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    2022,20(4):1-11, DOI: 10.6052/1672-6553-2021-070
    Multitarget rendezvous can effectively reduce the cost of a single mission and increase the benefit, so it is the first choice for asteroid exploration, in orbit service and other missions in the future. The trajectory optimization problem of such missions involves many variables and huge solution space, so it is difficult to obtain the optimal solution directly. The solution of this problem is usually divided into two steps: first, the rendezvous sequence is optimized, and then, for a given rendezvous sequence, the trajectory of each target to target transfer is optimized. Fast and accurate estimation of the transfer cost such as velocity increment or transfer time is needed to optimize the rendezvous sequence. Thus, the trajectory optimization problem of multitarget rendezvous can be divided into three subproblems: transfer cost estimation, rendezvous sequence optimization, and transfer trajectory optimization. In this paper, the methods of solving these three subproblems are summarized.
    2022,20(4):12-23, DOI: 10.6052/1672-6553-2021-056
    Flow-induced vibration is a typical phenomenon of fluid-structure interaction. The periodic force caused by flow-induced vibration will cause fatigue damage to the structure, which leads to safety problems. In recent years, with the development of vibration energy harvesting technology and the application of low energy consumption products such as microelectronics, wireless networks and Micro electro mechanical system. The energy capture technology based on flow-induced vibration has attracted more and more researchers’ attention, but at the same time there are many problems in the research of flow-induced vibration technology. The current development status of current flow-induced vibration energy capture technology is reviewed, and several measures to improve the efficiency of flow-induced vibration energy capture devices are discussed. Finally, the current problems and challenges in the field of flow-induced vibration energy harvesting are summarized, and the prospects for the future development of flow induced vibration energy harvesting are put forward.
    2022,20(4):24-31, DOI: 10.6052/1672-6553-2022-008
    Puiseux series is a mathematical tool for dynamics analysis of time-delay systems near a repeated characteristic root, and it has became a hot research topic in the recent years. This paper presents a new observation that under certain conditions, contradictions occur in calculating the Puiseux series expansion of time-delay systems when the method of undetermined coefficients is used, the reason that leads to contradictions, as well as some normal forms of the correct Puiseux series expansion under some specified conditions, are given.
    2022,20(4):32-39, DOI: 10.6052/1672-6553-2021-080
    There are a large number of meteoroids and space debris in space. The growing space objects will undoubtedly bring formidable challenges and negative impacts on the security of future space missions. This article reviews the evolution of meteoroid and space debris models, elaborates on the main characteristics and application scope of each model, and focuses on the rational use of different models from the occurrence of the fragmentation event to the evolution of the total amount of space debris in the future. The paper also studies the relationship between space events and models, compares the advantages and disadvantages of different models, offers scenario specific suggestions on model selection, and finally envisages China’s own space system model in the future.
    2022,20(4):40-47, DOI: 10.6052/1672-6553-2021-050
    The dynamic stability of rotating thin conical shells under periodic axial force is studied in this paper. Based on Donnell’s thin shell theory, the motion equation of rotating conical shell is derived. The parametric instability of the system under periodic axial load is analyzed by using the generalized differential quadrature method and Hill’s method. The variations of several instability regions with working conditions and geometric parameters are discussed. The results show that the instability region moves along the frequency axis with the increase of the rotating speed, but the instability width has little effect. Increasing the constant tensile axial load will not only significantly increase the instability width, but also cause the instability region shift to a higher frequency range. The variation of cone angle, thickness to diameter ratio or length to diameter ratio will cause the instability region to move along the frequency axis. Cone angle and thickness diameter ratio will increase the width of instability (length diameter ratio will decrease). With the increase of the number of circumferential waves, the influence of cone angle on the instability region gradually weakens, while the influence of thickness diameter ratio remains unchanged.
