Article
Mathematics
Cornel Marius Murea, Dan Tiba
Summary: The recent implicit parametrization theorem provides a general fixed domain approximation method in shape optimization problems. This article discusses the application of this method in topology and shape optimization, focusing on the challenging case of Neumann boundary conditions. An unexpected equivalence property with constrained optimal control problems, preserving differentiability, is presented. Experimental results demonstrate the applicability of this method in modifying topology.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2022)
Article
Engineering, Multidisciplinary
Yanglong Lu, Yan Wang
Summary: Periodic surface modeling is used to optimize the shape and topology of metamaterials, reducing search space and computational cost. Mixed-integer Bayesian optimization method and population-based genetic algorithms are applied to solve the structural optimization problem, resulting in the design of mechanical metamaterials with high strength-weight ratio and negative Poisson's ratio.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Ze Liu, Hao-Wen Dong, Gui-Lan Yu
Summary: Dispersion engineering is crucial in artificial periodic structures, with topology optimization being a key aspect focused on. The study presented in this paper introduces a topology optimization framework based on genetic algorithms and finite element methods to reduce surface waves through the design of periodic barriers in semi-infinite space. The results show stable convergence and effectiveness in optimizing surface wave bandgaps (SWBGs), with potential applications in designing high-performance surface wave devices and novel isolating structures for civil engineering.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Materials Science, Composites
Ruyi Gan, Shixu Li, Yaping Li, Song Qi, Miao Yu
Summary: This paper demonstrates a tunable magnetorheological (MR) electromagnetic absorber based on multiscale design and topological optimization. By incorporating multi-walled carbon nanotubes (MWCNTs) into the MR absorbers, the dielectric loss is reinforced while ensuring magnetic loss at the microscopic level. Advanced microcomputed tomography (mu-CT) is used to design the particles and microstructures, enhancing the absorption and attenuation characteristics. Through topology optimization, the thickness and mass can be reduced while improving the absorption property at the macroscopic level. The results show a peak value of reflection loss (RLmin) of -19.04 dB and an effective absorption bandwidth (EAB, RL below -10 dB) of 6.72 GHz with a thickness of 2.6 mm and magnetic flux density up to 563 mT. The MR absorbers also exhibit tunable absorption properties with reconfigurable multiscale structures under the combined effect of thermal and magnetic field.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Mathematics
Reda El Bechari, Frederic Guyomarch, Stephane Brisset
Summary: This paper provides a detailed explanation of the adjoint variable method in the context of electromagnetic modeling and presents a comprehensive methodology for optimizing engineering problems involving magnetostatics. The methodology supports both linear and nonlinear problems and has been successfully applied to optimize parameters in superconducting energy storage devices, magnet presses, and electromagnet topology.
Article
Computer Science, Interdisciplinary Applications
Gergely Molnar, Nawfal Blal
Summary: This paper presents a novel method based on the Cosserat theory to optimize the topology of slender beam-made metamaterials. It compares the optimal topology of discrete Euler-Bernoulli beam lattices with counterparts obtained using the homogenized Cosserat theory. The paper highlights the importance of second-order models for slender lattice structures and demonstrates the excellent quantitative agreement between continuum Cosserat and discrete beam results.
COMPUTERS & STRUCTURES
(2023)
Article
Mechanics
Jiao Jia, Daicong Da, Jianxing Hu, Sha Yin
Summary: Periodic cellular structures are widely used in structural protection for their lightweight and excellent energy absorption characteristics, but the corresponding crashworthy design is still limited. This study uses the framework of hybrid cellular automata to optimize the crashworthiness design of periodic cellular structures, achieving maximum energy absorption by redistributing elemental internal energy and iteratively modifying local EIE target. Results show improved energy absorption compared to solid structures and classical honeycombs, with discussions on the effects of cellular number and volume gradient on crashworthiness.
