Multiobjective optimization design of an rf gun based electron diffraction beam line

Abstract This research focuses on multi-objective system design and optimization. The primary goal is to develop and test a mathematically rigorous and efficient interactive multi-objective optimization algorithm that takes into account the Decision Maker’s (DM’s) preferences during the design process. An Interactive Multi-Objective Optimization Procedure (IMOOP) developed in [12] has been modified in this research to include the DM’s local preference functions in an Iterative Decision Making Strategy (IDMS). This enhanced multiobjective optimization procedure called the interactive MultiObjective Optimization Design Strategy (iMOODS) provides the DM with a formal means for efficient design exploration around a given Pareto point. The use of local preference functions allows the original algorithm [12] to be modified such that the second order Pareto surface approximation is more accurate in the preferred region of the Pareto surface. The iMOODS has been successfully applied to two test problems. The first problem consists of a set of simple analytical expressions for the objectives and constraints. The second problem is the design and sizing of a high-performance and low-cost ten bar structure that has multiple objectives. The results indicate that the class functions are effective in capturing the local preferences of the DM. The Pareto designs that reflect the DM’s preferences can be efficiently generated within IDMS.

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Multiobjective optimization design of hybrid composite laminates for vibration using sequential permutation table method

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211050455 ◽

2021 ◽

pp. 095440622110504

Author(s):

Zhao Jing ◽

Qin Sun ◽

Yongjie Zhang ◽

Ke Liang

Keyword(s):

Multiobjective Optimization ◽

Fundamental Frequency ◽

Hybrid Composite ◽

Composite Laminates ◽

Optimization Design ◽

Heuristic Algorithms ◽

Optimization Problems ◽

Design Flexibility ◽

The Cost ◽

Ply Orientation

Due to the large variable design space in optimization problems of composite laminates, it remains one of the challenging tasks to develop efficient optimization design methods to improve the design flexibility and efficiency. This work presents a sequential permutation table (SPT) method for the multiobjective optimization design of two-material hybrid composite laminates with simply supported boundary conditions, which maximizes the fundamental frequency and minimizes the cost/weight. Based on the vibration analysis of hybrid composite laminates, the approximate linear regularity of the square of fundamental frequency is derived, and two best ply orientations for the two materials are identified, respectively. By assigning one best ply orientation with maximum fundamental frequency at respective stacking positions, and using another best ply orientation to replace plies in the stacking sequence from the mid-plane to the outermost can lead to the optimum. Two multiobjective optimization problems are employed to verify the SPT method, results are compared with those obtained by heuristic algorithms. The obtained better solutions demonstrate the effectiveness and efficiency of the SPT method and its potentials for optimal design of hybrid composite laminates.

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Improvement of 6D brightness by a 1.4-cell photocathode RF gun for MeV Ultrafast electron diffraction

Journal of Physics Conference Series ◽

10.1088/1742-6596/1350/1/012048 ◽

2019 ◽

Vol 1350 ◽

pp. 012048

Author(s):

Y Song ◽

J Yang ◽

C Tsai ◽

K Fan

Keyword(s):

Electron Diffraction ◽

Ultrafast Electron Diffraction ◽

Photocathode Rf Gun ◽

Rf Gun

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Multiobjective optimization design of ultrahigh-head pump turbine runners with splitter blades

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/240/7/072036 ◽

2019 ◽

Vol 240 ◽

pp. 072036 ◽

Cited By ~ 1

Author(s):

Zanao Hu ◽

Baoshan Zhu ◽

Xiaobing Liu ◽

Zhe Ma ◽

Cheng Xue

Keyword(s):

Multiobjective Optimization ◽

Optimization Design ◽

Pump Turbine

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Design and Multiobjective Optimization of Magnetorheological Damper considering the Consistency of Magnetic Flux Density

Shock and Vibration ◽

10.1155/2020/7050356 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Zhizhen Dong ◽

Zhimin Feng ◽

Yuehua Chen ◽

Kefan Yu ◽

Gang Zhang

Keyword(s):

Magnetic Flux ◽

Multiobjective Optimization ◽

Flux Density ◽

Optimization Design ◽

Dynamic Range ◽

Mr Damper ◽

Magnetorheological Damper ◽

Magnetic Flux Density ◽

Damping Force ◽

Mr Dampers

The consistency of magnetic flux density of damping gap (CMDG) represents the balancing magnetic flux density in each damping gap of magnetorheological (MR) dampers. It can make influences on the performances of MR dampers and the accuracy of relevant objective functions. In order to improve the mechanical performances of the MR damper with a two-stage coil, the function for calculating CMDG needs to be found. By establishing an equivalent magnetic circuit model of the MR damper, the CMDG function is derived. Then, the multiobjective optimization function and the working flow of optimal design are presented by combining the parallel-plate model of the MR damper with the function posed before. Taking the damping force, the dynamic range, the response time, and the CMDG as the optimization objective, and the external geometric dimensions of the SG-MRD60 damper as the bound variable, this paper optimizes the internal geometric dimensions of MR damper by using a NSGA-III algorithm on the PlatEMO platform. The results show that the obtained scheme in Pareto-optimal solutions has existed with better performance than that of SG-MRD60 scheme. According to the results of the finite element analysis, the multiobjective optimization design including the CMDG function can improve the uniformity of magnetic flux density of the MR damper in damping gap, which meets the requirements of manufacture and application.

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