- document
-
Mishra, V. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)Topology optimization typically generates designs that exhibit significant geometrical complexity, which can pose difficulties for manufacturing and assembly. The number of occurrences of an important design feature, in particular intersections, increases with geometrical complexity. Intersections are essential for load transfer in many...journal article 2022
- document
-
Xia, Yi (author), Langelaar, Matthijs (author), Hendriks, M.A.N. (author)Strut-and-Tie modelling (STM) has been widely applied to design D-regions of reinforced concrete structures. For economic and environmental reasons there is a need for optimized Strut-and-Tie models. How to optimize Strut-and-Tie models considering multiple load combinations has not been investigated extensively in the literature. In order to...journal article 2022
- document
-
van Kootwijk, A. (author), Moosabeiki, Vahid (author), Cruz Saldivar, M. (author), Pahlavani, H. (author), Leeflang, M.A. (author), Kazemivand Niar, S. (author), Tümer, N. (author), Mirzaali, Mohammad J. (author), Zhou, J. (author), Zadpoor, A.A. (author)The reconstruction of large mandibular defects with optimal aesthetic and functional outcomes remains a major challenge for maxillofacial surgeons. The aim of this study was to design patient-specific mandibular reconstruction implants through a semi-automated digital workflow and to assess the effects of topology optimization on the...journal article 2022
- document
-
Delissen, A.A.T.M. (author), Boots, Elwin (author), Laro, Dick (author), Kleijnen, Harry (author), van Keulen, A. (author), Langelaar, Matthijs (author)The design of high-precision motion stages, which must exhibit high dynamic performance, is a challenging task. Manual design is difficult, time-consuming, and leads to sub-optimal designs that fail to fully exploit the extended geometric freedom that additive manufacturing offers. By using topology optimization and incorporating all...journal article 2022
- document
-
Mishra, V. (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)A remarkable elastic anisotropy in plates of austenitic stainless steel produced by the Wire and Arc Additive Manufacturing process is recently reported. The Young's modulus depends on the angle of orientation with respect to the material deposition direction. Here, for the first time, this anisotropy is exploited to maximize structural...journal article 2022
- document
-
Koppen, S. (author), Langelaar, Matthijs (author), van Keulen, A. (author)In topology optimization, the state of structures is typically obtained by numerically evaluating a discretized PDE-based model. The degrees of freedom of such a model can be partitioned in free and prescribed sets to define the boundary conditions. A multi-partition problem involves multiple partitions of the same discretization, typically...journal article 2022
- document
-
Wang, Junpeng (author), Wu, J. (author), Westermann, Rüdiger (author)The optimization of porous infill structures via local volume constraints has become a popular approach in topology optimization. In some design settings, however, the iterative optimization process converges only slowly, or not at all even after several hundreds or thousands of iterations. This leads to regions in which a distinct binary...journal article 2022
- document
-
Koppen, S. (author), Langelaar, Matthijs (author), van Keulen, A. (author)High-tech equipment critically relies on flexures for precise manipulation and measurement. Through elastic deformation, flexures offer extreme position repeatability within a limited range of motion in their degrees of freedom, while constraining motion in the degrees of constraint. Topology optimization proves a prospective tool for the...journal article 2022
- document
-
Zheng, Li (author), Kumar, Siddhant (author), Kochmann, Dennis M. (author)We present a two-scale topology optimization framework for the design of macroscopic bodies with an optimized elastic response, which is achieved by means of a spatially-variant cellular architecture on the microscale. The chosen spinodoid topology for the cellular network on the microscale (which is inspired by natural microstructures...journal article 2021
- document
-
van de Ven, E.A. (author), Maas, Robert (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)Although additive manufacturing (AM) allows for a large design freedom, there are some manufacturing limitations that have to be taken into consideration. One of the most restricting design rules is the minimum allowable overhang angle. To make topology optimization suitable for AM, several algorithms have been published to enforce a minimum...journal article 2021
- document
-
Bakker, Coen (author), Zhang, L. (author), Higginson, Kristie (author), van Keulen, A. (author)Stiffened shells and plates are widely used in engineering. Their performance is highly influenced by the arrangement, or layout, of stiffeners on the base shell or plate and the geometric features, or topology, of these stiffeners. Moreover, modular design is beneficial, since it allows for increased quality control and mass production. In...journal article 2021
- document
-
Zhai, X. (author), Chen, Falai (author), Wu, J. (author)Handling stress constraints is an important topic in topology optimization. In this paper, we introduce an interpretation of stresses as optimization variables, leading to an augmented Lagrangian formulation. This formulation takes two sets of optimization variables, i.e., an auxiliary stress variable per element, in addition to a density...journal article 2021
- document
-
van de Ven, E.A. (author), Maas, Robert (author), Ayas, C. (author), Langelaar, Matthijs (author), van Keulen, A. (author)It is attractive to combine topology optimization (TO) with additive manufacturing (AM), due to the design freedom provided by AM, and the increased performance that can be achieved with TO. One important aspect is to include the design rules associated with the process restrictions of AM to prevent the requirement of relatively large support...journal article 2020
- document
-
Xia, Y. (author), Langelaar, Matthijs (author), Hendriks, M.A.N. (author)Strut-and-Tie modelling (STM) is a well-known approach to design D-regions in reinforced concrete structures. Because the STM method is based on lower-bound analysis, finding a suitable truss-analogy model is the most important aspect to guarantee good structural and economic performance of a resulting design. Continuum topology optimization ...journal article 2020
- document
-
Delissen, A.A.T.M. (author), van Keulen, A. (author), Langelaar, Matthijs (author)In many engineering applications, the dynamic frequency response of systems is of high importance. In this paper, we focus on limiting the extreme values in frequency response functions, which occur at the eigenfrequencies of the system, better known as resonant peaks. Within an optimization, merely sampling the frequency range and limiting the...journal article 2020
- document
-
van den Boom, S.J. (author), Zhang, J. (author), van Keulen, A. (author), Aragon, A.M. (author)During design optimization, a smooth description of the geometry is important, especially for problems that are sensitive to the way interfaces are resolved, e.g., wave propagation or fluid-structure interaction. A level set description of the boundary, when combined with an enriched finite element formulation, offers a smoother description...journal article 2020
- document
-
Kumar, P. (author), Frouws, Jan (author), Langelaar, Matthijs (author)In various applications, design problems involving structures and compliant mechanisms experience fluidic pressure loads. During topology optimization of such design problems, these loads adapt their direction and location with the evolution of the design, which poses various challenges. A new density-based topology optimization approach...journal article 2020
- document
-
Xia, Y. (author), Wu, Yue (author), Hendriks, M.A.N. (author)In current optimization methods for free-form shells, the shape and topology are usually optimized separately. These methods are based on the assumption that the shape and topology of a shell influence each other only slightly, but this is not always correct. Moreover, different parameterization models are used in the shape optimization and...journal article 2019
- document
-
Kumar, P. (author), Fanzio, P. (author), Sasso, L. (author), Langelaar, Matthijs (author)The concept and synthesis approach for planar Compliant Fluidic Control Structures (CFCSs), monolithic flexible continua with embedded functional pores, is presented in this manuscript. Such structures are envisioned to find application in biomedicine as tunable microfluidic devices for drug/nutrient delivery. The functional pores enlarge and...journal article 2019
- document
-
Langelaar, Matthijs (author)This paper presents a topology optimization approach that incorporates restrictions of multi-axis machining processes. A filter is defined in a density-based topology optimization setting, that transforms an input design field into a geometry that can be manufactured through machining. The formulation is developed for 5-axis processes, but...journal article 2019