COMPOSITE STRUCTURES
(2021)
Article
Computer Science, Interdisciplinary Applications
Ahmad H. Bokhari, Emadeldeen Hassan, Eddie Wadbro
Summary: In this study, a material-distribution-based topology optimization method is used to design a three-port frequency dividing multiplexer at microwave frequencies. The aim is to split the incoming signal's frequencies and transmit them to their respective output ports by placing a good electric conductor inside the design domain. The Helmholtz equation is used to model the wave propagation problem, and the finite element method is employed to solve the governing equation and optimize the design using Svanberg's MMA algorithm.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Computer Science, Interdisciplinary Applications
Kenneth E. Swartz, Daniel A. Tortorelli, Daniel A. White, Kai A. James
Summary: In this paper, a series of constraints are proposed to ensure that topologically optimized structures are self-supporting and without enclosed voids. Homogenization-based constraints are also employed to allow the designer to adjust the elastic stiffness and isotropy of the optimized design. The effectiveness of these constraints is demonstrated in the design of 3D photonic crystals for maximum bandgap subject to manufacturing and stiffness constraints.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Materials Science, Multidisciplinary
Hong Fu, Chuxiong Hu, Ming Zhang, Yu Zhu
Summary: This paper proposes an integrated optimization method that combines 3D structural optimization and magnet parameter optimization to meet the increasing demand for mechanical stiffness and electromagnetic performance of maglev planar motors. The method improves the performance more directly and comprehensively than traditional optimization methods. Experimental results show that the proposed method can significantly improve the control bandwidth and reduce current consumption in maglev planar motor systems.
MATERIALS & DESIGN
(2023)
Article
Engineering, Multidisciplinary
Helmut Harbrecht, Michael Multerer, Remo von Rickenbach
Summary: This article presents an optimal design approach for the microstructure in scaffolds by combining shape optimization and homogenization. By calculating the effective tensor and using the shape gradient to update the microstructure, the desired effective tensor can be achieved. Extensive numerical studies demonstrate the applicability and feasibility of the approach.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Engineering, Geological
Xiao Wang, Shui Wan, Peng Zhou, Jundong Fu, Shuli Li
Summary: Periodic pile barriers with bandgaps can be used for ambient vibration mitigation. Evanescent modes exist in the bandgaps rather than propagating modes. The complex band structure is significant in identifying the evanescent waves. Topology optimizations were performed using a genetic algorithm to maximize the minimum imaginary part of the wave numbers in a specified frequency, resulting in opened bandgaps and higher levels of wave attenuation.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Simon Thomas, Qing Li, Grant Steven
Summary: This study proposes a new approach for designing finite periodic structures by allowing variable orientation states of individual unit-cells. Incorporating assembly flexibility within periodic topology optimization greatly expands the design space and enhances the advantage of structural periodicity. The new approach has been demonstrated to outperform traditional non-oriented periodic structures in both static and vibratory criteria.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Computer Science, Interdisciplinary Applications
Shengze Zhong, Parinya Punpongsanon, Daisuke Iwai, Kosuke Sato
Summary: We propose a methodology for generating topology-optimized structures with text-guided appearance stylization. This approach aims to enrich the concurrent design of a structure's physical functionality and aesthetic appearance, allowing users to easily control the style of the structure by inputting descriptive text. Our system utilizes a hash-encoded neural network as the underlying representation, ensuring the co-optimization of structural mechanical performance, style, and connectivity for full-color, high-quality 3D-printable solutions. The effectiveness of our system is demonstrated through extensive comparisons, demonstrations, and a 3D-printing test.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Computer Science, Artificial Intelligence
Jan-Hendrik Bastek, Dennis M. Kochmann
Summary: In this study, video diffusion generative models are used to predict and tune the nonlinear deformation and stress response of periodic stochastic cellular structures, including buckling and contact, which greatly simplifies and accelerates the identification of complex material properties.
NATURE MACHINE INTELLIGENCE
(2023)
Article
Computer Science, Interdisciplinary Applications
Ercan M. Dede, Yuqing Zhou, Tsuyoshi Nomura
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2020)
Article
Thermodynamics
Gil Ho Yoon, Ercan M. Dede, Tsuyoshi Nomura, Paul Schmalenberg
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2020)
Article
Computer Science, Interdisciplinary Applications
Yuqing Zhou, Tsuyoshi Nomura, Kazuhiro Saitou
Summary: This paper presents a multicomponent topology optimization method that simultaneously optimizes the structural topology, its partitioning, and the build orientations of each component to maximize assembly-level structural stiffness performance. The study demonstrates the significant impact of build orientation anisotropy and component interface behavior on multicomponent assemblies.
