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Decentralized Iterative Learning Controllers for Nonlinear Large-scale Systems to Track Trajectories with Different Magnitudes 被引量:3
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作者 RUAN Xiao-E CHEN Feng-Min WAN Bai-Wu 《自动化学报》 EI CSCD 北大核心 2008年第4期426-432,共7页
在为大规模工业进程的层次不变的优化编程,一种可行技术是使用真实系统的信息以便修改基于模型的最佳。在这种情形,有不同大小的步功能类型控制决定的一个序列被计算,由哪个真实系统连续地被刺激。在这份报纸,一套反复的学习控制器... 在为大规模工业进程的层次不变的优化编程,一种可行技术是使用真实系统的信息以便修改基于模型的最佳。在这种情形,有不同大小的步功能类型控制决定的一个序列被计算,由哪个真实系统连续地被刺激。在这份报纸,一套反复的学习控制器为大规模非线性的工业过程的一个班在分散的模式被嵌进层次不变的优化的过程。为每个分系统的控制器被用来产生升级的控制信号的一个序列以便与不同规模承担顺序的步骤控制决定的责任。学习控制设计的目的是连续地精制系统的短暂性能。借助于卷绕旋转积分的 Hausdorff 年轻的不平等,更新的规则的集中在 Lebesgue-p 标准的意义被分析。集中上的非线性和相互作用的发明被讨论。建议控制计划的有效性和有效性被一些模拟表明。 展开更多
关键词 恒星 非线性控制系统 轨迹 星等
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Optimal Control for Nonlinear Interconnected Large-scale Systems: A Successive Approximation Approach 被引量:30
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作者 唐功友 孙亮 《自动化学报》 EI CSCD 北大核心 2005年第2期248-254,共7页
The optimal control problem for nonlinear interconnected large-scale dynamic systems is considered. A successive approximation approach for designing the optimal controller is proposed with respect to quadratic perfor... The optimal control problem for nonlinear interconnected large-scale dynamic systems is considered. A successive approximation approach for designing the optimal controller is proposed with respect to quadratic performance indexes. By using the approach, the high order, coupling,nonlinear two-point boundary value (TPBV) problem is transformed into a sequence of linear decoupling TPBV problems. It is proven that the TPBV problem sequence uniformly converges to the optimal control for nonlinear interconnected large-scale systems. A suboptimal control law is obtained by using a finite iterative result of the optimal control sequence. 展开更多
关键词 非线性 互联大系统 最优控制 逐次逼近法
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Investigation on nonlinear multi-scale effects of unsteady flow in hydraulic fractured horizontal shale gas wells 被引量:3
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作者 Jiaxuan LIU Xinchun SHANG Weiyao ZHU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第2期181-192,共12页
A unified mathematical model is established to simulate the nonlinear unsteady percolation of shale gas with the consideration of the nonlinear multi-scale effects such as slippage, diffusion, and desorption. The cont... A unified mathematical model is established to simulate the nonlinear unsteady percolation of shale gas with the consideration of the nonlinear multi-scale effects such as slippage, diffusion, and desorption. The continuous inhomogeneous models of equivalent porosity and permeability are proposed for the whole shale gas reservoir includ- ing the hydraulic fracture, the micro-fracture, and the matrix regions. The corresponding semi-analytical method is developed by transforming the nonlinear partial differential governing equation into the integral equation and the numerical discretization. The nonlinear multi-scale effects of slippage and diffusion and the pressure dependent effect of desorption on the shale gas production are investigated. 展开更多
关键词 shale gas nonlinear effect multi-scale percolation inhomogeneous perme ability integral equation
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Optimal tracking control for nonlinear large-scale systems with persistent disturbances 被引量:1
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作者 Ruichun TANG Xianmin LU +1 位作者 Yili ZHAI Cunqun GONG 《控制理论与应用(英文版)》 EI 2010年第4期515-520,共6页
This paper studies the optimal control with zero steady-state error problem for nonlinear large-scale systems affected by external persistent disturbances.The nonlinear large-scale system is transformed into N nonline... This paper studies the optimal control with zero steady-state error problem for nonlinear large-scale systems affected by external persistent disturbances.The nonlinear large-scale system is transformed into N nonlinear subsystems with interconnect terms.Based on the internal model principle,a disturbance compensator is constructed such that the ith subsystem with external persistent disturbances is transformed into an augmented subsystem without disturbances.According to the sensitivity approach,the optimal tracking control law for the ith nonlinear subsystem can be obtained.The optimal tracking control law for the nonlinear large-scale systems can be obtained.A numerical simulation shows that the method is effective. 展开更多
关键词 nonlinear systems Large-scale systems Persistent disturbances Optimal tracking control Sensitivity approach
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Oscillation of Second-order Nonlinear Dynamic Equation on Time Scales 被引量:7
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作者 YANG Jia-shan 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第2期172-179,共8页