    2022,20(4):48-54, DOI: 10.6052/1672-6553-2021-060
    Butted cylindrical shell structure is widely used in aerospace, shipbuilding, civil engineering and mechanical engineering. Modal analysis is an important research direction to study its structural characteristics. This study briefly introduces the modal analysis technology and the basic principle of the polyreference least-squares complex frequency-domain method (PolyMAX), and the finite element modal analysis and experimental modal analysis of butted cylindrical shell structures are carried out. In the process of experimental modal analysis, the experimental realization of the free boundary and the correctness of the analysis results are discussed, and the analysis results are compared with the finite element modal analysis results. The results show that while the butted cylindrical shell structure has the general vibration characteristics of the cylindrical shell structure, the asymmetric vibration with the flange as the boundary occurs due to the existence of the docking form.
    2022,20(4):55-62, DOI: 10.6052/1672-6553-2021-076
    Metamaterial is a type of composite material structure, in which a cell is repeated periodically with different materials integrated. Owing to the phenomenon that metamaterial structures can form a bandgap in spectrum and make the elastic wave propagation confined in it, they has attracted attentions in the fields of noise and vibration control. In this paper, we proposed a piezoelectric metamarerial, in which a piezoelectric material and a oscillate circuit form the cell. From the theoretical analysis, it is proved that the frequency band gap is generated. Furthermore, this kind of piezoelectric metamaterial is put on a cantilever beam to show the effect of vibration attenuation. The simulation investigation is carried out, including the studies on the vibration energy absorption, the influence of resistance and the vibration attenuation characteristic (combined with the voltage curve on PZT). The results focus on the significance of transmission and voltage, and show that the piezoelectric metamaterial is effective in vibration attenuation.
    2022,20(4):63-73, DOI: 10.6052/1672-6553-2021-071
    The paper studies the two-body coupling dynamics between the space platform and server while launching process, as well as energy saving optimization of the double pulse control of the server during rendezvousing and docking to the target satellite. Firstly, the space platform forms an orbiting relationship with the target satellite, keeping its launch tube axis aiming at the target satellite. After receiving the launch command, the server shoots out from the launch tube. The Kane method is used to establish the platform-server two-body dynamics model. Due to the effect of the coupling of the two-bodies, the attitude of the platform is perturbed, causing the server unable to accurately aim at the target satellite while separating the tube. Two velocity pulses are applied to the server through its small rocket engine. The initial pulse occurs at the moment when the server is separating the tube, changing its course to ensure accurate rendezvous with the target satellite; the end pulse occurs at the moment when the server rendezvous to the target satellite, reducing its relative velocity to zero to achieve soft docking. The optimization index is the least energy-efficient, that is to minimize the sum of the squares of the two pulse amplitudes. The paper summarizes it as a nonlinear programming problem. Under the condition that the rendezvous flight time is small compared to the period of the platform orbiting the target satellite, the average angular velocity of the orbiting flight can be regarded as a small parameter, and the canonical perturbation method can be used to obtain the first-order approximate solution of the nonlinear programming. Then the optimizing iteration process is started from the approximate solution as its initial guess. Finally, a numerical simulation verification is carried out.
    2022,20(4):74-82, DOI: 10.6052/1672-6553-2021-075
    In this paper, the rotating flexible beam is taken as the research object, and the bilateral control problem for teleoperation systems is investigated via the multi objective optimization method based on cell mapping. Firstly, the dynamic equation of the rotating flexible beam system in teleoperation system is established. Then, the master controller and slave controller are designed considering the time delays in network transmission and the tracking error signal between the master and slave, and use the Lyapunov stability theory to obtain the conditions of control gains that must be met to ensure the stability of the closed loop control system. Finally, the stability of the system does not mean a good control performance, the multi objective optimization method based on cell mapping is used to optimize the control design, and the optimal solution set of the control gains satisfying multiple different goals at the same time is obtained. The simulation results show that the obtained control gains can realize the effective tracking between the master and slave beam in the teleoperation system effectively, and the operator can feel the change of the environment of slave system in time.
