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2012 Vol. 31, No. 13
Published: 2012-07-15
 
       论文
1 Prediction of Ultimate Load for Aircraft Vertical Tail Buffeting
YANG Zhi-chun;CHEN Shuai;JIN Wei
DOI:
Abstract: Aimed to achieve high speed and large maneuverability performance, the buffet loads should be considered to provide adequate strength in all corners of the operational envelope. Buffet subcases are split according to flight conditions, which are employed to establish storing relations of data base for buffet load data. A method is proposed to reconstruct buffet loads from limited buffet response measurements. The ultimate load for aircraft vertical tail buffeting is predicted based on the selected probabilistic distribution model. Finally, the procedure of this method is illustrated by the prediction of ultimate load for an aircraft vertical tail buffeting.
2012 Vol. 31 (13): 1-4 [Abstract] ( 653 ) HTML (0 KB)  PDF (1503 KB)  ( 933 )
5 Study on the Stress Impact Factor Difference of the Suspenders on theHalf-Through or Through Arch Bridge
ZHU Jin-song;;YI Qiang
DOI:
Abstract: In order to investigate the stress impact factor difference of the suspenders on the half-through or though
arch bridge under the dynamic loading of road vehicles, the vehicle-bridge vibration based analysis method is proposed.
Firstly, the vehicle is modeled as a four-degree-of-freedom system and the vibration equations of the vehicle modal are
deduced based on the D'Alembert principle. Then finite element method is used to discretize bridge and a 2D finite
element modal is set up. According to the condition of displacement and force compatibility between vehicle and bridge,
the vibration equations of vehicle modal and bridge modal are coupled. Secondly, a professional procedure VBAP is
programmed based on Newmark-β algorithm in MATLAB, which could analyze the vehicle-bridge system coupling
vibration. At last, taking one concrete-filled steel tube arch bridge as an example, the influence of damping ratio, road
roughness class, the weight of vehicle and vehicle speed on stress impact factors of the suspenders is analysed using
method and program mentioned in this paper.
2012 Vol. 31 (13): 5-10 [Abstract] ( 690 ) HTML (0 KB)  PDF (1789 KB)  ( 592 )
11 Self-powered MR dampers based on electromagnetic induction energy harvesting technology
Jiang Xuezheng Hu Hongsheng;Wang Jiong
DOI:
Abstract: In the current magnetorheological (MR) damping system, separate power supply is required. This paper addresses the feasibility and effectiveness of a new self-powered MR damper which contains an electromagnetic inductive (EMI) device and can harvest energy from the vibration in which it is deployed. The dynamic equation for the new self-powered MR damper is derived. A simulation study is conducted to check the ability of harvesting energy from the vibration. Based on the simulation, an electric energy conditioning module is designed to convert the harvested energy to stable voltage suitable to the MR damper. To evaluate the vibration isolation capability of the self-powered MR damper, a prototype of self-powered MR damper was designed, fabricated, and tested. The experimental results show that the self-powered MR damper is able to collect electric energy to activate electromagnetic coils inside damper and change its damping characteristics under vibration.
2012 Vol. 31 (13): 11-15 [Abstract] ( 1104 ) HTML (0 KB)  PDF (1909 KB)  ( 636 )
16 Numerical Investigation for Galloping of Iced Quad Bundle Conductor in Stochastic Wind Field
YAN Bo LIU Xiao-hui ZHANG Hong-yan ZHOU Song
DOI:
Abstract: Galloping of iced quad bundle conductor in stochastic wind field is numerically investigated by means of the finite element method. The variation of wind velocity with the height above the ground and the space correction between any two points are taken into account in the simulation of stochastic wind field. The aerodynamic loads on the iced conductor are determined based on the aerodynamic coefficients varying with angle of attack obtained by wind tunnel test. It is shown from the numerical results that the galloping mode of transmission line with smaller span in stochastic wind field is consistent with that in steady wind, but the galloping mode of transmission line with larger span is different from that in steady wind filed. Therefore, it is necessary to investigate the galloping behavior of iced transmission lines with large span in stochastic wind field for the design of anti-galloping device.
