Xiaoyan Teng¹, Qiang Li¹, Xudong Jiang^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.3, pp. 2479-2496, 2023, DOI:10.32604/cmes.2023.023110

Abstract A smooth bidirectional evolutionary structural optimization (SBESO), as a bidirectional version of SESO is proposed to solve the topological optimization of vibrating continuum structures for natural frequencies and dynamic compliance under the transient load. A weighted function is introduced to regulate the mass and stiffness matrix of an element, which has the inefficient element gradually removed from the design domain as if it were undergoing damage. Aiming at maximizing the natural frequency of a structure, the frequency optimization formulation is proposed using the SBESO technique. The effects of various weight functions including constant, linear and sine functions on structural optimization… More >

Hongliang Liu¹, Peijin Wang¹, Yuan Liang^2,*, Kai Long³, Dixiong Yang²

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.3, pp. 1941-1964, 2023, DOI:10.32604/cmes.2023.024921

Abstract Continuum topology optimization considering the vibration response is of great value in the engineering structure design. The aim of this study is to address the topological design optimization of harmonic excitation structures with minimum length scale control to facilitate structural manufacturing. A structural topology design based on discrete variables is proposed to avoid localized vibration modes, gray regions and fuzzy boundaries in harmonic excitation topology optimization. The topological design model and sensitivity formulation are derived. The requirement of minimum size control is transformed into a geometric constraint using the discrete variables. Consequently, thin bars, small holes, and sharp corners, which… More >

Haoran Zhu, Xinhao Gao, Aodi Yang, Shuting Wang, Xianda Xie, Tifan Xiong^*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1435-1456, 2023, DOI:10.32604/cmes.2022.023454

Abstract This work puts forward an explicit isogeometric topology optimization (ITO) method using moving morphable components (MMC), which takes the suitably graded truncated hierarchical B-Spline based isogeometric analysis as the solver of physical unknown (SGTHB-ITO-MMC). By applying properly basis graded constraints to the hierarchical mesh of truncated hierarchical B-splines (THB), the convergence and robustness of the SGTHB-ITOMMC are simultaneously improved and the tiny holes occurred in optimized structure are eliminated, due to the improved accuracy around the explicit structural boundaries. Moreover, an efficient computational method is developed for the topological description functions (TDF) of MMC under the admissible hierarchical mesh, which… More > Graphic Abstract

Xudong Jiang¹, Chang Liu^1,2,*, Shaohui Zhang³, Weisheng Zhang^1,2, Zongliang Du^1,2, Xiaoyu Zhang³, Huizhong Zeng³, Xu Guo^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 809-838, 2023, DOI:10.32604/cmes.2023.023561

Abstract This paper proposes an explicit method for topology optimization of stiffened plate structures. The present work is devoted to simultaneously optimizing stiffeners’ shape, size and layout by seeking the optimal geometry parameters of a series of moving morphable components (MMC). The stiffeners with straight skeletons and the stiffeners with curved skeletons are considered to enhance the modeling and optimization capability of the current approach. All the stiffeners are represented under the Lagrangian-description framework in a fully explicit way, and the adaptive ground structure method, as well as dynamically updated plate/shell elements, is used to obtain optimized designs with more accurate… More > Graphic Abstract

Zhaohui Yang^1,2,*, Tianhua Xiong¹, Fei Du^1,*, Baotong Li³

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1701-1718, 2023, DOI:10.32604/cmes.2023.022758

Abstract The structure optimization design under thermo-mechanical coupling is a difficult problem in the topology optimization field. An adaptive growth algorithm has become a more effective approach for structural topology optimization. This paper proposed a topology optimization method by an adaptive growth algorithm for the stiffener layout design of box type load-bearing components under thermo-mechanical coupling. Based on the stiffness diffusion theory, both the load stiffness matrix and the heat conduction stiffness matrix of the stiffener are spread at the same time to make sure the stiffener grows freely and obtain an optimal stiffener layout design. Meanwhile, the objectives of optimization… More >

Xudong Jiang^1,*, Jiaqi Ma¹, Xiaoyan Teng²

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.1, pp. 511-526, 2023, DOI:10.32604/cmes.2022.022785

Abstract Natural frequency and dynamic stiffness under transient loading are two key performances for structural design related to automotive, aviation and construction industries. This article aims to tackle the multi-objective topological optimization problem considering dynamic stiffness and natural frequency using modified version of bi-directional evolutionary structural optimization (BESO). The conventional BESO is provided with constant evolutionary volume ratio (EVR), whereas low EVR greatly retards the optimization process and high EVR improperly removes the efficient elements. To address the issue, the modified BESO with variable EVR is introduced. To compromise the natural frequency and the dynamic stiffness, a weighting scheme of sensitivity… More >

Jintao Liu¹, Juan Zhao¹, Xiaowei Shen^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 981-1003, 2023, DOI:10.32604/cmes.2022.021641

Abstract In this work, an acoustic topology optimization method for structural surface design covered by porous materials is proposed. The analysis of acoustic problems is performed using the isogeometric boundary element method. Taking the element density of porous materials as the design variable, the volume of porous materials as the constraint, and the minimum sound pressure or maximum scattered sound power as the design goal, the topology optimization is carried out by solid isotropic material with penalization (SIMP) method. To get a limpid 0–1 distribution, a smoothing Heaviside-like function is proposed. To obtain the gradient value of the objective function, a… More >

Qingyuan Hu^1,*, Yuan Liang², Menghao Liu¹, Manfeng Hu¹, Yawen Mao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.1, pp. 459-481, 2023, DOI:10.32604/cmes.2022.020327

Abstract Topological optimization plays a guiding role in the conceptual design process. This paper conducts research on structural topology optimization algorithm within the framework of isogeometric analysis. For multi-component structures, the Nitsche’s method is used to glue different meshes to perform isogeometric multi-patch analysis. The discrete variable topology optimization algorithm based on integer programming is adopted in order to obtain clear boundaries for topology optimization. The sensitivity filtering method based on the Helmholtz equation is employed for averaging of curved elements' sensitivities. In addition, a simple averaging method along coupling interfaces is proposed in order to ensure the material distribution across… More >

Jun Zou^*, Haolei Mou

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.2, pp. 451-469, 2022, DOI:10.32604/cmes.2022.020111

Abstract The integration of topology optimization (TO) and additive manufacturing (AM) technologies can create significant synergy benefits, while the lack of AM-friendly TO algorithms is a serious bottleneck for the application of TO in AM. In this paper, a TO method is proposed to design self-supporting structures with an explicit continuous self-supporting constraint, which can be adaptively activated and tightened during the optimization procedure. The TO procedure is suitable for various critical overhang angles (COA), which is integrated with build direction assignment to reduce performance loss. Besides, a triangular directional self-supporting constraint sensitivity filter is devised to promote the downward evolution… More >

Changkye Lee¹, Sundararajan Natarajan², Seong-Hoon Kee³, Jurng-Jae Yee^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.3, pp. 1615-1634, 2022, DOI:10.32604/cmes.2022.020377

Abstract The aim of this work is to employ a modified cell-based smoothed finite element method (S-FEM) for topology optimization with the domain discretized with arbitrary polygons. In the present work, the linear polynomial basis function is used as the weight function instead of the constant weight function used in the standard S-FEM. This improves the accuracy and yields an optimal convergence rate. The gradients are smoothed over each smoothing domain, then used to compute the stiffness matrix. Within the proposed scheme, an optimum topology procedure is conducted over the smoothing domains. Structural materials are distributed over each smoothing domain and… More >