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Nonlinear vibration analysis of hyperelastic and dielectric microbeams with a control parameter using nonlinear normal modes

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NONLINEAR DYNAMICS 2025年第3期113卷 2045-2059页

作者： Farvandi, Ahad Mohammadi, Ardeshir Karami Shahrood Univ Technol Dept Mech Engn Shahrood Iran

This study focuses on applying a nonlinear normal modes (NNM) method to analyze the nonlinear vibrations and static bifurcation of hyperelastic and dielectric microbeams in the presence of a control parameter. The microbeam mathematical model is based on the Euler-Bernoulli beam theory and von K & aacute;rm & aacute;n nonlinearity, and the strain energy of hyperelastic material is formulated according to the Yeoh model. The applied NNM method is based on an asymptotic approach to determine an invariant manifold. To achieve a reduced-order model, a master mode is selected and the effect of other modes is included through the manifold. The research encompasses three case studies. The first case examines a non-sandwiched hyperelastic microbeam subjected to an axial compressive force as the control parameter. The second and third case studies investigate hyperelastic dielectric microbeams sandwiched between conductive electrode layers. In the second case, the electrodes are made of hydrogel based on the Mooney-Rivlin hyperelastic model, while in the third case, the electrodes are made of aluminum. In both cases, voltage serves as the control parameter. In all three cases, static bifurcation diagrams are depicted and critical values of the control parameters are identified. Vibration analysis is performed for sub-critical control parameter values, where vibrations occur around the unbuckled state of the microbeam, and the effect of the control parameter on the vibration responses and frequencies is investigated. The first case study compares the accuracy of the NNM method with three-mode and single-mode Galerkin solutions, demonstrating close alignment with the three-mode response. The third case highlights the ability of the NNM method to detect internal resonance. Overall, this study highlights the advantages of NNM-based reduced-order models for efficiently predicting the dynamic behavior of hyperelastic microbeams in MEMS applications, providing useful insights for t

关键词： Nonlinear normal modes Hyperelastic microbeam Dielectric elastomer control parameter Static bifurcation Internal resonance

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control parameter estimation in a semi-linear parabolic inverse problem using a high accurate method

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APPLIED MATHEMATICS AND COMPUTATION 2011年第5期218卷 1798-1804页

作者： Davoodi, F. Nejad, A. Abbas Shahrezaee, A. Maghrebi, M. J. Shahrood Univ Technol Fac Mech Engn Shahrood Iran Alzahra Univ Dept Math Sci Tehran Iran

Parabolic inverse problems have an important role in many branches of science and technology. The aim of this research work is to solve these classes of equations using a high order compact finite difference scheme. We consider the following inverse problem for finding u(x, t) and p(t) governed by u(t) = u(xx) + p(t)u + phi(x, t) with an over specified condition inside the domain. Spatial derivatives are approximated using central difference scheme. The time advancement of the simulation is performed using a "third order compact Runge-Kutta method". The convergence orders for the approximation of both u and p are of o(k(3) + h(2)) which improves the results obtained in the literature. An exact test case is used to evaluate the validity of our numerical analysis. We found that the accuracy of the results is better than that of previous works in the literature. (C) 2011 Elsevier Inc. All rights reserved.

关键词： Inverse problem Parabolic equation control parameter Compact finite difference Compact Runge-Kutta

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control parameter Stability Domain of BBMC Speed control System with Finite-Time control

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ELECTRIC POWER COMPONENTS AND SYSTEMS 2023年第6期51卷 593-603页

作者： Zhang, Ruirui Zhang, Xiaoping Zhong, Daxu Hunan Univ Sci & Technol Natl Local Joint Engn Lab Marine Mineral Resources Xiangtan 411201 Peoples R China

The buck-boost matrix converter (BBMC) asynchronous motor speed control system based on finite time control has a good speed control performance, but its system stability is closely related to the selection of its control parameters. Therefore, a method for determining the stability region of control parameters is proposed. The discrete iterative mapping model of the BBMC speed control system is established, and the control function of the BBMC speed control system based on finite time control is determined. The BBMC output voltage sampling distribution diagram is used to analyze the influence of each control parameter in the finite time control on the stability of the speed control system. On this basis, the study determined the value range of each control parameter to realize the stable operation of the system. Finally, the correctness of the above theoretical analysis was verified through the BBMC output voltage waveform diagram and experiments. The stability region of control parameters can effectively ensure the stable operation of BBMC speed control system based on finite time control.