2012 Vol. 31 (13): 16-21 [Abstract] ( 1316 ) HTML (0 KB)  PDF (2823 KB)  ( 232 )
22 Effects of geometric parameter on vibration characteristics of rotating thin circular cylindrical shell
LIU Yan-qi;CHU Fu-lei
DOI:
Abstract: In this paper, according to Love’s shell theory, the free vibration of rotating circular cylindrical shell is studied. Aiming at the different boundary condition, the effects of geometric parameters on nature frequency and the ratio of vibration mode for the circular cylindrical shell are analyzed. The research results show that the effect of the thickness-to-radius ratio on nature frequency is not notable, and nature frequency of rotating cylindrical shell monotonically increases along with the increase of the thickness-to-radius ratio. While, the effect of the radius-to-length ratio on nature frequency is notable, and nature frequencies don’t monotonically change along with the change of the radius-to-length ratio. In addition, the effect of the radius-to-length ratio has great influence on the ratio of mode vibration for rotating cylindrical shell. Therefore, there exists remarkable difference between dynamic characteristic of slender shell and short shell. This research will supply reference to dynamic study of circular cylindrical shell.
2012 Vol. 31 (13): 22-25 [Abstract] ( 904 ) HTML (0 KB)  PDF (1552 KB)  ( 316 )
26 Machinery Fault Diagnosis Based on Bayes Optimal Kernel Discriminant Analysis
HAO Teng-fei;CHEN Guo
DOI:
Abstract: When kernel discriminant analysis is applied to machinery fault diagnosis, the main challenge is to determine the parameters of kernel function. Aiming at this problem, a method for machinery fault diagnosis based on bayes optimal kernel discriminant analysis is proposed. Firstly, the optimal kernel parameter is selected by optimizing the homoscedastic criterion using gradient descent; Secondly, with the optimal kernel parameter, the original examples are projected onto an optimal subspace where the examples are best separated. Finally, fault classification is performed in the optimal subspace by nearest neighbour method. the proposed method is applied to fault diagnosis of roller bearings and comparison is made with the results of related methods, experimental results demonstrate the performance of the proposed method is comparable to that of support vector machines, but avoiding the problem that kernel parameters need to be manually selected.
2012 Vol. 31 (13): 26-30 [Abstract] ( 929 ) HTML (0 KB)  PDF (1794 KB)  ( 326 )
31
LI Shao-hua;YANG Shao-pu;LI Hao-yu
DOI:
Abstract: The vehicle-road system acted by three-directional tire force is modeled as a 2DOF vehicle moving along a simply supported double-layer rectangular thin plate on a nonlinear visco-elastic foundation. The nonlinear Gim model and vertical point contact model is used to describe tire forces. The pavement response excited by the moving three-directional tire forces is obtained analytically by Galerkin method. The influence of tire forces on pavement response is studied when the vehicle is braking and lane changing. The pavement response under vertical tire force is compared with that under three-directional tire forces. The effect of parameters on this difference is also analyzed. The results found by this work will be benefit to researching the mechanism of three-directional interaction between vehicle and road and proposing a new research scheme of pavement response calculating and lifespan forecast.
2012 Vol. 31 (13): 31-35 [Abstract] ( 1198 ) HTML (0 KB)  PDF (1247 KB)  ( 404 )
36 Fault Diagnosis Model Based on Dimension Reduction with Linear Local Tangent Space Alignment
LI Feng TANG Bao-ping CHEN Fa-fa
DOI:
Abstract：Based on dimension reduction with Linear Local Tangent Space Alignment (LLTSA), a novel fault diagnosis model is proposed in this paper to achieve automation、high-precision and generality of fault diagnosis of rotating machinery. With this model, mixed-domain feature sets of training and test samples are first constructed to characterize the property of each fault comprehensively by the fusion of Empirical Mode Decomposition (EMD) and Autoregression(AR) model coefficients. After that, LLTSA is introduced to automatically compress the high-dimensional eigenvectors of training and test samples into the low-dimensional eigenvectors which have better discrimination. Finally, the low-dimensional eigenvectors of training and test samples are input into K-nearest neighbors classifier (KNNC) to carry out fault diagnosis. Compared to the existing approaches, the proposed diagnosis model combines the strengths of mixed-domain features fusion in extensive extraction of fault feature, LLTSA in effective compression of fault information and KNNC in classification decision-making, and realizes the automation、high-precision and generality of fault diagnosis method. The diagnosis example on different fault positions and severities of deep groove ball bearings validates the effectivity of proposed fault diagnosis model.
