Most cited articles

1 Advances in dynamics of rigid-flexible coupling system

Hong Jiazhen , You Chaolan

2004, 2(2):1-6.

[Abstract](1452) [HTML](0) [PDF 0.00 Byte](1932) [Cited by](16)

Abstract:
This paper first gives a brief review about the three phases of the research of flexible multi-body system dynamics.Then in order to solve the deficiency in the traditional zero-order approach coupling model,a new modeling theory is proposed,and the discretizing method and experiment about "dynamics stiffening" problem and rigid-flexible coupling dynamics problem are investigated based on the new one-order approach coupling model.A set of experiment platform used for the theoretical study and the discovery of dynamic phenomenon is designed and built.Some research results are introduced.Some research targets are given at the end of this paper.

2 Analytical structural mechanics and finite element

Zhong Wanxie

2004, 2(4):1-8.

[Abstract](791) [HTML](0) [PDF 0.00 Byte](1884) [Cited by](16)

Abstract:
Traditionally,analytical mechanics is described by means of dynamics,and the common foundation for structural mechanics and optimal control is analytical mechanics.So,under the framework of structural mechanics or optimal control theory,there should also be a whole set of analytical mechanics theory,which we define as analytical structural mechanics.A conservative system can be described with the Hamilton system methodology,and its characteristic is the symplectic conservation,which is the most important feature of conservative system.The finite element method was initiated from structural mechanics,and its element stiffness matrices should be symmetric,which is,in fact,the symplectic conservation.Based on the fact that the interval deformation energy depends only on the two end displacements vector,we derive the Lagrange and Poisson brackets analytically,the symplectic duality system,the canonical equations,and the canonical transformations,etc.

3 Linear feedback control for synchronization of Liu chaotic system

Chen Baoying

2006, 4(1):1-4.

[Abstract](807) [HTML](0) [PDF 0.00 Byte](1820) [Cited by](16)

Abstract:
This paper studied the chaotic synchronization of a new chaotic system Liu chaotic system. Based on the Lyapunov stable theory, linear single variable and multivariable feedback control methods were given. The two methods can both achieve chaotic synchronization of Liu chaotic system efficiently. Compared with nonlinear controls, the two linear controls have simpler structures and can be obtained more easily. Finally, the numerical simulation results verified the effectiveness of the two methods.

4 Chaos and its forming mechanism of a new Lorenzlike system

Wang Lin , Ni Qiao , Liu Pan , Huang Yuying

2005, 3(4):1-6.

[Abstract](988) [HTML](0) [PDF 0.00 Byte](1763) [Cited by](11)

Abstract:
This article introduced a new Lorenzlike system of threedimensional quadratic autonomous ordinary differential equations. For theoretical analysis, the Lyapunov criterion was applied to study the stability of the equalibria of the system. Based on this, numerical simulations indicated that the considered system may display abundant dynamical behaviour, such as chaotic and various periodic motions. Moreover,the effect of two key parameters on the stability of the system was investigated,and the forming mechanism of the chaotic attractor was studied via constructing a controller of the system.

5 Dynamics analysis and simulation of spacecraft docking mechanism

Yu Wei , Yang Lei , Qu Guangji

2004, 2(2):38-42.

[Abstract](920) [HTML](0) [PDF 0.00 Byte](1637) [Cited by](9)

Abstract:
This paper studied the internal-petal androgynous peripheral attachment system (APAS),its differential electro-mechanical attenuation mechanism,and the dynamics properties of the docking mechanism.The docking mechanism virtual prototyping model was establlished by using Automatic Dynamic Analysis of Mechanical Systems (ADAMS).According to the simulation,the characteristics of the mechanism's equivalent stiffness and damping were obtained.These findings have been essential in ensuring a successful mission.

6 Analysis of impact process model based on restitution coefficient

Qin Zhiying , Lu Qishao

2006, 4(4):294-298.

[Abstract](1161) [HTML](0) [PDF 0.00 Byte](1492) [Cited by](9)

Abstract:
The meaning and function of restitution coefficient were introduced， and some kinds of impact process models were analyzed. By deriving the relationship between the restitution coefficient and the model parameters， the energy dissipation was described as restitution coefficient， and the contact deformation was described as contact stiffness for different models. This also demonstrated the difference and connection between the impact process models and the rigid impact model. Through the numerical simulations of an impact system of falling ball， the derived relationship were verified and these models were compared in view of computation precision， efficiency and micro-contact process.

7 A study on optimal sensor placement for structural modal parameters testing

Wang Shanshan , Ren Qingwen

2005, 3(1):67-71.

[Abstract](476) [HTML](0) [PDF 0.00 Byte](1451) [Cited by](8)

Abstract:
The testing of structural modal parameters is an important basis of dynamic response analysis and structural damage detection. Modal parameters of real structure are usually tested by ambient excitation. The sensor placement affects testing accuracy during this detection. The affection of sensor placement on structural parameters testing are studied by finite bandwidth white noise vibration experiment. The experimental result shows that optimal sensor placement can improve testing accuracy of structural modal parameters.

