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2013 Vol. 32, No. 15
Published: 2013-08-15
 
       论文
1 Recent and future development of multi-degree-of-freedom ultrasonic motors
Guo Ji-feng;Bai Yang;Wang Jian
DOI:
Ultrasonic motors (USM) have the advantages of low speed, high torque, quick response, high resolution and anti-electromagnetic interference, which bring them broad application prospects in the field of robots, industrial instrument and security technologies. Multi-degree-of-freedom (MDOF) motor is one of the most cutting-edge aspects of the ultrasonic motor researches. In this paper, several typical MDOF ultrasonic motors of different types are introduced. The structure, working principle and characteristics are mainly discussed. Some typical examples are given and the key achievements are summarized, as well as their applications. The research and development trends are proposed in the end.
2013 Vol. 32 (15): 1-7 [Abstract] ( 486 ) HTML (0 KB)  PDF (1733 KB)  ( 809 )
8 Pull-in Stability of an Electrostatically ActuatedMEMS Resonant Sensor and Its Control
Huilin Shang Yongpeng Wen
DOI:
A model of electrostatically actuated MEMS resonant sensor is considered in this paper. Basing on the
theory of safe basin, we discuss dynamical pull-in instability caused by dc bias voltage and the amplitude of ac voltage in
detail. The threshold of the system parameters of the dynamical pull in is obtained by the Melnikov method. The 4th
Runge-Kutta and the point mapping methods are employed numerically to verify the effect of the amplitude of ac voltage
on the basin of attraction of pull in of the system. It is found that the increasing of dc bias voltage may cause the pull-in
phenomena, and the increasing of ac voltage may induce pull-in instability of the structure. Then the delayed position
feedback is applied to reduce the pull-in instability. The numerical results verify the effectiveness of the control approach.The paper provides some potential applications for the design of electrostatically actuated resonant MEMS sensors．
2013 Vol. 32 (15): 8-13 [Abstract] ( 461 ) HTML (0 KB)  PDF (1674 KB)  ( 283 )
14 Research on Natural Characteristics and Sensitivity for 3-stage Planetary Gears Train Used in Shield Machine Cutter Driver
Qi yinming;Gong xiansheng;Zhang ganqing;Sun shengmiao
DOI:
A translational-rotational coupling dynamic model of 3-stage planetary gears train was established, including complicated factors, such as, time-varying mesh stiffness, time-varying phase angles of planetary position, mesh synthetic errors and damping. Based on the eigenvalue problem, the natural frequencies were calculated. The vibration modes were classified into three types: rotational coupling modes, translational coupling modes and planet modes and the unique properties of each type were examined. The natural frequency sensitivities to system parameters were investigated. The results show that, for some sensitive regions of the parameters, the micro-changes of system parameters can cause great variation of the natural frequency sensitivities and the modal strain energy, the energy transfer between stages, as result, the vibration characteristic worsen.
2013 Vol. 32 (15): 14-19 [Abstract] ( 525 ) HTML (0 KB)  PDF (1685 KB)  ( 420 )
20 Gearbox state identification and remaining useful life prediction based on MoG-HMM
Xinghui Zhang Jianshe Kang Cunming Gao Duanchao Cao Hongzhi Teng
DOI:
A new approach for state recognition and remaining useful life (RUL) prediction based on Mixture of Gaussians Hidden Markov Model (MoG-HMM) was presented. State number optimization method was established based on cluster validity measures. One can recognize the state through identifying the MoG-HMM that best fits the observations. Then, the RUL prediction method was presented at the recognition base. Finally, the data of gearbox’s full life cycle test was used to demonstrate the proposed methods. The results showed that the mean accuracy performance was 90.94%.
2013 Vol. 32 (15): 20-25 [Abstract] ( 535 ) HTML (0 KB)  PDF (2541 KB)  ( 366 )
26 Floating Characteristics’ Impact on Vibration of Wind Turbine
Jin Xin;ZHONG Xiang;He Yulin;Du Jing;ＬＩＱｉｍｉ
DOI:
In this paper, the floating wind turbine system was researched based on former study. The sea environmental load analysis model and mooring system were established, based on which system dynamics analysis and load calculation was researched. Studies have shown that: floating platform has great influence on the vibration on wind turbine, under the same conditions suffered by floating wind turbine and fixed wind turbine, vibration on floating turbine changes in amplitude relatively large, which means reduction in fatigue life for floating wind turbine, therefore, the design method for the float wind turbine should be revised and improved.
2013 Vol. 32 (15): 26-31 [Abstract] ( 499 ) HTML (0 KB)  PDF (2489 KB)  ( 377 )
32 In-line VIV Analysis of Deep-water Top Tensioned Riser
QU Xue;XUE Hong-xiang;TANG Wen-yong
DOI:

In-line VIV analysis model of top tensioned riser is created based on the finite element method and the principle of energy conservation, by using hydrodynamic parameters which are derived from forced vibration experiments. Considering the influence of cross-flow vibration and the different sources of in-line lift force, response amplitudes are calculated in different frequency interval and superposed. Compared with measuring results from experiments of Chaplin, the forecast gives satisfactory results.

