TY - JOUR A1 - Ghafafian, Carineh A1 - Popiela, Bartosz A1 - Trappe, Volker T1 - Failure Mechanisms of GFRP Scarf Joints under Tensile Load N2 - A potential repair alternative to restoring the mechanical properties of lightweight fiberreinforced polymer (FRP) structures is to locally patch these areas with scarf joints. The effects of such repair methods on the structural integrity, however, are still largely unknown. In this paper, the mechanical property restoration, failure mechanism, and influence of fiber orientation mismatch between parent and repair materials of 1:50 scarf joints are studied on monolithic glass fiber-reinforced polymer (GFRP) specimens under tensile load. Two different parent orientations of [-45/+45]2S and [0/90]2S are exemplarily examined, and control specimens are taken as a baseline for the tensile strength and stiffness property recovery assessment. Using a layer-wise stress analysis with finite element simulations conducted with ANSYS Composite PrepPost to support the experimental investigation, the fiber orientation with respect to load direction is shown to affect the critical regions and thereby failure mechanism of the scarf joint specimens. KW - Scarf joint KW - Glass fiber reinforced polymers KW - Failure mechanisms PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-523952 VL - 14 IS - 7 SP - 1806 PB - MDPI CY - Basel, Switzerland AN - OPUS4-52395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Popiela, Bartosz A1 - Ghafafian, Carineh A1 - Trappe, Volker T1 - FEM-Analyse der Reparaturstellen an FKV-Sandwichplatten N2 - Untersuchung des Einflusses des Reparaturpatches auf das Verhalten der reparierten GFK-Sandwichproben unter Zug-, Druck- und Schubbeanspruchung. T2 - 25. Nationales SAMPE-Symposium CY - Kassel, Germany DA - 18.02.2020 KW - Rotorblätter KW - Glasfaserverstärkter Kunststoff KW - Sandwichstruktur PY - 2020 AN - OPUS4-50544 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh A1 - Popiela, Bartosz A1 - Nielow, Dustin A1 - Trappe, Volker T1 - Restoration of structural integrity – a comparison of various repair concepts for wind turbine rotor blade shells N2 - Localized patches are a cost- and time-effective method for repairing fiber-reinforced polymer (FRP) sandwich wind turbine rotor blade shells. To increase the understanding of their effect on the fatigue of the blades, this study examines the effect of various layup methods of localized repair patches on the structural integrity of composite sandwich structures. Manufactured with the vacuum-assisted resin infusion (VARI) process, the shell test specimens are produced as a curved structure with glass fiber reinforced polymer (GFRP) sandwiching a polyvinyl chloride (PVC) foam core. Patch repairs are then introduced with varying layup techniques, and material properties are examined with cyclic fatigue tests. The transition region between patch and parent material is studied in greater detail with finite element method (FEM) simulations, with a focus on the effect of fiber orientation mismatch. Damage onset, crack development, and eventual failure are monitored with in-situ non-destructive testing methods to develop a robust understanding of the effects of repair concepts on material stiffness and strength. T2 - SMAR 2019 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Potsdam, Germany DA - 27.08.2019 KW - Lightweight materials KW - Glass fiber reinforced polymers KW - Sandwich KW - Wind turbine blades PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-482170 SP - 1 EP - 8 PB - German Society for Non-Destructive Testing (DGZfP e.V.) AN - OPUS4-48217 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -