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Hernandez Quintanilla, Tomás (author)Similarity joins are operations which involve identifying similar pairs of records within one or multiple datasets. These operations are typically time-sensitive, as timely identification of relations can lead to increased profitability. Therefore, it is advantageous to analyze them using a stream processing system, which offers real-time...master thesis 2023
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van der Starre, Thom (author)Hall spars, a leading innovator in the composite mast-building industry with a long history of successful projects, provided a challenge which is the inspiration of this thesis. This thesis aims to contribute to the challenge: Joining techniques for the internal bonding of carbon fibre-reinforced polymer components into carbon fibre-reinforced...master thesis 2023
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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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Quan, D. (author), Ma, Yannan (author), Yue, Dongsheng (author), Liu, Jiaming (author), Xing, Jun (author), Zhang, Mingming (author), Alderliesten, R.C. (author), Zhao, Guoqun (author)In this study, an aerospace thermosetting composite was co-curing joined by Polyether-ether-ketone (PEEK) and Polyethylenimine (PEI) films, with an aim of developing advanced composite joints. The semi-crystalline PEEK films were surface activated upon a UV-irradiation technique to obtain a strong film–composite interface, while the amorphous...journal article 2023
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Sun, W. (author), Katsifodimos, A (author), Hai, R. (author)Recent advances in Graphic Processing Units (GPUs) have facilitated a significant performance boost for database operators, in particular, joins. It has been intensively studied how conventional join implementations, such as hash joins, benefit from the massive parallelism of GPUs. With the proliferation of machine learning, more databases...conference paper 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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Quan, D. (author), Wang, Guilong (author), Zhao, Guoqun (author), Alderliesten, R.C. (author)The inherently low surface energy of carbon fibre reinforced Polyether-ether-ketone (CF/PEEK) composites results in an extremely low compatibility with adhesives. This subsequently causes significant challenges in the adhesive joining of them to other dissimilar materials. Herein, the bonding surfaces of the CF/PEEK composites were treated by...journal article 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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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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van der Vlist, Klaas Jan (author)This report shows the development of a method that joins two chemically incompatible materials during Fused Deposition Modelling (FDM). State of the art FDM printers can extrude more than one material during the printing process. Due to chemical incompatibility of many polymers, the selection for combining materials is limited. This gives the...master thesis 2021
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Meijerman, Krista (author)Welding is a joining method for thermoplastic composites (TPCs) that offers multiple advantages over the more traditional methods of mechanical fastening and adhesive bonding. A particularly promising welding technique is ultrasonic welding, which features very short process times as a result of the high heating rates that can be achieved. This...master thesis 2021
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Marino, Luca (author), Cicirello, A. (author)This paper proposes an approach for the determination of the analytical boundaries of continuous, stick-slip and no motion regimes for the steady-state response of a multi-degree-of-freedom (MDOF) system with a single Coulomb contact to harmonic excitation. While these boundaries have been previously investigated for single-degree-of-freedom ...journal article 2021
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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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Tsiangou, E. (author), Teixeira De Freitas, S. (author), Benedictus, R. (author), Villegas, I.F. (author)This paper addresses the sensitivity of the ultrasonic welding process for joining dissimilar composites to variations in either the welding force or amplitude of vibrations. For that, carbon fibre (CF)/epoxy specimens were welded to CF/polyetheretherketone (PEEK) specimens, through a polyetheretherimide (PEI) coupling layer co-cured with the...journal article 2021
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Tsiangou, E. (author), Kupski, J.A. (author), Teixeira De Freitas, S. (author), Benedictus, R. (author), Villegas, I.F. (author)This study aims at assessing the sensitivity of the ultrasonic welding process for joining epoxy- to thermoplastic-based composites sensitivity to the heating time. For that, carbon fibre (CF)/epoxy adherends with a co-cured PEI coupling layer were ultrasonically welded to CF/polyetheretherketone (PEEK) adherends at different heating times....journal article 2021
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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 high-speed and energy-efficient joining method for thermoplastic composite structures. Our aim was to identify and understand differences between the static and continuous ultrasonic welding process for thermoplastic composites. In particular, melting of the interface, consumed power and energy...journal article 2020
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Kupski, J.A. (author)Adhesive bonding is one of the most suitable joining technologies in terms of weight and mechanical performance for current carbon fiber reinforced polymer aircraft fuselage structures. However, traditional joint topologies such as single overlap joints induce high peel stresses, resulting in sudden failure and low joint strength when compared...doctoral thesis 2020
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Quan, D. (author), Alderliesten, R.C. (author), Dransfeld, C.A. (author), Tsakoniatis, Ioannis (author), Teixeira De Freitas, S. (author), Scarselli, Gennaro (author), Murphy, Neal (author), Ivanković, Alojz (author), Benedictus, R. (author)A high-power UV-irradiation technique was proposed for the surface treatment of PPS and PEEK composites, aiming to achieve good adhesion with epoxy adhesives. The composite substrates were rapidly UV-irradiated for a duration of between 2–30s, and then bonded using an aerospace film adhesive to produce joints. Tensile lap-shear strength and...journal article 2020
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Quan, D. (author), Deegan, Brian (author), Byrne, Lorcán (author), Scarselli, Gennaro (author), Ivanković, Alojz (author), Murphy, Neal (author)Carbon fibre reinforced poly-etherether-ketone (PEEK) and poly-phenylene-sulfide (PPS) composites were rapidly surface-treated by high-power UV light, and then adhesively bonded to aluminium 2024-T3 and carbon fibre/epoxy composites. The results of a single lap-shear joint test demonstrated that a UV-treatment lasting for 5 s was sufficient...journal article 2020
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Jongbloed, B.C.P. (author), Teuwen, Julie J.E. (author), Palardy, G. (author), Villegas, I.F. (author), Benedictus, R. (author)Continuous ultrasonic welding is a high-speed joining method for thermoplastic composites. Currently, a thin film energy director is used to focus the heat generation at the interface. However, areas of intact energy director remain in the welded seam, which significantly lowers the weld strength, and result in a non-uniformly welded seam. To...journal article 2020