Article
Thermodynamics
Guoxian Jing, Jiao Jia, Jiawei Xiang
Summary: This study introduces a topology optimization method for maximizing total potential energy by combining the level set method and boundary element method. The effectiveness of the method is validated and the versatility of obtaining different material distributions by changing boundary conditions is explored.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mathematics, Applied
Baseer Ullah, Siraj-ul-Islam, Zahur Ullah, Wajid Khan
Summary: This paper utilizes a combination of LRBFs and LSM for topology optimization of two-dimensional thermal problems, achieving automatic control of topological variations and demonstrating efficiency and convergence in experiments.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2021)
Article
Thermodynamics
Guangpeng Feng, Lin Qiu, Yanhui Feng, Xinxin Zhang
Summary: A topology optimization framework based on isotropic material is developed to design highly thermal conductive porous structures. The study shows that by optimizing the microstructure, it is possible to achieve thermal conductivity and mass diffusivity close to theoretical bounds. The selective laser melting technique enables the accurate fabrication of the microstructure of these lattice materials.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Computer Science, Interdisciplinary Applications
Chi Wu, Jianguang Fang, Shiwei Zhou, Zhongpu Zhang, Guangyong Sun, Grant P. Steven, Qing Li
Summary: The paper incorporates a phase-field damage model into the topology optimization framework to account for crack initiation and propagation in a path-dependent manner. The proposed approach enhances fracture resistance of structures made of brittle materials and introduces a path-dependent shape derivative to drive the optimization effectively. Three 2D benchmark examples and one 3D biomedical example are studied to demonstrate the effectiveness of the method in improving fracture resistance with more efficient use of materials and reducing stress concentration and fracture risks.
COMPUTERS & STRUCTURES
(2021)
Article
Computer Science, Software Engineering
Hassan A. Jahangiry, Majid Gholhaki, H. Naderpour, S. Mehdi Tavakkoli
Summary: This paper addresses geometrically nonlinear topology optimization using IsoGeometric Analysis (IGA) and Level Set Method (LSM) under plane stress assumptions. The proposed method demonstrates its ability to obtain stable and manufacturable design layouts.
COMPUTER-AIDED DESIGN
(2022)
Article
Computer Science, Interdisciplinary Applications
L. Noel, K. Maute
Summary: Solving conjugate heat transfer design problems is important for efficient thermal management in various engineering applications. This study explores the use of an eXtended Finite Element Method (XFEM) to predict physical responses of turbulent conjugate heat transfer problems. The XFEM approach is integrated into a level set-based optimization framework, where the design domain is immersed into a background mesh and fluid/solid interfaces are defined implicitly by level set functions. Turbulence and thermal energy transport are described using mathematical models. The proposed XFEM approach is validated against benchmark problems and demonstrated in the design of turbulent heat exchangers.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Engineering, Mechanical
Hassan A. Jahangiry, Majid Gholhaki, H. Naderpour, S. Mehdi Tavakkoli
Summary: This article proposes a method for topology optimization of elastoplastic plane stress problems using IsoGeometric analysis and Level set method. The objective is to maximize the toughness of structure through techniques such as IGA modeling and reaction-diffusion equation.
INTERNATIONAL JOURNAL OF MECHANICS AND MATERIALS IN DESIGN
(2021)
Article
Computer Science, Interdisciplinary Applications
Matteo Pozzi, Giacomo Bonaccorsi, Francesco Braghin
Summary: In this study, we demonstrate the application of eigenfrequency optimization in the field of structural dynamics to minimize the variance of natural frequencies caused by external temperature uncertainties. We utilize a level-set optimization algorithm known for its computational efficiency and ability to define crisp interfaces.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Thermodynamics
Sandilya Kambampati, Justin S. Gray, H. Alicia Kim
Summary: This study presents the optimal design of load carrying battery packs with heat exchange capabilities using a multi-objective optimization approach. The efficiency of the optimized designs is demonstrated through numerical examples by showcasing their multifunctional nature of reducing battery cell temperatures while sustaining a given load.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Tiantian Zhang, Xiaoqing Yang
Summary: This paper develops a parametric level set-based topology optimization method for the design of micro-channel heat sinks, and its effectiveness is confirmed through numerical experiments and experimental tests.