2013 Vol. 32 (15): 32-36 [Abstract] ( 502 ) HTML (0 KB)  PDF (2021 KB)  ( 343 )
37 Wind Pressure Simulation and Key Influence Factors Analysis of Mexico-Hat like Spatial Structures
CHEN Yiran;ZHOU Dai;GUI Luosheng
DOI:
Based on computational fluid dynamics and SST k-ε turbulence model, the wind pressure distribution of Mexico-hat like spatial structures is numerically investigated and analyzed by using FLUENT software. The benchmark problem is used to verify numerical results by comparing the current simulation with the existing research results from related references. The influence of height-width ratio on the wind pressure distribution on different parts of Mexico-hat like spatial structure is studied in detail.
2013 Vol. 32 (15): 37-40 [Abstract] ( 422 ) HTML (0 KB)  PDF (2491 KB)  ( 319 )
41 Hysteresis behavior analysis of the mixed structures with concrete-filled steel tubular frame and RC shear wall
WANG Wen-da WEI Guo-qiang LI Hua-wei
DOI:
In order to study the seismic performance of the reinforced concrete (RC) shear walls with concrete-filled steel tubular (CFST) columns, the Open System for Earthquake Engineering Simulation (OpenSees), a open-source nonlinear analysis platform, was used to simulate the performance of this type of composite shear wall under low cyclic loading with nonlinear beam-column fiber model based on the other researchers’ experiments about the RC shear walls framed with CFST columns and RC shear walls, respectively. The shear force of fiber sections was simulated by defining the nonlinear shear restoring force in section level. The results obtained from the calculation are in good agreement with those from the experiment. The results show that the fiber modeling method of considering the shear effect could predict the maximum shear force, pinch effect and stiffness degradation of the composite shear walls effectively, and it can also save a lot of computing time because of its high arithmetic efficiency.
2013 Vol. 32 (15): 41-47 [Abstract] ( 566 ) HTML (0 KB)  PDF (2642 KB)  ( 536 )
47 Vibration Analysis and Control of the Spin-Drying Process of a Horizontal Axis Washing Machine during the Transient Stage
CHEN Haiwei ZHANG Qiuju
DOI:
To control vibrations of the spin-drying process of a horizontal axis washing machine during the transient stage, a planner model is built for a horizontal axis washing machine with MR dampers; Numerical simulations considering an acceleration process following an exponential curve is considered, the relation between the maximum vibration amplitude and the time constant of the exponential curve is studied; The average value of the maximum vibration amplitude under several different rotation speeds is calculated, and variations of the average value along with the increase of the mass of the clothes and control current of the MR damper are analyzed, the result shows that the control current of the MR damper has little influence on the optimal time constant, and for clothes with mass between 1 to 9 kilograms, the time constant can be set at 0.7 to achieve a good comprehensive control result. Besides, a simple control strategy of the MR damper considering vibration suppression at the transient stage and vibration isolation at the steady stage is proposed, the short time frontier transform is employed for tracing the vibration frequency of tub, once the frequency grows bigger than a preset value, the control current of the MR turns from the maximum value to the minimum one for vibration isolation, at last, the control effect is proved by numerical simulations.
2013 Vol. 32 (15): 47-53 [Abstract] ( 452 ) HTML (0 KB)  PDF (1570 KB)  ( 527 )
54 Analysis on dynamic characteristics of deep water mooring lines with buoys system
Qiao Dongsheng Yan Jun Ou Jinping;
DOI:
A dynamic analysis model of deep water mooring lines with buoys system is established in time domain. The contact interaction between mooring line and seabed is considered, the fluid drag force and inertia force on the mooring line are calculated according to the Morison formula. The dissipated energy by a mooring line from the floating platform as a result of its oscillation is applied to calculate the mooring-induced damping. Analysis on the impact that buoys system has on the mooring line tension and damping on which they are attached. Moreover, the parameter sensitivity analysis of buoys size and location are executed. The results above may be helpful for reducing the tension in the design of mooring system for deep water floating platform.
2013 Vol. 32 (15): 54-58 [Abstract] ( 505 ) HTML (0 KB)  PDF (2449 KB)  ( 238 )
59 Finite Element Simulation of Ultrasonic Assisted Turning of Titanium Alloy Based on ALE Method
LU Dong HUANG Hong-fu WU Yong-bo;;ＬＥＮＧＣｈａｏｑｕｎ
DOI:
A finite element simulation model for ultrasonic assisted turning (UAT) of Ti-6Al-4V was developed. Cutting force was predicted during one vibration period. The average simulated cutting force was compared with the experimental data with the same cutting parameters. The simulated cutting force was well agreed with the experimented one. The average simulated cutting force was compared with the experimental data in conventional turning (CT). The result shows that the average force of ultrasonic assisted turning is much smaller than the corresponding force during conventional turning. Cutting temperatures for both workpiece and cutting tool were predicted. The results indicate that a drastic increase of the maximum temperature for both workpiece and cutting tool can be observed in the initial cutting stage, and this temperature will present a swift drop after the trajectory of cutting tool reaches its maximum dislocation. The influences of frequency and amplitude were analyzed. The cutting forces increase obviously with the increase of the frequency and amplitude, and the temperature of cutting tool decrease a little with the increase of frequency and amplitude.