2012 Vol. 31 (13): 36-40 [Abstract] ( 599 ) HTML (0 KB)  PDF (1427 KB)  ( 634 )
41 A Nonlinear Dynamic Model and Its Solution of Labyrinth Seal-Rotor System
LIU Si-yong;XUE Zi-hua;LU Yi;ZHENG Tie-sheng
DOI:
Abstract: Labyrinth seals are widely used in rotating machineries. The research on the interaction between the fluid and rotor in the seal is important to the system stability analysis. With the Two-Control-Volume model, the controlling equations were deduced for incompressible flow in the labyrinth seal. The rotor-labyrinth seal system was modeled as a Jeffcot rotor subject. With the nonlinear dynamic model, the numerical solution of the rotor’s displacement and the pressure in seal cavity were analyzed. An eccentric rotor-seal system example was calculated to show the nonlinear characters of the system which could be observed in Hopf bifurcation diagrams and Poincare maps. The results suggested that it was important to reduce the rotor eccentricity for the improvement of the system stability.
2012 Vol. 31 (13): 41-45 [Abstract] ( 1116 ) HTML (0 KB)  PDF (1423 KB)  ( 336 )
46 Influence mechanism of mean values on the application of POD for random fields
ZHANG Jun-feng;GE Yao-jun;REN Peng-jie
DOI:
Abstract: Based on the theories of Proper Orthogonal Decomposition(POD) and matrix analysis, the cross-correlation function matrix(CORM) of the mean values is introduced and decomposed, with which to demonstrate the influence mechanism of mean values on the application of POD for random fields with the whole signals or just the fluctuating signals(without the mean values included) concerned. With the section wind pressure fields of a cooling tower model and a box girder model, POD method is applied using the whole signals and just the fluttering signals. According to the POD results from two signals, the influence mechanism of mean values is illustrated, which is also a verification for the theoretical explanation obtaine. The mean values have no effects on the decomposition or reconstruction of random fields, but the POD results such as spatial modes, eigenvalues and principle coordinates got form the two signals are quite different because they are reflections of their original signals and shouldn’t be confused. If POD is applied on the cross-correlation function matrix of whole signals, POD results of all modes will be distorted by the mean values, especially the POD results of low order modes. As the mean values and fluctuating signals are always treaded separately, CORM should be formed by the fluctuating signals for POD application to reflect the characteristics genuinely and avoid the distortion of mean values.
2012 Vol. 31 (13): 46-52 [Abstract] ( 967 ) HTML (0 KB)  PDF (2323 KB)  ( 812 )
53 STUDY ON DYNAMIC MECHANICAL PROPERTY OF EPS CONCRETE UNDER IMPACT LOADING
BAI Er-lei;XU Jin-yu;GAO Zh-igang
DOI:
Abstract: The EPS concrete with 10%，20%，30%，40%，50% EPS volume fraction were prepared. Taking critical strain and dynamical compressive strength as the index, the dynamic property of EPS concrete with different EPS volume fraction under impact loading were studied using a 100-mm-diameter split Hopkinson pressure bar(SHPB) apparatus, and the dynamical mechanism of the concrete was discussed. The results show that the critical strain and dynamical compressive strength of the EPS concrete increases with the average strain rate for the strain rate effect, which takes on obvious strain rate dependency. For the EPS microscopic structure effect, the deformation property of the EPS concrete increases with the EPS volume fraction in 0~40%. Its deformation property reduces somewhat when the EPS volume fraction reaches 50%. To improve the deformation property, the optimum volume fraction of EPS is 40%.
2012 Vol. 31 (13): 53-58 [Abstract] ( 1190 ) HTML (0 KB)  PDF (1842 KB)  ( 280 )
58 Model Investigation on Mechanics of Cracks PropagationIn Coal under Blast Loading
MU Chao-min;;Qi Juan
DOI:
Abstract: In order to study the cracks propagation in the coal under blasting loads, the model experiment of loosening explosion is established using the method of Froude ratio method. Through the model experiment, we measure the waves of pressure in the model and the waves of acceleration, displacement and strain on the surface of the model. The macro damage characteristics of model are presented by experiments. According to analysis of the test data, the cracks propagation law of coal is obtained. The results show that cracks are formed by combined action of pressure wave and tensile wave under explosion loads. The direction of cracks propagation is perpendicular to the axes of explosion hole.
