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van Bergen, Steven (author), Norte, R.A. (author), Aragon, A.M. (author)
The computational analysis of nanophotonic devices is usually carried out via the standard finite element method (FEM). However, FEM requires meshes that are fitted to the devices’ boundaries, so making changes to the geometry (and thus the mesh) results in an inefficient process at best. Such an approach is therefore at odds when conducting...
journal article 2024
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Zhai, X. (author), Wang, Weiming (author), Chen, Falai (author), Wu, J. (author)
Recent years have seen a growing interest in topology optimization of functionally graded microstructures, characterized by an array of microstructures with varying volume fractions. However, microstructures optimized at slightly different volume fractions do not necessarily connect well when placed adjacently. Furthermore, optimization is...
journal article 2024
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Munro, D.P. (author)
This note communicates a simple modification of the optimality criteria (OC) design update—as found in well-known Matlab implementations of the classical topology design problem—to an update based on a quadratic program (QP) with a single linear constraint. This QP update is a special case of the dual of Falk, which in general accommodates...
journal article 2024
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Ranjan, R. (author)
With the advent of Additive Manufacturing (AM) techniques, the design principle of `form follows function' no longer remains a utopian proposition. The unprecedented design freedom offered by AM is making it possible to conceptualize highly performant designs by efficiently leveraging geometrical complexity. The increase in design freedom...
doctoral thesis 2023
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Wang, Junpeng (author), Westermann, Rüdiger (author), Wu, J. (author)
We present a novel dehomogenization approach for the efficient design of high-resolution load-bearing structures. The proposed approach builds upon a streamline-based parametrization of the design domain, using a set of space-filling and evenly spaced streamlines in the two mutually orthogonal direction fields that are obtained from...
journal article 2023
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van den Boom, S.J. (author), Abedi, Reza (author), van Keulen, A. (author), Aragon, A.M. (author)
Phononic crystals can be designed to show band gaps—ranges of frequencies whose propagation is strongly attenuated in the material. In essence, their working principle is based on destructive interference of waves reflecting from the periodic arrangement of material interfaces (i.e., Bragg scattering). Consequently, capturing accurately the...
journal article 2023
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Slebioda, Marek (author), Giele, R.J.P. (author), Langelaar, Matthijs (author)
This paper presents a density based topology optimization method for infinite fatigue life constraints of non-proportional load cases, with a specific focus on parts with cyclic symmetry. Considering non-proportional loads in topology optimization significantly broadens the types of design problems that can be handled. The method estimates...
journal article 2023
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Moosabeiki, Vahid (author), de Winter, N. (author), Cruz Saldivar, M. (author), Leeflang, M.A. (author), Witbreuk, M. M.E.H. (author), Lagerburg, V. (author), Mirzaali, Mohammad J. (author), Zadpoor, A.A. (author)
Orthopedic plates are commonly used after osteotomies for temporary fixation of bones. Patient-specific plates have recently emerged as a promising fixation device. However, it is unclear how various strategies used for the design of such plates perform in comparison with each other. Here, we compare the biomechanical performance of 3D...
journal article 2023
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Kumar, Prabhat (author), Pinskier, Josh (author), Howard, David (author), Langelaar, Matthijs (author)
Compliant mechanisms actuated by pneumatic loads are receiving increasing attention due to their direct applicability as soft robots that perform tasks using their flexible bodies. Using multiple materials to build them can further improve their performance and efficiency. Due to developments in additive manufacturing, the fabrication of...
conference paper 2023
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Noel, L.F.P. (author), Maute, K. (author)
Solving conjugate heat transfer design problems is relevant for various engineering applications requiring efficient thermal management. Heat exchange between fluid and solid can be enhanced by optimizing the system layout and the shape of the flow channels. As heat is transferred at fluid/solid interfaces, it is crucial to accurately resolve...