    2022,20(4):83-90, DOI: 10.6052/1672-6553-2021-066
    Based on the Timoshenko beam theory, the finite element equation for bending and vibration of fluid-conveying pipes is derived using the principle of virtual work. The transverse acceleration of fluid is derived using the theorem of acceleration composition. The deflection and slope of the pipe subjected to the combined actions of gravity and fluid under two boundary conditions are obtained, and the influence of fluid velocity on the deflection and slope is analyzed. Under simply supported boundary constraint at both ends the pre-stress effect is transformed to integrate into the strain energy of the pipe, and the relationship between axial pre-stress and bending deflection is studied. The relationships between the first three natural frequencies and the flow velocity of the pipe under the simply supported and cantilever boundary conditions are obtained, and the influence of the axial pre-stress on the natural frequency under the simply supported condition is presented. The results show that under the condition of simply supported boundary, the deflection and slop increase with the increase of fluid velocity, and the deflection and slop decrease with the increase of pre-stress. With the increase of velocity, the first three natural frequencies decrease, while an increase in pre-stress results in higher natural frequencies. For the cantilever boundary condition, the deflection and slope decrease with the increase of fluid velocity, and the first three natural frequencies decrease with increasing flow velocity.
    2022,20(4):91-96, DOI: 10.6052/1672-6553-2021-067
    The low frequency vibration of flexible appendage of the satellite is easy to be coupled with the whole satellite, and affect the attitude control effect and imaging performance of the satellite. In this paper, a new type of fluid damper is designed, which can quickly stabilize the low frequency vibration of the flexible appendage by connecting the fluid damper in series between the flexible appendage and the satellite. The specific structural model of the damper are established, and the damping characteristics of the fluid damper are studied by using the finite element analysis method. The variation of damping coefficient with orifice diameter, orifice length and excitation frequency is obtained. The result shows that under low frequency excitation,the damping coefficient decreases with the increase of excitation frequency. The damping coefficient increases first and then decreases with the increase of the diameter and length of the damping hole. The result in this paper can provide useful design reference for the application of this kind of damper in engineering practice.
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    2014,12(3):193-200, DOI: 10.6052/1672-6553-2014-046
    [Abstract] (2135) [HTML] (0) [PDF 748.46 K] (4608)
    The spacecraft's ability to adapt to the harsh dynamics environment is critical for the whole space mission. Vibration test control technology is the key part of the dynamic environment test. The current progress, fundamental principles and key techniques development level of the spacecraft and vibration control algorithms overseas were analyzed. The basic ideas, effective ways and suggestions were given to domestic following research.
    2014,12(1):18-23, DOI: 10.6052/1672-6553-2013-068
    [Abstract] (2193) [HTML] (0) [PDF 1.13 M] (4445)
    The electromechanical coupling model of cantilevered piezoelectric harvester was developed by considering the nonlinearities of piezoelectric material, based on Hamilton theory, Rayleigh-Ritz method, Euler-Bernoulli beam theory and constant electrical field across the piezoelectric element. The response characteristics of the system were investigated numerically, and the influences of piezoelectric material nonlinear coefficient on the system response were analyzed. By exploring the nonlinear characteristics of the piezoelectric vibrator near the resonant frequency, the nature of the multi-solutions and jump phenomena in the resonance region was revealed. The results were verified experimentally. which provides a theoretical basis for the study of nonlinear mechanism of piezoelectric power generation system.
    2015,13(5):361-366, DOI: 10.6052/1672-6553-2014-064
    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.
    2014,12(3):243-247, DOI: 10.6052/1672-6553-2014-054
    [Abstract] (1965) [HTML] (0) [PDF 1.07 M] (4190)
    Random vibration test is very important to the aerospace equipment. The windage of ASD outside the frequency bandwidth was analyzed. The reason, premonition, affection and effective way were given. And the commonly used random vibration test and vibration test metrology standard for the ASD outside the frequency bandwidth were analyzed.