2012 Vol. 31 (13): 58-61 [Abstract] ( 1080 ) HTML (0 KB)  PDF (1163 KB)  ( 302 )
62 Wireless vibration control of plate and the layout optimization of photostrictive actuators
Chen De-jin Zheng Shi-jie
DOI:
Abstract: Dynamics and modal control equations of a photostrictive laminated a simply supported plate are presented in this paper. The layout of photostrictive actuators for active vibration control of a simply supported plate is optimized by using a binary-coded genetic algorithm, in which the normalized modal control force indexes are chosen as fitness function of GA. The simulation results demonstrate that the new control method is more effective. Furthermore, a novel multiple modal control method is researched in this paper and numerical examples show that the present approach can be used to control the first two modes of a plate effectively.
2012 Vol. 31 (13): 62-65 [Abstract] ( 917 ) HTML (0 KB)  PDF (2027 KB)  ( 268 )
66 Simulation and Experiment on Aimable Warhead of Premade Fragment
Mao Liang;Jiang Chun-lan;Yan Han-xin;Zhang Li-yang;Wang Chao
DOI:
Abstract：By using ANSYS/LS-DYNA, the deforming process of the aimable warhead of premade fragment and the projectile process of its fragments were numerically simulated; finally, the scattering velocity, scattering angle and density in different distance of fragments are obtained. By the way, an experiment of explosion was carried out to validate the design of the aimable warhead. It reveals that the scattering velocity and the fragments density of the aimable warhead’s fragments are high and the scattering angle is fixed. So, when the missile can exactly detect the target and accurately computed the target position, the aimable warhead can adopted firstly by the further air defense missile. Otherwise, the contact surface to surface is suitable for the aimable warhead of double-layer premade fragment.
2012 Vol. 31 (13): 66-71 [Abstract] ( 1130 ) HTML (0 KB)  PDF (1693 KB)  ( 448 )
72 Dynamics Influence Analysis of the Satellite with Reaction Wheel Joint Clearance
PAN Dong;ZHAO Yang;WANG Xing-gui;MA Wen-lai
DOI:
Abstract: Reaction Wheel has been identified as one of the main disturbance sources that affect the precision of attitude control system of spacecraft. and the joint clearance is inevitable in the reaction wheel mechanism, Research the influence of the joint clearance to satellite is particularly important for the established of the accurately reaction wheel disturbance model. Based on virtual prototype, The contact dynamics model in joint clearance is established using the nonlinear equivalent spring-damp model and the friction effect is considered by using correction Coulomb friction model, then establish the virtual prototype of the satellite with clearance and the simulation is made, Furthermore, analysis the influence of the Clearance to the mechanism dynamic characteristics, provide the reference for the satellite system's design and the development of the Control strategy.
2012 Vol. 31 (13): 72-75 [Abstract] ( 607 ) HTML (0 KB)  PDF (1519 KB)  ( 211 )
76 Damage Identification of Composite Structures Based on Reconstruction Algorithm for Probabilistic Inspection of Damage
YAN Hong;ZHOU Li
DOI:
Abstract: In this paper, the reconstruction algorithm for probabilistic inspection of damage (RAPID) is proposed for continuous on-line monitoring of composites based on wavelet analysis and the theory of probability and statistics. First, the wavelet analysis is applied to extract the features of the Lamb wave signals of the reference and present states on each sensing path. The difference coefficient between the features is called as a damage index (DI). Then, the probabilistic method is used to judge that the DI is caused by either the structural damage or the environmental factors. Finally, a tomogram generated by the RAPID algorithm is obtained to identify the damage. An experimental study on a composite panel with a 12-PZT sensor network is conducted and presented to verify the capability of the RAPID algorithm for damage identification. Experimental results demonstrate that the proposed method is quite feasible and effective for composite structural damage identification. And also, it has certain application value for the practical engineering.
2012 Vol. 31 (13): 76-80 [Abstract] ( 697 ) HTML (0 KB)  PDF (1995 KB)  ( 420 )
81 Gear fault diagnosis of incipient localized tooth wear based on transmission error detection method
Wang Yan-gang;Zheng Hai-qi Cui Yan-ping Li Hui-yong
DOI:
Abstract: With the difficulty of gear system’s diagnosis at the incipient tooth failure under complex structure and work condition, referencing transmission error detection method used in detecting gear setting error and machining error in the precision machine, this paper established a transmission error signal model of two-stage fault gear system, analyzed the effect of incipient gear face wear of middle axis and geometrical offset to the transmission error. Experimental examples were conducted to evaluate the effectiveness of the proposed approach. The results show that transmission error signal had high SNR and the performance of the transmission error detection method is good to diagnosis incipient tooth wear under the complexity structure and work condition.
