Article
Computer Science, Interdisciplinary Applications
Matteo Pozzi, Giacomo Bonaccorsi, Hyunsun Alicia Kim, Francesco Braghin
Summary: Most manufacturing processes have process tolerances that affect component behavior and compliance with design requirements. This study presents a simple approach for conducting robust structural topology optimization in the presence of manufacturing uncertainties. It uses a computationally efficient boundary-perturbation technique to describe etching errors and does not require frequent re-initialization or mapping between etched and nominal structures. Additionally, it allows for dealing with spatially varying errors without increasing computational cost.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Computer Science, Interdisciplinary Applications
Chao Wang, Bin Xu, Zunyi Duan, Jianhua Rong
Summary: This work proposes a robust and efficient approach to structural topology optimization considering manufacturable connectivity and manufacturing uncertainties. The proposal includes a rational inclusion of the Poisson equation-based potential constraint for manufacturable connectivity in three projected fields, which helps achieve manufacturable designs with reliable performance. Furthermore, the paper develops an effective potential constraint strategy and provides an applicable solving scheme to reduce computational cost and address numerical difficulties.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Computer Science, Interdisciplinary Applications
Van-Nam Hoang, Trung Pham, Sawekchai Tangaramvong, Stephane P. A. Bordas, H. Nguyen-Xuan
Summary: This paper presents a novel robust concurrent topology optimization method for the design of uniform/non-uniform porous infills under the accidental change of loads. The method directly models multiscale structures and seeks robust designs by simultaneously optimizing macro- and microscopic structures through the minimization of the weighted sum of the expected compliance and standard deviation.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Computer Science, Interdisciplinary Applications
Van-Nam Hoang, Trung Pham, Duc Ho, H. Nguyen-Xuan
Summary: This paper presents a novel multiscale topology optimization approach that can optimize incompressible multi-material designs at both macro and micro scales, and demonstrates the effectiveness of the technique through examples of solving incompressible porous multi-material designs under single and multiple random loads.
ENGINEERING WITH COMPUTERS
(2022)
Article
Optics
Rasmus E. Christiansen, Philip Trost Kristensen, Jesper Mork, Ole Sigmund
Summary: Using topology optimization, compact wavelength-sized devices are designed to study the effect of optimizing geometries for enhancing different optical processes. The findings show that different field distributions lead to maximization of different processes, emphasizing the importance of targeting the appropriate metric when designing photonic components for optimal performance.
Article
Computer Science, Interdisciplinary Applications
Song Bai, Zhan Kang
Summary: The paper presents a robust topology optimization method for structures with bounded loads and spatially correlated material uncertainties. The method combines random structural loads with bounded nature and random field discretization to model uncertainties, with a focus on minimizing mean value and standard deviation of structural compliance. Numerical examples show that the proposed method results in structurally robust designs against uncertainties.
COMPUTERS & STRUCTURES
(2021)
Article
Computer Science, Interdisciplinary Applications
Wenjie Yao, Francesc Verdugo, Rasmus E. Christiansen, Steven G. Johnson
Summary: This study presents a trace formulation for solving the emission problems of spatially incoherent light sources. The formulation can be efficiently combined with inverse design for topology optimization. By utilizing the low-rank structure of emission problems, the formulation generalizes to a continuum of emission directions. The study provides several examples of incoherent-emission topology optimization and discusses potential applications in Raman sensing and cathodoluminescence.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Computer Science, Interdisciplinary Applications
Jing Zheng, Hong Chen, Chao Jiang
Summary: This paper develops a new robust topology optimization method for structures under thermo-mechanical loadings considering hybrid uncertainties. It introduces an efficient dimension reduction-based orthogonal polynomial expansion method for hybrid uncertainty analysis. The method takes into account both random and interval uncertainties related to material properties and loadings.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Correction
Computer Science, Interdisciplinary Applications
Liang Meng, Weihong Zhang, Dongliang Quan, Guanghui Shi, Lei Tang, Yuliang Hou, Piotr Breitkopf, Jihong Zhu, Tong Gao
Summary: Reference number 190 in this article is incorrect and needs to be checked for accuracy.
ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Lei Wang, Zeshang Li, BoWen Ni, Xiaojun Wang, Wenpin Chen
Summary: This paper proposes a robust topology optimization method considering bounded field parameters with uncertainties based on the variable time step parametric level-set method. The method develops a variable time step strategy for level set function evolution by utilizing the gradient of the level set function and radial basis function interpolation to separate time and space, achieving better design results. Furthermore, dimension reduction methods and dimension wise methods based on polynomials are employed to characterize and quantify the uncertainties of bounded field parameters. Finally, the sensitivity of the robust optimization model is derived based on the shape derivative principle, serving as the basis for gradient-based optimization algorithms. Three examples are provided to illustrate the effectiveness, necessity, and influence of important parameters in the proposed method.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Materials Science, Multidisciplinary
Rossana R. Fernandes, Ali Y. Tamijani
Summary: This paper presents an experimentally validated framework for performing topology and orientation optimization of lattice structures subject to stress constraints. Effective stiffnesses and yield stresses of a unit cell are obtained using numerical homogenization and implemented via macrostructure topology optimization to improve lattice structure stiffness.