8 PID control based on BP neural network adjusting

Zhu Haifeng , Li Wei , Zhang Lin

2005, 3(4):93-96.

[Abstract](1198) [HTML](0) [PDF 0.00 Byte](1361) [Cited by](8)

Abstract:
Traditional PID control has been widely used in real applications. But for traditional PID control, mathematical model must exist when adjusting PID parameters, and the parameters are constant after adjusted. However, in real systems, when the system state and parameters change and become uncertain, system performance cannot keep in the best state. For the purpose of improving system performance of PID control and making use of the existing study fruit of PID control, BP neural network was used for adjusting PID parameters. After simulating, the results show that the algorithm based on BP neural network adjusting has better control characteristics than those of traditional PID and BP neural network.

9 Optimal synchronization of hyperchaotic Lü system with uncertain parameters

Gao Jie , Lu Junan

2006, 4(4):320-325.

[Abstract](437) [HTML](0) [PDF 0.00 Byte](1688) [Cited by](8)

Abstract:
This paper investigated the optimal synchronization of the hyperchaotic Lü system. Based on the Hamilton-Jocobi-Bellman equation, a scheme for the optimal synchronization of the hyperchaotic Lü system with uncertain parameters was designed. The optimal controllers and the control laws of parameters were respectively derived on the infinite and finite time intervals. And the numerical simulations were given to verify the correctness of the theoretical analysis.

10 Study on the laterally nonlinear vibration of axially moving beams

Chen Shuhui , Huang Jianliang , She Jinyan

2004, 2(1):40-45.

[Abstract](669) [HTML](0) [PDF 0.00 Byte](1654) [Cited by](7)

Abstract:
The laterally nonlinear vibration of axially moving beams weve analyzed by the incremental harmonic balance(IHB) method.Firstly the motion equations of an axially moving beam weve derived by Hamilton's principle,Then the Galerkin method was used to discretize the governing equations.Finally, the IHB method was employed to solve the nonlinear vibration equations.Particular attention was paid to the fundamental,subharmonic resonance with internal resonance under the condition ω20/ω10≈3 as ω is near ω20,ω10,where ω is the forcing frequency,and ω10 and ω20 are the first and the second natural frequencies.The number results show that the IHB method is a very effective semi-analytical and seminumerical method for nonlinear vibration of axially moving system.

11 A simplified trial function method for seeking the exact solutions to a class of nonlinear pdes

Xie Yuanxi , Tang Jiashi

2005, 3(1):15-18.

[Abstract](648) [HTML](0) [PDF 0.00 Byte](1609) [Cited by](7)

Abstract:
By utilizing the trial function method, a class of nonlinear partial differential equations (PDEs for short) that are hard to be solved by the usual ways can be reduced to a set of algebraic equations, which can be easily solved, and their related coefficients can be easily determined by the undetermined coefficients method. Then, the exact analytical solutions to the class of nonlinear PDEs were successfully derived. Moreover, the method was applied to the Burgers equation, the KdV equation and the KdV-Burgers equation and the results were in very good agreement with those given in the reference. The method may be generalized to construct the solutions of other nonlinear PDEs.

12 A general solution of free vibration for rectangular thin plates in hamilton systems

Bao Siyuan , Deng Zichen

2005, 3(2):10-16.

[Abstract](730) [HTML](0) [PDF 0.00 Byte](1485) [Cited by](7)

Abstract:
Based on the basic equations of free vibration of thin plate, the Hamilton canonical equations were obtained. By variable selection of moment, equivalent shear force, rotation angel and deflection forming dual variables, the analytical solutions for free vibration of thin plate were obtained under different boundary conditions, which were divided into symmetrical and asymmetrical about xaxial. The computational example of a quadrilateral rectangular plate bending was given, which demonstrated the effectiveness of the proposed method, thus extending the application of Hamilton system.

13 Development and problems of nonlinear dynamics of the mechanisms with clearances for spacecrafts

Yan Shaoze

2004, 2(2):48-52.

[Abstract](556) [HTML](0) [PDF 0.00 Byte](1697) [Cited by](6)

Abstract:
This paper introduces the development of dynamics of space mechanisms for aerospace,and discusses the important senses to study nonlinear clearance models for both designing the structures of new spacecrafts and analyzing the performances of spacecrafts on orbit.Some key problems to be solved are proposed,which include the dynamic modeling and analyzing of space mechanisms with clearances,the movement stability analysis of the mechanisms,the simulation software for realizing the global simulations of performances of the mechanisms.

14 Hopf bifurcation and chaos of a two-degree-of-freedom vibro-impact systems

Le Yuan , Xie Jianhua , Ding Wangcai

2004, 2(3):36-41.