JOURNAL OF COMPUTING AND INFORMATION SCIENCE IN ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Jaewook Lee, Tsuyoshi Nomura, Ercan M. Dede
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2020)
Article
Engineering, Multidisciplinary
Dongjin Kim, Jaewook Lee, Tsuyoshi Nomura, Ercan M. Dede, Jeonghoon Yoo, Seungjae Min
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2020)
Article
Engineering, Manufacturing
Jaewook Lee, Chiyoung Kwon, Jeonghoon Yoo, Seungjae Min, Tsuyoshi Nomura, Ercan M. Dede
Summary: This paper introduces a systematic design procedure for shell-infill structures in additive manufacturing, utilizing multiscale topology optimization and a de-homogenization scheme compatible with Computer-Aided Design (CAD). The effectiveness of the design procedure is demonstrated through validation with design examples and fabrication using a multi-jet printing machine.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Mechanical
Yuqing Zhou, Tsuyoshi Nomura, Enpei Zhao, Kazuhiro Saitou
Summary: This paper presents a method for designing variable-axial fiber-reinforced composites that allows for customization of fiber orientation and thicknesses. The method addresses computational challenges associated with large-scale 3D anisotropic topology optimization and is applied to designing a heavy-duty drone frame. The paper also discusses the manufacturability gaps between the optimized design and the fabrication-ready design.
JOURNAL OF MECHANICAL DESIGN
(2022)
Article
Mechanics
Taehoon Jung, Jaewook Lee, Tsuyoshi Nomura, Ercan M. Dede
Summary: This paper presents a three-dimensional topology optimization for the inverse design of unidirectional fiber reinforced composite structures, including the co-design of composite macrostructure, spatially-varying fiber size, and orientation. The effectiveness of the proposed design scheme is validated through three design examples for compliance minimization and compliant mechanism problems.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Electrical & Electronic
Atsuhiro Takahashi, Katsuya Nomura, Takashi Kojima, Tsuyoshi Nomura
Summary: This article uses topology optimization to design a new magnetic core structure for an EMI filter circuit, resulting in significantly improved performance. By evaluating the noise reduction effects, it was found that the EMI filter with the optimized magnetic core showed about 30 dB higher performance compared to a filter with conventional ring-shaped cores.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Environmental
Yuqing Zhou, Danny J. Lohan, Feng Zhou, Tsuyoshi Nomura, Ercan M. Dede
Summary: In this paper, an inverse design and dehomogenization framework is proposed to discover innovative microreactor flow field designs. Through numerical simulations, trade-offs between reaction performance and fluid flow performance are found for multiple optimized microreactor flow fields. Applying the findings of this study to new reactor flow field designs can enhance performance in biomedical, pharmaceutical, and energy applications.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Paul Schmalenberg, Ercan M. Dede, Tsuyoshi Nomura, Shinji Nishiwaki
Summary: This research introduces an optimization method for a vehicular volumetric beam-scanning radar to minimize sidelobe power by determining the placement of array elements. The optimization is achieved using a gradient-based nonlinear programming technique, with the speed accelerated by extending uv-projection planes. Compared to a reference triangular grid array, the optimization method allows for a larger azimuth scanning FOV in typical automotive applications.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2022)
Article
Engineering, Multidisciplinary
Fan Feng, Shiying Xiong, Ziyue Liu, Zangyueyang Xian, Yuqing Zhou, Hiroki Kobayashi, Atsushi Kawamoto, Tsuyoshi Nomura, Bo Zhu
Summary: Cellular structures exhibit remarkable mechanical properties in many biological systems. This paper presents a topology optimization algorithm based on a differentiable and generalized Voronoi representation that allows the continuous evolution of cellular structures. The method uses a hybrid particle-grid representation to encode the discrete Voronoi diagram into a continuous density field. It enables the integration of an effective cellular representation into state-of-the-art topology optimization pipelines.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Yuki Sato, Hiroki Kobayashi, Changyoung Yuhn, Atsushi Kawamoto, Tsuyoshi Nomura, Noboru Kikuchi
Summary: Topology optimization methods are widely used in various industries to provide potential design candidates for mechanical devices. However, their applications are limited to stationary objects due to the difficulties in handling contact and interactions among multiple structures or with boundaries using conventional simulation techniques. In this study, we propose a topology optimization method for moving objects that incorporates the material point method commonly used in computer graphics. Several numerical experiments demonstrate the effectiveness and utility of the proposed method.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Multidisciplinary Sciences
Masato Tanaka, S. Macrae Montgomery, Liang Yue, Yaochi Wei, Yuyang Song, Tsuyoshi Nomura, H. Jerry Qi
Summary: Turing patterns are used to convert a design with distributed anisotropic materials to a distribution with two materials, which can be fabricated by grayscale digital light processing 3D printing. This study suggests the possibility of applying patterns in biological systems and nature to engineering composites and offers new concepts for future material design.