2013 Vol. 32 (15): 59-62 [Abstract] ( 528 ) HTML (0 KB)  PDF (1525 KB)  ( 534 )
63 Rational stiffness of single outrigger trusses in frame-core structure with outriggers
LIN Shao-ming;ZHOU Yun;DENG Xue-song;WU Cong-xiao
DOI:
The characteristic parameters of bending stiffness ratio i, shearing stiffness ratio g of outrigger trusses and bending stiffness ratio p of column were investigated in order to get the simplified calculation formula of structural roof displacement in frame-core structure with outriggers. The relationships among the structural roof displacement, internal forces and i, g, p under uniformly distributed loading and earthquake loading were studied through a 253.2-meter super-rise building using the software ETABS. The results show that i, g, p adopted for optimizing the structural lateral stiffness are reasonable and feasible, and p has the greatest influence on the structural lateral stiffness while the second is g and i has the smallest effect. As for the characteristic parameters,
i should not be bigger than 0.6, g should be 0.9～3.5, and p should be 1.3～4.6.
2013 Vol. 32 (15): 63-70 [Abstract] ( 452 ) HTML (0 KB)  PDF (3277 KB)  ( 445 )
71 Prediction of High Frequency Noise Spectrum and Cavitation Inception Speed for Full Scale Propeller behind Submarine in Engineering
YANG Qiongfang WANG Yongsheng ＹＵＬｉａｎｇｑｉｎZHANG Minming
DOI:
For predicting the cavitation inception speed (CIS) and high frequency noise spectrum of full scale propeller behind submarine in engineering, combing cavitation multiphase simulation for model scale with semi-empirical formulas for high frequency noise spectrum prediction of the full scale propeller was used to investigate the CIS, cavitating noise spectrum curves and spectrum source level at the characteristic frequency 1kHz of the 7-bladed highly-skewed propeller behind full-appended SUBOFF submarine’s nominal wake. Validation of the cavitation simulation and tip vortex inception prediction were conducted by the calculated cavity pattern, area, and initial inception point of E779A propeller. Reasonability of the semi-empirical formulations was validated by the predicted noise spectrum of both USS212 submarine and the Agosta-80 submarine’s full scale propellers, and the precision was acceptable. The calculated results show that the CIS of the 7-bladed highly-skewed propeller is 12.8 knots under 16.8m water depth condition, and the spectrum level at 1kHz frequency for 6 knots speed is 101.7dB, which is 2.6 knots higher than that of the Agosta-80 submarine and 0.3dB lower for the spectrum level, so as to present its best noise performances. The numerical method proposed can be a productive approach to assess the full scale propeller’s critical speed and high frequency noise characteristics behind the submarine in engineering.
2013 Vol. 32 (15): 71-76 [Abstract] ( 493 ) HTML (0 KB)  PDF (2278 KB)  ( 209 )
77 The quantitative detection of valve internal air leakage based on acoustic emission theory
LI Zhen-lin;ZHANG Hai-feng;XIA Guang-hui
DOI:
The objective of this paper is to establish the quantitative relations between the valve internal air leakage rate and the root mean square of characteristic parameters of acoustic emission signal ( ). AE testing for valves internal air leakages under test platform was performed to detect and the factors such as the valve internal leakage rate and the valve type were discussed about the effects on AERMS. It is clearly demonstrated that the volume of air leakage rate was successful detected using AERMS, and the max measurement error of acoustic emission detection technology within 10%，therefore the acoustic emission detection technology can be used for the detection of valve internal air leakages.
2013 Vol. 32 (15): 77-81 [Abstract] ( 534 ) HTML (0 KB)  PDF (1083 KB)  ( 294 )
82 Dynamic Characteristics and Coupling Vehicle-Bridge Vibration Analysis of the HSR Sesia Bridge in Italy
GUO Weiwei;XIA He;DE ROECK Guido
DOI:
A 3-D rail-sleeper-ballast-beam FE model is established for the Sesia Bridge in Italy. The natural vibration characteristics of the bridge are analyzed by numerical study and field measurements. The coupled equations of motion are deduced for the vehicle-bridge system by assuming that the wheel-track interaction obeys the wheel-track corresponding assumption both in lateral and vertical directions. Taking the track irregularity samples based on German low disturb track spectra as excitation, the dynamic responses of the Sesia Bridge and the Italian high-speed ETR500Y train vehicles on the bridge are analyzed. The resonant train speeds are discussed and the running safety and stability of the train vehicles are evaluated. Some results are compared with the measured ones and a good agreement is found, thus the efficiency and validity of the established bridge model and proposed method are verified. Numerical results show that the Sesia Bridge is very stiff: as the train runs at the speed of 288km/h, the ratio of dynamic deflection to bridge span is only 1/17510. The vertical displacement of the bridge appears a peak value at the train speed of 340 km/h, indicating that bridge resonance may occur. The dynamic indices of the vehicle on the bridge are small, thus can well satisfy the high-speed train passage.