2012 Vol. 31 (13): 81-84 [Abstract] ( 977 ) HTML (0 KB)  PDF (1556 KB)  ( 522 )
85 The Mechanical Properties and Earthquake Response Influences of LRB in Low Temperature State
LIU Wen-guang.;QIN Huang-ting;HE Wen-fu.;FENG De-min;WANG Hui-qiang
DOI:

Abstract: The effect and variation characteristics of the mechanical properties of Lead Rubber Bearing(LRB) used for isolation structure in Low Temperature is studied in the paper, the low temperature is -40℃, and the temperature correlation of LRB with temperature range from ﹣40℃ to 40℃ is also been studied. Three LRB specimens with diameter of 600mm are tested, and the low-cycle reversed loading experiment under 100% shear deformation and different temperatures is completed by adopting electro-hydraulic servo loading system. The research show that the difference of the mechanical properties of LRB under extremely low temperature compared with room temperature is significant. Based on the test results of the mechanical properties of LRB under low temperature, the temperature correction formulas of stiffness after yielding and yield load and parameters value range of isolation structure design are proposed. Finally, the example of temperature effects on seismic response of isolation structure is given. The results show that temperature effects on the displacement of isolating system、story shear force and the acceleration response in the top of upper structure under strong earthquake is significant.
2012 Vol. 31 (13): 85-90 [Abstract] ( 1145 ) HTML (0 KB)  PDF (2811 KB)  ( 350 )
91 Transformation of implicit method to explicit method
Li Chang-qing;Lou Meng-lin
DOI:
Abstract: The generalized acceleration methods taken as an example,it was proved that implicit method coulbe be transformed to implicit method by solving inverse matrix of coefficient matrix through series expansion and series truncation. The adjoint explicit method of constant acceleration method was detailed described.Afther revealing the relationship between implicit method and explicit method, a kind of implicit method with high accuracy and efficiency could be obtained.
Keywords: general linear acceleration method, dynamic analysis, explicit method, implicit method, stability
2012 Vol. 31 (13): 91-94 [Abstract] ( 1071 ) HTML (0 KB)  PDF (1014 KB)  ( 320 )
95 Time Domain Finite Element Method of Gyroscopic Systems
Sui Yongfeng;;Gao Qiang;Zhong Wan-xie
DOI:
Abstract: Based on the variational principle, time domain finite element method of gyroscopic systems is presented. The corresponding trial function matrix, element stiffness matrix and inhomogeneous force are given. The method inherits the property of symplectic conservation and enhances computational accuracy. The example comparing the numerical results obtained from three different methods: time domain FEM, 4th order Runge-Kutta method and Newmark method demonstrates the advantages of time domain FEM.
2012 Vol. 31 (13): 95-98 [Abstract] ( 1055 ) HTML (0 KB)  PDF (1189 KB)  ( 540 )
99 A Semi-Analytical Method to Identify Dynamic Load in Time Domain
CHEN Shuai;YANG Zhi-chun;LI Bin;DANG Hui-xue
DOI:
Abstract: A semi-analytical method of dynamic load identification in time domain is proposed based on modal space transformation, least square fitting and modal superposition. At first, the problem of dynamic load identification is converted to the identification of modal coordinate functions by modal space transformation; then using the structural characteristic parameters and dynamic responses of some given degrees of freedom as the input of load identification, the least square fitting is employed to obtain the fitting functions of modal coordinates; finally, the dynamic loads in time domain are identified by utilising the principle of modal superposition and the governing equations of structural dynamics. The processes of load identification are carried out by taking the acceleration responses derived from simulation and experiment respectively as the inputs. The comparisons between the identified loads and the real ones show that, this method can meet the requirements of identifying the values of dynamic loads and their locations.
