• Volume 13,Issue 5,2015 Table of Contents
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    • >混沌理论与控制
    • Advances indynamics and control of tethered satellite formations

      2015, 13(5):321-328. DOI: 10.6052/1672-6553-2015-046

      Abstract (795) HTML (0) PDF 1.46 M (1819) Comment (0) Favorites

      Abstract:The paper gives a brief summarization on the research of tethered satellite formation, starting with formation configurations and their stabilities. The dynamical behavior such as spinning motion, tether vibration, and periodic motion in the vicinity of L2 libration point are summarized. The dynamics and control concerned on the deployment/retrieval of system and the rigid attitude of satellites are presented. Finally, future development issues of tethered satellite formation are put forward.

    • Generalized skew gradient representation for Birkhoff system

      2015, 13(5):329-331. DOI: 10.6052/1672-6553-2015-011

      Abstract (931) HTML (0) PDF 229.39 K (1189) Comment (0) Favorites

      Abstract:A generalized skewgradient system is proposed, and the generalized skewgradient representation for a Birkhoff system is studied. A condition under which the Birkhoff system can be considered as a generalized skewgradient system is obtained. The characteristic of generalized skewgradient system is then used to study the stability of the Birkhoff system. The application of this developed generalized skewgradient system is also presented through some case studies in this paper.

    • Study on dynamics performance for vehicle passing through the turnout based on multibody dynamics

      2015, 13(5):332-337. DOI: 10.6052/1672-6553-2015-053

      Abstract (862) HTML (0) PDF 1.35 M (1839) Comment (0) Favorites

      Abstract:The key factors causing the vehicle vibration or derailment is the complex wheel/rail contact relationship and variable crosssections characteristics when the vehicle passing through the turnout .According to the design and disposition of the Chinese 60kg/m rail NO.18 turnout with movablenose, a vehicleturnout coupling model is built up in the multibody dynamics analysis software. The dynamics model is verified. The dynamics responses are calculated when the vehicle passing through the turnout on the divergent route and the major track respectively. The results show that the major effects on the dynamics parameters of the vehicle are the cross section variation in switch and frog and the geometrical contact between wheels and rails. At last, the effect of the integral stiffness and damping of the track on the dynamics performance of the vehicle system is discussed based on the dynamics response analysis aiming at the optimal vehicle security, stability and comfort and providing a reference for the matching scheme of the subrail stiffness and damping parameters with the discrete the track model.

    • Steady state response of an infinite beam on a nonlinear foundation to a moving harmonic load

      2015, 13(5):338-342. DOI: 10.6052/1672-6553-2014-037

      Abstract (929) HTML (0) PDF 356.70 K (1585) Comment (0) Favorites

      Abstract:This paper studied the steady state response of infinite beams supported by nonlinear viscoelastic foundations with 4-parameters. A moving harmonic concentrated load was considered, and the nonlinear foundation was assumed to be cubic. The domain decomposition method was used to deal with the nonlinear term of the foundation reaction, and the complex Fourier transformations, Green′s function, and the theorem of residues were employed to determine the steady state response of the infinite beam on a nonlinear foundation. The numerical examples were used to investigate the effects of the frequency and the speed of moving harmonic load on the steady state responses of infinite beams supported by nonlinear foundations. Moreover, the influences of the nonlinear elastic parameter and the shear modulus of foundations on the steady state responses were also studied.

    • The global solution for a class coupled of nonlinear abstract beam equations

      2015, 13(5):343-347. DOI: 10.6052/1672-6553-2014-073

      Abstract (616) HTML (0) PDF 275.14 K (952) Comment (0) Favorites

      Abstract:This paper studied the abstract coupled nonlinear beam equations with initial conditions in a Hilbert space. Two equations were solved effectively by using FaedoGalerkin method, the convergence was studied and the existence of the global weak solution for the nonlinear beam equations was proved.

    • Response analysis of the coupled thermoelastic vibration for the axially flying viscoelastic sandwich beam

      2015, 13(5):348-354. DOI: 10.6052/1672-6553-2014-069

      Abstract (684) HTML (0) PDF 1.81 M (1452) Comment (0) Favorites

      Abstract:The coupled thermoelstic vibration response of the axially flying viscoelastic sandwich beam was investigated. Considering the interaction of the material deformation and the heat conduction, the coupled governing equations of the axially moving viscoelastic sandwich beam were derived. The exciting load, which consists of temperature function and external excitation force, of the equations was interpolated by a quadratic polynomial of time, then the vibration equation was solved by the method of Galerkin, and the displacement was obtained in every small time by using the numerical method of iteration and convergence to solve heat conduction equation, thus the temperature was gained. The influence of the axially moving speed and thermal loading duration on the response of the structures was studied by using numerical method. The results show that the influence of flying speed on the beam’s displacement is obvious, but on the temperature is small when the beam vibrates stably; thermal impact has a large influence on the beam’s response, and changes the vibration characteristics.

    • Studyon the equivalent mechanics model and model parameters of sloshing motion of water inside the moonpool of a Spar platform

      2015, 13(5):355-360. DOI: 10.6052/1672-6553-2014-075

      Abstract (565) HTML (0) PDF 747.06 K (1288) Comment (0) Favorites

      Abstract:This paper studied the equivalent mechanics model of sloshing motion of water inside the moonpool of a deep sea Spar platform, and the model parameters were calculated. The dynamic equations of water inside the moonpool were derived based on the potential flow theory. The equivalent pendulum models of the sloshing motions of water inside the moonpool were established. ANSYS software was used to set up model and mesh, and the Matlab software was used to carry out the numerical calculation. The Galerkin method was used to solve the natural frequencies, modal functions and discrete solutions of the potential function of the sloshing motions, and the model parameters of the equivalent pendulum were calculated. The validity of the calculating method was verified by comparing the numerical simulation results with the analytical results. The parameter library of the equivalent mechanics model was established considering the different water heights of the moonpool. This lays the foundation for studying the coupling motions between the platform and water inside the moonpool.