2013 Vol. 32 (15): 82-88 [Abstract] ( 504 ) HTML (0 KB)  PDF (3275 KB)  ( 570 )
89 A cubic spline symplectic algorithm for dynamic analysis of space truss structure
LI Wei-hua;WANG Yu;LUO En
DOI:
According to the basic idea of dual-complementarity, the unconventional Hamilton-type variational principle in phase space for dynamics of space truss structure is established, which can fully characterize the initial-boundary-value problem of this dynamics．In addition, the Euler function of this variation principle has symplectic structure character．Based on this vairiational principle, a symplectic algorithm which is the result of combining finite element method in space domain with time subdomain method by applying the cubic spline interpolation as approximation to the time subdomain is conducted. The results of numerical example show that the method is a highly efficient method with better computational performance and superior ability of stability compared to Wilson-θ and Newmark-β methods.
2013 Vol. 32 (15): 89-94 [Abstract] ( 442 ) HTML (0 KB)  PDF (1154 KB)  ( 141 )
95 WIND TURBINE ADAPTIVE GUARANTEED PERFORMANCE CONTROLLER DESIGN
Wu Zhongqiang;Xie Jianping
DOI:
Based on the variable speed variable pitch wind generator for wind energy utilization and the dynamic stability of the high demand characteristics，a linear parameter varying(LPV) system model is established，a sufficient condition of the adaptive robust guaranteed cost controller is presented and a new adaptive guaranteed cost controller(AGCC) is proposed in this paper. First，the uncertain parameters of the system is estimated by using the adaptive method，then the estimated uncertain parameters and robust guaranteed cost control are used design state feedback gain，the feedback gain is obtained by a set of method of linear matrix in equality(LMI) constraints，and the controller can meet a quadratic performance evaluation．The simulation results show that，in terms of low or high wind speed，the controller has good robust interference su¬ppression．
2013 Vol. 32 (15): 95-99 [Abstract] ( 491 ) HTML (0 KB)  PDF (974 KB)  ( 217 )
100 Shaking table model design of multilayer simple frame structure
HE Zhi-jian WANG She-liang
DOI:
Considering the performance parameters of the shaking table and the operability of the shaking table test, then adopting the general similitude law, a sliding base isolation five-story reinforced concrete frame structure and roof of the additional layer model was designed. A double deck chassis design was adopted. Model reinforcement area was made equivalent. As much as artificial quality was purchased. Three methods were used to calculate the model including the artificial mass law, the gravity forces-neglecting law and not enough artificial mass law. The results of the study show that: the weight set is reasonable. The not enough artificial mass law is appropriate and feasible. It can reduce the gravitational distortion effect of the model and control the acceleration amplification factor within reasonable limits, to reduce the noise influence and experimental error.
2013 Vol. 32 (15): 100-105 [Abstract] ( 539 ) HTML (0 KB)  PDF (974 KB)  ( 227 )
106 Subsection Forward Modeling Technology of Blasting Stress Wave Underground
Yan Bo;Zeng Xinwu
DOI:
The subsection calculating numerical simulating technology is presented to solve the problem of forward modeling of blasting stress wave which spans scales of time, space and strain rate. The simulated region is divided into the blasting source region where the dynamic finite element algorithms are applied and the elastic region where the traditional numerical simulating algorithms are applied, as well as the displacement compatibility boundary conditions of nodes in boundaries between different regions are introduced in the technology. The reasonability and implementation steps of the subsection calculating numerical simulating technology are illustrated. Numerical simulations of stress wave propagation in rock under blasting indicate that the subsection calculating technology is correct and effective.
2013 Vol. 32 (15): 106-110 [Abstract] ( 443 ) HTML (0 KB)  PDF (1436 KB)  ( 220 )
111 Sensitivity Calculation of Beam-Mass Structure Using Higher-Order Beam Element
WANG Dong;MA Jian-jung
DOI:
The calculation of dynamic behaviors of a beam structure with a lumped mass of both translational and rotary inertias is studied using two types of higher–order beam elements. By adding respectively independent variables of the curvature and its first-order derivative at a node, the frequency and its sensitivity with respect to the position of the lumped mass attachment can be calculated accurately using the higher-order beam elements. Further, numerical results show that use of the generic beam element of the cubic polynomial displacement can also achieve the frequency sensitivity satisfactorily with a dense finite element mesh.
2013 Vol. 32 (15): 111-115 [Abstract] ( 529 ) HTML (0 KB)  PDF (1067 KB)  ( 327 )
116 Coalmine Roadway Excavation Blasting Seismic Wave Signal Analysis Based on HHT Method
ZONG Qi.;WANG Haibo.;XU Ying.;FU Jugen.
DOI:
Blasting seismic wave signal frequency spectrum characteristics and energy distribution of coalmine roadway excavation was studied by the HHT method and EMD decomposition. The results show that: the master frequency of roadway excavation blasting in range of 100 Hz to 250 Hz, and the main energy concentrated in range of 160 to 260 Hz; energy distribution in range of 0 to 160 Hz weak, and distributed uniform. Due to millisecond blasting, correspond with particle vibration amplitude, vibration energy mainly concentrated in two time periods: 0.25 s to 0.31 s, 0.35 s to 0.4 s, and there are four instantaneous peaks, the largest instantaneous energy was caused by charge of caving holes. According to the research results, countermeasures for blasting seismic effect reduction were given from view of blasting energy control.
2013 Vol. 32 (15): 116-120 [Abstract] ( 455 ) HTML (0 KB)  PDF (1826 KB)  ( 183 )
121 Studies on the dynamic response and the perforation failure of the cylindrical shell subjected to lateral local impulsive loading
JI Chong;LONG Yuan;FANG Xiang;LIU Qiang;GAO Fu-yin
DOI:

By means of an explicit nonlinear dynamic finite element computer code LS-DYNA and the plastic kinematic Cowper-Symonds model, the nonlinear dynamic response process of fully clamped cylindrical shell subjected to lateral local impact by a hemispherical-nosed projectile were numerically simulated. The dynamic deformation and failure modes of cylindrical shells under different impact conditions were acquired. The minimum impact speed at which cracks through the thickness of the shell wall were generated, termed the speed for rupture, was studied. The results demonstrate that the failure modes of cylindrical shell relates to circumferential impact oblique angle and impact speed. The local dent, dish-shaped deformation and perfoation will occure. The speed for rupture increases with increasing angle of obliquity. The study can be applied to the engineering prediction of the damage or safety of cylindrical shell under lateral local impact and can provide theory reference for safety design.
2013 Vol. 32 (15): 121-125 [Abstract] ( 513 ) HTML (0 KB)  PDF (2278 KB)  ( 263 )
126 Analysis on the Dissipation Power of Near-field at Beam Junctions Considering Internal Damping
ZHENG Guo-tao GUO Feng-lin
DOI:
This study establishes wave equation of simple three semi-infinite beams coupled at arbitrary angles based on the theory of Euler-Bernoulli beam with internal damping taken into account. According to the equilibrium and continuity conditions of the junction, near-field amplitude subjected to flexural wave and longitudinal wave excitations is derived. Due to the introduction of internal damping coefficient, the near-field terms will be attenuated. Near-field dissipation power coefficients are obtained from the relationship between the vibration amplitude and the vibration power. An example of three semi-infinite beam junctions coupled at arbitrary angles is studied to reveal the effects of internal damping coefficient, coupled angles and excitation frequency on near-field dissipation power coefficient. Numerical results show some interesting phenomena and this study can provide references and guidelines for the design of vibration of coupled beams.
2013 Vol. 32 (15): 126-129 [Abstract] ( 440 ) HTML (0 KB)  PDF (1428 KB)  ( 282 )
130 Shaking table test of earthquake-damaged masonry structure strengthened with BFRP
LEI Zhen;ZHOU Deyuan;ZHANG Hui;LI Yaming
DOI:
The earthquake investigation shows that masonry buildings are prone to severe damage or even collapse due to their seismic vulnerability. BFRP has excellent physical and mechanical properties as well as its low cost, but it isn’t widely used in the strengthening of earthquake-damaged structures. Based on the shaking table tests of pre-damaged model (1:4 scaled three-storeyed masonry structure model) and earthquake-damaged model strengthened with BFRP, the validity of strengthening with BFRP on earthquake-damaged masonry structure was verified through contrasting and analyzing the dynamic characteristics, seismic response and damage of models in each test. The experimental results show that this strengthening technique without changing the structure weight can not only ameliorate the brittleness of masonry and delay the crack development in the wall, but also increase the structural integrity and stiffness and improve the ductility and the energy dissipation capacity. The seismic performance of earthquake-damaged masonry structure after reinforcement can reach or even exceed that of the undamaged structure, which proves the highly effective of strengthening with BFRP on earthquake-damaged masonry structures.
2013 Vol. 32 (15): 130-137 [Abstract] ( 481 ) HTML (0 KB)  PDF (2365 KB)  ( 427 )
138 Research in the end issue of EMD based on mean generating functionperiod superposition extrapolation
LI Zhao;ZHOU Xiao-jun;XU Yun
DOI:
The end effect exists in HHT. According to the generation mechanism and through the research in the existing method of the end effect, a method based on Mean Generating Function (MGF) period superposition extrapolation is proposed for the end effect. Through the construction of the MGF matrix about the signal, extract the advantage cycle, superposition and extension, then it can be used to forecast the data beyond the ends of the signal. This method can overcome the defect that only finite extremes near the ends are used in the existing extreme extension methods. What’s more, compared with other prediction methods, it is more accurate and easy, and can save more time of calculation. It is verified from the simulation and real signal that this method can effectively inhibit the end effect.