    2017,15(5):385-405, DOI: 10.6052/1672-6553-2017-039
    [Abstract] (1269) [HTML] (0) [PDF 1.91 M] (4168)
    In this review article, the growth and related academic communications in the dynamics of multibody systems are firstly surveyed. Then, the recent advances in the numerical algorithms for solving the dynamic equations of flexible multibody systems, the contact/impact dynamics of flexible multibody systems and the deployment of flexible space structures are systematically reviewed, together with several open problems of concern. Finally, some suggestions are made for the prospective researches on the dynamics of flexible multibody systems.
    2014,12(3):225-229, DOI: 10.6052/1672-6553-2014-051
    [Abstract] (1618) [HTML] (0) [PDF 1.38 M] (3806)
    Based on the staggered solution procedure of ANSYS and CFX software, the fluid structure coupling response of projectile during tail slapping has been researched. Structural response was simulated by using FEM and flow field was simulated by using inhomogeneous model and SST turbulence model. Finally, the influences of fluid structure coupling effect have been analyzed and the change law of body stress has been given.
    2014,12(3):269-273, DOI: 10.6052/1672-6553-2014-043
    [Abstract] (2461) [HTML] (0) [PDF 336.30 K] (3781)
    Aiming at the problem that the longitudinal modes of structural system of rocket need to be identified from its integral modes in engineering, a method that automatically identifies the longitudinal modes of structural system of rocket was proposed according to the theory of modal effective mass. Taking the vibration characteristics of system with lumped mass as a computing example, applying the finite element software, the beam model of system with lumped mass was established, and the longitudinal modes of the system were automatically identified based on the method. Compared with the system modal information calculated by the method of modal analysis, this automatic identification method not only can accurately identify the longitudinal modes of vibrating system, but also has automatic and high efficiency identification feature. It provides a theoretical basis for the dynamic model of POGO vibrating system in liquid rockets and other model of engineering systems to be accurately and promptly established.
    2012,10(1):21-26, DOI:
    A discrete finite dimensional dynamical model was built to describe the space large overall motion of tethered satellite system with an infinite dimensional viscoelastic tether in a long time. The tethered satellite system is a complex nolinear dynamic system. Considering the tether’s viscoelasticity, distributed mass and space form, the established improved bead model can meticulously describe the tether’s vertical and horizontal vibration. According to tether’s characteristic of tensile and not compressive, the slack tether unit model was set up to accurately reflect real stress of tether. The determination of the number of degrees of freedom of the system was studied. Based on numerical integral calculation, the dynamic response was obtained via numerical simulation of the deployment, retrievement and retainment process of tethered satellite system in a long time. The result is convergent. The simulation proves the important role of the stable equilibrium position in the dynamics of tethered space system.
    2016,14(2):97-108, DOI: 10.6052/1672-6553-2015-009
    [Abstract] (1427) [HTML] (0) [PDF 1.87 M] (3620)
    Based on the current research status of multi agents system control theory and technology, the paper makes a detailed overview for unmanned ground systems. From two aspects of behaviour and task cooperative control for multi agents, the relevant theory and application problem is discussed. Moreover, some existed open problems are presented and a possible future development is proposed. For unmanned ground systems, cooperative control will be of great importance in promoting social and military benefits and maximizing the executive function of ground mission.
    2008,6(4):301-306, DOI:
    The problem of P and PI feedback control to a time delay system was investigated,with the emphasis on the determination of the feedback gains that ensured the asymptotical stability of the delayed system. By means of Lambert W function,the feedback gain of P control can be expressed explicitly,so that the optimal feedback gain can be easily obtained. For the system under a PI control,the stable region of the feedback gains was determined on the basis of stability switches and D subdivision,and the optimal feedback gains that enabled the system to admit maximal stable margin were figured out numerically by using Lambert W function. From the viewpoint of computation,the present method is much simpler than the available methods.