关键词： buck-boost matrix converter speed regulation system finite time control control parameter stable region

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control parameter Extraction Model for Reconfigurable Bandpass Filter Based on Bayesian Optimized Multiple-Output XGBoost

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IEEE MICROWAVE AND WIRELESS TECHNOLOGY LETTERS 2024年第3期34卷 263-266页

作者： Shi, Jian Dong, Jiancheng Wang, Zhenyu Liu, Bin Yang, Tao Wang, Yong Wang, Sheng Shen, Jihong Harbin Engn Univ Coll Intelligent Syst Sci & Engn Harbin 150001 Peoples R China Res Ctr Adv RF Chips & Syst Nanhu Lab Jiaxing 314001 Peoples R China Univ Elect Sci & Technol China Sch Informat & Commun Engn Chengdu 610054 Peoples R China Univ Elect & Sci Technol China Sch Elect Sci & Engn Chengdu 610054 Sichuan Peoples R China Northern Inst Elect Equipment Beijing 100091 Peoples R China

This letter proposes a control parameter extraction (CPE) model for the reconfigurable bandpass filter (RBPF) to achieve fast reconfiguration of center frequency and broadband. The CPE model consists of an automatic hyperparameter generation (AHG) module and a multioutput XGBoost (MO-XGB) module. AHG, based on Bayesian optimization, is used to generate the MO-XGB module hyperparameters. Through experiments on the fabricated circuit, the model extracted the control parameters of RBPFs in 15 ms with root mean square error (RMSE) of 0.0098 and 0.0129 for center frequency and bandwidth, respectively. Therefore, the model's effectiveness has been proven.

关键词： Integrated circuit modeling Optimization Microwave filters Bayes methods Microwave circuits Band-pass filters Predictive models Bayesian optimization control parameter reconfigurable bandpass filter (RBPF) XGBoost (XGB)

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Determination of temperature distribution and control parameter in a two-dimensional parabolic inverse problem with overspecified data

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Chinese Physics B 2011年第10期20卷 1-7页

作者：李福乐张洪谦 College of Science and Information Qingdao Agricultural University

In this paper, we present a new algorithm to solve a two-dimensional parabolic inverse problem with a source parameter, which appears in many physical phenomena. A linearized compact difference scheme for this problem is constructed using the finite difference method. The discretization accuracy is second-order in time and fourth-order in space. We obtain the unique solvability and present an alternating direction implicit algorithm to solve this difference scheme. The results of numerical experiments are presented to demonstrate the accuracy of this algorithm.

关键词： control parameter temperature distribution finite difference scheme solvability

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control parameter Optimization for Autonomous Vehicle Software Using Virtual Prototyping 28

Control Parameter Optimization for Autonomous Vehicle Softwa...

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28th IEEE International Symposium on Software Reliability Engineering

作者： Dai, Siyuan Hite, Joseph Masuda, Takato Kashiba, Yusuke Arechiga, Nikos Shiraishi, Shinichi Eisele, Scott Scott, Jason Bapty, Ted Toyota InfoTechnol Ctr 465 Bernardo Ave Mountain View CA 94043 USA Vanderbilt Univ 1025 16th Ave South Nashville TN 37212 USA

ISBN: (纸本)9781538623879

Reliability and safety are important properties in the development of complex cyber-physical systems such as autonomous vehicles. Achieving a reliable autonomous vehicle is a challenging problem, as the unpredictability of the environment demands a reliable design methodology. Additionally, current testing procedures for ADAS features on vehicles are exhausting and time-consuming, so that a better way to do testing is required. In order to address these challenges, we propose a co-simulation tool-chain which integrates multiple simulation environments, optimizes the control parameters of autonomous vehicle software based on metrics, and visualizes the vehicle behavior using a video game engine.

关键词： Solid modeling Vehicle dynamics Object oriented modeling Acceleration Measurement Engines Mathematical model Object oriented modeling Engines entity modeling Autonomous Vehicles Vehicle dynamics Virtual prototyping control parameter acceleration Mathematical Model Vehicle performance EXHAUSTING Property development advanced driver assistance systems (ADAS)

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A greedy MLPG method for identifying a control parameter in 2D parabolic PDEs

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INVERSE PROBLEMS IN SCIENCE AND ENGINEERING 2018年第11期26卷 1676-1694页

作者： Takhtabnoos, Fariba Shirzadi, Ahmad Persian Gulf Univ Dept Math Bushehr Iran

In this paper, we consider coefficient inverse problems, which are associated with the identification of unknown time dependent control parameter and unknown solution of two-dimensional parabolic inverse problem with overspecialization at a point in the spatial domain. After suitable finite difference approximation of time variable, an MLPG method is used for spatial discretization. To improve the efficiency of the MLPG method, a greedy algorithm is used. In fact, using the greedy algorithm, we avoid using more points from the data site than absolutely necessary and therefore, the method becomes more efficient. Comparison of the different kind of point selection and the effect of noisy data are performed for four test problems while our last test problem considers a problem with unknown solution. The results reveal that the method is efficient.