APPLIED THERMAL ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Ali Azari Nejat, Alexander Held, Niklas Trekel, Robert Seifried
Summary: This study proposes an efficient and stable topology optimization algorithm for slender structures by modifying the pseudo-time step size and Lagrange multiplier to replace unacceptable designs, adjusting the normal velocity formulation to avoid instabilities, and adding filtering-like adaptation terms to achieve smoother optimization convergence.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Acoustics
Bin Xu, Yuanhao Liu, Jingdan Xue, Yonghui Zhao
Summary: A two-scale concurrent topology optimization method based on the couple stress theory is proposed to maximize structural fundamental eigenfrequency. By considering both macrostructures and their periodic composite material microstructures, the method effectively describes the size effect in topology optimization using the couple stress theory.
JOURNAL OF VIBRATION AND CONTROL
(2021)
Article
Computer Science, Interdisciplinary Applications
Yaguang Wang, Zhan Kang
Summary: This paper presents MATLAB implementations of the velocity field level set method for topology optimization, providing codes for 2D and 3D static compliance minimization problems. The method allows for clear and smooth material boundaries in structural designs and enables the use of general mathematical programming algorithms to handle additional constraints efficiently.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Thermodynamics
Xiaoqiang Xu, Xianfeng David Gu, Shikui Chen
Summary: This paper proposes a design method for thermal cloaks using level-set-based shape and topology optimization. The distribution of bulk heat conductive materials is optimized to eliminate the temperature disturbance caused by the introduction of an insulator into a homogeneous thermal conduction medium. The optimized thermal cloaks are free of high anisotropy and nonhomogeneity commonly seen in other methods. Rating: 8 points
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Computer Science, Interdisciplinary Applications
Brian S. Cohen, Andrew March, Karen E. Willcox, David W. Miller
Summary: This paper introduces a level-set based topology optimization approach for designing thermally efficient radiating structures. The authors derive the shape sensitivity using the adjoint method and apply gradient-based algorithm and augmented Lagrangian method to solve the problem of maximizing heat power. A case study demonstrates that maximizing the thermal compliance functional is insufficient for solving this type of problem.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Mathematics, Applied
S. Ogawa, T. Yamada
Summary: A topology optimization method is proposed for thermoelastic models in transient response problems, aiming to optimize structures under time-dependent dynamic and thermal loads. The method can be applied to problems involving thermal deformation and stress from heated machine parts. Sensitivity analysis using the adjoint variable method and discretize-then-differentiate approach is conducted, and the method is validated through numerical examples.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2022)
Article
Engineering, Multidisciplinary
Shun Ogawa, Takayuki Yamada
Summary: This paper proposes a new approach for the design of thermal actuators using topology optimization. The method introduced an objective function that combines evaluation functions to derive a structure with the same deformation mode of real phenomena, without spring elements and with low computational cost.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2022)
Article
Engineering, Manufacturing
T. Yamada, Y. Noguchi
Summary: This paper proposes a topology optimization method that considers the geometric constraint of no closed cavities to improve the effectiveness of additive manufacturing based on the fictitious physical model approach. Numerical examples are provided to validate the proposed method.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Yuki Noguchi, Kei Matsushima, Takayuki Yamada
Summary: In this paper, a topology optimization method for the design of labyrinthine metamaterials with a large path length for acoustic wave propagation is presented. The optimal design of the labyrinthine structure is achieved by maximizing the pressure gradient in an air-filled region at a low frequency, using a level set-based optimization method and the concept of topological derivative. Numerical examples demonstrate the effectiveness of the proposed method.
MATERIALS & DESIGN
(2022)
Article
Optics
Kei Matsushima, Yuki Noguchi, Takayuki Yamada
Summary: The study designs a piecewise homogeneous dielectric structure with parity-time (PT) symmetry that achieves the unidirectional invisibility of a perfect electric conductor in two dimensions. Topology optimization is used to design a PT-symmetric material that minimizes the total scattering cross section for a given plane wave, and a rigorous mode-matching finite element method is used for all computations.
