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Force density sensitivity form-finding design method for cable-mesh reflector antennas considering interactive effects between cable network and supporting truss

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ENGINEERING STRUCTURES 2021年 244卷 112722-112722页

作者： Zhang, Shunji Zhang, Shuxin Zhang, Yiqun Ye, Jing Shaanxi Key Lab Space Solar Power Stn Syst Xian 710071 Peoples R China Xidian Univ Sch Electromech Engn Xian 710071 Peoples R China

Form-finding design is critical in determining whether a cable-mesh reflector antenna can meet electrical performance requirements. However, the current methods rarely consider the interactive effects between the cable network and the supporting truss in the form-finding process, which requires more iteration steps for good design results. This study presents a force density sensitivity form-finding design method for cable-mesh reflector antennas based on systematic equilibrium equations. The sensitivity matrix of the support truss vertex and the cable network free node is derived with respect to force density, and the form-finding process of the reflector antenna is transformed into a sequential quadratic programming problem that can be easily solved. The antenna meets the accuracy requirements, and has a more uniform distribution of internal cable net tension and a smaller truss deformation as a result of constraining the vertex deformation of the supporting truss and cable tension. For practical engineering problems, more accurate design results can be obtained quickly. The effectiveness of the proposed method is verified through numerical examples.

关键词： Form-finding Force density sensitivity matrix sequential quadratic programming Cable-mesh reflector

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Airfoil shape optimization using a nonuniform rational B-splines parameterization under thickness constraint

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AIAA JOURNAL 2006年第10期44卷 2170-2178页

作者： Painchaud-Ouellet, Simon Tribes, Christophe Trepanier, Jean-Yves Pelletier, Dominique Ecole Polytech Montreal PQ H3C 3A7 Canada

Results for 2-D airfoil shape optimization in transonic regime are presented. Airfoil shapes are represented by nonuniform rational B-splines with appropriate regularity properties. A Navier-Stokes How solver is used to compute the flow field and to obtain aerodynamic coefficients. A design of experiment is conducted to select the most sensitive design variables among the nonuniform rational B-splines parameters to reduce their number in the final optimization process. Single-point and multipoint formulations of the optimization problem are proposed and compared. The nonuniform rational B-splines parameterization guarantees smooth optimized airfoils. The multipoint optimization formulation combined with the nonuniform rational B-splines parameterization leads to airfoils with good performance over a specified Mach range.

关键词： Shape Optimization B Splines Supercritical Airfoils Aerodynamic Coefficients Design of Experiments Aerodynamic Performance sequential quadratic programming CFD Reynolds Averaged Navier Stokes Friction Coefficient

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Dynamic verification of an optimisation algorithm for power dispatch of integrated energy systems

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FRONTIERS IN ENERGY RESEARCH 2024年 12卷

作者： Sandoval, Daniel A. Morales de la Cruz-Loredo, Ivan Saikia, Pranaynil Abeysekera, Muditha Ugalde-Loo, Carlos E. Cardiff Univ Sch Engn Cardiff Wales

The urgent need to achieve net-zero carbon emissions by 2050 has led to a growing focus on innovative approaches to producing, storing, and consuming energy. Integrated energy systems (IES) have emerged as a promising solution, capitalising on synergies between energy networks and enhancing efficiency. Such a holistic approach enables the integration of renewable energy sources and flexibility provision from one energy network to another, reducing emissions while facilitating strategies for operational optimisation of energy systems. However, emphasis has been mostly made on steady-state methodologies, with a dynamic verification of the optimal solutions not given sufficient attention. To contribute towards bridging this research gap, a methodology to verify the outcomes of an optimisation algorithm is presented in this paper. The methodology has been applied to assess the operation of a civic building in the UK dedicated to health services. This has been done making use of real energy demand data. Optimisation is aimed at improving power dispatch of the energy system by minimising operational costs and carbon emissions. To quantify potential discrepancies in power flows and operational costs obtained from the optimisation, a dynamic model of the IES that better captures real-world system operation is employed. By incorporating slow transients of thermal systems, control loops, and non-linearity of components in the dynamic model, often overlooked in traditional optimisation modules, the methodology provides a more accurate assessment of energy consumption and operational costs. The effectiveness of the methodology is assessed through model-in-the-loop co-simulations between MATLAB/Simulink and Apros alongside a series of scenarios. Results indicate significant discrepancies in power flows and operational costs between the optimisation and the dynamic model. These findings illustrate potential limitations of conventional operational optimisation modules in addressin