2012 Vol. 31 (13): 99-104 [Abstract] ( 1077 ) HTML (0 KB)  PDF (2994 KB)  ( 535 )
105 ELEMENT RESIDIAL ENERGY SENSITIVITY-BASED STRUCTURAL DAMAGE IDENTIFICATION
WU He-liang;Xie Ju-jing;Xiong Zao
DOI:
Abstract: The element residual energy is defined, then， its sensitivity is analyzed.Furthermore， the structural damage identification method based on the sensitivity of element residual energy is presented, responding equations are established. Damage location and severity can be simultaneously determinated by solving the equation. Numerical simulation studies show that the proposed method is effective in different damage cases.
2012 Vol. 31 (13): 105-107 [Abstract] ( 907 ) HTML (0 KB)  PDF (893 KB)  ( 320 )
108 Nonlinear Flutter Analysis and Control of the Supersonic Missile Wings
Jia Shang-shuai Ding Qian Liu Wei
DOI:
Abstract: The nonlinear aeroelastic stability and active control of the supersonic missile wings are investigated. Adopting the third-order piston, the nonlinear aeroelastic dynamic equations with freeplay nonlinearity are derived, both linear and nonlinear flutter speed are obtained through hopf bifurcation theory and numerical method respectively. The design method based on differential geometry and quadratic optimal control for nonlinear system controller is used to stabilize the flutter. At last, the influence of the controller and the system parameters are analyzed. The simulation result shows that the method based on differential geometry and linear quadratic optimal is an effective way in control of nonlinear flutter.
2012 Vol. 31 (13): 108-112 [Abstract] ( 1156 ) HTML (0 KB)  PDF (1447 KB)  ( 333 )
113 Characteristics variation of blasting seismic wave energy affected by a damping ditch
DING Kai;FANG Xiang;FAN Lei;LI Dong;ZHANG Yang-yi
DOI:
Abstract: A blasting vibration test was monitored by laying 5 measurement points at both sides nearby of a damping ditch. The collected signals were investigated with the method of wavelet packet energy spectrum analysis. The energy variation of blasting seismic wave and the energy distribution of each measurement point were obtained. The results of test and analysis showed that the energy of blasting seismic wave is effectively attenuated by the damping ditch, whereas energy magnification exists in a certain distance after the damping ditch; The damping ditch decreases the frequency bands of the signal whose original energy is distributed in high or intermediate frequency bands, and increases the frequency bands of the signal whose original energy is distributed in low frequency bands.
2012 Vol. 31 (13): 113-118 [Abstract] ( 701 ) HTML (0 KB)  PDF (2069 KB)  ( 369 )
119 A Diesel Engine Fault Diagnosis Method Based on the Instantaneous Angular Speed Fluctuation Ratio
Ma Jin;Jiang Zhi-nong Gao Jin-ji
DOI:
Abstract: Instantaneous angular speed fluctuation ratio(IASFR) of a diesel engine contains a lot of information about gas pressure in cylinders, which can be used to diagnose combustion-related faults and other faults affecting the gas pressure, such as fuel leakage in fuel system, valve leakage, ignition fault, etc. In this paper, a dynamic model was presented, and the relationship between the instantaneous angular speed, gas pressure torque, inertia torque and the load torque was analyzed in theory. Four feature parameters of the time domain and harmonic IASFO waveform were presented. Finally, it is verified the effectiveness of analyzing diesel engine ignition problem by a set of simulation data and a fault instance, and providing an early warning method on diesel engine ignition condition.
2012 Vol. 31 (13): 119-124 [Abstract] ( 987 ) HTML (0 KB)  PDF (2155 KB)  ( 256 )
125 Research on the Control of Electromagnetic Suspension Vibration Isolator based on LMS Algorithm with Saturation Constraint
CHEN Hao;WANG Yong;LI Jia-quan;LU Yang
DOI:
Abstract: Limiting the output power of the electromagnetic suspension vibration isolator is researched in this thesis .Because limiting anti-saturated LMS algorithm is very likely aroused and deteriorates the effect of control of the system and the threshold is difficult to determine of Boaz Rafaely algorithm, if the threshold is large, the system is very likely aroused and deteriorates the effect of control, if the threshold is small, the effect of the system control is bad,a novel approach, namely adding continuous punished function, is proposed in the framework of the adaptive feedforward control on the basis of LMS algorithm. The improvement LMS algorithm is reduced and the anti-saturation adaptive feedforward control law is designed accordingly. In order to verify the method is more superior than limiting anti-saturated LMS algorithm and Boaz Rafaely algorithm, simulation and active vibration control experiment on the electromagnetic suspension vibration isolation system was designed.