Article
Engineering, Multidisciplinary
S. Ogawa, T. Yamada
Summary: The article introduces the causes of damage to mechanical components due to thermal deformation and the required structural design methods, and proposes a topology optimization method for transient thermomechanical coupling problems. The article also discusses an interpolation scheme for material properties and a sensitivity analysis method.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Mathematics, Applied
S. Ogawa, T. Yamada
Summary: In this study, a new topology optimization problem for minimizing creep deformation is proposed. The viscoelastic model is used to account for creep deformation, and a new objective function is devised to directly evaluate it. Sensitivity analysis is formulated to consider the time dependence accurately, and the proposed method is validated through numerical examples.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Yuki Noguchi, Takashi Yamamoto, Kei Matsushima, Takayuki Yamada
Summary: In this study, a structural design for labyrinthine acoustic metamaterial is proposed using a topology optimization method to realize a subwavelength bandgap preventing the transmission of low-frequency sounds. The optimized design consists of air-filled channels of different widths, which exhibit the subwavelength bandgap based on the monopole resonance induced in the meta-atom. Numerical analysis based on the finite-element method demonstrates the low transmission coefficients of the obtained designs for a wide- and low-frequency range. Experimental results show the functionality of the optimized and simplified meta-atoms constructed using 3D printing.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Engineering, Multidisciplinary
Naoki Murai, Yuki Noguchi, Kei Matsushima, Takayuki Yamada
Summary: This study introduces a multiscale topology optimization method for the design of electromagnetic metamaterials. The method combines a level set-based topology optimization method with a high-contrast homogenization method. The high-contrast homogenization method accurately represents the wave propagation behavior in metamaterials at different frequencies and captures unusual properties caused by local resonances. The study formulates multiscale topology optimization problems based on macroscopic wave propagation behavior and uses microstructures as design variables. Numerical examples demonstrate optimized designs of metamaterials with multiple unit cell structures functioning as demultiplexers based on negative permeability. The mechanism of the obtained metamaterials is discussed using homogenized coefficients.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Kohei Shintani, Tomotaka Sugai, Takayuki Yamada
Summary: This paper proposes a novel data-driven set-based ATC method for hierarchical design optimization problems using machine learning techniques. The method decomposes hierarchical design optimization problems into sets of suboptimization problems and employs a Bayesian active learning strategy to determine feasible regions. The effectiveness of the proposed method is evaluated through numerical examples of hierarchical optimization problems.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Kaiwen Guan, Kei Matsushima, Yuki Noguchi, Takayuki Yamada
Summary: This paper presents a topology optimization method based on direct simulation Monte Carlo (DSMC) for rarefied gas flows. The distribution of fluid and solid is characterized by a pseudo density in the design domain. The traditional DSMC algorithm is extended to include the pseudo density, and design sensitivity is obtained using the Lagrangian multiplier method and adjoint state method. The extended DSMC algorithm is verified through numerical examples and applied to optimize the design of a bent pipe.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Mechanics
Daichi Akamatsu, Yuki Noguchi, Kei Matsushima, Yuji Sato, Jun Yanagimoto, Takayuki Yamada
Summary: Recent developments in 3D printing technology have made it possible to fabricate metamaterials with unique mechanical properties, but fabricating complex shapes with cavities remains a challenge. In this study, a composite structure without a cavity was optimized and a mechanical metamaterial with a negative Poisson's ratio was developed using additive manufacturing. A level set-based topology optimization method was proposed to achieve a negative Poisson's ratio, and numerical examples confirmed its effectiveness. Furthermore, a sample with the optimized negative Poisson's ratio design was fabricated and mechanical performance was evaluated through experiments.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Multidisciplinary
Tomoyuki Oka, Takayuki Yamada
Summary: This paper focuses on topology optimization using a level set method with (doubly) nonlinear diffusion equations. The method enables determining optimal configurations by updating level set functions and minimizing objective functionals. The paper proposes using (doubly) nonlinear diffusion equations with reaction terms as update equations for level set functions to achieve fast convergence and damping oscillation. The proposed method relaxes sensitivity analysis by not relying on topological derivatives in the reaction terms. A numerical algorithm is developed and applied to demonstrate the method's validity. The paper justifies and generalizes a method developed by Yamada et al. (2010) using reaction-diffusion equations.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Mathematics, Applied
K. Miyajima, Y. Noguchi, T. Yamada
Summary: Stress-constrained topology optimization is used to design compliant displacement magnification mechanisms. The objective function is formulated based on effective energy, eliminating the need for artificial spring components at the output and input ports. The method allows for the design of mechanisms that do not receive reaction forces at the output port, such as sensors, and avoids problems like stress concentration by imposing a constraint on maximum stress. Numerical examples are provided to demonstrate the effectiveness of the proposed method.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2023)
Article
Engineering, Mechanical
Naoyuki Ishida, Tsuguo Kondoh, Kozo Furuta, Hao Li, Kazuhiro Izui, Shinji Nishiwaki
Summary: This paper presents a level-set based topology optimization method for maximizing the lowest linear buckling load under a mean compliance constraint in the design of thin-walled structures.
MECHANICAL ENGINEERING JOURNAL
(2022)