关键词： integrated energy system sequential quadratic programming low-carbon technologies energy storage energy efficiency optimisation dynamic modelling

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CFD OPTIMIZATION OF A THEORETICAL MINIMUM-DRAG BODY

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JOURNAL OF AIRCRAFT 1995年第1期32卷 193-198页

作者： CHEUNG, S AARONSON, P EDWARDS, T NASA Ames Research Center Moffett Field California 94035

This article describes a methodology behind coupling a fast, parabolized Navier-Stokes flow solver to a nonlinear constrained optimizer. The design parameters, constraints, grid refinement, behavior of the optimizer, and flow physics related to the CFD calculations are discussed. Pressure drag reduction in the supersonic regime of a theoretical minimum-drag body of revolution is performed. Careful selection of design variables allows the optimization process to improve the aerodynamic performance. A calculation including nonlinear and viscous effects produces a different minimum drag geometry than linear theory and results in a drag reduction of approximately 4%. Effect of grid density on the optimization process is also studied. In order to obtain accurate optimization results, CFD calculations must model physical phenomena that contribute to the optimization parameters.

关键词： Freestream Mach Number Aerodynamic Performance Pressure Coefficient Supersonic Flow Numerical Optimization sequential quadratic programming Skin Friction Drag Bow Shock Numerical Integration Perturbation Method

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APPLICATIONS OF GUDERMANNIAN NEURAL NETWORK FOR SOLVING THE SITR FRACTAL SYSTEM

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FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY 2021年第8期29卷 2150250-2150250页

作者： Sabir, Zulqurnain Umar, Muhammad Raja, Muhammad Asif Zahoor Baleanu, Dumitru Hazara Univ Dept Math & Stat Mansehra Pakistan Natl Yunlin Univ Sci & Technol Future Technol Res Ctr 123 Univ RdSect 3 Touliu 64002 Yunlin Taiwan Cankaya Univ Dept Math Ankara Turkey Inst Space Sci Magurele Romania

This study is related to explore the Gudermannian neural network (GNN) for solving a nonlinear SITR COVID-19 fractal system by using the optimization efficiencies of a genetic algorithm (GA), a global search technique and sequential quadratic programming (SQP) and a quick local search scheme, i.e. GNN-GA-SQP. The nonlinear SITR COVID-19 fractal system is dependent on four collections: "susceptible", "infected", "treatment" and "recovered". For the optimization procedures through the GNN-GA-SQP, a merit function is constructed using the nonlinear SITR COVID-19 fractal system and its corresponding initial conditions. The description of each collection of the nonlinear SITR COVID-19 fractal system is provided along with comprehensive detail. The comparison of the achieved numerical result performances of each collection of the nonlinear SITR COVID-19 fractal system is performed with the Adams results to verify the exactness of the designed computational GNN-GA-SQP. The statistical processes based on different operators are presented for 30 independent trials using 5 neurons to authenticate the consistency of the designed computational GNN-GA-SQP. Moreover, the graphs of absolute error (AE), performance indices, and convergence measures along with the boxplots and histograms are also plotted to check the stability, exactness and reliability of the designed computational GNN-GA-SQP.

关键词： Gudermannian Function SITR COVID-19 Fractal System Nonlinear Genetic Algorithm Reference Solutions sequential quadratic programming

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Intelligent computing framework to analyze the transmission risk of COVID-19: Meyer wavelet artificial neural networks

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COMPUTATIONAL BIOLOGY AND CHEMISTRY 2024年 113卷 108234页

作者： Nisar, Kottakkaran Sooppy Naz, Iqra Raja, Muhammad Asif Zahoor Shoaib, Muhammad Prince Sattam Bin Abdulaziz Univ Coll Sci & Humanities Al Kharj Dept Math Al Kharj 11942 Saudi Arabia SIMATS Saveetha Sch Engn Chennai India COMSATS Univ Islamabad Dept Math Attock Campus Islamabad Pakistan Natl Yunlin Univ Sci & Technol Future Technol Res Ctr 123 Univ RdSect 3 Yunlin 64002 Taiwan Yuan Ze Univ AI Ctr Taoyuan 320 Taiwan

