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Anand, S. (author), Alderliesten, R.C. (author), Castro, Saullo G.P. (author)Carbon emissions from commercial aircraft are expected to reach more than twice as much as the current levels by 2050. Unconventional aircraft, such as the Flying-V, are projected to achieve more than 20% fuel savings when compared to conventional configurations. However, these unconventional aircraft configurations pose a unique set of design...conference paper 2024
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Keijzer, D.M. (author), Simon Soria, C. (author), Arends, J.J. (author), Sarıgöl, B. (author), Scarano, F. (author), Castro, Saullo G.P. (author)As of present the Urban Air Mobility market has been dominated by fully electric aircraft. However, hydrogen vehicles have remained relatively undeveloped in this segment, also because hydrogen poses additional design complexities and uncertainties concerning crashworthiness, fuel cell cooling, and low volumetric density. Nevertheless, hydrogen...conference paper 2024
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Maathuis, H.F. (author), De Breuker, R. (author), Castro, Saullo G.P. (author)Design optimisation potentially leads to lightweight aircraft structures with lower environmental impact. Due to the high number of design variables and constraints, these problems are ordinarily solved using gradient-based optimisation methods, leading to a local solution in the design space while the global space is neglected. Bayesian...conference paper 2024
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Anand, S. (author), Alderliesten, R.C. (author), Castro, Saullo G.P. (author)To design crash structures for disruptive aircraft designs, it is required to have fast and accurate methods that can predict crashworthiness of aircraft structures early in the design phase. Axial crushing is one of the key energy absorbing mechanisms during a crash event. In this study, various analytical models proposed for calculation of...journal article 2024
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Nedelcu, Alex (author), Mendes Florindo, A.M. (author), Han, S.H. (author), Dekker, Jaap (author), de Vlieger, M.J. (author), Castro, Saullo G.P. (author), Peeters, D.M.J. (author)Double-curved composite structures that are manufactured via automated fiber placement, such as pressure vessels, can take advantage of tow steering to reduce weight. This design freedom comes with the cost of adding internal normal stresses to the tow, possibly leading to wrinkles or pull up. The present work investigates tow pull up both...journal article 2024
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Rahman, H. (author), De Breuker, R. (author), Castro, Saullo G.P. (author)In this paper, an innovative design methodology is proposed to simultaneously optimize the size, layout, and number of stiffeners of a stiffened panel using a gradient-based optimizer. In the proposed method, CAD-based parameterization is used to parameterize the layout of the stiffeners. The location and orientation of each stiffener are...conference paper 2023
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Silva, Higor Luis (author), Machado Guimarães, Thiago Augusto (author), Castro, Saullo G.P. (author)Modular structures come with the promise of efficient manufacturing and reduced maintenance costs. The amount of modularization is usually limited by weight efficiency, meaning that the minimum weight always lies on the most customized design, where all the structural elements are allowed to be different across the structural domain. This work...conference paper 2023
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Chen, Sian Ying (author), van de Waerdt, W.A. (author), Castro, Saullo G.P. (author)The Flying-V aircraft concept promises better fuel-burn performance over conventional tube-and-wing configurations, integrating the passenger cabin and cargo volume into the lifting surface. However, the wing-fuselage and cockpit windows of the Flying-V are exposed to the flight direction, posing a new challenge to the design and...journal article 2023
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Smeets, E.T.B. (author), Rans, C.D. (author), Castro, Saullo G.P. (author), Villegas, I.F. (author)In thermoplastic composite joints with a circular ultrasonic spot weld, the damage growth is located at the interface between the joined components. This means that any damage in these joints is invisible from the outside. This experimental study compares three different in-situ methods to measure the damage growth indirectly. The motivation...journal article 2023
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Saberi, Saeid (author), Nasiri, Hamid (author), Ghorbani, Omid (author), Friswell, Michael I. (author), Castro, Saullo G.P. (author)Material properties, geometrical dimensions, and environmental conditions can greatly influence the characteristics of bistable composite laminates. In the current work, to understand how each input feature contributes to the curvatures of the stable equilibrium shapes of bistable laminates and the snap-through force to change these...journal article 2023
