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18 October 2011, Volume 31 Issue 5 Previous Issue    Next Issue
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2.振动理论与数值解法
3.运载工具振动与噪声
4.环境振动与环境声学
5.建筑振动与建筑声学
6.信号处理与故障诊断
7.减振降噪设备和器材
9.振动噪声测试技术
10.工程实践


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2.振动理论与数值解法

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Study on Influence of Vibration Absorber’s Base on Its Vibration Attenuation Effect XU Zhen-Bang 2011, 31(5): 1-4.  DOI: 10.3969/j.issn.1006-1355-2011.05.001 Abstract ( )   In reality, all vibration absorbers have bases. When the vibration absorber is fixed to a flexible base, the base will affect its vibration attenuation effect. Aiming at this problem, simulation researches are carried out with the power flow method in this paper. A mathematical model of the system composed of the vibration absorber with a base and coupled with an ends-fixed beam is established. With this model, the vibration attenuation effects of the vibration absorbers fixed at different positions of the beam are simulated, and the influence of the base size on the vibration attenuation effect is analyzed. On the basis, the vibration attenuation effect with double vibration absorbers attached is compared with that with a single vibration absorber attached. The results show that the vibration attenuation effect of the vibration absorber can be improved effectively by optimizing its base and installation condition. This work provides guidance for the engineering application of the vibration absorbers. Related Articles | Metrics

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Analysis of Sound Power Sensitivity of Plates with Displacement Degrees of Freedom Using Improved Acoustic Radiation Modes WU Jin-wu;TAN Fei 2011, 31(5): 5-8.  DOI: 10.3969/j.issn.1006-1355-2011.05.002 Abstract ( )   A new method to solve the sound power sensitivity of plates with displacement degrees of freedom is proposed by using the improved acoustic radiation modes model to deal with acoustic radiation and using FEM vibration model for vibration analysis to trcat the structural vibration .Taking a simply supported plate with displacement degrees of freedom as a simulation example, the simulation results show the validity of the presented method. Related Articles | Metrics

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Radiation Noise Estimation Method for Compartment Structure TIAN Tao;PENG Xu;ZHAO Zhi-gao;YU Yong-feng 2011, 31(5): 9-12.  DOI: 10.3969/j.issn.1006-1355-2011.05.003 Abstract ( )   Underwater mechanical noise is one of the main noise sources of submarines. In this paper, the transfer paths of radiation noises of mechanical equipments of the submarines are analyzed, and the procedure from shell vibration to radiation noise prediction is studied theoretically and experimentally. Distribution of vibration acceleration of the inner and outer shells is measured by model testing. The mean-square vibration velocity of the inner and outer shells is computed. With sub-band radiation efficiency formula of stiffened cylindrical shell, the values of radiation sound pressure are predicted using the mean-square vibration velocities of the inner-and-outer shells. The results are compared with the experimental data. It shows that the computation and experimental results are in good agreement. It is concluded that only the inner-shell vibration signal is necessary for prediction of radiation noise of the double-layer shell structure. Therefore, the feasibility of radiation noise prediction through the shell structural vibration is demonstrated. Related Articles | Metrics

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Analysis and Assessment of Vibration Energy Transmission of Fluid-filled Pipelines Yao Yu-Zhong;Jun Zhou;Zhu-Shi Rao;TA Na 2011, 31(5): 13-16.  DOI: 10.3969/j.issn.1006-1355-2011.05.004 Abstract ( )   Solving the finite element equation for vibration analysis, the force and displacement responses of a fluid-filled pipeline are obtained. Using the solution, the power flow and energy distribution in the pipeline are gained. Then, pipeline vibration can be assessed quantitatively according to the energy. Taking the energy of the average length of the pipeline as the assessment parameter, the magnitudes of vibration of the pipeline with different constraint conditions are assessed quantitatively. Comparing the results with those of the traditional displacement-based assessment method, it is concluded that the energy-based assessment method proposed in this paper is more reasonable and accurate. The energy-based assessment parameter provides an effective theoretical base for vibration control of fluid-filled pipelines. Related Articles | Metrics

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Modeling of Vibration Drive by Electromagnetic Field for Rotary Permanent Magnet LV Yang-ming;YANG Bin-tang;MENG Guang;XU Wen-bing;XIA Ming-lu;QIAN Wen-tao 2011, 31(5): 17-21.  DOI: 10.3969/j.issn.1006-1355-2011.05.005 Abstract ( )   A theoretical modeling method and the experimental verification for a proposed principle of rotary permanent magnet drive excited by electromagnetic field are presented in this paper. Electromagnetic torque of a permanent magnetic rotor under electromagnetic excitation is usually a nonlinear function of external electromagnetic field and its rotary angle. So, it is difficult to compute the electromagnetic torque directly by using common electromagnetic analysis methods. Based on surface magnetic charge, this study searches for a numerical method for calculating the drive torque with the electromagnetic field applied to the rotary permanent magnet. Meanwhile, the theoretical model for analyzing the relation of the torque of the combined magnetic field versus the excitation current and the rotary angle of the permanent magnet is established. This model may present a quasi-static and dynamic vibration drive process of the rotary permanent magnet under electromagnetic field excitation. The research finally validates the theoretical analysis and modeling method by experimental tests in terms of modeling accuracy and applicability of this theory in vibration drive. Related Articles | Metrics

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Supporting Characteristics of Bearings and Their Effects on Dynamical Behaviors of Rotor System MA Jun;DAI Jun;SUN Bing-nan;KOU Xi-ping;JING Jian-ping 2011, 31(5): 22-26.  DOI: 10.3969/j.issn.1006-1355-2011.05.006 Abstract ( )   Aiming at the rotor test rig，the rotor-bearing system is modeled for different types of lubrication bearings, the dynamical behaviors of the rotor system are then investigated. The dynamical stiffness and damping coefficients for different bearing key parameters are also studied. Via comparison, the dynamical supporting characteristics under different bearing parameters are discussed. With consideration of the different foundation support stiffness, the critical speeds of the rotor-bearing system are also investigated. Related Articles | Metrics

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Review on Complex Flexible Vibration Isolation System GAO Yun-jian;XU Shi-yin 2011, 31(5): 27-31.  DOI: 10.3969/j.issn.1006-1355-2011.05.007 Abstract ( )   A detailed literature reviews on complex flexible isolation system, especially for floating raft system, are given in the aspects of research objects, modelling approaches and vibration isolation performance index. The flexibiltiy of substructures and stationary wave effects in isolators are discussed. Some modeling approaches such as substructure method, finite element method and power flow analysis are summarized. Related Articles | Metrics

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ummary on Vibro-acoustic Modeling of Complex Underwater Cylindrical Shell Structure HOU Lei;HUANG Xiu-chang;XU Shi-yin 2011, 31(5): 32-36.  DOI: 10.3969/j.issn.1006-1355-2011.05.008 Abstract ( )   A detailed literature review on vibro-acoustic modeling of complex underwater cylindrical shell structure is given, in both aspects of research objects and modeling approaches. Reviews on infinitely long and finitely cylindrical shell, double layer cylindrical shell, ribbed cylindrical shell, and the cylindrical shell with internal bases (floors, foundations etc) and complex vibration isolation system are presented. Methods for modeling dynamic responses of fluid-loaded cylindrical shell in low frequency, mid-frequency and high frequency ranges are given. Some potential modeling techniques are provided. Related Articles | Metrics

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Summary on Vibration Control of Periodic Structure CHEN Bin;HUANG Xiu-chang 2011, 31(5): 37-41.  DOI: 10.3969/j.issn.1006-1355-2011.05.009 Abstract ( )   A detailed literature review on vibration of periodic structure is given, in both aspects of research objects and modeling approaches. The researches on periodically supported structure, periodic ribbed plate and shell, periodic truss, periodic chiral lattice, phononic crystal, disordered periodic structure, metamaterials are addressed. Methods for solving the band gaps and dynamic responses of periodic structure are summarized. Related Articles | Metrics

3.运载工具振动与噪声

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Performance Simulation and Noise Reduction of Engine Intake System HOU Xian-jun;;ZHU Mei-ying;; LIU Zhi-en;;YAN Fu-wu;;YANG Xiao 2011, 31(5): 42-44.  DOI: 10.3969/j.issn.1006-1355-2011.05.010 Abstract ( )   Performance simulation and optimization of noise reduction of engine’s intake system are researched in this paper. The models for simulating the intake system performance are established by GT-Power. Due to the problem that the noise in inlet port is higher than the target noise at some individual rotary speeds under the Sound Pressure Level (SPL) of order, the volume of air-filter is increased, and the parameters of Helmholtz resonator and 1/4 wavelength pipe are adjusted. The results of simulation verify that after optimization the total SPL and the SPL of order in the inlet port are lower than the target noise, and the pressure loss is less than 2.5kPa, which means that the engine noise is reduced significantly. Related Articles | Metrics

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Study and Improvement on Sound Quality of Car’s Interior Noise LIU Zhi-en;;ZHAO Nan-nan;;HOU Xian-jun;;YUAN Shou-li; 2011, 31(5): 45-48.  DOI: 10.3969/j.issn.1006-1355-2011.05.011 Abstract ( )   Aiming at the interior abnormal noise during idling and rapid acceleration of a car, the main noise sources, which are the second order and resonance noises, are identified by the tailpipe noise measurement and modal test respectively. A resonant chamber is designed to lower the sound level of the second order and resonant frequencies. A pinch-can structure is used to reduce the high frequency flow noise. And the tailpipe noise at transient accelerating is simulated by GT-Power software. The test results show that the maximum values of transient tailpipe noises at idling and rapid acceleration can be reduced by 11.7 dB(A) and 8 dB(A) respectively. Related Articles | Metrics

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Study on the Effect of Torsional Stiffness of Driveline’s Component on Torsional Vibration Modes of RWD Driveline ZHAO Qian;DENG Jiang-hua;WANG Hai-yang 2011, 31(5): 49-52.  DOI: 10.3969/j.issn.1006-1355-2011.05.012 Abstract ( )   The model of the RWD’s SUV for torsional vibration analysis is established, and the torsional vibration modes of the SUV are computed. The validity of the model and algorithm is proved by comparing the results with measured data. Subsequently, the model and algorithm are employed to study the sensibility of the driveline’s torsional modes to the clutch damper stiffness, transmission-shaft stiffness and axle shaft stiffness. Finally, the influence of the torsional stiffness of the driveline’s components, such as conventional clutch damper, transmission shaft and axle shaft, on the torsional vibration modes of the driveline is summarized. This work is of significance for target setting of driveline’s torsional vibration modes and the development of driveline’s NVH. Related Articles | Metrics

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Research on Optimization Strategy of Power- plant Mounting System for Idle Shake Control CHEN Da-liang;LV Jing;LI Hong-liang 2011, 31(5): 53-57.  DOI: 10.3969/j.issn.1006-1355-2011.05.013 Abstract ( )   Design of power-plant mounting systems is mostly based on Modal Decupling at the early development process of a new case of cars. For obtaining a good mounting system, it is important to choose a reasonable coordinate system for modal decoupling and to make an effective modal optimization strategy. In this paper, the correlation between the rigid body modal parameters and dynamic engine mounting force is investigated in detail. Some general principles are proposed to improve the validity of idle shake control based on the method of modal decoupling. Related Articles | Metrics

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Study on Objective Sound Quality Evaluation of Automotive Door Closing Sound DENG Jiang-hua;XIA Hong-bing 2011, 31(5): 58-61.  DOI: 10.3969/j.issn.1006-1355-2011.05.014 Abstract ( )   Currently, research of sound quality of automobiles is mainly focused on the steady sound, and there are very few methods for transient sound quality evaluation. In addition, traditional FFT method is often adopted in sound signal processing, while the transient property of the acoustic signal has not been considered adequately. Automotive door closing sound is a transient impulse sound, and the quality of door closing sound can reflect the quality of vehicles. In this paper, first of all, the quality of door closing sound of some types of vehicles is evaluated using traditional evaluation parameters. Then, the wavelet transform method is used to analyze the sound signal of the door closing sound in time frequency domain. It is indicated that the traditional parameters such as loudness, sharpness, roughness, and so on can not sufficiently reflect the sound quality characteristics of transient sound, while the time-frequency analysis is a good complement for the sound quality evaluation. However, selection of the evaluation parameters remains a problem for further study. Related Articles | Metrics

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Study on Simulation Method for Sound Quality Evaluation of Vehicle Exhaust Noise SHI Yan;;SHU Ge-qun;BI Feng-rong 2011, 31(5): 62-66.  DOI: 10.3969/j.issn.1006-1355-2011.05.015 Abstract ( )   Subjective evaluation of vehicle’s exhaust noises is executed by paired comparison jury test, and the sound quality prediction model of vehicle exhaust noise is established based on back-propagation (BP) neural network. The acoustic characteristic of muffler is obtained through the computational fluid dynamics simulation, and the frequency spectrum of the exhaust noise of the vehicle with muffler fitted is derived. The objective parameters of the simulated exhaust noise, such as loudness, sharpness, roughness and so on, are calculated based on psychoacoustics theory. Then, the sensory pleasantness is simulated by importing these objective parameters into the sound quality prediction model which is established previously. Thus, the whole numerical simulation method for sound quality evaluation of vehicle’s exhaust noise is fulfilled. The reliability of the simulation method is verified by comparison of the simulation results with the experimental data. Related Articles | Metrics

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Study on the Influence of Rubber Block Materials on NVH Performance of Vehicle Door YUE Yang;LIU Qiang;MA Fang-wu;XIEYu;ZHANG Meng;LIU Fang;ZHAO Fu-quan 2011, 31(5): 66-70.  DOI: 10.3969/j.issn.1006-1355-2011.05.016 Abstract ( )   A model for NVH performance simulation for vehicle’s door subsystem is established based on FEM (Finite Element Method). A set of material test methods is developed to acquire the mechanical property of vibration isolating rubber block in complex technological conditions. Parameters of different materials are incorporated into the simulation model. By comparison of the results, the influence of different materials of the vibration isolating rubber blocks on the NVH performance of vehicle’s door subsystem can be found. This work may provide with guidance for selection of the materials of vibration isolating rubber blocks and for improvement of material proparation. Related Articles | Metrics

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perational Energy Transfer Path Analysis of Vehicle Interior Noise WANG Bin-xing;ZHENG Si-fa;HAO Peng;LIAN Xiao-min 2011, 31(5): 71-74.  DOI: 10.3969/j.issn.1006-1355-2011.05.017 Abstract ( )   Transfer path analysis is an important tool to analyze the vehicle’s interior noise. In medium and high frequency range, there exist significant variations in transfer functions among individual products which are produced to be identical. To provide more universal and instructive analysis results to the ensemble of products, operational transfer path analysis based on energy is put forward and applied to the interior noise analysis of a heavy truck cab. Results of the analysis are validated by comparison with those of test method. Comparison of the results with those from the traditional operational-transfer-path analysis method shows that under the same given condition, the transfer functions estimated by the new method are more stable. Related Articles | Metrics

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Study on Torsional and Bending Vibration of Rear-drive Transmission XIA Yuan-feng;LI Hong-cheng;TANG Yu;TIAN Xiong; 2011, 31(5): 75-79.  DOI: 10.3969/j.issn.1006-1355-2011.05.018 Abstract ( )   A rigid-flexible coupling model for torsional vibration analysis of a rear-drive transmission system is established using multi-body dynamic theory. Natural frequencies and modes of the torsional vibration are calculated for each transmission gear of the transmission system. The system frequencies which influence the transmission rattle are analyzed and verified by NVH testing. The harmonic responses and forced vibration are analyzed and the results are verified by the system’s torsional vibration testing. ?The bending modes for the transfer shaft system are calculated by a modal synthesis method. The result is compared with that by finite element method, and both results are in good agreement. Finally, the influence of the stiffness of middle support on the first vibration mode of the transmission system is analyzed. Related Articles | Metrics

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Study on Idle Vibration Control of Steering System YANG Liang;;WU Xing-rang;;ZHANG Shuo;;TAN Wang-jun; 2011, 31(5): 80-85.  DOI: 10.3969/j.issn.1006-1355-2011.05.019 Abstract ( )   The mechanism and control methods of vibration of the steering wheel at idle are analyzed. Study is focused on the transmission path of the half shaft universal joint and the main influencing factors of natural frequency of the steering system. Aiming at the problem of overly large vibration of the steering wheel at idle condition for an AT vehicle when the air conditioner is switched on, the excitation source, the main transfer path and the steering system modals are analyzed. The main cause of the huge vibration is found to be the extremely large force from the half shaft and the coupling effect of the steering wheel natural frequency and the engine excitation frequency. Through reducing the idle target speed of the engine by 50rpm, changing the drive shaft universal joint from DO-type to GI-type and strengthening the steering column structure, the transfer force of the half shaft is reduced significantly and the natural frequency of the steering system is increased, so that the idle vibration of the steering wheel is controlled effectively. Related Articles | Metrics

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Study on Gearbox Vibration Performance Based on Statistical Energy Analysis FENG Hui-hua;ZHAO Zhi-fang;LU Shou-wei;ZUO Zheng-xing 2011, 31(5): 86-89.  DOI: 10.3969/j.issn.1006-1355-2011.05.020 Abstract ( )   The statistical energy analysis (SEA) is applied to analyze the high frequency vibration characteristics of a gearbox. Number of modals of the gearbox is acquired by the Finite Element Analysis in the 1/3 octave frequency domain to define the suitable frequency range for SEA. The equivalent masses of two subsystems of gearbox are acquired by experimental measurement. The internal loss factors and coupling loss factors of the two subsystems are measured by the modified power injection method. The SEA model of the gearbox is established in software VAONE using the measured SEA parameters, and then the vibration response of random force excitation is calculated. Since the simulation solution and measured results agree well, the validity of the measurement method and the effectiveness of analysis of vibration response using SEA is proved. The vibration response of the gearbox under operation condition is analyzed using the gearbox SEA modal established in previous work. The results show that SEA method can analyze the vibration response of complex structure effectively. Related Articles | Metrics

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R&D of Sound Quality of Automotive Throttle Flow Noise ZHANG Jun;LIU Han-jie;YE Peng; 2011, 31(5): 90-92.  DOI: 10.3969/j.issn.1006-1355-2011.05.021 Abstract ( )   Very few works on sound quality research of automobile’s throttle can be found in our Country. In this paper, mechanism analysis and control method of throttle’s flow noise are elaborated in combination with a practical engineering case in automobile development. By optimizing the EFI match, adding deflector and improving sound package acoustic insulation performance, the throttle’s sound quality, when the vehicle is accelerating or rapid braking, is significantly improved. And the product market risk of the user’s complaints is greatly reduced. At the same time, influence of improvement of the throttle’s sound quality on the external characteristics of powertrain is analyzed. This work may be helpful for further study of the throttle’s flow noise and the transient NVH performance. Related Articles | Metrics

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The Study of Vehicle Active Suspension and EPS Integrated Control Based on Fuzzy Neural Network YUAN Chuan-yi;BEI Shao-yi;HE Qing;ZHANG Yan 2011, 31(5): 99-103.  DOI: 10.3969/j.issn.1006-1355-2011.05.023 Abstract ( )   The dynamic model of vehicle’s active suspension for steering analysis is established. The EPS model, tire model and road-condition input model are introduced. Fuzzy neural network control method is used to design the vehicle’s active suspension and the integrated EPS control system. According to the changes of the body posture of the vehicle, the active force and the EPS assistant torque of the actuator of the active suspension system can be adjusted dynamically. The simulation and analysis are carried out for different steering-wheel angle input. The results show that compared to the uncontrolled suspension and steering system, the vertical acceleration peak and standard deviation of the active suspension and the EPS integrated control system are decreased by 40.94% and 26.06%, and the peak and standard deviation of transverse angular velocity of the vehicle are decreased by 6.24% and 48.15%. Thus, the vehicle body’s vibration is suppressed effectively, and the ride-comfort and handling stability are greatly improved. Related Articles | Metrics

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Co-simulation on Semi-active Suspension of Vehicles ZHAO Yong-guang;CHEN Jian 2011, 31(5): 104-107.  DOI: 10.3969/j.issn.1006-1355-2011.05.024 Abstract ( )   This paper presents the co-simulation of a semi-active suspension of a vehicle. Firstly, a multi-body dynamic model of the suspension is established by using ADAMS code. Secondly, a fuzzy controller for semi-active suspension is programmed by means of Matlab/Simulink. Finally, the co-simulation is carried out based on ADAMS and Matlab/Simulink. Simulation results show that the semi-active suspension system can improve the ride performance of the vehicle. Related Articles | Metrics

4.环境振动与环境声学

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Study On location of Damping Material for Vibration of Metal Brush Of Micromotor HAN Xu;MA Jun;WANG Jia-ke;CUI Zhao-long 2011, 31(5): 108-112.  DOI: 10.3969/j.issn.1006-1355-2011.05.025 Abstract ( )   In order to increase the lifespan and efficiency of micromotors, the damping effect of the metal brushes of micromotors is studied. The relationship between Rayleigh damping model and dissipation factor of materials is established. The location of rubber damper in the structure is simulated and optimized by means of the transient dynamic analysis module of MSC.Marc. Meanwhile, the vibration magnitudes of the metal brushes are measured with Polytec Scanning Vibrometer when the rubber damper attached at the original and optimal locations respectively. The results show that the vibration magnitude of triple frequency after the optimization can be reduced to 12.1 % (clockwise rotation) and 11.2 % (counterclockwise rotation) respectively. This method can improve the vibration performance of metal brushes. It is of significance for engineering practice. Related Articles | Metrics

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Effect of Penetration on Aerodynamic Acoustic Characteristics of Chevron Nozzle ZHU Xi-jia;OU-YANG Hua;TIAN Jie;DU Zhao-hui 2011, 31(5): 113-116.  DOI: 10.3969/j.issn.1006-1355-2011.05.026 Abstract ( )   Using TR-PIV technique and far-field measurement method, the aerodynamic acoustic characteristics of chevron nozzles with different penetrations have been studied at the Mach number Ma=0.12. Flow field results show that the chevron nozzles can reduce the potential core length and increase the mixing of the air flows in the core with the environment. With the penetration being higher, this tendency is increased. It is found that the chevron nozzles with high penetration can reduce low frequency noise, but increases high frequency noise; while the chevron nozzles with low penetration can reduce the global sound pressure level of the noise effectively. At aft angle of 150°, the chevron nozzle with low penetration can bring noise suppression by 1.3 dB. This work is of practical significance for jet noise control of factories. Related Articles | Metrics

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Experimental Study on Sound Barrier Equivalent Frequency of Passenger Trains GONG Kai;LIU Lin-ya 2011, 31(5): 117-120.  DOI: 10.3969/j.issn.1006-1355-2011.05.027 Abstract ( )   Setting sound barriers is becoming one of the important measures all over the world for control of railway noises. While the sound barrier’s design is affected by many factors. Equivalent frequency of the sound barrier is one of the key factors, which has direct influence upon the calculation of the sound barrier attenuation. To make the sound barrier’s design reasonable, fast and reliable, the noise frequencies of passenger trains under the condition of different kinds of locomotive tractions at various speeds are studied experimentally. Through the statistical analysis of the measurement data, the sound barrier’s equivalent frequencies of the passenger trains under different conditions are obtained. Related Articles | Metrics

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Research of Noise Reduction with Steeper Approach YAN Guo-hua;FEI Dai-xiang 2011, 31(5): 121-125.  DOI: 10.3969/j.issn.1006-1355-2011.05.028 Abstract ( )   With the development of civil aviation industry, the aircraft’s noise around the airports has been becoming a serious problem. In this paper, several domestic and international noise reduction procedures are studied. The attention is paid mainly to the steeper (6 degrees) approach noise reduction procedures. The potential benefits of the steeper approach are evaluated by the reduction of the area covered by the noise of aircraft’s landing. This work is a part of the project supported by the International Civil Aviation Organization (ICAO). Related Articles | Metrics

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Location Optimization of Piezoelectric Actuators for Active Control Decoupling Based on the Theory of Radiation Modes LENG Zhen-bo;JIANG Zhe 2011, 31(5): 126-129.  DOI: 10.3969/j.issn.1006-1355-2011.05.029 Abstract ( )   The location of optimization of piezoelectric actuator based on the theory of radiation modes in the active control decoupling is studied. Previous researches have proposed that as long as four groups of actuators are arranged symmetrically, active control decoupling based on radiation modes can be achieved. Since there are many symmetrical layouts for the four groups of actuators, it is worth studying which layout is the best. In this paper, based on the object of minimizing the input control power, the locations of the four groups of piezoelectric actuators are optimized. Related Articles | Metrics

5.建筑振动与建筑声学

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Computer Simulation of Wind Induced RandomVibration on Stay Cables FANG Zhi-hua;LI Chen 2011, 31(5): 130-132.  DOI: 10.3969/j.issn.1006-1355-2011.05.030 Abstract ( )   Stay cable is one of the main components in cable-stayed bridge. Since this component has large compliance, light weight, small damp and low natural vibration frequency, the wind-induced vibration may occur very often. Thus, it is necessary to study the vibration response of the stay cable to the wind load excitation. In this paper, random wind load is introduced to the finite element model of the cable. Wind induced vibration of cables is simulated with the computer. The method is proved economic and effective. It has significance for design of the cable-stayed bridge, and provides a base for further study of wind-induced response control. Related Articles | Metrics

6.信号处理与故障诊断

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Research of Rolling Bearings Fault Diagnosis CHEN Yong-hui;JIANG Xu;ZHANG Xue-liang;LI Hai-hong 2011, 31(5): 133-136.  DOI: 10.3969/j.issn.1006-1355-2011.05.031 Abstract ( )   For the non-stationary and modulation features of rolling bearing’s fault signals, a method based on wavelet analysis is employed. The signals including fault information are decomposed and reconstructed by wavelet analysis method. Then, demodulation and fine spectral analysis of the signals are carried out by using Hilbert transform. The characteristic frequencies of the fault signals are extracted, and the fault patterns of the rolling bearings can be recognized. It is found that the wavelet analysis and Hilbert transform are effective in identifying the local defects of rolling bearings. Related Articles | Metrics

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Study on Moving Detrended Fluctuation Analysis Applied in Machinery Fault Diagnosis GUO Yu-xiu;ZHANG Jin-min;YUAN Jing 2011, 31(5): 137-141.  DOI: 10.3969/j.issn.1006-1355-2011.05.032 Abstract ( )   The method of Moving Detrended Fluctuation Analysis (MDFA) is studied, and the scaling exponent of the signal time sequence is obtained. It is found that the scaling exponent fluctuates greatly at the signal mutation point, while it fluctuates slightly in the trouble-free places. Thus, MDFA method can be used to detect the mutations in engineering signals. In this paper, the MDFA method is applied to the simulation of the signals due to mutation faults in gears and bearings, and the results show that the MDFA method is effective in mutations fault diagnosis of rotary machines. Related Articles | Metrics

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Study on Application of EMD and HOC in Fault Diagnosis for Rolling Bearings YANG Wei-xin;JIANG Qin-yu;WANG Zhen;GUO Fang 2011, 31(5): 142-145.  DOI: 10.3969/j.issn.1006-1355-2011.05.033 Abstract ( )   Resonant demodulation is one of the most commonly used methods for rolling bearing fault diagnosis. However, this method is less effective sometimes since the early fault signal contains strong background noise. In this paper, a new denoising method based on empirical mode decomposition (EMD) and high-order cumulative quantities (HOC) is proposed. Fault signals are firstly decomposed into several intrinsic mode functions and then each function is analyzed and reconstructed using higher-order cumulative quantities. Finally, the fault characteristics of rolling bearing are extracted by using resonance demodulation. A practical example of fault diagnosis shows that this method has more preponderant than the traditional resonance demodulation method. Related Articles | Metrics

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Study on Application of WCPSO Optimizing Wavelet Neural Network for Gear Box Fault Diagnosis LIU Fen;PAN Hong-xia 2011, 31(5): 146-149.  DOI: 10.3969/j.issn.1006-1355-2011.05.034 Abstract ( )   Aiming at the problem of complex vibration signal and the difficulty to predict the fault type of gearboxes, this paper proposes a wavelet neural network optimization algorithm (WCPSO) for fault diagnosis of the gearboxes. This algorithm is a particle swarm optimization based on the dynamic acceleration constant coordinating with inertia weight. The diagnosis result of the WCPSO optimizing wavelet neural network is compared with that of the traditional wavelet neural network. It is concluded that this method can obviously improve the accuracy and raise the convergence speed, and has high recognition rate for multi-fault symptoms. Thus, it is an effective method for fault diagnosis. Related Articles | Metrics

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Atudy on Application of Multi-model Estimation Method on Human Pulse Objectivity GONG Qi-miao 2011, 31(5): 150-152.  DOI: 10.3969/j.issn.1006-1355-2011.05.035 Abstract ( )   Via the analysis of the previous studies of the objectivity of human pulse, the multi-model estimation method (MME) is proposed to identify the feature information and its key parameters of human pulse. It is expected that the proposed MME method may become an effective method for human pulse identification. Related Articles | Metrics

7.减振降噪设备和器材

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Research on Protective Performance of Low-density Metal Foam Cushion on Ship Personnel Subjected to Shock Loads ZHAO Yong-jie;ZHANG Qing-qing 2011, 31(5): 153-156.  DOI: 10.3969/j.issn.1006-1355-2011.05.036 Abstract ( )   In this study, the potential attenuation performance of an metal foam cushion inserted between standing-man and ship deck is investigated theoretically. An 5-DOF lumped-parameter model is used to predict the standing-man’s biodynamic responses. The cushion is modeled by rigid-perfectly plastic-locking（RPPL）model. The influence of critical buckling force level and some other design factors on the attenuation performance of the foam cushion is discussed in detail. Some general design rules are also presented. Related Articles | Metrics

9.振动噪声测试技术

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Design and Construction of Semi-anechoic Chamber of Whole Vehicle KANG Run-cheng;LU Ye;LIU Yong 2011, 31(5): 157-160.  DOI: 10.3969/j.issn.1006-1355-2011.05.037 Abstract ( )   The acoustic environmental requirements for whole-vehicle noise testing according to the ISO 362, ECE R51, and GB 1495-2002 standards are introduced. Referring to the national and international standards such as GB 6882-1986 and ISO 3745-2003 and considering the requirements in actual usage, some indexes of the whole vehicle’s semi-anechoic chamber construction are proposed for the National Automobile Quality Supervision Test Center (NAQSTC) in Xiangfan. The laboratory for the testing in the NAQSTC has been appraised by China’s Institute of Metrology. The detail of the design, construction and the appraisement of the whole vehicle semi-anechoic chamber is introduced. Related Articles | Metrics

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Analysis of Facilities of Norwegian Acoustic Testing Field in Heggernes LIU Xing-zhang;CHEN Tao 2011, 31(5): 161-164.  DOI: 10.3969/j.issn.1006-1355-2011.05.038 Abstract ( )   Testing of underwater radiation noise of submarines using acoustic testing field is one of the important measures for improving the submarine’s silence in some developed countries. The Norwegian acoustic testing field in Heggernes is the most important testing field for measuring underwater noise of submarines of the members of NATO such as Germany, Holland, Demark, Norway and so on. In this paper, the characters of location and main facilities of the testing field are introduced. The advantages and disadvantages of the testing field construction in bay area are analyzed. Roles of the static testing field and the dynamic ranging to the testing field construction are studied. This discussion may be helpful for construction of acoustic testing field in our country. Related Articles | Metrics

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Sensitivity Analysis of Engine’s Mounting System Based on Orthogonal Experiments ZHANG Wu;;CHEN Jian;CHEN Ming 2011, 31(5): 168-172.  DOI: 10.3969/j.issn.1006-1355-2011.05.040 Abstract ( )   Based on orthogonal experiments, sensitivity analysis of an engine’s mounting system is made to show the influence of the mounting locations on the sixth-order natural frequency and vibration decoupling rate. The mounting coordinates parameters determined by the natural frequency and main vibration coupling are analyzed and identified. The calculation shows that the change of the natural frequency and decoupling rate depends on several mounting coordinate parameters, and the coordinates of the right and back mountings play an important role. The experiment results provide a theoretical basis for the decoupling layout and robust design. This method can be employed for sensitivity analysis of discrete, non-differential or implicit-expression structures, and is of great significance for optimization design of these structures. Related Articles | Metrics

10.工程实践

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Research of Typical Noise Control Technology of Substation in Urban Area ZHOU Jian-fei;ZHOU Nian-guang;YANG Jin-cun;LV Jian-hong;CHEN Shao-yi 2011, 31(5): 173-177.  DOI: 10.3969/j.issn.1006-1355-2011.05.041 Abstract ( )   In this paper, a technical scheme for noise control of 220 kV and 110 kV substations in urban area is proposed. Based on the principle of energy-saving and environment protection, several issues, such as the location, typical design, planning, main equipments, noise control and so on, in the technical scheme are discussed. Some effective technical measures for noise control are provided. This work may provide a technical guidance for noise control of substations in urban area. Related Articles | Metrics

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Improving Raft Fixing Technique Liang xiang-dong 2011, 31(5): 178-180.  DOI: 10.3969/j.issn.1006-1355-2011.05.042 Abstract ( )   The raft is a kind of effective vibration isolators. Recently, the rafts with larger and larger sizes have been developed and produced. Because of the large size of the raft, location change of the supports of the raft frame will leads to large deflection, and there will be different shapes of fixing surface corresponding to the different distributions of supports. If the raft were installed according to its altitude only, the change of deflection of the fixing surface would cause the difference between actual loads and the design loads of the isolators. In order to confirm the efficiency of isolators, the cause of the load error is analyzed and some suggestions for improving the raft fixing technique are proposed. Related Articles | Metrics