Article
Engineering, Manufacturing
S. Macrae Montgomery, Liang Yue, Yuyang Song, Tsuyoshi Nomura, Xiaohao Sun, Masato Tanaka, H. Jerry Qi
Summary: Additive manufacturing, also known as 3D printing, can create complex structures that traditional methods cannot. However, current multi-material 3D printing techniques lack accuracy for small-scale property control, making it difficult to print highly anisotropic structures at a small scale. This study proposes a method using grayscale vat photopolymerization to 3D print locally tunable anisotropic patterns, allowing for flexible adjustment of the degree and orientation of anisotropy. This method only requires one resin feedstock, preserving the accuracy and efficiency of vat photopolymerization printing.
ADDITIVE MANUFACTURING
(2023)
Article
Mathematics, Applied
Guo Zheng, Zengqiang Cao, Yuehaoxuan Wang, Reza Talemi
Summary: This study introduces two novel methods for predicting the fatigue response of Dynamic Cold Expansion (DCE) and Static Cold Expansion (SCE) open-hole plates. The accuracy of the prediction is enhanced by considering stress distributions and improving existing methods. The study also discusses the mechanisms behind fatigue life enhancement and fatigue crack propagation modes in cold expansion specimens.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Eric Heppner, Tomohiro Sasaki, Frank Trommer, Elmar Woschke
Summary: This paper presents a modeling approach for estimating the bonding strength of friction-welded lightweight structures. Through experiments and simulations, a method for evaluating the bonding strength of friction-welded lightweight structures is developed, and the plausibility and applicability of the model are discussed.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Piermario Vitullo, Alessio Colombo, Nicola Rares Franco, Andrea Manzoni, Paolo Zunino
Summary: Many applications in computational physics involve approximating problems with microstructure, characterized by multiple spatial scales in their data. However, these numerical solutions are often computationally expensive due to the need to capture fine details at small scales. Traditional projection based reduced order models (ROMs) fail to resolve these issues, even for second-order elliptic PDEs commonly found in engineering applications. To address this, we propose an alternative nonintrusive strategy to build a ROM, that combines classical proper orthogonal decomposition (POD) with a suitable neural network (NN) model to account for the small scales.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Chanh Dinh Vuong, Xiaofei Hu, Tinh Quoc Bui
Summary: In this paper, we present a dynamic description of the smoothing gradient-enhanced damage model for the simulation of quasi-brittle failure localization under time-dependent loading conditions. We introduce two efficient rate-dependent damage laws and various equivalent strain formulations to analyze the complicated stress states and inertia effects of the dynamic regime, enhancing the capability of the adopted approach in modeling dynamic fracture and branching.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Alexandre D. C. Amaro, A. Francisca Carvalho Alves, F. M. Andrade Pires
Summary: This study focuses on analyzing various deformation mechanisms that affect the behavior of PC/ABS blends using computational homogenization. By establishing a representative microstructural volume element, defining the constitutive description of the material phases, and modeling the interfaces and matrix damage, accurate predictions can be achieved. The findings have important implications for broader applications beyond PC/ABS blends.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
David Hoffmeyer, A. R. Damanpack
Summary: This paper introduces a method for determining all six stress components for a cantilever-type beam that is subjected to concentrated end loads. The method considers an inhomogeneous cross-section and employs cylindrically orthotropic material properties. The efficacy of the method is validated by numerical examples and a benchmark example, and the analysis on a real sawn timber cross-section reveals significant disparities in the maximum stresses compared to conventional engineering approaches.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Vladimir Stojanovic, Jian Deng, Dunja Milic, Marko D. Petkovic
Summary: The present paper investigates the dynamic analysis of a coupled Timoshenko beam-beam or beam-arch mechanical system with geometric nonlinearities. A modified p-version finite element method is developed for the vibrations of a shear deformable coupled beam system with a discontinuity in an elastic layer. The main contribution of this work is the discovery of coupled effects and phenomena in the simultaneous vibration analysis of varying discontinuity and varying curvature of the newly modelled coupled mechanical system. The analysis results are valuable and have broader applications in the field of solids and structures.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Gihwan Kim, Phill-Seung Lee
