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Perimeter control in the bidirectional evolutionary optimization method

STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION 2003年第6期24卷 430-440页

作者： Yang, XY Xie, YM Liu, JS Parks, GT Clarkson, PJ Hawker & Havilland Port Melbourne Vic 3207 Australia RMIT Univ Sch Civil & Chem Engn Melbourne Vic 3001 Australia Univ Hull Dept Engn Kingston Upon Hull HU6 7RX N Humberside England Univ Cambridge Dept Engn Engn Design Ctr Cambridge CB2 1PZ England

As an extension of the evolutionary Structural Optimization [ESO] method, the bidirectional ESO [BESO] method has effectively addressed various topology optimization problems. It is observed in ESO/BESO applications that the optimal solution obtained strongly depends on the finite element mesh. This paper presents an improved BESO methodology incorporating a means of controlling the optimization process in order to satisfy a constraint on structural perimeter and thus to solve this size effect problem. Numerical tests are conducted on three examples at different levels of finite element discretization. Solutions convergent with respect to the grid refinement are obtained, especially when the perimeter bound is sufficiently low. Simpler topologies consisting of fewer and larger structural members and holes are generated when a more restricting constraint is imposed. Therefore, it is concluded that BESO combined with perimeter control is capable of suppressing mesh dependency and controlling the structural complexity for topology optimization problems.

关键词： topology optimization evolutionary method mesh independency perimeter control

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Automated Optimal Design of EMI Filters Based on Internal Impedance Measurements and evolutionary method

Automated Optimal Design of EMI Filters Based on Internal Im...

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2013 International Conference on Electrical,Control and Automation Engineering(ECAE 2013)

作者： Rong ZHANG Ting GE Rui XIONG Jin HUANG Huazhong University of Science and Technology

Based on an impedance measurement approach, the noise source internal impedances of a switched-mode converter under its normal operating condition are measured. With the accurate noise source impedances, a systematic approach is presented to the conductive EMI filter design by means of evolutionary method. A practical example of the design of a common mode filter to comply with a regulatory conducted EMC limit using the proposed procedure is demonstrated and compared with the cases, where the impedances are not taken into account, or coarse estimate. This method for design the EMI filter can leads to optimal component values and avoids overdesign.

关键词： EMI filter Insertion loss evolutionary method Internal impedance

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A new evolutionary optimization method for osteoporotic bone augmentation

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COMPUTER methodS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING 2017年第7期20卷 691-700页

作者： Artiles, Maria E. Santana Venetsanos, Demetrios T. Univ Kingston Sch Mech & Automot Engn London England

Bone augmentation is a preventative osteoporosis intervention, comprising the injection of bone cement into an osteoporotic bone. As injection of excessive amounts of bone cement may result into thermal necrosis of bone tissue or even embolism, the minimum cement volume required to achieve a predefined level of augmentation must be sought. To this end, the present paper introduces a new evolutionary optimization method, applicable to any osteoporotic bone. The method was numerically evaluated through a typical case of femoral augmentation and compared to another powerful optimization method. The results demonstrate the efficiency and low computational cost of the proposed method.

关键词： Bone augmentation femoroplasty osteoporosis optimization evolutionary method

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Bi-directional evolutionary topology optimization using element replaceable method

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COMPUTATIONAL MECHANICS 2007年第1期40卷 97-109页

作者： Zhu, J. H. Zhang, W. H. Qiu, K. P. NW Polytech Univ Sino French Lab Concurrent Engn Xian 710072 Peoples R China

In the present paper, design problems of maximizing the structural stiffness or natural frequency are considered subject to the material volume constraint. A new element replaceable method (ERPM) is proposed for evolutionary topology optimization of structures. Compared with existing versions of evolutionary structural optimization methods, contributions are twofold. On the one hand, a new automatic element deletion/growth procedure is established. The deletion of a finite element means that a solid element is replaced with an orthotropic cellular microstructure (OCM) element. The growth of an element means that an OCM element is replaced with a solid element of full materials. In fact, both operations are interchangeable depending upon how the value of element sensitivity is with respect to the objective function. The OCM design strategy is beneficial in preventing artificial modes for dynamic problems. Besides, the iteration validity is greatly improved with the introduction of a check position (CP) technique. On the other hand, a new checkerboard control algorithm is proposed to work together with the above procedure. After the identification of local checkerboards and detailed structures over the entire design domain, the algorithm will fill or delete elements depending upon the prescribed threshold of sensitivity values. Numerical results show that the ERPM is efficient and a clear and valuable material pattern can be achieved for both static and dynamic problems.