: The oscillation for a class of second order nonlinear variable delay dynamic equation on time scales with nonlinear neutral term and damping term was discussed in this article. By using the generalized Riccati tech... : The oscillation for a class of second order nonlinear variable delay dynamic equation on time scales with nonlinear neutral term and damping term was discussed in this article. By using the generalized Riccati technique, integral averaging technique and the time scales theory, some new sufficient conditions for oscillation of the equation are proposed. These results generalize and extend many knownresults for second order dynamic equations. Some examples are given to illustrate the main results of this article. 展开更多
关键词 time scales dynamic equations nonlinear neutral term damping term variable delay Riccati transformation OSCILLATION
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ROBUST OBSERVER DESIGN FOR A CLASS OF UNCERTAIN NONLINEAR LARGE SCALE SYSTEMS *
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作者 姜斌 王江 王先来 《Transactions of Tianjin University》 EI CAS 1996年第2期32+29-31,共4页
In this paper, a mathematic description of a class of uncertain nonlinear large scale systems based on some practical application is given. A designing method to construct observers for su... In this paper, a mathematic description of a class of uncertain nonlinear large scale systems based on some practical application is given. A designing method to construct observers for such kind of nonlinear composite systems is developed. The unknown parameters and disturbances are assumed to be neither linear nor matched. A numerical example is used to illustrate the efficiency of our results. 展开更多
关键词 nonlinear large scale systems uncertainty observer design
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Robust non-fragile control for discrete-delay nonlinear large-scale systems
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作者 吴忠强 李卓 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2010年第4期481-485,共5页
Time-delays,due to the information transmission between subsystems,naturally exist in large-scale systems and the existence of the delay is frequently a source of instability. This paper considers the problems of robu... Time-delays,due to the information transmission between subsystems,naturally exist in large-scale systems and the existence of the delay is frequently a source of instability. This paper considers the problems of robust non-fragile fuzzy control for a class of uncertain discrete nonlinear large-scale systems with time-delay and controller gain perturbations described by T-S fuzzy model. An equivalent T-S fuzzy model is represented for discrete-delay nonlinear large-scale systems. A sufficient condition for the existence of such non-fragile controllers is further derived via the Lyapunov function and the linear matrix inequality( LMI) approach. Simulation results demonstrate the feasibility and the effectiveness of the proposed design and the proper stabilization of the system in spite of controller gain variations and uncertainties. 展开更多
关键词 non-fragile control discrete-delay nonlinear large-scale systems T-S fuzzy model linear matrix inequality
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An Adaptive Sliding Mode Tracking Controller Using BP Neural Networks for a Class of Large-scale Nonlinear Systems
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作者 刘子龙 田方 张伟军 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第6期753-758,共6页
A new type controller, BP neural-networks-based sliding mode controller is developed for a class of large-scale nonlinear systems with unknown bounds of high-order interconnections in this paper. It is shown that dece... A new type controller, BP neural-networks-based sliding mode controller is developed for a class of large-scale nonlinear systems with unknown bounds of high-order interconnections in this paper. It is shown that decentralized BP neural networks are used to adaptively learn the uncertainty bounds of interconnected subsystems in the Lyapunov sense, and the outputs of the decentralized BP neural networks are then used as the parameters of the sliding mode controller to compensate for the effects of subsystems uncertainties. Using this scheme, not only strong robustness with respect to uncertainty dynamics and nonlinearities can be obtained, but also the output tracking error between the actual output of each subsystem and the corresponding desired reference output can asymptotically converge to zero. A simulation example is presented to support the validity of the proposed BP neural-networks-based sliding mode controller. 展开更多
关键词 BP NEURAL networks SLIDING mode control LARGE-scale nonlinear systems uncertainty dynamics
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A Nonlinear Sub-grid Scale Model for Compressible Turbulent Flow
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作者 Li Bin Wu Songping 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第6期495-500,共6页