[Abstract](429) [HTML](0) [PDF 0.00 Byte](1078) [Cited by](6)

Abstract:
The periodic motion and Poincaré maps of a two-degree-of-freedom vibro-impact system are studied in this paper.The stability of the periodic motion is determined by the eigenvalues of the Jacobian matrix.It is shown that there exist Hopf bifurcations and period-doubling bifurcations in the vibro-impact system under suitable system parameters.The quasi-periodic responses of the system represented by invariant circles in the projected Poincaré section are obtained by numerical simulations, and routes to chaos are described briefly.

15 A new analytic approximate technoque for strongly nonlinear dynamic systems

Sun Zhongkui , Xu Wei , Yang Xiaoli

2005, 3(2):29-35.

[Abstract](386) [HTML](0) [PDF 0.00 Byte](926) [Cited by](6)

Abstract:
A new homotopy technique based on the parameter expansion (PEHAM) was proposed to strongly nonlinear oscillation. By means of the technique of parameter expansion and the theory of homotopy, we transformed the original nonlinear dynamical system into a set of linear differential equations which can be solved easily. This method is a more general one in which the magnitude of the nonlinear need not be a small parameter. A typical cubic system in the form of oscillator was employed to show its feature. Not only the zeroth and firstth approximation of the conservative Duffing oscillator but also the approximate period were obtained by the method. The results verify that when　αis not a small parameter, even when α→∞,the relative error between the exact period and the approximate period exceeds no more than 3% . The analytical results obtained by the method agreed well with the numerical result obtained by the forth order RungeKutta method.

16 Design and realization of real FFT based on DSP

Chen Hengliang , Jiang Yong

2005, 3(2):50-53.

[Abstract](649) [HTML](0) [PDF 0.00 Byte](964) [Cited by](6)

Abstract:
The design principle and realization of a real FFT algorithm were proposed. In the proposed algorithm, real FFT computation of 2N points were transformed to complex FFT computation of N points according to the symmetry of input serial at first. Then after properly processing the N complex outputs of FFT, the 2N FFT complex outputs of original real inputs were gotten. The proposed algorithm can almost half reduce the operation time of FFT and resolve the conflict between the request of real-time operation in digital signal processing system and the lots of accounting in FFT. The software design of real FFT based on TMS320VC5402 DSP was given. The code length and operation time of the real FFT with 16, 32, 64, 128, 256, 512,1024 points were compared with that of complex FFT. The experiment results proved the correctness of the method.

17 The chaotic characters of a 3dimensional nonlinear dynamics

Zhang Lili , Lei Youfa

2006, 4(1):5-7.

[Abstract](845) [HTML](0) [PDF 0.00 Byte](1729) [Cited by](6)

Abstract:
Based on the linear coefficient character of Lorenz attractor and Chen's attractor, we coined a 3dimension nonlinear dynamics, and studied its chaotic characters, including the space trajectory, the largest Lyapunov exponent, the Lyapunov exponent spectra and the Poincare map. All these characters show that the nonlinear dynamics exists chaotic attractor.

18 Adaptive synchronization of Liu chaotic system with uncertain parameters

Shan Liang , Li Jun , Wang Zhiquan

2006, 4(4):338-343.

[Abstract](588) [HTML](0) [PDF 0.00 Byte](1191) [Cited by](6)

Abstract:
Based on the synchronization by single-variable drive method, and applying the adaptive control theory, we studied the synchronization of Liu chaotic system in the condition that one or more uncertain parameters existed, and deduced the sufficient conditions of asymptotic stability for error systems with different unknown parameters using Lyapunov function. Simulation results showed that the adaptive controllers can quickly identify system parameters and synchronize two Liu chaotic systems.

19 The simulation study on the pattern of muscles controlled by CPG in rhythm gait movement

Dong Wei , Wang Rubin , Shen Enhua , Zhang Zhikang

2008, 6(4):327-331.

[Abstract](850) [HTML](0) [PDF 0.00 Byte](1713) [Cited by](6)

Abstract:
According to the structure of human leg muscles, the Dingguo Zhang’s CPG model was modified. The CPG model was based on neural oscillator theory,which was developed from the combination of neuroscience and biomechanics’s perspective.The modified CPG model can overcome the limitations of movement that only reflect the rhythm of single leg,and can show the rhythm and harmony of two legs in gait movement,which is more approximate to the reality.By numerical simulation,the gait movement patterns were obtained.The result shows the rhythm characteristic of human gait movement,and can reflect the nervous system's regulatory role in human rhythm gait movement.

20 Experimental research on sound waves excitation to aero-engine compressor rotor blade

Lin Zuoming , Li Ke′an , Yang Shengqun

2010, 8(1):12-18.

[Abstract](974) [HTML](0) [PDF 1.09 M](1848) [Cited by](6)

Abstract:
The vibration faults of aeroengine highpressure compressor rotor blade were analyzed. The highintensity sound waves contained in the high-strength noise generated by the compressor in a non-normal working condition one of the reasons for rotor blade excitation resonance or flutter. By theoretical analysis and experimental verification, the following conclusions were obtained: If the high stress caused by mechanical excitation and aerodynamic excitation and the superposition of the resonance stress caused by sound waves together affect the rotor blade, it can produce cracks and damages.

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