journal article 2023
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Wang, W. (author), van Keulen, A. (author), Wu, J. (author)
Additive manufacturing of metal parts involves phase transformations and high temperature gradients which lead to uneven thermal expansion and contraction, and, consequently, distortion of the fabricated components. The distortion has a great influence on the structural performance and dimensional accuracy, e.g., for assembly. It is therefore...
journal article 2023
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Ranjan, R. (author), Chen, Z. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)
Overheating is a major issue especially in metal Additive Manufacturing (AM) processes, leading to poor surface quality, lack of dimensional precision, inferior performance and/or build failures. A 3D density-based topology optimization (TO) method is presented which addresses the issue of local overheating during metal AM. This is achieved...
journal article 2023
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van der Zwet, J.M. (author), Delissen, A.A.T.M. (author), Langelaar, Matthijs (author)
Topology optimization has seen increased interest with the rise of additive manufacturing (AM) as a fabrication method, because of its ability to exploit the geometric complexity that AM offers. However, AM still imposes some geometric restrictions on the design, most notably on minimum feature size, overhang angles, and enclosed voids....
journal article 2023
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Komini, Ludian (author), Langelaar, Matthijs (author), Kriegesmann, Benedikt (author)
This paper presents a method to consider uncertainties in the distortion prediction of additive manufacturing processes within robust topology optimization. The random variable of the stochastic additive manufacturing process is the inherent thermomechanical strain, typically determined by process characterization experiments. The value of...
journal article 2023
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Mishra, V. (author), Ayas, C. (author), Langelaar, Matthijs (author)
In metal Additive Manufacturing (AM), the deposited material is subjected to a series of heating and cooling cycles. The locally occurring temperature extremes and cooling rates determine solid-state phase fractions, material microstructure, texture, and ultimately the local material properties. As the shape of a part determines the local...
journal article 2023
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Bayat, Mohamad (author), Zinovieva, Olga (author), Ferrari, Federico (author), Ayas, C. (author), Langelaar, Matthijs (author), Spangenberg, Jon (author), Salajeghe, Roozbeh (author), Poulios, Konstantinos (author), Mohanty, Sankhya (author), Sigmund, Ole (author), Hattel, Jesper (author)
Additive manufacturing (AM) processes have proven to be a perfect match for topology optimization (TO), as they are able to realize sophisticated geometries in a unique layer-by-layer manner. From a manufacturing viewpoint, however, there is a significant likelihood of process-related defects within complex geometrical features designed by TO...
review 2023
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Theulings, M.J.B. (author), Langelaar, Matthijs (author), van Keulen, A. (author), Maas, Robert (author)
Modeling of fluid flows in density-based topology optimization forms a longstanding challenge. Methods based on the Navier–Stokes equations with Darcy penalization (NSDP equations) are widely used in fluid topology optimization. These methods use porous materials with low permeability to represent the solid domain. Consequently, they suffer...
journal article 2023
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Smit, Thijs (author), Koppen, S. (author), Ferguson, Stephen J. (author), Helgason, Benedikt (author)
A promising new treatment for large and complex bone defects is to implant specifically designed and additively manufactured synthetic bone scaffolds. Optimizing the scaffold design can potentially improve bone in-growth and prevent under- and over-loading of the adjacent tissue. This study aims to optimize synthetic bone scaffolds over...
journal article 2023
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Zhang, L. (author), Zhang, Y. (author), van Keulen, A. (author)
High computational costs are encountered in topology optimization problems of geometrically nonlinear structures since intensive use has to be made of incremental-iterative finite element simulations. To alleviate this computational intensity, reduced-order models (ROMs) are explored in this paper. The proposed method targets ROM bases...
journal article 2023
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Koppen, S. (author)
High-tech equipment critically relies on the precise and reliable fine alignment of components such as mirrors and lenses for calibration and adaptation of instrumentation. To meet the ever-increasing requirements on precision, engineers typically resort to monolithic compliant mechanisms. These mechanisms gain mobility by deformation of the...
doctoral thesis 2022
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