Article
Mathematics, Applied
Youngsuk Jung, Jaewook Lee, Seungjae Min
Summary: This paper proposes a new method for multi-material topology optimization that can concurrently determine the structural layout and joint interface. By using a modified discrete material optimization approach, the method allows for independent control of different materials and expands the applicability of the method to cases with more than two design materials.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2021)
Review
Physics, Multidisciplinary
Geon Lee, Dongwoo Lee, Jeonghoon Park, Yeongtae Jang, Miso Kim, Junsuk Rho
Summary: Mechanical metamaterials and phononic crystals can localize, focus, and guide elastic or acoustic waves in various ways. These man-made structures allow for more efficient collection of energy and have a wide range of potential applications in renewable energy transformation.
COMMUNICATIONS PHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Lixue Fang, Zeng Meng, Huanlin Zhou, Xuan Wang, Xin Guo
Summary: This paper proposes a two-phase MMV method for designing an in-plane piezoelectric actuator considering the piezoelectric material distribution and the polarization direction. The first phase MMV determines the layout of the piezoelectric material, while the second phase MMV distinguishes the positive and negative polarizations. The objective of this method is to maximize displacement at a prescribed output port under a material volume constraint, and the MMA algorithm is used to update the optimization design variables.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Computer Science, Information Systems
Ahmed Koran, Saher Albatran, Doaa Alshorman
Summary: This research proposes a two-step efficiency optimization approach for a three-phase voltage source inverter with series R damped LCL filter. The first step optimizes the filter parameters and designs inductor cores, while the second step optimizes the switching frequency of the inverter while limiting power losses and harmonic levels. Experiment and simulation are conducted to validate the proposed optimization procedure.
Article
Engineering, Multidisciplinary
Lukas C. Hoghoj, Erik A. Traff
Summary: This paper introduces a simple formulation for topology optimization problems ensuring manufacturability by machining. The method uses the advection-diffusion equation with Robin boundary conditions to filter the design variables, distinguishing itself from existing methods. Furthermore, it is easy to implement and suitable for unstructured meshes and distributed memory settings. The proposed approach allows for few to no continuation steps in any system parameters. Applications demonstrate topology optimization on unstructured meshes with up to 64 million elements and up to 29 milling tool directions.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Junyi Liu, Ke-Li Wu
Summary: This article presents a rigorous and straightforward framework for an exhaustive search of all viable coupling topologies and their real-valued coupling matrices for a given filtering function. The framework establishes simultaneous equations based on the proven uniqueness of the folded coupling matrix, providing a method for a well-behaved numerical solution search process. Demonstration examples show that the framework can systematically find all viable coupling topologies and their real-valued solutions, leading to the discovery of new useful coupling configurations.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Computer Science, Information Systems
Qingzhen Xu, Shuang Liu, Han Qiao, Miao Li
Summary: This paper proposes a dual optimization method (CMRDO) for cross-modal retrieval, which improves retrieval accuracy by optimizing the common representation space and introducing an efficient sample construction strategy, and has strong generalization ability.