    2013,11(1):12-19, DOI: 10.6052/1672-6553-2013-003
    [Abstract] (1523) [HTML] (0) [PDF 530.95 K] (3371)
    The dynamics of the whole aero-engine system has always been the important part that cannot be neglected in the research and design of the engine, as the framework of the engine, the vibration of the casing directly reflects the level of the whole aero engine vibration. In this paper, an analysis was made on the research of the problems and fault classification of aero-engine casing dynamics, and an overview was made on the research of present situation, development trend, problems and solutions of the domestic and foreign of casing dynamics, which expanded the present situation of the Inclusiveness problems of aero-engine casing dynamics. Finally, some proposals were put forward for the development of the casing dynamics suitable for our country aero-engine technology level.
    2013,11(4):357-362, DOI: 10.6052/1672-6553-2013-041
    At present, the main task of designing a mounting system of automotive engine powertrain is to select appropriate stiffness, position and angle of mounting components so that free-vibration modal frequency of the mounting system can avert from the exciting-force frequency at the idle speed of the engine and the natural frequency of vibration of the vehicle body and that the decoupling degree of each mode shape is increased as far as possible, so as to improve the vibration-isolation effect of the mounting system. The design of a mounting system based on strict decoupling at predetermined frequencies is to make the modal frequencies of the designed mounting system completely equal to the frequencies predetermined in accordance with the frequency planning of automotive design, and to enable strict decoupling of each mode shape of each mode, i.e., the decoupling degree of vibration energy in every direction equals to 1. Based on a free-vibration equation for a mounting system, this paper presents an equation system for designing a mounting system with strict decoupling at predetermined frequencies, provides a solving method for this equation system by using the theory of generalized inverse matrix or method of constructing function, so as to provide an optimal design method more efficient and simpler than the current modal optimization method of mounting system. Relevant example has validated the correctness of equations and solving method of the strict-decoupling design at predetermined frequencies.
    2014,12(3):283-288, DOI: 10.6052/1672-6553-2014-061
    [Abstract] (2118) [HTML] (0) [PDF 479.50 K] (3180)
    A method was presented to analyze the nonlinear flutter. Based on this method, the flutter characteristics of the high aspect wing were illustrated. The numerical results show that the flutter speed is decreased when the first horizontal bending mode involved. Secondly, this study discussed how the main direction of the composite influenced the character of the nonlinear vibration and flutter, and established the method of the flutter clipping to the high aspect wing. And the result shows that the stiffness of structure can be changed by changing the main direction of the composite. It mainly changes the horizontal bending mode, makes the main direction tend to the trailing edge, and then makes the section line move to the leading edge. Further analyzing the nonlinear flutter reveals that it is the changing of the horizontal bending mode that causes the flutter speed change obviously. And by the section line of this mode moves ahead, the flutter speed will become larger. In the study, two examples were illustrated to validate its truthiness.
    2014,12(3):205-209, DOI: 10.6052/1672-6553-2014-059
    [Abstract] (1692) [HTML] (0) [PDF 467.15 K] (3158)
    This paper investigated the passive nonlinear vibration control method used for energy absorbing in structures of spacecrafts. The structure and the dynamic model of the nonlinear energy sink which could adapt to the space environment were proposed. As nonlinear spring could not be acquired easily in reality, we proposed a new design for the NES based on employing an asymmetric NES force which was generated by two pairs of aligned permanent magnets. Then, the dynamic model for a cantilever beam structure coupled with nonlinear energy sink had been built theoretically. In addition, the passive vibration suppression effect of the nonlinear energy sink on the cantilever beam structure under transient excitation had been analyzed through Galerkin method and numerical analysis method. The results showed that the NES acquired up to 92% dissipation of the system energy imposed by shock excitation, hence the NES could adapt to the space environment and improve the reliability of space system.
    2014,12(2):183-187, DOI: 10.6052/1672-6553-2014-025
    PMSM due to little harmonic, high precision torque, commonly is used in the servo system and the high performance speed control system. In this paper,the physical model of PMSM is simplified and the mathematical model of the motor is established in order to facilitate research.Thispaper uses id=0 control manner which is the simplest manner is vector control methods,motor electromagnetic torque equation is established based on rotor field oriented vector control.The system model, speed and current control block are build and simulated with MATLAB/Simulink.Simulation results shows that the waveform is consistent with thoretical analysis,the model has fast response and small overshoot.The system runs stably with good dynamic and static characteristics. The simulation makes full use of modularization design. All the parameters and their influence on the system can be changed and observed.It also can easily validate the control strategies and select the most suitable one. So this kind of simulation is good for system design and adjusting and validating.