2012 Vol. 31 (13): 125-128 [Abstract] ( 549 ) HTML (0 KB)  PDF (1913 KB)  ( 433 )
129 Experimental Study and Fault Signals Analysising of Rotating Machinery Based on Dual EEMD and Wigner-Ville
GUO Qi;LIU Bu-yu;SHI Li-bo;LI bo
DOI:
Abstract Wigner-Ville distribution(WVD) is widely used in the filed of signal processing dues to all kinds of excellent mathematical characteristics. However, the cross-terms of the WVD often brings us lots of problems, because the WVD is not additive in the calculation. Aiming at this problem, cross-terms erasing method based on dual Ensemble Empirical Mode Decomposition(EEMD) is put forward in this paper. This method firstly decomposes the original signal into several Intrinsic Mode Functions(IMFs) by EEMD. Then deal with the IMFs obtained with the EEMD again and now a group of new IMFs can be gained. After calculating each of the IMFs’ WVD we can gain the WVD of original signal by adding the results together. The method presented in this paper effectively avoids the cross-terms of WVD with less mode mixing while keeps the advantages of WVD. The method is used in the signal processing of the rub fault and has gained a perfect effect.
2012 Vol. 31 (13): 129-133 [Abstract] ( 1100 ) HTML (0 KB)  PDF (2367 KB)  ( 746 )
134 Research of AutomotiveTransmission Noise Source Identification based on Microphone Array
SHI Quan;GUO Dong;SHI Xiao-hui;Yi Peng
DOI:
Abstract: The source of gear whine in automotive transmission is identified. Firstly, the whine noise is tested in the Hemi-anechoicroom.Through frequency spectrum analysis and noise contribution analysis ,the whine spectrum is found. The problem is special that different gears have the same mesh frequency. Aim at this special problem, the acoustic camera is used and the source of the gear whine is found.Finally,through FEM the nature frequency of the transmission house is caculated.The transmission house is resonated in some frequency.The research provides experiment basis for modification of the gear design parameter and the structure of the transmission house to achive low noise transmission.
2012 Vol. 31 (13): 134-137 [Abstract] ( 971 ) HTML (0 KB)  PDF (1511 KB)  ( 351 )
138 Force identification in time domain based on dynamic programming
ZHU Tao;XIAO Shou-na;YANG Guang-wu
DOI:
Abstract: A new method was proposed for identifying the time history of the input excitation based on dynamic programming in time domain. Using the state-space formulation and the least square error method, the objective function is established between measured and identified system responses. Then Bellman's Principle of Optimality is commonly used for the minimization of the objective function to estimate the excitation forces, finally the dynamic programming method of identification formulations are deduced. The numerical example is provided to verify the proposed model, and satisfactory results are achieved even the measurement noise is taken into the measurement system responses.
2012 Vol. 31 (13): 138-141 [Abstract] ( 985 ) HTML (0 KB)  PDF (1435 KB)  ( 243 )
142 Nonlinear vibrations of axially moving viscoelastic Timoshenko beams under strong external excitation
Li Biao;Tang You-Qi;Ding Hu;Chen Li-Qun;
DOI:
Abstract: This paper investigated nonlinear vibrations under strong external excitations of axially moving viscoelastic Timoshenko beams. The governing partial-differential equations are derived from extended Hamilton’s principle. The effects of shear deformation and rotary inertia are taken into account by the Timoshenko beam theory. The beam material obeys the Kelvin model in which the viscoelastic constitution relation use material derivative, not simple the partial time derivative. The method of multiple scales is applied to obtain the steady state response and establish the solvability conditions. The stability boundaries are formulated analytically via Routh-Hurwitz criterion. Some numerical examples are presented to demonstrate the effects of related parameters on the response.
2012 Vol. 31 (13): 142-146 [Abstract] ( 1039 ) HTML (0 KB)  PDF (1002 KB)  ( 882 )
147 The analysis of the coupling response of the track-tunnel-ground system based on FEM and TMM
Zhou Biao;Xie Xiong-yao;
DOI:
Abstract: A theoretical model that combined the FEM (Finite Element method) and TM(Transfer Method) is presented to simulate the dynamic response induced by the moving quasi-static or harmonic load in metro line in this paper. In this model, the tunnel is simplified as an Euler beam and coupled with the track system and the surrounding layers, where the track system is modelled by FEM while the surrounding layers is modelled by TM. Based on this theoretical model for the track-tunnel-ground layers, the dispersion characteristics of the propagating modes of vibration in the track, tunnel and the ground are presented, and the response of the ground includes the surface motion and ground stress are discussed in relation to these propagating wavenumbers. Based on this analysis, the influence factor to the wave propagation at the track and tunnel are given and Some important features of the coupled system is found.