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Baciu, Theodor D. (author), Degenhardt, Richard (author), Franzoni, Felipe (author), Gliszczynski, Adrian (author), Arbelo, Mariano A. (author), Castro, Saullo G.P. (author), Kalnins, Kaspars (author)The Vibration Correlation Technique (VCT) is a non-destructive method to predict buckling loads for imperfection-sensitive structures. While successfully used to validate numerical models and predict experimental buckling loads, recommendations for defining the VCT experiment are scarce. Here, its sensitivity towards the number of load steps...journal article 2023
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Anand, S. (author), Alderliesten, R.C. (author), Castro, Saullo G.P. (author)This paper reviews analytical models proposed by Abramowicz et al.[1, 2] and Stefan et al.[3] for the axial crushing of metallic tubular structures with square and circular cross-sections. First, a database of experiments for square and circular tubes was created based on the literature. Subsequently, the predictions obtained using these...conference paper 2023
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Beyne, E.E.A. (author), Castro, Saullo G.P. (author)The electric aircraft industry is starting to gain traction mainly due to the growing specific energy capacity of new batteries. Within this industry electric vertical takeoff and landing (eVTOL) aircraft serve the urban and regional air mobility market, requiring less infrastructure investments such as large airports, due to their vertical...conference paper 2022
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Castro, Saullo G.P. (author), Jansen, E. L. (author)The multi-modal formulation of Koiter's asymptotic method provides a systematic and efficient procedure to evaluate the initial post-buckling behaviour and to assess the nonlinear behavior of structures. This manuscript presents a displacement-based multi-modal formulation of Koiter's method for cylindrical shells, which are structures known for...conference paper 2022
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Smeets, E.T.B. (author), Rans, C.D. (author), Alderliesten, R.C. (author), Castro, Saullo G.P. (author), Villegas, I.F. (author)Ultrasonic spot welding is a joining technique for thermoplastic composites with great potential regarding processing speed and cost. To investigate the damage tolerance and possible inherent damage arresting behavior of multi-spot welded joints, a technique is necessary to measure damage growth in the joints under cyclic loading. Visual...conference paper 2022
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Dos Santos, Rogério R. (author), Castro, Saullo G.P. (author)The present study investigates how to apply continuous tow shearing (CTS) in a manufacturable design parameterization to obtain reduced imperfection sensitivity in lightweight, cylindrical shell designs. The asymptotic nonlinear method developed by Koiter is applied to predict the postbuckled stiffness, whose index is constrained to be...journal article 2022
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Wadia, K.K. (author), Buszek, M.J. (author), Poliakov, M. (author), Castro, Saullo G.P. (author)In aircraft structural design it is of utmost importance to minimise the structural mass while maintaining a durable structure that is able to sustain the design loads for a predetermined number of flight cycles. The present manuscript investigates a methodology for the preliminary design and analysis of a tandem-wing long-range electric...conference paper 2022
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Schoser, J.J. (author), Cuadrat-Grzybowski, M. (author), Castro, Saullo G.P. (author)This study proposes a strategy to incorporate control and stability aspects into the preliminarydesign of a tandem-wing, long-range eVTOL aircraft concept. Four operational phases areconsidered: cruise, transition, hover, and ground operation. For cruise, a method to designfor open-loop stability and size aerodynamic control surfaces is...conference paper 2022
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Saberi, Saeid (author), Sadat Hosseini, Alireza (author), Yazdanifar, Fatemeh (author), Castro, Saullo G.P. (author)For the last three decades, bistable composite laminates have gained publicity because of their outstanding features, including having two stable shapes and the ability to change these states. A common challenge regarding the analysis of these structures is the high computational cost of existing analytical methods to estimate their natural...journal article 2022
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Wang, Z. (author), Almeida, José Humberto S. (author), Ashok, Aravind (author), Wang, Zhonglai (author), Castro, Saullo G.P. (author)Variable-angle filament-wound (VAFW) cylinders are herein optimized for minimum mass under manufacturing constraints, and for various design loads. A design parameterization based on a second-order polynomial variation of the tow winding angle along the axial direction of the cylinders is utilized to explore the nonlinear steering-thickness...journal article 2022