Summary: The phantom-node method is applied in the phase field model for mesh coarsening to improve computational efficiency. By recovering the fine mesh in the crack path domain into a coarse mesh, this method significantly reduces the number of degrees of freedom involved in the computation.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Souhail Chaouch, Julien Yvonnet
Summary: In this study, an unsupervised machine learning-based clustering approach is developed to reduce the computational cost of nonlinear multiscale methods. The approach clusters macro Gauss points based on their mechanical states, reducing the problem from macro scale to micro scale. A single micro nonlinear Representative Volume Element (RVE) calculation is performed for each cluster, using a linear approximation of the macro stress. Anelastic macro strains are used to handle internal variables. The technique is applied to nonlinear hyperelastic, viscoelastic and elastoplastic composites.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Hoang-Giang Bui, Jelena Ninic, Christian Koch, Klaus Hackl, Guenther Meschke
Summary: With the increasing demand for underground transport infrastructures, it is crucial to develop methods and tools that efficiently explore design options and minimize risks to the environment. This study proposes a BIM-based approach that connects user-friendly software with effective simulation tools to analyze complex tunnel structures. The results show that modeling efforts and computational time can be significantly reduced while maintaining high accuracy.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Aslan Nasirov, Xiaoyu Zhang, David Wagner, Saikumar R. Yeratapally, Caglar Oskay
Summary: This manuscript presents an efficient model construction strategy for the eigenstrain homogenization method (EHM) for the reduced order models of the nonlinear response of heterogeneous microstructures. The strategy relies on a parallel, element-by-element, conjugate gradient solver, achieving near linear scaling with respect to the number of degrees of freedom used to resolve the microstructure. The linear scaling in the number of pre-analyses required to construct the reduced order model (ROM) follows from the EHM formulation. The developed framework has been verified using an additively manufactured polycrystalline microstructure of Inconel 625.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Atticus Beachy, Harok Bae, Jose A. Camberos, Ramana V. Grandhi
Summary: Emulator embedded neural networks leverage multi-fidelity data sources for efficient design exploration of aerospace engineering systems. However, training the ensemble models can be costly and pose computational challenges. This work presents a new type of emulator embedded neural network using the rapid neural network paradigm, which trains near-instantaneously without loss of prediction accuracy.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Arash Hajisharifi, Michele Girfoglio, Annalisa Quaini, Gianluigi Rozza
Summary: This paper introduces three reduced order models for reducing computational time in atmospheric flow simulation while preserving accuracy. Among them, the PODI method, which uses interpolation with radial basis functions, maintains accuracy at any time interval.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
D. Munoz, S. Torregrosa, O. Allix, F. Chinesta
Summary: The Proper Generalized Decomposition (PGD) is a Model Order Reduction framework used for parametric analysis of physical problems. It allows for offline computation and real-time simulation in various situations. However, its efficiency may decrease when the domain itself is considered as a parameter. Optimal transport techniques have shown exceptional performance in interpolating fields over geometric domains with varying shapes. Therefore, combining these two techniques is a natural choice. PGD handles the parametric solution while the optimal transport-based methodology transports the solution for a family of domains defined by geometric parameters.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
Article
Mathematics, Applied
Jothi Mani Thondiraj, Akhshaya Paranikumar, Devesh Tiwari, Daniel Paquet, Pritam Chakraborty
Summary: This study develops a diffused interface CPFEM framework, which reduces computational cost by using biased mesh and provides accurate results using non-conformal elements in the mesh size transiting regions. The accuracy of the framework is confirmed through comparisons with sharp and stepped interface results.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2024)
