports of Materials Science and Engineering. Springer Fachmedien Wiesbaden.
  Scholz, Ronja Victoria