The governing equations for large eddy simulation (LES) are obtained by filtering the Navier-Stokes (N-S) equations with standard (non-Favre filtering) spatial filter function. The filtered scale stress due to t... The governing equations for large eddy simulation (LES) are obtained by filtering the Navier-Stokes (N-S) equations with standard (non-Favre filtering) spatial filter function. The filtered scale stress due to the standard filtering is then reconstructed by using the Taylor series expansion. The loss of information due to truncating the expansion up to the first derivative term is modeled by a dynamic nonlinear model (DNM), which is free from any empirical constant and wall damping function. The DNM avoids the singularity of the model and shows good local stability. Unlike the conventional dynamic Smagorinsky model (DSM), the DNM does not require the plane averaging and reduces the computational cost. The turbulent flow over a double ellipsoid for Reynolds number of 4.25 × 10^6 and Mach number of 8.02 is simulated numerically to validate the proposed approach. The results are compared with experiment data, as well as the data of Reynolds averaged numerical simulation (RANS). 展开更多
关键词 large eddy simulation subgrid scale compressible flow nonlinear
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The Multi-scale Method for Solving Nonlinear Time Space Fractional Partial Differential Equations
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作者 Hossein Aminikhah Mahdieh Tahmasebi Mahmoud Mohammadi Roozbahani 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2019年第1期299-306,共8页
In this paper, we present a new algorithm to solve a kind of nonlinear time space-fractional partial differential equations on a finite domain. The method is based on B-spline wavelets approximations, some of these fu... In this paper, we present a new algorithm to solve a kind of nonlinear time space-fractional partial differential equations on a finite domain. The method is based on B-spline wavelets approximations, some of these functions are reshaped to satisfy on boundary conditions exactly. The Adams fractional method is used to reduce the problem to a system of equations. By multiscale method this system is divided into some smaller systems which have less computations. We get an approximated solution which is more accurate on some subdomains by combining the solutions of these systems. Illustrative examples are included to demonstrate the validity and applicability of our proposed technique, also the stability of the method is discussed. 展开更多
关键词 Adams FRACTIONAL METHOD B-SPLINE WAVELETS MULTI-scale METHOD nonlinear FRACTIONAL partial differential equations
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THE METHOD OF MULTIPLE SCALES APPLIED TO THE NONLINEAR STABILITY PROBLEM OF A TRUNCATED SHALLOW SPHERICAL SHELL OF VARIABLE THICKNESS WITH THE LARGE GEOMETRICAL PARAMETER
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作者 KANG Sheng-liang(康盛亮) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第10期1198-1209,共12页
Using the modified method of multiple scales, the nonlinear stability of a truncated shallow spherical shell of variable thickness with a nondeformable rigid body at the center under compound loads is investigated. Wh... Using the modified method of multiple scales, the nonlinear stability of a truncated shallow spherical shell of variable thickness with a nondeformable rigid body at the center under compound loads is investigated. When the geometrical parameter k is larger, the uniformly valid asymptotic solutions of this problem are obtained and the remainder terms are estimated. 展开更多
关键词 shallow shell of variable thickness nonlinear stability modified method of multiple scales
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A SPARSE SUBSPACE TRUNCATED NEWTON METHOD FOR LARGE-SCALE BOUND CONSTRAINED NONLINEAR OPTIMIZATION
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作者 倪勤 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1997年第1期27-37,共11页
In this paper we report a sparse truncated Newton algorithm for handling large-scale simple bound nonlinear constrained minimixation problem. The truncated Newton method is used to update the variables with indices ou... In this paper we report a sparse truncated Newton algorithm for handling large-scale simple bound nonlinear constrained minimixation problem. The truncated Newton method is used to update the variables with indices outside of the active set, while the projected gradient method is used to update the active variables. At each iterative level, the search direction consists of three parts, one of which is a subspace truncated Newton direction, the other two are subspace gradient and modified gradient directions. The subspace truncated Newton direction is obtained by solving a sparse system of linear equations. The global convergence and quadratic convergence rate of the algorithm are proved and some numerical tests are given. 展开更多
关键词 The TRUNCATED NEWTON method LARGE-scale SPARSE problems BOUND constrained nonlinear optimization.
