TY - CONF A1 - Trappe, Volker A1 - Kraus, David A1 - Kübler, Stefan A1 - Eisermann, René T1 - Multiaxial fatigue damage of glass fiber reinforced polymers N2 - Fiber reinforced polymers (FRPs) are a well established material in lightweight applications, e.g. in automotive, aerospace or wind energy. The FRP components are subjected to multiaxial mechanical as well as hygrothermal loads. Common operation temperatures are in the range of 213 K and 373 K (-60 °C and 100 °C) at a relative humidity of 10% to 90%. In spacecraft applications, the environmental conditions are even more extreme. However, the correlation between multiaxial mechanical loading and harsh environment conditions have to-date not been investigated in detail. The project aims to investigate the fatigue behavior of FRPs dependent on multiaxial mechanical loading, temperature, and humidity. Extensive experimental testing is performed on flat plate and cylindrical tube specimens, accompanied by numerical and analytical calculations. T2 - 24. Nationales SAMPE Symposium CY - Dresden, Germany DA - 06.02.2019 KW - Composite KW - Fatigue KW - Thermomechanics KW - Distributed fiber optic sensors PY - 2019 AN - OPUS4-47335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisermann, René A1 - Schukar, Marcus A1 - Nagel, Lukas A1 - Hickmann, Stefan A1 - Munzke, Dorit A1 - Trappe, Volker T1 - Characterising the material degradation of inner pressure-loaded GFRP-tube specimens using distributed strain sensing N2 - Glass-fibre-reinforced plastics (GFRP) are commonly used for the construction of pressure vessels and tanks for example in automotive and aerospace industries. Especially for pressure vessels used for the storage of natural gas or hydrogen with operation pressures up to 700 bar, an early material fatigue detection is of great interest. Measuring the distributed strain profile of GFRP structures helps to understand and detect material fatigue. In this article, we demonstrate the great potential of swept wavelength interferometry (SWI) based distributed strain sensing for the monitoring of pressure vessels made from GFRP. A resin transfer molding (RTM) process was used to manufacture GFRP-tube specimens. Commercial optical fibres with polyimid coating were glued to the surface externally in circumferential and axial direction. A cyclic load of up to 150 bar was applied to the samples using a servo-hydraulic test bench. Comparing the loaded and unloaded test conditions, we determined up to 2 % elongation in circumferential direction. We demonstrate reliable distributed strain measurements with sub-centimetre spatial resolution. By monitoring these high-resolution strain profiles, we were able to detect local material degradation that manifested itself as localized strain changes. Crucially, the material Degradation could be detected already after 75 % of dat the fatigue life before a crack appeared that led to leakage. T2 - Sensoren und Messsysteme - 19. ITG/GMA-Fachtagung CY - Nürnberg, Germany DA - 26.06.2018 KW - Distributed fibre optic sensors KW - Optical backscatter reflectometry KW - Swept wavelength interferometry (SWI) KW - Structural health monitoring (SHM) KW - Composite structures KW - Optical fibre PY - 2018 UR - https://ieeexplore.ieee.org/document/8436172/ SN - 978-3-8007-4683-5 SP - 239 EP - 242 PB - VDE VERLAG GMBH CY - Berlin AN - OPUS4-45887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -