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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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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), 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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Koutras, N. (author), Benedictus, R. (author), Villegas, I.F. (author)The effect of temperature on the lap shear strength (LSS) and failure mechanisms of ultrasonically welded carbon fibre reinforced polyphenylene sulphide (CF/PPS) joints was investigated, correlating the weld performance to the crystallinity degree of PPS at the weldline. The single-lap shear tests were carried out at temperatures ranging from...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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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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Tsiangou, E. (author), Teixeira De Freitas, S. (author), Villegas, I.F. (author), Benedictus, R. (author)Ultrasonic welding is a highly promising technique for joining thermoplastic to thermoset composites. A neat thermoplastic coupling layer is co-cured on the surface to be welded to make the thermoset composite ‘weldable’. A reliable bond is attained when miscible thermoplastic and thermoset materials are chosen. For welding carbon fibre...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
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Koutras, N. (author), Villegas, I.F. (author), Benedictus, R. (author)The influence of the ultrasonic welding process parameters, namely the force and the vibration amplitude, on the crystallinity degree at the welding interface of CF/PPS (carbon fibre reinforced poly(phenylene) sulphide) joints is investigated. Two different sets of parameters, one representing high force and high vibration amplitude (1000 N,...conference paper 2020
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Tsiangou, E. (author), Teixeira De Freitas, S. (author), Villegas, I.F. (author), Benedictus, R. (author)With its short heating times, ultrasonic welding is a highly promising technique for joining thermoplastic (TPC) to thermoset (TSC) composites, to prevent thermal degradation of the thermoset adherend. A neat thermoplastic coupling layer is co-cured on the surface to be welded to make the TSC “weldable”. For welding CF/PEEK to a TSC adherend,...conference paper 2020
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Zhao, T. (author), Tsakoniatis, Ioannis (author), Rans, C.D. (author), Villegas, I.F. (author), Benedictus, R. (author)Thermoplastic composite spot welded joints are more well-suited for carrying shear load rather than peel load. However, peel load is difficult to be eliminated in single-lap joint configuration. In this paper, a series of mechanical tests were carried out to study the effects of the spot spacing and the number of welded spots on the secondary...conference paper 2020
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Jongbloed, B.C.P. (author), Teuwen, Julie J.E. (author), Villegas, I.F. (author), Benedictus, R. (author)Continuous ultrasonic welding is a new promising high-speed joining technique for thermoplastic composites. At the moment no straightforward method exists to find an optimum welding speed to easily obtain high strength joints. However, for static ultrasonic welding a systematic approach is available. Therefore, the aim of this study is to...conference paper 2019
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Ochôa, Pedro (author), Villegas, I.F. (author), Groves, R.M. (author), Benedictus, R. (author)This article presents research about the propagation of ultrasonic guided waves in ultrasonically welded thermoplastic composite joints. The goal of the study was to understand the effect of weld manufacturing defects on guided wave transmission across the joint. Triangular energy-directors integrated into the lower composite adherends...journal article 2019
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Köhler, F. (author), Jongbloed, B.C.P. (author), Morgado Martins Filipe, T.M. (author), Herrmann, Axel (author), Villegas, I.F. (author), Benedictus, R. (author)The increasing use of fibre-reinforced plastics in the aerospace industry leads to challenges in joining these materials. The traditionally used mechanical fasteners introduce damage when used in composites by disrupting the fibres. However, thermoplastic composites allow for fusion bonding processes to join parts. Ultrasonic welding has shown...conference paper 2018
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Zhao, T. (author), Broek, C.A. (author), Palardy, G. (author), Villegas, I.F. (author), Benedictus, R. (author)The research in this paper is an essential part of a bigger effort on developing robust sequential ultrasonic welding of multi-spot welded joints in thermoplastic composites. It mainly focused on assessing the impact of the changes in boundary conditions on the welding process and whether it could be circumvented by using an appropriate...journal article 2018
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Ochôa, Pedro (author), Villegas, I.F. (author), Groves, R.M. (author), Benedictus, R. (author)One of the advantages of thermoplastic composites relative to their thermoset counterparts is the possibility of assembling components through welding. Ultrasonic welding in particular is very promising for industrialization. However, uncertainty in the fatigue and fracture behaviour of composites is still an obstacle to the full utilisation...journal article 2018
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Zhao, T. (author), Palardy, G. (author), Villegas, I.F. (author), Benedictus, R. (author)Ultrasonic welding is a promising assembly technique for thermoplastic composites and it is well-suited for spot welding. In this study, two typical welding process control strategies, i.e. displacement-controlled and energy-controlled welding, were selected to manufacture spot-welded joints. The influence of different boundary conditions,...conference paper 2017
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Ochôa, Pedro (author), Villegas, I.F. (author), Groves, R.M. (author), Benedictus, R. (author)Ultrasonic welding is a very promising technique for joining thermoplastic composite (TpC) components in aircraft primary structures [1, 2]. The potential introduction of new lightweight structures in civil aviation has been driving the change towards condition-based maintenance (CBM) as an alternative to the regular inspection interval approach...abstract 2016
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Zhao, T. (author), Palardy, G. (author), Villegas, I.F. (author), Rans, C.D. (author), Martinez, M.J. (author), Benedictus, R. (author)The in-plane and out-of-plane mechanical behaviour of both ultrasonically spot-welded and mechanically fastened joints was investigated by double-lap shear and pull-through tests, respectively. Spot-welded specimens showed comparable onset failure load and significantly higher joint stiffness compared to mechanical fasteners when carrying shear...journal article 2016