    • Stochastic response surface based sensitivity analysis of uncertain parameters

      2015, 13(5):361-366. DOI: 10.6052/1672-6553-2014-064

      Abstract (820) HTML (0) PDF 826.19 K (4430) Comment (0) Favorites

      Abstract:Dynamic and control systems often contain uncertain parameters that may result in uncertain predictions. In the interest of quantifying the effects of parameter uncertainties on response variability, this paper develops a stochastic response surface based method for the sensitivity analysis of uncertain parameters. Stochastic response surfaces were firstly constructed to describe the explicit relationships between uncertain parameters and responses. Then partial derivations were performed on the mathematical expressions of stochastic response surfaces in order to obtain sensitivity indices that simultaneously embody the effects of parameter means and standard deviations. Lastly, the developed method has been verified against a numerical cantilever beam containing uncertain geometric and material parameters. The sensitivity analysis results were compared with those given by the analysis of variance method.

    • Active flutter suppression of a lifting surface based on piezoelectric actuators/sensors

      2015, 13(5):367-376. DOI: 10.6052/1672-6553-2014-020

      Abstract (748) HTML (0) PDF 1.70 M (1531) Comment (0) Favorites

      Abstract:Typical application of piezoelectric materials was used in active flutter suppression of a swept-back cantilevered composite laminate plate. The structures containing distributed piezoelectric sensors and actuators have self-monitoring and control capabilities due to the direct/converse piezoelectric effect. A generalized finite element formulation was derived for modeling the electromechanical coupling system. The doublet lattice method was used to model the unsteady aerodynamic loads acting on the lifting surface. Modal transformation and Roger approximation were involved to develop the equation of motion in state-space. LQG controller based on multi-input multi-output system was designed. The flutter characteristic of the closed-loop system was compared with the open-loop system by stability analysis. The flutter suppression results were presented in the time domain using the Runge-Kutta method. Numerical simulations demonstrate the effectiveness of the above methods.

    • The research on synchronizatioin in purkinje neural circuit

      2015, 13(5):377-381. DOI: 10.6052/1672-6553-2014-034

      Abstract (598) HTML (0) PDF 783.85 K (1154) Comment (0) Favorites

      Abstract:Purkinje neurons are the unique output of the cerebellar cortex, and the inputs mainly come from climbing fibers and parallel fibers from olivary nucleus and granule cells. Based on the anatomic model, which is very similar to the real neural system, this paper analyzed the Phase Response Curve (PRC) of three different neurons (Purkinje neurons, granule neurons, climbing fibers) and classified their neural excitatory by comparing their fI curves, and then further studied the synchronization in this circuit by changing the synaptic conductance and CaP conductance principally. The analysis results show that the synchronization is very significant in the information transfer.

    • On the control stablity of a three dimensional stock price system with time delays

      2015, 13(5):382-387. DOI: 10.6052/1672-6553-2014-065

      Abstract (698) HTML (0) PDF 733.11 K (1010) Comment (0) Favorites

      Abstract:A three dimensional price system with time delays and impulsive control was constructed, and the change of impulsive control parameters and delays on the stability of stock price was studied. Sufficient and conservative conditions for this system's unstable positive equilibrium to approach asymptotic stability were derived by applying the stability theory of impulsive differential equation. Then the stock financial market arrives at a new stable state in which it can sustainably develop. Numerical simulations results verify the feasibility and validity of impulsive control method, and the accuracy of theoretical results. It is concluded that reasonable impulsive control can effectively realize the stability of the system with time delays.

    • Structural damage identification based on quantumbehaved particle swarm optimization

      2015, 13(5):388-393. DOI: 10.6052/1672-6553-2014-066

      Abstract (715) HTML (0) PDF 1.34 M (951) Comment (0) Favorites

      Abstract:This paper presented an approach of structural damage identification with the damage index of generalized flexibility matrix based on Quantumbehaved Particle Swarm Optimizationalgorithm. According to the relationship between the changes of structural physical parameters and generalized flexibility matrix difference of structural before and after damage,the generalized flexibility matrix identification issue was changed into intelligent optimization issue. Optimization issue was solved by Quantumbehaved Particle Swarm Optimizationalgorithm, and then the structural damageconditionwas identified with the damage location and damage extent at the same time. Finally, a numerical simulation of simple beam was applied to verify the effectiveness of the method herein.

    • Numerical simulation of wind pressure distribution on different cornice construction of low rise hip roofed duilding

      2015, 13(5):394-400. DOI: 10.6052/1672-6553-2015-002

      Abstract (519) HTML (0) PDF 2.34 M (768) Comment (0) Favorites

      Abstract:Based on the data of wind tunnel test by Tokyo Polytechnic University, and validated RNG model hipped building surface pressure low reliability study. Study that cornice length and height of the influence on the low hipped roof surface wind pressure deeply. The results show that: The length and height of the cornice on the roof overhangs pressure affect apparently when cornice overhanging the same length, vertical height increases with cornice, windward wind suction increases, the vertical height unchanged when the cornice height of 0.5m or 1.0m, with overhanging eaves to increase the length of the windward side of the negative air pressure decreases, the cornice overhang length of 1.5m, 1.0m vertical height of the surface is most conducive to windresistant design, the conclusion can be shed some light on design of lowrise residential areas where typhoon occur frequently.

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