关键词： evolutionary method topology optimization microstructure checkerboard control artificial mode

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On various aspects of application of the evolutionary structural optimization method for 2D and 3D continuum structures

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FINITE ELEMENTS IN ANALYSIS AND DESIGN 2006年第6期42卷 478-491页

作者： Abolbashari, MH Keshavarzmanesh, S Ferdowsi Univ Mashhad Dept Mech Engn Mashhad 917751111 Iran

The evolutionary structural optimization (ESO) is an evolutionary based method, which has been broadly used for structural optimization in recent years. The concept behind the simple ESO method is the removal of inefficient material from a structure in an iterative process. The process involves a number of selections like the choice of rejection ratio and evolutionary rate. On the other hand, in the finite element analysis (FEA) of the problem, the designer should decide about the size of the mesh and the type of the element used. The influence of the rejection ratio, evolutionary rate and the size of elements choice on the optimized shape of 2D and 3D continuum structures are investigated in this paper. Different mesh sizes and boundary conditions are considered. In all examined cases the rejection criterion for removing material (elements) is the von Mises stress level of the elements. The results show the ability of the ESO method for generating optimum 2D and 3D continuum structures with different boundary conditions. In a series of examples of 2D and 3D continuum structures, it is shown that different initial rejection ratios and evolutionary rates may have no significant effect on the maximum and minimum stress histories and on the volume reduction histories as well, but have a significant effect on the resulting shape. Furthermore, the optimized topology is more sensitive to the evolutionary rate changes than the variation of initial rejection ratios. It is also concluded that the element sizes have a significant effect on the histories of minimum stress and the volume reduction. Moreover, the optimized shape is completely changed by variation of the element sizes. (c) 2005 Elsevier B.V. All rights reserved.

关键词： evolutionary method structural optimization continuum structure finite element

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An evolutionary structural optimization method for sizing problems with discrete design variables

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COMPUTERS & STRUCTURES 1998年第4期68卷 419-431页

作者： Nha, CD Xie, YM Steven, GP Victoria Univ Technol Dept Civil & Bldg Engn Melbourne Vic 8001 Australia Univ Sydney Dept Aeronaut Engn Sydney NSW 2006 Australia

This paper presents a simple evolutionary method for minimizing the weight of structures subject to displacement constraints, where sizing design variables are discrete. Sensitivity numbers for element size reduction are derived using optimality criteria methods. An optimal design can be obtained by gradually reducing elements which have the lowest sensitivity numbers until one of the constrained displacements reaches its given limit. It is shown;that the proposed method can directly deal with discrete design variables. A simple smoothing technique is employed to suppress formation of checker-board patterns. Examples are provided to demonstrate the capability of the proposed method for discrete sizing optimization problems. (C) 1998 Elsevier Science Ltd. All rights reserved.

关键词： structural optimization evolutionary method displacement constraints discrete sizing variables checker-board patterns

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Electro-thermal compliant mechanisms design by an evolutionary topology optimization method

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ENGINEERING COMPUTATIONS 2013年第7期30卷 961-981页

作者： Ansola, Ruben Vegueria, Estrella Canales, Javier Alonso, Cristina Univ Basque Country Engn Fac Bilbao Dept Mech Engn Bilbao Spain

Purpose - This paper aims to show an evolutionary topology optimization procedure for the design of compliant electro-thermal mechanisms. Design/methodology/approach - The adopted methodology is based in the evolutionary structural optimization (ESO) method. This approach has been successfully applied by this group for compliant mechanisms optimization under directly applied input loads and simple thermal loads. This work proposes an extension of this procedure, based on an additive version of the method, to solve the more complicated case of electro-thermal actuators optimum design, based on Joule's resistive heating. Findings - Examples solved for the design of plane compliant mechanisms are presented to check the validity of this technique. The designs obtained are compared favorably with results obtained by other authors to illustrate and validate the method, showing the viability of this technique for the optimization of compliant mechanisms under electro-thermal actuation. Research limitations/implications - This investigation is based on and additive version of the evolutionary method. Since this approach does not have the capability to remove material it could be combined with the classic element rejection evolutionary method to overcome these deficiencies, developing an improved bi-directional algorithm, which should be analyzed and applied for these types of designs in future works. Practical implications - Electro-thermal actuators have widespread use in MicroElectroMechanical Systems applications. Since these elements cannot be manufactured using typical assembly processes compliant mechanisms optimization play a crucial role for their successful design. The proposed methodology could help engineers to rapidly conceive complex and efficient actuators. Social implications - The topology optimization procedure developed in this paper enables systematic design of these devices, which can result in a save of manufacturing time and cost Originality/value - Mo