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A two scaled numerical method for global analysis of high dimensional nonlinear systems
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作者 Jun Jiang) MOE Key Laboratory of Strength and Vibration, Xi’an Jiaotong University, Xi’an 710079, China 《Theoretical & Applied Mechanics Letters》 CAS 2011年第6期45-50,共6页
This paper first analyzes the features of two classes of numerical methods for global analysis of nonlinear dynamical systems, which regard state space respectively as continuous and discrete ones. On basis of this un... This paper first analyzes the features of two classes of numerical methods for global analysis of nonlinear dynamical systems, which regard state space respectively as continuous and discrete ones. On basis of this understanding it then points out that the previously proposed method of point mapping under cell reference (PMUCR), has laid a frame work for the development of a two scaled numerical method suitable for the global analysis of high dimensional nonlinear systems, which may take the advantages of both classes of single scaled methods but will release the difficulties induced by the disadvantages of them. The basic ideas and main steps of implementation of the two scaled method, namely extended PMUCR, are elaborated. Finally, two examples are presented to demonstrate the capabilities of the proposed method. 展开更多
关键词 nonlinear systems global analysis multi-scaled numerical methods point mapping cell mapping point mapping under cell reference
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具有正负系数和非线性中立项的3阶时滞动力方程的振动性
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作者 赵春茹 《安徽大学学报(自然科学版)》 北大核心 2026年第1期34-40,共7页
研究一类具有非线性中立项的3阶时滞动力方程振动性和渐近性.首先应用积分的不等式技巧得出具有次线性中立项的动力方程振动性和渐近性的充分条件,然后应用不等式技巧得出具有超线性中立项和负系数的动力方程振动性的充分条件.论文的定... 研究一类具有非线性中立项的3阶时滞动力方程振动性和渐近性.首先应用积分的不等式技巧得出具有次线性中立项的动力方程振动性和渐近性的充分条件,然后应用不等式技巧得出具有超线性中立项和负系数的动力方程振动性的充分条件.论文的定理就非线性中立项而言提供了新方法.最后给出例子验证主要结果. 展开更多
关键词 振动性 非线性中立项 3阶动力方程 时间轴
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ADAPTIVE TRACKING CONTROL FOR A CLASS OF NONLINEAR COMPOSITE SYSTEMS *
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作者 姜斌 万健如 +1 位作者 王先来 王江 《Transactions of Tianjin University》 EI CAS 1998年第1期88-91,共4页
In this paper, the problem of adaptive tracking control for a class of nonlinear large scale systems with unknown parameters entering linearly is discussed. Based on the theory of input output linearization of nonli... In this paper, the problem of adaptive tracking control for a class of nonlinear large scale systems with unknown parameters entering linearly is discussed. Based on the theory of input output linearization of nonlinear systems, direct adaptive control schemes are presented to achieve bounded tracking. The proposed control schemes are robust with respect to the uncertainties in interconnection structure as well as subsystem dynamics. A numerical example is given to illustrate the efficiency of this method. 展开更多
关键词 nonlinear large scale systems adaptive tracking control input output linearization
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A Novel Nonlinear Scaling Method for Optimal Motion Cueing Algorithm in Flight Simulator 被引量:2
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作者 ZHU Daoyang DUAN Shaoli +1 位作者 SHANG Jinqiu GUO Ping 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2020年第5期452-460,共9页
Motion cueing algorithm plays a key role in simulator motion reproduction and improves the realism of movement sensation by combining with the human vestibular system.It is well established that scaling&limiting s... Motion cueing algorithm plays a key role in simulator motion reproduction and improves the realism of movement sensation by combining with the human vestibular system.It is well established that scaling&limiting should be used to decrease the amplitude of the acceleration and angular velocity signals for making full use of limited workspace of motion platform.A novel nonlinear scaling method based on a third-order polynomial and back propagation(BP)neural networks for the motion cueing algorithm is proposed in this paper.The third-order polynomial method is applied to the low amplitude segment of the input signal to minimize the trigger delay of the sensation acceleration;in the high amplitude segment,the BP neural network is used to adaptively adjust the scaling factor of the input signal,to avoid washout displacement and angular displacement beyond the boundary of the workspace.The simulation experiment is verified in the longitudinal/pitch direction for flight simulator,and the result implies that the proposed method not only can overcome the problem of constant scaling parameter and improve motion platform workspace utilization,but also reduce the false cues during the motion simulation process. 展开更多
关键词 optimal motion cueing algorithm nonlinear scaling human vestibular system dynamic fidelity
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Modified nonlinear chirp scaling algorithm for curvilinear trajectory synthetic aperture radar 被引量:1
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作者 王建涛 秦玉亮 +2 位作者 范波 王宏强 黎湘 《Journal of Central South University》 SCIE EI CAS 2014年第7期2751-2758,共8页
