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Belo Gomes Brito, C. (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author), Villegas, I.F. (author)This paper evaluates the potential of changing the welding force and the compliance of the energy director (ED) to reduce the effects caused by misaligned adherends, which were: increased through-thickness heating, reduced size of welded area and increased heating time. In the methodology that was followed, we welded adherends misaligned by...journal article 2023
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Jongbloed, B.C.P. (author), Teuwen, Julie J.E. (author), Villegas, I.F. (author)Continuous ultrasonic welding is an attractive welding technique for thermoplastic composite structures. In this process, a metallic sonotrode connected to a piezoelectric transducer and to a press moves along the parts to be welded applying ultrasonic vibrations and a static welding force on the welding overlap. Thus far, the research carried...journal article 2023
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Verma, Amrit Shankar (author), Yan, Jiquan (author), Hu, Weifei (author), Jiang, Zhiyu (author), Shi, Wei (author), Teuwen, Julie J.E. (author)A fiber-reinforced composite wind turbine blade (WTB) is exposed to numerous impact threats during its service life causing damages that can be detrimental to its structural integrity. Currently, impact loads are not considered during blade design, so high safety factors are introduced, which result in a conservative design. However, as wind...review 2023
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Teuwen, Julie J.E. (author), Farooq, U. (author), Alderliesten, R.C. (author), Dransfeld, C.A. (author)Toughness of epoxies is commonly improved by adding thermoplastic phases, which is achieved through dissolution and phase separation at the microscale. However, little is known about the synergistic effects of toughening phases on multiple scales. Therefore, here, we study the toughening of epoxies with layered poly(ether imide) (PEI) structures...journal article 2023
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Jimenez del Toro, A. (author), Teuwen, Julie J.E. (author), Tomás, Flanagan (author), Finnegan, William (author)Laser-assisted tape placement (LATP) and thermoplastic composites (TPCs) pre-impregnated (prepreg) tapes are a promising combination of technologies; given the in-situ capabilities of the TPCs and the high degree of automation achievable with LATP. However, laminate quality, measured as final void content, tends to decrease when increasing...conference paper 2022
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Jongbloed, B.C.P. (author), Vinod, R. (author), Teuwen, Julie J.E. (author), Benedictus, R. (author), Villegas, I.F. (author)Continuous ultrasonic welding is a promising high-speed and energy-efficient joining technique for thermoplastic composite structures. However, in the current state-of-the-art research on the topic numerous deconsolidation voids could be identified at the welding interface, which results in a strength knock-down. The aim of this study is,...journal article 2022
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Farooq, U. (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author)Epoxies with high cross-linking densities are brittle and hence have a low fracture toughness. However, different methods are known to increase fracture toughness. Numerous approaches are known to incorporate a second phase into the epoxy matrix, such as rubber, inorganic nanoparticles or thermoplastics, referred to as bulk resin modification....conference paper 2022
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Antoniou, A (author), Dyer, K (author), Finnegan, William (author), Herring, Robbie (author), Holst, Bodil (author), Ilsted Bech, Jakob (author), Katsivalis, Ioannis (author), Kutlualp, Tazefidan (author), Teuwen, Julie J.E. (author)In the immediate future, wind power will provide more electricity than any other technology based on renewable and low-emission energy sources. As a result, the size of offshore wind turbines has increased to harvest more wind energy in order to achieve the 2050 EU carbon neutral targets. The use of composites opens great prospects in the design...conference paper 2022
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Zweifel, Lucian (author), Brauner, Christian (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author)This study presents two novel methods for in situ characterization of the reaction-diffusion process during the co-curing of a polyetherimide thermoplastic interlayer with an epoxy-amine thermoset. The first method was based on hot stage experiments using a computer vision point tracker algorithm to detect and trace diffusion fronts, and the...journal article 2022
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Brito, B.C.Q.B. (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author), Villegas, I.F. (author)Ultrasonic welding is a promising joining technique for thermoplastic composite parts. On the way towards upscaling and industrialisation of this technology, it is crucial to understanding how it is affected by manufacturing tolerances. The objective of the research presented in this paper was to investigate the influence that misaligned...journal article 2022