MATERIALS & DESIGN
(2021)
Article
Engineering, Multidisciplinary
Hongjia Lu, Linwei He, Matthew Gilbert, Filippo Gilardi, Jun Ye
Summary: Additive manufacturing (AM) has rapidly developed and offers the potential to fabricate structurally optimized components. The use of truss topology optimization methods has been effective in identifying optimal forms for highly design free components. However, geometric complexity and overhanging elements often require support structures when using traditional 3-axis AM machines. To eliminate the need for support structures, multi-axis AM machines with 5 or more axes can be used. A novel process-aware truss layout optimization strategy tailored for multi-axis AM machines is proposed in this study, which combines curved printing surface identification with truss layout and geometry optimization. The proposed strategies aim to achieve highly material-efficient structures and fully self-supporting structures with minimal material consumption. The effectiveness of the approach is demonstrated through several examples, showing that fully self-supporting optimized structures can be identified without sacrificing structural performance.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Chemistry, Multidisciplinary
Fernando Senhora, Emily D. Sanders, Glaucio H. Paulino
Summary: Spinodal architected materials optimize design of multiscale structures by varying spinodal class, orientation, and porosity, leading to efficient material placement along stress trajectories with enhanced mechanical and biological functions.
ADVANCED MATERIALS
(2022)
Article
Optics
Guowu Zhang, Dan-Xia Xu, Yuri Grinberg, Odile Liboiron-Ladouceur
Summary: A novel and energy efficient switch building block is proposed and demonstrated on a silicon-on-insulator platform. It uses a compact mode insensitive phase shifter with a mode exchanger to achieve the same phase shift for all modes, leading to reduced power consumption.
Article
Engineering, Electrical & Electronic
Jiqi Wu, Xiaoyong Zhu, Deyang Fan, Zixuan Xiang, Lei Xu, Li Quan
Summary: This article proposes a robust optimization method for hybrid permanent magnet machines, aiming to eliminate the influence of permanent magnets asymmetric uncertainties. The method comprehensively analyzes the uncertainties, constructs a robustness index, and applies a multi-objective optimization algorithm for the optimal design. The experimental results show that the proposed method can effectively reduce the additional torque caused by the asymmetric uncertainties of permanent magnets.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Engineering, Multidisciplinary
Martin Ohrt Elingaard, Niels Aage, Jakob Andreas Baerentzen, Ole Sigmund
Summary: This paper presents a deep learning-based de-homogenization method for structural compliance minimization, showing excellent generalization properties and performance within 7-25% of homogenization-based solutions at a fraction of the computational cost, while being robust and insensitive to domain size, boundary conditions, and loading.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Ole Sigmund
Summary: Topology optimization has grown rapidly, but how to fairly evaluate and compare new concepts to existing ones remains an open question. Common benchmark examples would be helpful, but it is often up to authors to evaluate their own contributions. This note provides recommendations and tools for promoting good scientific practice in the field of topology optimization.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Review
Computer Science, Interdisciplinary Applications
Rebekka V. Woldseth, Niels Aage, J. Andreas Baerentzen, Ole Sigmund
Summary: The question of how artificial intelligence methods can improve traditional frameworks for topology optimization has gained attention in the past few years. While different model variations have been proposed with varying levels of success, few significant breakthroughs have been achieved. The literature tends to have a strong belief in the magical capabilities of artificial intelligence, leading to misunderstandings about its limitations. This article presents a critical review of the current state of research in this field and provides recommendations for future scientific progress.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Multidisciplinary Sciences
Marcus Albrechtsen, Babak Vosoughi Lahijani, Rasmus Ellebaek Christiansen, Vy Thi Hoang Nguyen, Laura Nevenka Casses, Soren Engelberth Hansen, Nicolas Stenger, Ole Sigmund, Henri Jansen, Jesper Mork, Soren Stobbe
Summary: This study integrates fabrication constraints into topology optimization to achieve the strongest light-matter interaction in a photonic nanocavity. The researchers demonstrated a nanocavity with a small mode volume, high quality factor, and compact footprint, using near-field optical measurements.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Fengwen Wang, Marie Brons, Ole Sigmund
Summary: Stretch-dominated truss and plate microstructures are competing in the development of highly rigid and strong architected materials. Although closed-cell isotropic plate microstructures meet theoretical upper bounds on stiffness, they have low buckling strength, whereas open-cell truss microstructures have high buckling strength but reduced stiffness. Hollow truss lattice and hierarchical microstructures outperform both in terms of buckling strength, but are challenging to build. In this study, single-scale non-hierarchical microstructures are designed, built, and tested, surpassing the buckling strength of hollow truss lattice and plate microstructures. The microstructures are realized with 3D printing and both experiments and numerical modeling validate the theoretical predictions.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Optics
Rasmus E. Christiansen, Philip Trost Kristensen, Jesper Mork, Ole Sigmund
Summary: Using topology optimization, compact wavelength-sized devices are designed to study the effect of optimizing geometries for enhancing different optical processes. The findings show that different field distributions lead to maximization of different processes, emphasizing the importance of targeting the appropriate metric when designing photonic components for optimal performance.
Article
Engineering, Multidisciplinary
Yafeng Wang, Ole Sigmund
Summary: This study aims to optimize the buckling capacity of mechanical structures subjected to thermal and mechanical loading through a density-based topology optimization scheme. By decoupling the effects of mechanical and thermal loadings, the buckling aspects induced by each loading can be separately analyzed and optimized. The study also employs a multi-material topology optimization scheme to optimize the buckling capacity of active structures and prestressed structures.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Erik A. Traff, Anton Rydahl, Sven Karlsson, Ole Sigmund, Niels Aage
Summary: This work presents three-dimensional linear elastic compliance minimisation using topology optimisation implementations accelerated by Graphics Processing Units (GPUs). Two GPU-accelerated implementations, based on OpenMP 4.5 and the Futhark language, are presented. Both implementations utilize high level GPU frameworks, avoiding the need for expertise knowledge of CUDA or OpenCL. Additionally, a vectorised and multi-threaded CPU code is included for reference. The results show that the GPU accelerated codes are able to solve large-scale topology optimisation problems faster than the reference CPU code, and they can also handle nonlinear problems.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Christoffer Fyllgraf Christensen, Fengwen Wang, Ole Sigmund
Summary: Topology optimization has been used for maximizing stiffness or minimizing compliance in multiscale structures. This study focuses on optimizing buckling stability of multiscale structures with isotropic porous infill, by considering both local and global instability.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Federico Ferrari, Ole Sigmund
Summary: In this study, a strategy is introduced to prevent the occurrence of spurious modes in the spectrum computed by linearized buckling analysis in the context of topology optimization. Spurious buckling modes commonly appear in low density regions, but this study also highlights the occurrence of localized modes in solid areas due to the limitations of linearized buckling analysis. The proposed remedy involves using filtering and erosion operations on the stress field, helping to mitigate the occurrence of spurious modes and improve the optimization process towards high performance designs.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Lukas C. Hoghoj, Cian Conlan-Smith, Ole Sigmund, Casper Schousboe Andreasen
Summary: This paper presents a method for simultaneous optimization of the outer shape and internal topology of aircraft wings, with the objective of minimizing drag subject to lift and compliance constraints for multiple load cases. The physics are evaluated by the means of a source-doublet panel method for the aerodynamic response and linear elastic finite elements for the structural response, which are one-way coupled. Wings of small fixed-wing airplanes both with and without a stiffening strut are optimized. The resulting wings show internal topologies with struts and wall-truss combinations, depending on the design freedom of the shape optimization. The lift distributions of the optimized wings show patterns like the ones obtained when performing optimization of wing shapes with constraints on the bending moment at the root.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Mathematics, Interdisciplinary Applications
Andreas Henrik Frederiksen, Ole Sigmund, Konstantinos Poulios
Summary: This paper addresses the limitations of incorporating contact in topology optimization and proposes a new method for topology optimization problems with internal contact. The method ensures stability and robustness of the optimized designs by introducing a tangent stiffness requirement and penalizing small features. The examples demonstrate the effectiveness of the method in topology optimization under large deformations.
COMPUTATIONAL MECHANICS
(2023)
Article
Engineering, Multidisciplinary
Weichen Li, Yingqi Jia, Fengwen Wang, Ole Sigmund, Xiaojia Shelly Zhang
Summary: This study systematically investigates several precisely programmed nonlinear extreme responses in 3D structures under finite deformations through multimaterial inverse design by topology optimization. Unique complex 3D geometries with deformation capabilities are discovered and utilized to deliver the target responses. The optimized structure is accurately fabricated through a proposed hybrid fabrication method and the design's programmed behavior is validated.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2023)
Article
Multidisciplinary Sciences
Felipe Gomez-Lozada, Carlos Andres del Valle, Julian David Jimenez-Paz, Boyan S. Lazarov, Juan Galvis
Summary: In this study, a mathematical model is developed to describe the phenomenon of brinicles. The model is able to capture the general behavior of the physical system, generating structures similar to brinicles and recovering dendrite composition in alignment with previous experimental results.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Engineering, Multidisciplinary
Rebekka Woldseth, J. Andreas Baerentzen, Ole Sigmund
Summary: This paper presents an alternative approach to dehomogenisation of elastic Rank-N laminate structures based on the computer graphics discipline of phasor noise. The proposed methodology offers an improvement of existing methods, where high-quality single-scale designs can be obtained efficiently without the utilisation of any least-squares problem or pre-trained models. Numerical tests verifies the performance of the proposed methodology compared to state-of-the-art alternatives, and the dehomogenised designs achieve structural performance within a few percentages of the optimised homogenised solution.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