    2014,12(3):253-258, DOI: 10.6052/1672-6553-2014-056
    [Abstract] (1503) [HTML] (0) [PDF 1.00 M] (3080)
    Taking account of the structural stiffness and the low order vibration frequencies, two schemes of multi-objective topology optimization were proposed to obtain the best aircraft lifting-surface structural design. Based on penalized density theory, the scheme one (named as constrain method) is to convert the multi-objective optimization to single-objective optimization by considering the minimum structural mass as the objective with constraints of reference points displacements and the low order vibration frequencies. The scheme two (named as the combination of constrain method and criterion function method) settles the multi-objective optimization by defining combined compliance index (CCI) as the objective, with the constraints of volume fraction and the low order vibration frequencies. The CCI is the function of structural compliance and low order vibration frequencies. Numerical results demonstrate the proposed schemes not only realize reducing the structural mass but also raise the first and second order frequencies.
    2016,14(3):247-252, DOI: 10.6052/1672-6553-2015-052
    [Abstract] (1326) [HTML] (0) [PDF 2.18 M] (3068)
    Tires are the only carrier of the contact between the vehicle and road surface. Their mechanical property is important for analysis and control on the vehicle dynamic response. At present, the tire simulation mostly focuses on the steady state model. But it can not describe the dynamic characteristic of the tire accurately. Therefore, it plays a significant role to add the dynamic tire model in the vehicle dynamics simulation. The tire friction model in the multi body dynamical software ADAMS is static, where the friction is regarded as a static value. However, in actual, the friction between the tire and road surface is dynamic, and it should be a dynamic function of the relative velocity and displacement. To this end, in this paper, the dynamic tire LuGre model using the Matlab/Simulink software is constructed. Through connecting the interface with Adams/Car, co simulation between the vehicle model and the simulink tire model is carried out in order to achieve the dynamic contact between tire and road and improve the accuracy of vehicle system analysis.
    2014,12(1):36-43, DOI: 10.6052/1672-6553-2013-110
    [Abstract] (1320) [HTML] (0) [PDF 2.22 M] (2994)
    The coupling nonlinear dynamic model of dual rotor system was established by using finite element method, and then the critical speed of revolution and mode shape were calculated by using the software MATLAB. In addition, the unbalance responses of dual rotor system were studied, and the vibration performances in different speeds of dual rotor casing systems were obtained. The research provides a theoretical basis for the design of the dual rotors system in engineering.
    2014,12(3):201-204, DOI: 10.6052/1672-6553-2014-048
    [Abstract] (1768) [HTML] (0) [PDF 296.79 K] (2902)
    Non-linear factors cannot be avoided in the design of aircraft structures. In this paper, a two-degree-of-freedom airfoil and cubic stiffness nonlinearities in pitching degree-of-freedom operating in supersonic flight speed regimes has been analyzed. The averaging method and the theory of flutter were used to analyze the nonlinear dynamic system of the dualistic airfoil in the supersonic flow. Then the correctness of the theoretical calculation was verified by numerical calculation, and the analysis result was given.
    2014,12(1):62-66, DOI: 10.6052/1672-6553-2013-097
    A spline finite point method was presented to study the natural frequency of arch. The displacement mode shape function of the arch free vibration was simulated with a linear combination of cubic B spline. The free vibration frequency equation of arch structures was derived according to Hamilton principle, in which the effect of the dead load was considered. Meanwhile, the effect of the dead load on the natural frequency of arch structures was analyzed. The results show that the natural frequency of arch is reduced. The effect of influence depends on the stiffness of the arch itself. When the arch stiffness is certain, the bigger the rise span ration and the radius to thickness ration, the higher the effect of the dead load on the natural frequency of arch structures.

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