The optimum control methods for the epidemiology of the COVID-19 model are acknowledged using a novel advanced intelligent computing infrastructure that joins artificial neural networks with unsupervised learningbased optimizers i.e., Genetic Algorithms (GA) and sequential quadratic programming (SQP). Unsupervised learning strategy is provided which depends on the wavelet basis's sequential deconstruction of stochastic data. The weights or selection values of neural networks are utilizing cumulative algorithms of Meyer wavelet artificial neural networks (MWANNs) optimized with global search Genetic Algorithms (GAs) and sequential quadratic programming (SQP), referred to as MWANNs-GA-SQP and the design technique is utilized to determine the COVID-19 model for five different scenarios employing different step sizes and input intervals. The findings of this research article examined that in order to minimize the total disease transmission at the lowest cost and complexity, safety, focused medical care, and exterior sterilization methods applicability. The provided data is validated through various graphical simulations, which surely authenticate the effectiveness and robustness of the proposed solver. The suggested solver, MWANNs-GA-SQP, is tested in a variety of circumstances to examine that how reliable, safe, and tolerant. Using the proposed MWANNs hubristic intelligent approach, an objective optimization function is created in feed forward neural networking to minimize the mean square error. An investigation of the hybrid GA-SQP is used to confirm the accuracy and dependability of the MWANNs model results. Mean absolute graphs have been constructed to assess the integrity and efficiency of the proposed methodology. The accuracy and reliability of the suggested method are demonstrated by constantly achieving maximum variables of analytical assessment criteria computed for a large appropriate variety of distinct trials.

关键词： Epidemiology COVID-19 sequential quadratic programming Meyer wavelet Artificial neural networks (ANN)

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Toolpath Generation for Robotic Flank Milling via Smoothness and Stiffness Optimization

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ROBOTICS AND COMPUTER-INTEGRATED MANUFACTURING 2024年 85卷

作者： Chen, Yongxue Lu, Yaoan Ding, Ye Shanghai Jiao Tong Univ Sch Mech Engn State Key Lab Mech Syst & Vibrat Shanghai 200240 Peoples R China Guangdong Univ Technol Sch Electromech Engn Guangzhou 510006 Peoples R China

Robotic flank milling has outstanding advantages in machining large-scale slender surfaces. Currently, the paths for this process are mainly generated by optimizing redundant robot degrees of freedom (DoFs) on the basis of conventional 5-axis flank milling paths. This two-step framework, however, does not enable optimal robot kinematic and dynamical performance compared to the direct generation of 6-DoF robot paths, limiting the machining efficiency and effectiveness. This paper presents an optimization method to directly generate a toolpath with six DoFs for robotic flank milling. Firstly, the kinematic model of the milling system and the representation of the 6-DoF toolpath are established. Then, the standard geometric error for flank milling that conforms to the geometric specification is defined, and an efficient algorithm based on conformal geometric algebra is proposed to solve it. On this basis, the toolpath optimization model with toolpath smoothness and robot stiffness as objective functions is established. A sequential quadratic programming algorithm is proposed to solve this highly non-linear problem based on the lexicographic order of arrays. The simulations and experiments demonstrate that the proposed method has better efficiency, robustness, and effectiveness compared with the existing methods. Due to the improvement of smoothness and stiffness, the productivity, accuracy, and finish of the machining are all enhanced.

关键词： Robotic milling Toolpath optimization Flank milling sequential quadratic programming

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Active Polynomial Chaos Expansion for Reliability-Based Design Optimization

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AIAA JOURNAL 2019年第12期57卷 5431-5446页

作者： Zhou, Yicheng Lu, Zhenzhou Northwestern Polytech Univ Sch Aeronaut POB 120 Xian 710072 Shaanxi Peoples R China

The aim of the present paper is to develop a strategy for solving reliability-based design optimization (RBDO) problems by sparse polynomial chaos expansion (PCE). Because classic sparse regression methods cannot provide the surrogate error measure that can be employed to improve the sampling performance for failure probability estimation in RBDO, Bayesian compressed sensing with state-of-the-art performance is employed to build sparse PCE in the paper. In the meanwhile, a new active learning function is proposed to adaptively select new training points. Two goals can be achieved using this criterion;that is, most of the selected training points are selected from the desired regions to approximate limit state surfaces, and these points tend to be far away from the existing points in the current design to avoid the clustering problem. Because the sparse PCEs are built in an augmented space, it is made numerically affordable to solve the RBDO problem with no extra computational cost. The computation capability of the proposed method is demonstrated by several analytical RBDO problems. Meanwhile, the design optimization of a stiffened rib of the wing edge in a certain aircraft also verifies its good engineering applicability.

