Article
Computer Science, Interdisciplinary Applications
Haijun Xia, Zhiping Qiu, Lei Wang
Summary: This study explores a novel reliability-based topology optimization framework for determining optimal material configurations for freely vibrating continuum structures with unknown-but-bounded uncertainties. By introducing the concept of non-probabilistic reliability and utilizing the performance measure approach, the study overcomes convergence difficulties and demonstrates its validity through numerical examples.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Computer Science, Interdisciplinary Applications
Dongliang Liu, Zhiping Qiu
Summary: This study focuses on the robust topology optimization of structures with truss-like lattice materials under unknown but bounded uncertainties. A formulation for robust topology optimization is developed to account for uncertainties in load magnitude and direction, as well as truss-like lattice material diameter. Absolute and relative robustness indices are established to measure structure robustness, and a subinterval dimension-wise method is proposed to address difficulties in determining response intervals caused by large uncertainties. Two examples are provided to demonstrate the effectiveness of the method in complex structures with significant uncertainty.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(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
Engineering, Multidisciplinary
Zeshang Li, Lei Wang, Geng Xinyu
Summary: With the diversification of engineering structure performance requirements and the continuous development of structural design refinement, structural design methods are facing more and more factors to be considered. This paper proposes a sensitivity mapping technique for topology optimization based on a gradient optimization algorithm and considers the influence of multi-source uncertainties.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Automation & Control Systems
Junbo Tan, Sorin Olaru, Maria M. Seron, Feng Xu
Summary: This paper focuses on designing an input sequence via the minimization of a suitable cost function to ensure active fault diagnosis of discrete-time linear parameter-varying systems regardless of changes in scheduling variables. It uses convex polyhedrons to characterize system uncertainties and proposes an efficient optimization method by analyzing the geometric properties of the objective function to obtain the optimal input sequence.
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
Automation & Control Systems
Van-Truong Nguyen, Chyi-Yeu Lin, Shun-Feng Su, Wei Sun, Meng Joo Er
Summary: This article presents a global finite-time active disturbance rejection control (ADRC) scheme for tracking control of redundant parallel manipulators with unknown bounded uncertainties, which combines ADRC and global finite-time control for high accuracy trajectory tracking control. The proposed approach removes the condition in the original ADRC that the derivative of the uncertainties is required to be bounded, and utilizes an extended state observer for real-time estimation of total uncertainty. The scheme shows fast convergence to a semi-global finite-time stable equilibrium and superior tracking control performance, with advantages including uncertainty rejection, ease of implementation, robustness, chattering-free operation, high precision, and no need for prior knowledge of bounded uncertainties. Simulation results validate the effectiveness of the proposed method.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2021)
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
Engineering, Mechanical
Jin Cheng, Wei Lu, Yibin Lou, Weifei Hu, Zhenyu Liu, Jianrong Tan
Summary: A new robust topology optimization scheme considering uncertainties in graphene platelet reinforced functionally graded materials is proposed, ensuring boundedness of probabilistic variables using a generalized Beta distribution. The approach effectively addresses the issue of critical loads in existing optimization methods, and integrates innovative strategies to enhance efficiency and accuracy.
JOURNAL OF MECHANICAL DESIGN
(2022)
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
Automation & Control Systems
Oleg Granichin, Victoria Erofeeva, Yury Ivanskiy, Yuming Jiang
Summary: This article discusses estimation and tracking problems in a distributed sensor network, focusing on SPSA-based consensus algorithms. Sufficient conditions are introduced to guarantee stability of estimates without relying on stringent statistical assumptions about observation noise.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2021)
Article
Thermodynamics
Junjie Zhong, Yijia Cao, Yong Li, Yi Tan, Yanjian Peng, Lihua Cao, Zilong Zeng
Summary: A distributed synergistic model with min max-min robust optimization is proposed for a 3-block integrated energy system, which effectively handles multiple uncertainties and accelerates the solution process with the developed C&CG-AOP algorithm. The simulation results show that the constructed uncertainty set considering spatial-temporal correlation and symmetry can reduce operating costs.
Article
Computer Science, Interdisciplinary Applications
Jonghyun Kim, Ikjin Lee
Summary: This paper presents a reliability-based topology optimization framework using nodal design variables for dealing with geometric uncertainties. The structural layout is represented by a density field constructed using nodal densities, and the geometric variation is modeled through nodal shifts and density field perturbations. The optimization problem is decoupled using sequential optimization and reliability assessment method, and the sensitivities are derived analytically. Numerical examples demonstrate the effectiveness of the proposed framework for handling geometric uncertainties.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
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
Automation & Control Systems
Hao Liu, Shaodong Wang, Ben Niu, Yuzhe Li
Summary: This article proposes a novel attack detection approach based on zonotopes for linear parameter-varying systems with unknown-but-bounded noises. It considers DoS, RAs, and FDI attacks, introduces a free-weighting matrix to reduce conservativeness, and guarantees the radius of the intersection zonotope to be limited. Additionally, the method does not require prior knowledge of the specific type of attack.
IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS
(2022)
Article
Engineering, Multidisciplinary
Deepak K. Gupta, Fred van Keulen, Matthijs Langelaar
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2020)
Article
Engineering, Multidisciplinary
Elena De Lazzari, Sanne J. van den Boom, Jian Zhang, Fred van Keulen, Alejandro M. Aragon
Summary: Enriched finite element methods have been increasingly used for modeling problems involving material interfaces and cracks. While NURBS can accurately preserve interface geometries, they do not significantly improve the extraction of stress intensity factors for cracked specimens, and the complexity of exact geometry representation outweighs the benefits in low-order elements.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Emiel van de Ven, Can Ayas, Matthijs Langelaar, Robert Maas, Fred van Keulen
Summary: Additive manufacturing and topology optimization have a synergistic relationship, with TO providing high-performance parts that leverage the form freedom of AM; Recently, TO has been tailored towards AM by including a minimum allowable overhang angle as a design constraint to allow designs to be built without support structures. This study introduces an accessibility-aware overhang filter to improve part performance and convergence behavior.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Computer Science, Interdisciplinary Applications
S. J. van den Boom, J. Zhang, F. van Keulen, A. M. Aragon
Summary: Smooth geometry description is crucial in design optimization, and combining level set description with a new enriched topology optimization methodology can generate correct topologies without the drawbacks of existing enriched methods.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Instruments & Instrumentation
R. J. F. Bijster, F. van Keulen
Summary: Multilayer cantilever beams are utilized for measuring near-field radiative heat transfer, and analytical model is employed for design to enhance system performance. Constraints are placed on thermal noise, temperature drift, and spring constant, while maximizing optical reflectance and sensitivity.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Engineering, Multidisciplinary
S. J. van den Boom, F. van Keulen, A. M. Aragon
Summary: An immersed enriched finite element method is proposed for analyzing phononic crystals with completely decoupled finite element meshes from geometry. The method effectively transforms non-conforming discretization into an enriched node-to-node periodic discretizations and eliminates the need for generating matching or fitted meshes during the design process. This approach shows the same performance as standard finite element analysis on fitted meshes in analyzing phononic crystals in structured meshes.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Grzegorz Misiun, Emiel van de Ven, Matthijs Langelaar, Hubert Geijselaers, Fred van Keulen, Ton van den Boogaard, Can Ayas
Summary: This study combines additive manufacturing simulation and topology optimization to propose a solution to the distortion issue in powder bed additive manufacturing, modeling and optimizing for two possible causes of failure. The formulated constraints were found to effectively prevent excessive part distortion and associated build failures.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Jian Zhang, Fred van Keulen, Alejandro M. Aragon
Summary: The study proposes a fully immersed topology optimization procedure for designing structures with tailored fracture resistance in brittle materials under linear elastic fracture mechanics assumptions. By using a level set function and the Interface-enriched Generalized Finite Element Method (IGFEM), accurate structural responses are obtained. The technique approximates energy release rates (ERRs) of all potential cracks using topological derivatives after a single enriched finite element analysis, and demonstrates the ability to tailor fracture resistance through several numerical examples.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Coen Bakker, Lidan Zhang, Kristie Higginson, Fred van Keulen
Summary: This study focuses on optimizing the topology and layout of stiffened shells and plates by introducing modular design and density-based topology optimization. The method is able to generate clear topologies for any number of modules, demonstrating distinct layouts of stiffeners on the base shell or plate.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Engineering, Mechanical
Yong Zhang, Marcel Tichem, Fred van Keulen
Summary: Metastructures composed of snapping beams can deform into stable states with different curvatures, and the beam thickness is crucial for tuning the snap-through response. Curvature can be adjusted by changing the beam height and span.
EXTREME MECHANICS LETTERS
(2022)
Article
Engineering, Multidisciplinary
S. Koppen, M. Langelaar, F. van Keulen
Summary: In this paper, a novel method is proposed to efficiently calculate responses and design sensitivities in multi-partition problems for gradient-based topology optimization. The method is applicable to various linear problems and shows particular effectiveness in the topology optimization of small-displacement multi-input-multi-output compliant mechanisms. Numerical experiments demonstrate its efficiency for large-scale multi-partition problems.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Engineering, Mechanical
S. Koppen, M. Langelaar, F. van Keulen
Summary: Flexures are crucial in high-tech equipment for precise manipulation and measurement. This study proposes a novel topology optimization formulation for designing short-stroke flexures, based on strain energy measures. It demonstrates versatility in flexure types and additional design requirements.
MECHANISM AND MACHINE THEORY
(2022)
Article
Engineering, Manufacturing
R. Ranjan, Z. Chen, C. Ayas, M. Langelaar, F. Van Keulen
Summary: Overheating is a major issue in metal Additive Manufacturing (AM) processes, leading to poor surface quality, lack of dimensional precision, inferior performance and/or build failures. This study presents a 3D density-based topology optimization (TO) method that integrates a simplified AM thermal model and a thermal constraint to address the issue of local overheating during metal AM. The proposed physics-based method reduces the risk of overheating and delivers efficient designs compared to commonly used geometry-based TO methods.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Multidisciplinary
Sanne J. van den Boom, Reza Abedi, Fred van Keulen, Alejandro M. Aragon
Summary: Phononic crystals can exhibit band gaps, which are frequency ranges with strong attenuation in the material. The working principle is based on destructive interference of waves reflecting from the periodic arrangement of material interfaces. However, the commonly used density-based representation in topology optimization methods leads to diffuse staircased boundaries, resulting in large and expensive optimization problems. This paper demonstrates the adverse effect of density-based boundary description and proposes a level set-based topology optimization procedure with an enriched finite element method for improved performance.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Weiming Wang, Fred van Keulen, Jun Wu
Summary: Additive manufacturing of metal parts often leads to distortion due to phase transformations and high temperature gradients. This paper proposes a computational framework that optimizes the fabrication sequence to minimize distortion in multi-axis additive manufacturing. By encoding the fabrication sequence using a continuous pseudo-time field and using gradient-based numerical optimization, the framework successfully reduces distortion by orders of magnitude compared to planar fabrication.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