关键词： Topology Optimization evolutionary method Electro-thermal actuator Compliant mechanisms Optimization techniques

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A Study on Topology Optimization of Plasmonic Waveguide Devices Using Function Expansion method and evolutionary Approach

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2019年第3期37卷 981-988页

作者： Koda, Akino Morimoto, Keita Tsuji, Yasuhide Muroran Inst Technol Div Informat & Elect Engn Muroran Hokkaido 0508585 Japan

We propose a novel topology optimization method for plasmonic devices. Plasmonic devices that have a great potential to downsize various optical devices beyond the diffraction limit attract a lot of attention. In order to develop high-performance plasmonic devices, a novel design theory is expected to be established instead of the conventional theory for dielectric waveguide devices. In this paper, we employ the function expansion method to express a device structure in the design region and optimize the design variables by using several evolutionary approaches, which do not require the sensitivity analysis. The validity and usefulness of this approach are demonstrated through the design examples of optical diode and optical circulator.

关键词： evolutionary method finite element method (FEM) function-expansion method plasmonic waveguide device

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An Online evolutionary Aeromagnetic Compensation method Using Woodbury Equation

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IEEE GEOSCIENCE AND REMOTE SENSING LETTERS 2023年 20卷

作者： Xu, Yujing Liu, Zhongyan Zhang, Qi Huang, Bo Pan, Mengchun Hu, Jiafei Guan, Feng Chen, Zhuo Ding, Qiaochu Qiu, Xiaotian Tang, Ying Natl Univ Def Technol Coll Intelligence Sci & Technol Changsha 410073 Peoples R China Naval Res Acad Beijing 100161 Peoples R China

Aeromagnetic compensation is important in aeromagnetic detection. Traditionally, a calibration flight would be implemented to estimate the interference model. However, the magnetic interference is not constant during the mission flight, which makes the interference model constructed in the calibration flight inapplicable in the mission. To solve that problem, this letter proposes an evolutionary aeromagnetic compensation method based on the Woodbury equation. With this method, the magnetic interference model parameters can be evolved during the mission flight on basis of the previous interference model and the updated acquired data. To evaluate the performance of the evolutionary method, both simulation and the experiment were conducted. The results indicate that the proposed method can effectively reduce the influence of changing magnetic interference. In the experiment, the standard deviation (STD) of measured data before compensation in the last mission flight is 1.2070 nT, the traditional compensation can reduce the STD to 0.0863 nT, while our evolutionary aeromagnetic compensation method can reduce STD to 0.0450 nT. The results show that increasing changes in magnetic interference will make evolutionary aeromagnetic compensation vital for isolating signals created by geologic features from signals created by the aircraft.

关键词： Interference Mathematical models Atmospheric modeling Calibration Data models Aircraft Magnetometers Aeromagnetic compensation evolutionary method Woodbury equation

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Robust optimization approach to production system with failure in rework and breakdown under uncertainty: evolutionary methods

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ASSEMBLY AUTOMATION 2015年第1期35卷 81-93页

作者： Rabbani, Masoud Manavizadeh, Neda Aghozi, Niloofar Sadat Hosseini Univ Tehran Sch Ind Engn Fac Engn Tehran Iran KHATAM Inst Higher Educ Dept Ind Engn Tehran Iran Univ Tehran Coll Engn Tehran Iran

Purpose - This paper aims to consider a multi-site production planning problem with failure in rework and breakdown subject to demand uncertainty. Design/methodology/approach - In this new mathematical model, at first, a feasible range for production time is found, and then the model is rewritten considering the demand uncertainty and robust optimization techniques. Here, three evolutionary methods are presented: robust particle swarm optimization, robust genetic algorithm (RGA) and robust simulated annealing with the ability of handling uncertainties. Firstly, the proposed mathematical model is validated by solving a problem in the LINGO environment. Afterwards, to compare and find the efficiency of the proposed evolutionary methods, some large-size test problems are solved. Findings - The results show that the proposed models can prepare a promising approach to fulfill an efficient production planning in multi-site production planning. Results obtained by comparing the three proposed algorithms demonstrate that the presented RGA has better and more efficient solutions. Originality/value - Considering the robust optimization approach to production system with failure in rework and breakdown under uncertainty.

关键词： Rapid manufacturing Breakdown evolutionary method Failure in rework Robust optimization Uncertain demand

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