关键词： Numerical Stability Cumulative Distribution Function sequential quadratic programming Finite Element Modeling Design of Experiments Mathematical Models Monte Carlo Simulation Support Vector Machine Sensitivity Analysis Iterative Algorithm

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NUMERICAL COMPUTING TO SOLVE THE NONLINEAR CORNEAL SYSTEM OF EYE SURGERY USING THE CAPABILITY OF MORLET WAVELET ARTIFICIAL NEURAL NETWORKS

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FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY 2022年第5期30卷 2240147-2240147页

作者： Wang, Bo Gomez-Aguilar, J. F. Sabir, Zulqurnain Raja, Muhammad Asif Zahoor Xia, Wei-Feng Jahanshahi, Hadi Alassafi, Madini O. Alsaadi, Fawaz E. Aba Teachers Univ Sch Elect Informat & Automat Wenchuan 623002 Peoples R China Univ Elect Sci & Technol China Sch Appl Math Chengdu 610054 Peoples R China CONACyT Tecnol Nacl Mexico CENIDET Interior Internado Palmira S-N Cuernavaca 62490 Morelos Mexico Hazara Univ Dept Math & Stat Mansehra Pakistan Natl Yunlin Univ Sci & Technol Future Technol Res Ctr 123 Univ Rd Sect 3 Touliu 64002 Yunlin Taiwan Huzhou Univ Sch Engn Huzhou 313000 Peoples R China Hangzhou Normal Univ Inst Adv Study Honoring Chen Jian Gong Hangzhou 311121 Peoples R China Univ Manitoba Dept Mech Engn Winnipeg MB R3T 5V6 Canada King Abdulaziz Univ Fac Comp & Informat Technol Dept Informat Technol Jeddah Saudi Arabia

In this study, a novel heuristic computing technique is presented to solve bioinformatics problem for the corneal shape model of eye surgery using Morlet wavelet artificial neural network optimized by the global search schemes, i.e. genetic algorithm (GA), local search technique, i.e. sequential quadratic programming (SQP) and the hybrid of GA-SQP. To measure the performance of the design network configuration, different cases based on nonlinear second-order differential equations governing the corneal model have been solved effectively. The numerical procedure of Adams method is implemented for the comparison purpose of the presented outcomes of the stochastic solver, which shows the wort Ii of the present scheme based on accuracy and convergence with negligible values of absolute error in the range 10(-7) to 10(-8). Furthermore, statistical measures are presented based on "mean absolute error", "root mean square error" and "coefficient of Theil's inequality" which additionally endorsed consistently accurate performance of integrated intelligent computing framework for solving the corneal shape model.

关键词： Morlet Wavelet Kernel Corneal Model Nonlinear Genetic Algorithm Artificial Neural Network Statistical Analysis sequential quadratic programming

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3-DIMENSIONAL SHAPE OPTIMIZATION USING THE BOUNDARY-ELEMENT METHOD

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AIAA JOURNAL 1994年第6期32卷 1295-1301页

作者： YAMAZAKI, K SAKAMOTO, J KITANO, M Kanazawa University Kanazawa 920 Japan

A practical design sensitivity calculation technique of displacements and stresses for three-dimensional bodies based on the direct differentiation method of discrete boundary integral equations is formulated in detail. Then the sensitivity calculation technique is applied to determine optimum shapes of minimum weight subjected to stress constraints, where an approximated subproblem is constructed repeatedly and solved sequentially by the mathematical programming method. The shape optimization technique suggested here is applied to determine optimum shapes of a cavity in a cube and a connecting rod.

关键词： Boundary Integral Equation Shape Optimization Sensitivity Analysis Finite Element Analysis Stress Distribution Mechanical Properties sequential quadratic programming Structural Analysis Internal Combustion Engines Nonlinear programming

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