Carbon Nanotube Fiber Composites for Simultaneous Structural Health Monitoring and Strengthening of Steel Structures
Fiber composites have been extensively researched as a potential candidate for strengthening of steel structures and have been recently used in field applications. While these structures are under rehabilitation, it is critical to continuously monitor the structural health and the effectiveness of the fiber composite applied. We propose a unique solution where piezo-resistive carbon nanotube sensing layers are integrated with structural carbon fiber composites capable of concurrent structural health monitoring and strengthening of steel structures. This poster describes the fabrication of this novel composite and demonstrates its sensing response along with improved mechanical properties.
Identifying the Strain-Free Condition of Non-Symmetric Carbon Fiber Laminates Using Digital Image Correlation
Processing carbon fiber composite laminates creates molecular-level strains in the thermoset matrix upon curing and cooling which can lead to shape deformations, micro-cracking, and other issues. Non-symmetric [0x/90x] laminates are often used to demonstrate the presence of residual strains, wherein laminate curvature is indicative of the strain magnitudes. In this study, 16 ply [0x/90x] laminates were fabricated using a commercially-available prepreg and cured per the manufacturer’s recommended cure cycle. Digital Image Correlation was used to observe curvature compensation by thermal means, with the aim to demonstrate its potential as a highly-sensitive technique for probing residual strain levels in composite laminates.
The University of Southern Mississippi, Kyler R. Knowles, Jeffrey Wiggins
Method to Reduce Costs for Production of PAN Based Carbon Fibres
Carbon fibres feature excellent mechanical properties combined with low density. However, carbon fibres still have a low market. The bottleneck during production is the stabilization with process times up to 2 hours and temperatures of up to 300 Â°C. Industrially the stabilization is carried out in 4 to 6 different ovens with increasing temperature and equal residence time. Through a DSC analysis of the exothermic reactions it can be shown, that the residence times in the first ovens can be reduced by 50 % to 15 min. The strength of the carbonized samples is equal to a Toho Tenax HTS40.
Institut für Textiltechnik der RWTH Aachen University, Franz Pursche, Gunnar Seide, Thomas Gries
Microstructural Investigation of Commercially Available Pristine Composite Bars for Concrete Reinforcement
This Poster presents the result of scanning electron microscopy (SEM) imaging on four different commercially available pristine glass fiber reinforced polymer (GFRP) bars. It captures the: (I) existing crack/void patterns in the matrix, (II) fiber/matrix interface and (III) fiber distribution in the matrix. Moreover, panorama images of the entire cross sections are provided to give a proper comparison between different bars. Considering lack of a GFRP microstructure notation in the literature, these results can be used as a benchmark for microstructure of commercially available pristine GFRP bars and serve as a base for monitoring possible changes after any experiment.
University of Miami, Omid Gooranorimi, Wimal Suaris, Edward Dauer, Antonio Nanni
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