2013 Vol. 32 (15): 138-143 [Abstract] ( 435 ) HTML (0 KB)  PDF (2463 KB)  ( 483 )
144 Analysis of Dynamic Responses for rails and panels of rectangle electromagnetic rail launcher
He Wei Bai Xiangzhong
DOI:

Simply the rectangle electromagnetic rail launcher’s rails and panel as double elastic foundation beam, and use the Dirac and Heaviside function to represent the distribution electromagnetic force caused by the moving armature and the concentrated loads on the rail respectively, then the dynamic response equation of the rail and panels in working condition was established in this paper. By the theory of modal orthogonality and regularization, the analytic solution of the rail and panels was calculated. Through an example, the rail and panels’ dynamic response was analyzed when the motion parameter and structural parameter were given, and the analytic solution’s reliability was verified through compared with the ANSYS numerical results. The research results in this paper give a foundation for rectangle electromagnetic rail launcher’s dynamic response analysis.
2013 Vol. 32 (15): 144-148 [Abstract] ( 428 ) HTML (0 KB)  PDF (1473 KB)  ( 214 )
149 Effects of to Near-Fault Directivity Pulse -like Ground Motion on Elastic-Plastic Seismic Response of High-speed Railway Bridge
Chen Ling-kun;Zhang Nan;Hu Chao;Xu Qing-yuan
DOI:
Based on the PEER-NAG Strong Ground Motion Database, the finite element model of the multi-span simply supported bridge is set up by means of ANSYS software, ANSYS-APDL language and moment-curvature program in the paper, the natural vibration properties of structure is analyzed, the elastic-plastic seismic responses of bridge subjected to the near/far-fault ground motions are calculated. The calculation results show that, for the hysteretic characteristics of the near-fault directivity pulse-like earthquake, the more just expression should be the moment-rotation relationship of pier bottom is characterized by the central strengthened hysteretic cycles at some point of the loading time-history curve corresponding to the time of the pulse, it require the bridge piers to dissipate considerable input energy in a single or relatively few plastic cycles, it is mean that the ductility capacity of the piers should be improved; the displacement of girder and pier top, moment of the pier bottom increase under near fault ground motion compared with far-fault ground motion; the energy dissipation on the bridge system subjected to a far-fault motion tends to gradually increase over a longer duration, causing an incremental build-up of input energy; as the greater vertical earthquake action of the near-fault earthquake, there are the large vertical deflection in the mid-span of girder; GB 50111-2006 Code for seismic design of railway engineering specify that the vertical earthquake force can be taken as 67% of the lateral earthquake, it's advisable that the reasonable value of vertical earthquake acceleration should be utilized to carried simulation calculation.
2013 Vol. 32 (15): 149-155 [Abstract] ( 516 ) HTML (0 KB)  PDF (2747 KB)  ( 198 )
156 Research on the durability of particle impact dampers
LI Hai-chao;WANG Shu-lin;DU Yan-chen;LI Sheng-juan;XU Bo;Dunliang Jian;ZHU Yu-fang
DOI:
As passive vibration absorber, particle impact damper performance will be influenced by the evolution of particles size and morphology during the impact process. This paper for the first time deals with the durability of the ball impact dampers with Zn particles of median diameter 35m as the damping agent in the container installed on a cantilever subjected to sinusoidal vibration within 96-hour impacting. We show that the response of the primary system is slightly increased three times in the period investigated. It may be ascribed to the change of the morphology and energy state of the Zn particles inside the absorber. With the impacts progressing, particles cold welding may occur which decreases the velocity of the impactor (the ball) and consequently the momentum exchange. On the other hand, the decreased strain energy and dislocation energy of the Zn particles could also reduce the irreversible energy consumption of the system. At the same time, particle size decreasing with working time makes the particles difficult to be further cloven. All these may reduce the irreversible energy consumption. That is why the cantilever response increases step by step with extended step length.

2013 Vol. 32 (15): 156-160 [Abstract] ( 472 ) HTML (0 KB)  PDF (1695 KB)  ( 254 )
161 Study on Response Analysis of Smart Spring Vibration Isolation System under Harmonic Base Excitation Using Piecewise Analytic Method
NI De ZHU Ru-Peng BAO He-Yun HU Zheng-Gen
DOI:
The model of negative vibration isolation system based on the Smart Spring was established. Firstly, it was proposed that the non-smooth system caused by dry friction is piecewise linear, so that the analytical solution of system response could be solved by connected-seam method. And then the possible response pattern of the system was studied. Lastly, using numeric simulation, the motion characteristics varied with the operating frequency which near the slip-starting frequency, for a set of structural parameters, was analyzed. The following conclusions may be drawn from the analysis result. The response curve of the vibration isolation system has a greater distortion in the slip region, and it possesses rich motion features. The results show that the single- period response, multi-period sub-harmonic response, super-harmonic response, qusi-periodic and chaotic response arise in the system. The system tends to maintain sticking motion outside the slipping region, as a result, the primary spring and the active spring are rigidly coupling to a single degree of freedom system. So there are two kinds of motion status in the system, including multi-period and aperiodic response. The vibration isolation system based on the Smart Spring Mechanism(SSM) can be used to suppress the vibration transmission in a adaptive manner by control the piezoelectric actuator voltage in order to vary both the stiffness and damping.
2013 Vol. 32 (15): 161-167 [Abstract] ( 480 ) HTML (0 KB)  PDF (2044 KB)  ( 192 )
168 Research on vibration characteristics of the seat semi-active suspension system
Zhu Sihong;Zhu Xingxing;Ma Ran;Zhuge Ping
DOI:
Based on air spring with auxiliary chamber and MR damper, a new experimental system of semi-active air suspension seat was established. Suspension stiffness and damping were respectively adjusted by proportional valve input voltage and damper input current. The seat suspension vibration characteristics under different parametric were experimentally studied. The results show that the proportional valve input voltage and damper input current have a greater effect on dynamic amplification factor and acceleration RMS in resonance region, while the low frequency vibration and the isolation region are less affected. The natural frequency of seat suspension will decrease with the increase of proportional valve input voltage, the dynamic amplification factor and acceleration RMS in resonance region will decrease with the increase of damper input current.
2013 Vol. 32 (15): 168-172 [Abstract] ( 497 ) HTML (0 KB)  PDF (2842 KB)  ( 218 )
173 Longitudinal Vibration on Hoisting Systems with Time-varying Length
BAO Ji-hu;ZHANG Peng;ZHU Chang-ming
DOI:
Aimed at the longitudinal vibration of rope hoisting systems with time-varying length, the governing equations are developed employing energy method and the Lagrange method considering mutual influence of the rigid motion and deformation of rope. In the mean time, The motions of elevator hoisting systems were illustrated to evaluate the proposed mathematical models. The results of simulation show that the modeling methods can represent the longitudinal vibration of rope hoisting systems with time-varying length in the paper. The governing equations derived can provide reference for further study.
2013 Vol. 32 (15): 173-177 [Abstract] ( 470 ) HTML (0 KB)  PDF (1192 KB)  ( 406 )
178 Study on the hybrid algorithm of computational dynamics of multibody system introduced discrete time transfer matrix method of multibody system
GAO Hao-peng;HUANG Ying-yun;ZHAO Jian-hua;SUN Yu-peng
DOI:
Taking the modeling of complex system dynamics as research background, with the instruction of computational dynamics of multi-body systems theory and discrete time transfer matrix method, this paper discusses the advantages and disadvantages of the two methods about modeling and solving. On that basis, the hybrid algorithm of dynamics of multibody system introduced discrete time transfer matrix method is proposed. And, this paper discusses the dynamics modeling process of mechanical system using this hybrid algorithm. The hybrid algorithm is fit for dynamics modeling and solving of complex mechanical system, and it is easily achieved by computer application softwares. Taken the typical mechanical structure as example, the whole process of modeling and solving by hybrid algorithm is achieved. The results show the feasibility and characteristics of the hybrid algorithm.
2013 Vol. 32 (15): 178-183 [Abstract] ( 514 ) HTML (0 KB)  PDF (1570 KB)  ( 758 )
184 Modeling and Control of Giant Magnetostrictive Actuator Based on a Hammerstein-like Model by Using Fuzzy Tree Method
Wei Zhang;Ping Liu;Qingsong Liu;Zhen Zhang;Jianqin Mao;Kemin Zhou
DOI:
A Hammerstein-like model based on Fuzzy Tree method (FT) is proposed to model the rate-dependent Hysteresis nonlinearity of the Giant Magnetostrictive Actuator (GMA) and is validated through experimental data. The proposed dynamic modeling method can realize constructing a unique model in a given frequency range with respect to both single frequency and multiple frequency input signals. Based on the proposed model, a PID feedback controller combined with an inverse compensation of the nonlinearity in the feedforward loop is used for tracking control. Experimental results show that the control strategy is effective.
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2013 Vol. 32 (15): 184-189 [Abstract] ( 404 ) HTML (0 KB)  PDF (2335 KB)  ( 209 )
190 mailSeismic response analysis of long-period SDOF system under typical ground motions
WANG Bo BAI Guo-liang DAI Hui-juan
DOI:
Pseudo-resonance and transient effects of long-period structures were analyzed based on the analysis of seismic response of SDOF (single degree of freedom) system. Far-field harmonic-like ground motions and near-fault pulse-like ground motions are two types of long-period ground motions which can lead to pseudo-resonance of long-period structures, but contrast analysis of characteristics for long-period ground motions and seismic response is still rare. Firstly, based on the contrast analysis of predominant frequency and energy distribution coefficient, characteristics of energy time-frequency distribution were analyzed. The results show that: energy of two types of long-period ground motions are concentrated in lower frequency bands, especially far-field harmonic-like ground motions; in time domain, energy distribution of near-fault pulse-like ground motions and ordinary ground motions are more concentrated than far-field harmonic-like ground motions. Secondly, elastic response spectrum were analyzed and the results show that: in long-period bands, response spectrum values corresponding to far-field harmonic-like ground motions and near-fault pulse-like ground motions are greater than ordinary ground motions, especially velocity response spectrum, displacement response spectrum and input energy spectrum; all kinds of reaction for far-field harmonic-like ground motions are much greater than near-fault pulse-like ground motions and attenuation of the former is much more slowly. Finally, concept of the transient effect was put forward, and transient effects of actual ground motions were analyzed. The results show that: transient effects are natural attributes of high-frequency components of ground motions, which couldn’t cause transient displacement damage of long-period structures. In long-period structural seismic design, it is necessary to consider the pseudo-resonance caused by two types of long-period ground motions, while it is unnecessary to consider transient effects.
2013 Vol. 32 (15): 190-196 [Abstract] ( 462 ) HTML (0 KB)  PDF (1897 KB)  ( 586 )
197 Nonlinear dynamics of a rub-impact rotor supported by oil film bearings with a elastic stator
Tao Hai-liang;Pan Bo;Gao Qing;Tan Chun-qing;Chen Hai-sheng
DOI:
A dynamic model of rotor-bearing system with rub-impact fault was established, taking the stator elasticity and nonlinear oil-film force into account. The response of the rotor with rub-impact fault was calculated by Rugge-Kutta method, and the bifurcation diagrams were obtained to analyze dynamic characteristics of the system. The dynamic characteristics of the system with or without rubbing were compared and discussed. The effects of stator mass and rubbing stiffness on the response of the system was studied. The results indicate that the bigger stator mass and rubbing stiffness is, the greater coupling effects will happen on the rotor and stator. If the rubbing stiffness is small enough, the rubbing force of the stator has little effect on the dynamic characteristics of the system.
2013 Vol. 32 (15): 197-202 [Abstract] ( 444 ) HTML (0 KB)  PDF (2589 KB)  ( 217 )
203 The Influence of Vibration Shock on Transient Thermal Elastohydrodynamic Lubrication of Seawater-lubricated Plastic Bearings
Zhang Lijing Wang Youqiang
DOI:
A numerical model of elastohydrodynamic lubrication considering thermal and transient effects for seawater-lubricated plastic bearings subjected to impact load is built. The distributions of lubricating film pressure and film thickness are obtained by numerical simulation by using the multi-grid method for pressure, the multi-integration method for deformation and the column scanning method for temperature rise. The characteristics of variation with time of central pressure, central film thickness and minimum film thickness are analyzed when the bearing is subjected to continuous impact loads, such as sine pulse and triangular pulse, and the influences of load amplitude and pulse width on pressure and film thickness are discussed. Numerical results reveal that the variation period of pressure is in the same of that of the impact load, but variation of the film thickness lags behind the variations of the load and the pressure. With the increase of the load amplitude, the amplitudes of the pressure and film thickness increase, the symmetric line of the central pressure moves down, the symmetric line of the film thickness moves up. The maximum value of the central pressure becomes higher, and the minimum value of the minimum film thickness turns smaller when the pulse width increases.
2013 Vol. 32 (15): 203-208 [Abstract] ( 461 ) HTML (0 KB)  PDF (1764 KB)  ( 208 )
209 Study on coupling faults of rotary machinery diagnosis method based EMD and fractal box dimension
HAN Dongying LI Geng SHI Peiming
DOI:
Aiming at coupling faults diagnosis of rotary machinery, based on EMD (Empirical Mode Decomposition) and fractal box dimension method of faults diagnosis is proposed. With the method combining adaptability of EMD processing nonlinear signal and characteristic that fractal box dimension can quantificationally describe nonlinear behaviors, the method through the first to process fault signal by EMD and obtain Intrinsic Mode Function (IMF) containing fault characteristic, than to solve box dimension of IMF and to diagnose fault through comparing and analyzing the box dimension. A dynamic model of the rotor -bearing system is established consider in coupling fault of crack rub-impact and pedestal looseness, vibration signal of fault model is obtained with Runge-Kutta method. Through to analyze coupling fault signal, getting coupling fault feature vector, meanwhile, comparing with the traditional boundary spectrum diagnosis method, proving the method for coupling fault diagnosis of rotating machinery validity and advantage.
2013 Vol. 32 (15): 209-214 [Abstract] ( 465 ) HTML (0 KB)  PDF (1369 KB)  ( 313 )
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