关键词： MLPG control parameter radial basis functions greedy algorithm inverse problem

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Determination of low-temperature crack control parameter of binding asphalt materials based on gray correlation analysis

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CONSTRUCTION AND BUILDING MATERIALS 2019年 217卷 226-233页

作者： Zheng, Chuanfeng Li, Ruiming Hu, Mingjun Zou, Linlin Jilin Univ Coll Construct Engn Changchun 130026 Jilin Peoples R China Tongji Univ Minist Educ Key Lab Rd & Traff Engn Shanghai 200092 Peoples R China

Convenient evaluation indexes for the low-temperature cracking of matrix asphalt, asphalt mastic, and asphalt-fine aggregate combination under different low-temperature conditions are determined. On the basis of bending failure test, the stress-strain curves of the three asphalt materials under different low-temperature conditions are ascertained to obtain the critical value of the bending strain energy density, which can effectively characterize the low-temperature crack resistance. On the basis of gray relational analysis, the correlation between the critical value of the bending strain energy density of the above-mentioned materials and their ultimate bending failure strength and strain under low-temperature conditions is determined, and the reasonable strength or strain index of different materials at dissimilar temperatures is acquired. Experimental results show that the three asphalt materials exhibit different low-temperature performance changes due to dissimilar material ratios. The changes of asphalt mastic and matrix asphalt are similar, whereas the change of the asphalt-fine aggregate combination differs from those of the two. Gray correlation analysis results show that, for the matrix asphalt and asphalt mastic, the critical fitting effect of ultimate bending failure strength with the bending strain energy density is better at 0 degrees C to -10 degrees C. Thus, the ultimate bending failure strength can be reasonably used as the low-temperature cracking control index. Under the condition of -10 degrees C to -30 degrees C, the ultimate bending failure strain can be considered the evaluation index of low-temperature cracking. For the asphalt-fine aggregate combination, the deformation capacity can be suitably used as the evaluation method of low-temperature cracking in the entire low-temperature range of 0 degrees C to -30 degrees C. These results simplify the evaluation method of low-temperature cracking performance of asphalt materials, which is importan

关键词： Asphalt mastic Asphalt-aggregate Index of flexural strain energy density Gray correlation analysis Low-temperature crack control parameter

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Finding a control parameter in one-dimensional parabolic equations

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APPLIED MATHEMATICS AND COMPUTATION 2003年第2-3期135卷 491-503页

作者： Dehghan, M Amirkabir Univ Technol Fac Math & Comp Sci Dept Appl Math Tehran 15914 Iran

An inverse problem concerning diffusion equation with source control parameter is' considered. Several finite difference schemes are presented for identifying the control parameter which produces at each time a desired temperature at a given point in a spatial domain. These schemes are based on the second-order 3-point forward time centred space (FTCS) explicit formula, and the fourth-order 5-point FTCS explicit scheme, and the second-order 3-point backward time centred space (BTCS) implicit technique and the fourth-order (3,3) Crandall's implicit formula. The 5-point FTCS scheme has a bounded range of stability, but its fourth-order accuracy is significant. The 3-point BTCS method uses less central processor (CPU) time than the (3,3) Crandall's technique, but it is only second-order accurate. The basis of analysis of the finite difference equations considered here is the modified equivalent partial differential equation approach, developed from the 1974 work of Warming and Hyett. This allows direct and simple comparison of the errors associated with the equations as well as providing a means to develop more accurate finite difference schemes. The results of a numerical experiment are presented, and accuracy and the CPU time needed for the parabolic inverse problem are discussed. (C) 2002 Elsevier Science Inc. All rights reserved.

关键词： finite difference methods control parameter diffusion processes temperature overspecification parabolic partial differential equations CPU time modified equivalent partial differential equation

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Fourth-order techniques for identifying a control parameter in the parabolic equations

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INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE 2002年第4期40卷 433-447页

作者： Dehghan, M Amirkabir Univ Technol Fac Math & Comp Sci Dept Appl Math Tehran 15914 Iran Inst Studies Theoret Phys & Math IPM Tehran Iran

This paper considers the problem of finding u = u (x, y, t) and p = p(t) which satisfy u(t) = u(xx) + u(yy) +p(t)u + phi in R x (0,T], u(x,y,0) =f(x,y), (x,y) epsilon R = [0,1] x [0, 1], u is known on the boundary of R and also u (x(0), y(0), t) = E(t) 0 less than or equal to t less than or equal to T, where E(t) is known and (x(0), y(0)) is a given point of R. Three different finite difference schemes are developed for identifying the control parameter p(t), in this two-dimensional diffusion equation. These schemes are considered for identifying the control parameter which produces, at any given time, a desired temperature distribution at a given point in the above spatial domain. The numerical methods discussed are based on the 13-point forward time centred space (FTCS) explicit finite difference formula, and the (3,9) alternating direction implicit (denoted ADI) finite difference scheme, and the (9, 9) fully implicit finite difference technique. These schemes have the fourth-order accuracy with respect to the spatial grid size. The (1, 13) FTCS finite difference scheme has a bounded range of stability, but the (3 9) ADI formula and the (9,9) fully implicit finite difference method are unconditionally stable. The results of numerical experiments are presented, and accuracy and central processor (CPU) times needed for each of the methods are discussed. The (1, 13) FTCS scheme and the (3,9) ADI technique use less CPU times than the (9, 9) fully implicit finite difference method. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： control parameter explicit schemes parabolic partial differential equations finite difference techniques alternating direction implicit formula numerical differentiation fully implicit methods

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