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Jongbloed, B.C.P. (author), Teuwen, Julie J.E. (author), Benedictus, R. (author), Villegas, I.F. (author)Continuous ultrasonic welding is a promising technique for joining thermoplastic composites structures together. The aim of this study was to gain further insight into what causes higher through-the-thickness heating in continuous ultrasonic welding of thermoplastic composites as compared to the static process. Thermocouples were used to measure...journal article 2021
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Çelik, O. (author), Choudhary, A. (author), Peeters, D.M.J. (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author)In this study, the effect of rapid laser heating, which is typical during laser-assisted fiber placement (LAFP), on the micro- and meso- structure of the thermoplastic tape was investigated. Thermoplastic tapes were heated above the melting temperature with different heated lengths (30 and 80 mm and heating times (0.2 and 0.8 s) in a dedicated...journal article 2021
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Farooq, U. (author), Heuer, Sönke (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author)Epoxies are inherently brittle materials and to overcome this brittleness, a second microphase (i.e., thermoplastic) is typically added. This modification of epoxy resin using thermoplastics results in reaction-induced phase separating morphologies in the micrometer range. In this study, the influence of the curing history, beyond phase...journal article 2021
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Verma, Amrit Shankar (author), Di Noi, Sandro (author), Ren, Zhengru (author), Jiang, Zhiyu (author), Teuwen, Julie J.E. (author)Leading edge erosion (LEE) repairs of wind turbine blades (WTBs) involve infield application of leading edge protection (LEP) solutions. The industry is currently aiming to use factory based LEP coatings that can applied to the WTBs before they are shipped out for installation. However, one of the main challenges related to these solutions is...journal article 2021
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- Rans, C.D. (author), Teuwen, Julie J.E. (author) conference paper 2021
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Çelik, O. (author), Bussink, T. (author), Peeters, D.M.J. (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author)The effects of laser-induced deconsolidation on the compaction process of CF/PEEK tapes were investigated. First, tapes with different degrees of deconsolidation were manufactured using a laser heater. This procedure resulted in samples with different waviness, thickness, void content and surface roughness values. Then, as-received and laser...journal article 2021
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Verma, Amrit Shankar (author), Vedvik, Nils Petter (author), Gao, Zhen (author), Castro, Saullo G.P. (author), Teuwen, Julie J.E. (author)The leading edges of wind turbine blades are adhesively bonded composite sections that are susceptible to impact loads during offshore installation. The impact loads can cause localized damages at the leading edges that necessitate damage tolerance assessment. However, owing to the complex material combinations together with varying bondline...journal article 2021
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Verma, Amrit Shankar (author), Jiang, Zhiyu (author), Caboni, Marco (author), Verhoef, Hans (author), van der Mijle Meijer, Harald (author), Castro, Saullo G.P. (author), Teuwen, Julie J.E. (author)Rain-induced leading-edge erosion of wind turbine blades is associated with high repair and maintenance costs. For efficient operation and maintenance, erosion models are required that provide estimates of blade coating lifetime at a real scale. In this study, a statistical rainfall model is established that describes probabilistic...journal article 2021
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Verma, Amrit Shankar (author), Jiang, Zhiyu (author), Ren, Zhengru (author), Hu, Weifei (author), Teuwen, Julie J.E. (author)The presence of rain-induced leading edge erosion of wind turbine blades (WTBs) necessitates the development of erosion models. One of the essential parameters for erosion modeling is the relative impact velocity between rain droplets and the rotating blade. Based on this parameter, the erosion damage rate of a WTB is calculated to estimate...journal article 2021
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Çelik, O. (author), Hosseini, S.M.A. (author), Baran, Ismet (author), Grouve, Wouter J.B. (author), Akkerman, Remko (author), Peeters, D.M.J. (author), Teuwen, Julie J.E. (author), Dransfeld, C.A. (author)The effect of thermal contact resistance (TCR) correlated to the degree of intimate contact (DIC) between the incoming tape and the substrate on the temperature history during laser-assisted fiber placement (LAFP) was investigated. A novel experimental methodology was designed to understand the effect with a non-contact method which did not...journal article 2021