Yu Cheng^1,2,5, Yajun Huang³, Shuai Li⁴, Zhongbin Zhou⁵, Xiaohui Yuan^1,2,*, Yanming Xu^5,*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1935-1960, 2024, DOI:10.32604/cmes.2023.045668

Abstract A new approach for flexoelectric material shape optimization is proposed in this study. In this work, a proxy model based on artificial neural network (ANN) is used to solve the parameter optimization and shape optimization problems. To improve the fitting ability of the neural network, we use the idea of pre-training to determine the structure of the neural network and combine different optimizers for training. The isogeometric analysis-finite element method (IGA-FEM) is used to discretize the flexural theoretical formulas and obtain samples, which helps ANN to build a proxy model from the model shape to the target value. The effectiveness… More >

Chuang Lu¹, Leilei Chen^2,3, Jinling Luo⁴, Haibo Chen^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.1, pp. 847-872, 2024, DOI:10.32604/cmes.2023.044446

Abstract We propose a combined shape and topology optimization approach in this research for 3D acoustics by using the isogeometric boundary element method with subdivision surfaces. The existing structural optimization methods mainly contain shape and topology schemes, with the former changing the surface geometric profile of the structure and the latter changing the material distribution topology or hole topology of the structure. In the present acoustic performance optimization, the coordinates of the control points in the subdivision surfaces fine mesh are selected as the shape design parameters of the structure, the artificial density of the sound absorbing material covered on the… More >

Shude Fu^1,2, Xinye Wu^1,2,*, Wenjie Wang³, Yixin Hu^1,3,*, Zhengke Li¹, Feng Jiang³

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2357-2382, 2024, DOI:10.32604/cmes.2023.031118

Abstract In this paper, given the shortcomings of jellyfish search algorithm with low search ability in the early stage and easy to fall into local optimal solution, this paper introduces adaptive weight function and elite strategy, improving the global search scope in the early stage and the ability to refine the local development in the later stage. In the numerical study, the benchmark problem of dimensional optimization with a 10-bar truss structure and simultaneous dimensional shape optimization with a 15-bar truss structure is adopted, and the corresponding penalty method is used for constraint treatment. The test results show that the improved… More > Graphic Abstract

Xuhang Lin¹, Haibo Chen^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09388

Abstract As an important and useful tool for reducing noise, the sound barrier is of practical significance. The sound barrier has different noise reduction effects for different sizes, shapes and properties of the sound absorbing material. Liu et al. [1] have performed shape optimization of sound barriers by using isogeometric boundary element method and method of moving asymptotes (MMA). However, in engineering practice, it is difficult to determine some parameters accurately such as material properties, geometries, external loads. Therefore, it is necessary to consider these uncertainty conditions in order to ensure the rationality of the numerical calculation of engineering problems. In… More >

Masanori Honda^1,3, Chikara Kawamura^1,3, Isamu Kizaki¹, Yoichi Miyajima¹, Akihiro Takezawa^2,*, Mitsuru Kitamura³

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.2, pp. 731-742, 2021, DOI:10.32604/cmes.2021.016181

Abstract A body frame composed of thin sheet metal is a crucial structure that determines the safety performance of a vehicle. Designing a correct weight and high-performance automotive body is an emerging engineering problem. To improve the performance of the automotive frame, we attempt to reconstruct its design criteria based on statistical and mechanical approaches. At first, a fundamental study on the frame strength is conducted and a cross-sectional shape optimization problem is developed for designing the cross-sectional shape of an automobile frame having a very high mass efficiency for strength. Shape optimization is carried out using the nonlinear finite element… More >

Ellie Vineyard¹, Xin-Lin Gao^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 819-854, 2021, DOI:10.32604/cmes.2021.015688

Abstract 2-D and 3-D micro-architectured multiphase thermoelastic metamaterials are designed and analyzed using a parametric level set method for topology optimization and the finite element method. An asymptotic homogenization approach is employed to obtain the effective thermoelastic properties of the multiphase metamaterials. The -constraint multi-objective optimization method is adopted in the formulation. The coefficient of thermal expansion (CTE) and Poisson’s ratio (PR) are chosen as two objective functions, with the CTE optimized and the PR treated as a constraint. The optimization problems are solved by using the method of moving asymptotes. Effective isotropic and anisotropic CTEs and stiffness constants are obtained… More >

Daoyuan Yu, Shouyu Cai^*, Wenya Fan, Lan Zhang^*

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.3, pp. 787-806, 2020, DOI:10.32604/cmes.2020.09936

Abstract In this study, a patch removing based Isogeometric analysis (PR-IGA) method is proposed to conduct the holed structural analysis with only one parametric domain, in which there are also no trimmed elements. The theoretical foundation of this novel patch removing approach is that any holed structure can be obtained by removing sub-patches (i.e., the holes) from an intact base patch. Since the parametric domains of these patches are all meshed by rectangular grids, the elements in the resulted holed structural parametric domain could all be untrimmed rectangles under certain mapping conditions. To achieve the special condition, a systematic technique consisting… More >

Yingjun Wang^1,*, Zhenpei Wang^2,*, Zhaohui Xia³, Leong Hien Poh²

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.3, pp. 455-507, 2018, DOI:10.31614/cmes.2018.04603

Abstract Isogeometric analysis (IGA), an approach that integrates CAE into conventional CAD design tools, has been used in structural optimization for 10 years, with plenty of excellent research results. This paper provides a comprehensive review on isogeometric shape and topology optimization, with a brief coverage of size optimization. For isogeometric shape optimization, attention is focused on the parametrization methods, mesh updating schemes and shape sensitivity analyses. Some interesting observations, e.g. the popularity of using direct (differential) method for shape sensitivity analysis and the possibility of developing a large scale, seamlessly integrated analysis-design platform, are discussed in the framework of isogeometric shape… More >

H. T. Wang, L. Shi

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.1, pp. 11-12, 2011, DOI:10.3970/icces.2011.019.011

Abstract A three-dimensional fast boundary element solver is developed for the shape optimization of nozzles of nuclear reactor pressure vessels (RPVs). In a RPV, pressure and mechanical loads may lead to high stress concentration due to the discontinuity of the structure, especially at the inner surface of the cold/hot legs. This work aims to minimize these stress concentrations by optimizing the geometry of the openings using modern shape optimization techniques and fast boundary element method. Shape optimization methods based on the principle of biological adaptive growth are incorporated into a boundary element method program and used to optimize the design of… More >

Zhenhan Yao, Yintao Wei

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.2, pp. 51-52, 2011, DOI:10.3970/icces.2011.016.051

Abstract Shape optimization is very important in many engineering fields. As conventional engineering design, the shape optimization is generally based on the finite element analysis. Because many engineering strutures are related to different nonlinear problems in their working state, the analysis for each design sample is quite time consuming. For example for the shape optimization of automotive tires, it is related to the geometrical, material nonlinearity, and boundary nonlinearity caused by the contact problem. Therefore, the finite element analysis combined with sensitivity analysis to get more information for each design sample is a strategy usually adopted. For the sensitivity analysis, the… More >