The original nonlinear chirp scaling(NCS) algorithm was extended for high precision processing of the highly squinted curvilinear trajectory synthetic aperture radar(CTSAR).Based on the analysis of slant range model a... The original nonlinear chirp scaling(NCS) algorithm was extended for high precision processing of the highly squinted curvilinear trajectory synthetic aperture radar(CTSAR).Based on the analysis of slant range model and the frequency spectrum characteristics of the echo signal,a novel nonlinear chirp scaling function and more complex phase compensation factors with both velocity and acceleration parameters were proposed in the new algorithm for accommodation to curvilinear trajectory.The processing flow and computational complexity of modified NCS algorithm were fundamentally the same as the original NCS algorithm.However,the higher order phase compensation,range cell migration correction(RCMC) and range-variant secondary range compression(SRC) caused by the non-linear aperture and the severe range-azimuth coupling were accomplished accurately and efficiently without interpolation.Simulation results show that data acquired with a curvilinear aperture and a squint angle up to about 50° for X-band can be processed with no evident degradation of impulse response function. 展开更多
关键词 synthetic aperture radar nonlinear chirp scaling curvilinear trajectory ACCELERATION
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Nonlinear Dimensionality Reduction and Data Visualization:A Review 被引量:4
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作者 Hujun Yin 《International Journal of Automation and computing》 EI 2007年第3期294-303,共10页
Dimensionality reduction and data visualization are useful and important processes in pattern recognition. Many techniques have been developed in the recent years. The self-organizing map (SOM) can be an efficient m... Dimensionality reduction and data visualization are useful and important processes in pattern recognition. Many techniques have been developed in the recent years. The self-organizing map (SOM) can be an efficient method for this purpose. This paper reviews recent advances in this area and related approaches such as multidimensional scaling (MDS), nonlinear PC A, principal manifolds, as well as the connections of the SOM and its recent variant, the visualization induced SOM (ViSOM), with these approaches. The SOM is shown to produce a quantized, qualitative scaling and while the ViSOM a quantitative or metric scaling and approximates principal curve/surface. The SOM can also be regarded as a generalized MDS to relate two metric spaces by forming a topological mapping between them. The relationships among various recently proposed techniques such as ViSOM, Isomap, LLE, and eigenmap are discussed and compared. 展开更多
关键词 Dimensionality reduction nonlinear data projection multidimensional scaling self-organizing maps nonlinear PCA principal manifold
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Small-time scale network traffic prediction based on a local support vector machine regression model 被引量:10
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作者 孟庆芳 陈月辉 彭玉华 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第6期2194-2199,共6页
In this paper we apply the nonlinear time series analysis method to small-time scale traffic measurement data. The prediction-based method is used to determine the embedding dimension of the traffic data. Based on the... In this paper we apply the nonlinear time series analysis method to small-time scale traffic measurement data. The prediction-based method is used to determine the embedding dimension of the traffic data. Based on the reconstructed phase space, the local support vector machine prediction method is used to predict the traffic measurement data, and the BIC-based neighbouring point selection method is used to choose the number of the nearest neighbouring points for the local support vector machine regression model. The experimental results show that the local support vector machine prediction method whose neighbouring points are optimized can effectively predict the small-time scale traffic measurement data and can reproduce the statistical features of real traffic measurements. 展开更多
关键词 network traffic small-time scale nonlinear time series analysis support vector machine regression model
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Approximate and numerical analysis of nonlinear forced vibration of axially moving viscoelastic beams 被引量:15
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作者 Hu Ding Li-Qun Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第3期426-437,共12页
Steady-state periodical response is investigated for an axially moving viscoelastic beam with hybrid supports via approximate analysis with numerical confirmation. It is assumed that the excitation is spatially unifor... Steady-state periodical response is investigated for an axially moving viscoelastic beam with hybrid supports via approximate analysis with numerical confirmation. It is assumed that the excitation is spatially uniform and temporally harmonic. The transverse motion of axially moving beams is governed by a nonlinear partial-differential equation and a nonlinear integro-partial-differential equation. The material time derivative is used in the viscoelastic constitutive relation. The method of multiple scales is applied to the governing equations to investigate primary resonances under general boundary conditions. It is demonstrated that the mode uninvolved in the resonance has no effect on the steady-state response. Numerical examples are presented to demonstrate the effects of the boundary constraint stiffness on the amplitude and the stability of the steady-state response. The results derived for two governing equations are qualitatively the same,but quantitatively different. The differential quadrature schemes are developed to verify those results via the method of multiple scales. 展开更多
关键词 Axially moving beam. nonlinearity . Mate-rial time derivative . Method of multiple scales. Differentialquadrature method
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