2012 Vol. 31 (13): 147-153 [Abstract] ( 1053 ) HTML (0 KB)  PDF (1576 KB)  ( 357 )
154 Coupling vibration analysis of train and simply-supported bridge system subjected to floating-ice collision
XIA Chaoyi;LEI Junqing;ZHANG Nan
DOI:

Abstract: A coupled vibration analysis model is established for train-bridge system subjected to floating-ice collision load. The collision load time history curve of floating-ice obtained via site experiment is applied on the bridge piers in transient style. The dynamic responses of railway bridges subjected to floating-ice collision and their influences on the running safety of high-speed trains are analyzed by computer simulation. Using the computer code programmed by the authors to simulate the whole histories of a train traveling on a seven-span simply-supported bridge with 24m box girders when the floating-ice strikes on bridge piers, the dynamic responses of the bridge and the train vehicles are studied. The calculation results show that the lateral acceleration of the bridge and running safety indices such as the derailment factors and offload factors of train vehicles exceed the corresponding allowances when the train speed is higher than 250 km/h, indicating that collision of floating-ice has obvious effect on the coupled vibration responses of train-bridge system.
2012 Vol. 31 (13): 154-158 [Abstract] ( 1016 ) HTML (0 KB)  PDF (1659 KB)  ( 360 )
159 Responses Prediction of Satellite Structures Vibration Caused by Disturbances of Flying Wheels Using Energy Method
WANG Kun ZHAO Yang MA Wen-lai WANG You-yi
DOI:
Abstract: Energy Finite Element Method (EFEM) was used to predict structural vibration responses caused by disturbances of flying wheels. The main cause of the disturbances was discussed and a sinusoidal force was used as an excitation after analyzing the characteristics of the model of the flying wheels disturbances. The energy density responses of the vibration in space and frequency fields were calculated and compared with the responses from the wave method. It is indicated that the results from the EFEM correspond to the averaged results from the traditional wave method. Besides, the results show that the EFEM demands less for the mathematical models of the excitations and the boundaries, and as a newly introduced method for responses calculation of the spacecraft under flying wheels disturbances, the EFEM is expected more practical in the engineering and high-frequency field.
2012 Vol. 31 (13): 159-162 [Abstract] ( 1124 ) HTML (0 KB)  PDF (1291 KB)  ( 288 )
163 Rotational Vibration Modeling and Optimization Design of Serpentine Belt Accessory Drive System with One-Way Clutch
ZHANG Shao-fei;SHANGGUAN Wen-bin;ZENG Xiang-kun
DOI:
Abstract: A mathematical model for nonlinear rotational vibration analysis of a three pulley-Serpentine Belt Accessory Drive system (SBADs) with a One-Way Clutch is established. Gear’s method is used to calculate the angle fluctuations of driven pulleys and tensioner arm. Calculation results present that, the dynamic characteristics of the SBADs including angle fluctuations of driven pulleys and tensioner arm, tension of each belt span, and slip rate between belt and pulley decrease significantly with an one-way clutch. Then, the dynamic properties of the SBADs are investigated by different spring stiffness of the one-way clutch, and different inertia ratio of the accessory shaft and driven pulley. Moreover, an optimization design model of two parameters including the spring stiffness of the one-way clutch, and the inertia of the accessory shaft is established. In the optimization model, the minimum of the angle fluctuation of the tensioner arm, the spring torque of the one-way clutch, and the slip ratio between belt and driven pulley are taken as objective functions. The optimization parameters can be obtained by using Fminimax function in the Matlab software. The analytical results show that the dynamic responses of the SBADs decrease significantly with the optimization parameters. The methods of modeling, calculation and optimization design are instructive for the vibration control of an engine Front End Accessory Drive (FEAD) system with an one-way clutch.
2012 Vol. 31 (13): 163-168 [Abstract] ( 1176 ) HTML (0 KB)  PDF (2225 KB)  ( 1077 )
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