MULTIMEDIA TOOLS AND APPLICATIONS
(2023)
Article
Engineering, Multidisciplinary
Sun-Yong Kim
Summary: CSFM method is proposed to save computational expenses in topology optimization. It controls the change of filtered sensitivity values based on previous iterations, resulting in lower compliance and reduced computational expenses.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Abbas Homayouni-Amlashi, Thomas Schlinquer, Abdenbi Mohand-Ousaid, Micky Rakotondrabe
Summary: This paper presents two separate topology optimization MATLAB codes for a piezoelectric plate, utilizing the PEMAP-P method and optimizing variables using the optimality criteria and MMA algorithm. The efficiency of the codes is illustrated through numerical examples, and they are easy to extend to various problem formulations.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Multidisciplinary Sciences
Shin Hur, Hyunggyu Choi, Gil Ho Yoon, Nam Woon Kim, Duck-Gyu Lee, Yong Tae Kim
Summary: In this study, a new ultrasonic transducer with improved focusing performance was designed and tested. The experimental results demonstrated that the transducer had a high ability to produce needle-like subwavelength focusing beams in water, making it potentially useful for high-resolution imaging devices or medical ultrasound focusing devices.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
Yifan Li, Xun Luo
Summary: In this article, an adaptive synthesis method based on the hybrid genetic algorithm and particle swarm optimization (HGAPSO) is proposed for reflectionless filter design with lumped capacitors, resistors, and inductors. The HGAPSO is used to trim branches and obtain proper element values for the required filtering response. Local searching policies, classifier-based strategy, and probabilistic method are introduced to improve the searching ability, accelerate convergence, and boost iteration. The fabricated filters in this study demonstrate good selectivity and low reflection coefficient in measurements.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Robotics
Thomas Schlinquer, Abbas Homayouni-Amlashi, Micky Rakotondrabe, Abdenbi Mohand-Ousaid
Summary: This letter investigates the use of topology optimization method to improve the stroke of piezoelectric materials based actuators by considering the optimization of electrodes polarity. The optimized design with polarization showed an improved factors of 2.8 and 2.02 compared to full plate and actuator without electrodes optimization.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Xiaoying Zhuang, Chuong Nguyen, S. S. Nanthakumar, Ludovic Chamoin, Yabin Jin, Timon Rabczuk
Summary: This paper presents a methodology for inverse design of reconfigurable topological insulators in plate-like structures. By utilizing topology optimization and piezoelectric patches, the space inversion symmetry is broken, leading to the real-time reconfigurability of topological interfaces for waveguide applications.
MATERIALS & DESIGN
(2022)
Article
Construction & Building Technology
Xuyun Ding, Xiaojun Wang, Yunlong Li, Lei Wang, Linxi Zeng
Summary: This paper presents a two-step damage identification method for small penetrating damage in fiber-reinforced composite laminates, combining active and passive monitoring concepts using distributed piezoelectric and strain sensors. The method first utilizes Lamb waves generated through active excitation and an alternating excitation technique for piezoelectric sensors to focus energy on suspicious damage areas. Then, damage extent is identified by minimizing error in strain information between reference and damage models using an optimization method based on the modified quasi-Newton search (MQNS) method. Numerical and experimental cases demonstrate the validity, accuracy, and efficiency of the proposed methodology, with robustness assessment through discussion of important parameters and noisy interference.
STRUCTURAL CONTROL & HEALTH MONITORING
(2022)
Article
Meteorology & Atmospheric Sciences
Milija Zupanski
Summary: The new method combines covariance localization, numerical optimization, and Bayesian inference, showing improved performance. Resampling of posterior perturbations for ensemble update proves to be advantageous for assimilating integrated nonlinear observations. In low-dimensional applications like the Lorenz model, the method outperforms other methods, especially in case of severe rank reduction.
MONTHLY WEATHER REVIEW
(2021)
Correction
Computer Science, Interdisciplinary Applications
Fengwen Wang, Boyan Stefanov Lazarov, Ole Sigmund
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(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
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
Computer Science, Interdisciplinary Applications
A. Donoso, E. Aranda, D. Ruiz
Summary: This paper presents a new method for designing piezoelectric transducers with connected two-phase electrode. The electrode design problem is formulated as an optimization problem, and the significant contribution lies in modeling connectivity constraints using graph theory. Several examples demonstrate that optimized electrode configurations lead to devices of easier manufacturability while maintaining functionality.
COMPUTERS & STRUCTURES
(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
Alberto Donoso, Ernesto Aranda, David Ruiz
Summary: The aim of this work is to propose a continuous mathematical model that captures and enforces connectivity in topology optimization. This is achieved by constraining the second eigenvalue of an auxiliary eigenproblem solved alongside the governing state law during each iterative step. The effectiveness of our density-based approach is demonstrated through 2D and 3D numerical examples in the field of structural design.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(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
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)
