bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Investigation of Automobile Interior Wind Noise Using a Production Vehicle
Authors: He Yin Zhi , Yang Zhi Gang , Wang Yi Gang
Published: September 2011

Based on the analysis of automobile aerodynamic noise generation mechanisms and the components of interior wind noise, the spectra characteristics and spatial distribution rule of sound level of interior wind noise were investigated at first, then the frequency characteristics and noise level under different wind speeds, different yaw angles in SAWTC full-scale aeroacoustic wind tunnel were studied. The results show that: the interior noise level was nearly symmetric on vehicle left and right side, noise level of outboard ear was normally higher than that of inboard ear. The frequency characteristics under different wind speeds were almost the same, the linear OASPL of interior noise increased at about 4.4th power and A-weighted OASPL at about 5.5th power of wind speed. In addition, the acoustic power increased as yaw angle rose up, and noise level by leeward side was normally higher than that by windward under the same yaw angle.
The Calculation of Energy Flow of Equal Inclination Interference Fringes
Authors: Xue Jiang Rong , Zhang Xiao
Published: September 2011

The energy flow of equal inclination interference fringes in Michelson interference measurement is theoretically calculated, and its variation with the optical path difference is also analyzed. When the ratio order of interference radius to focal length of the lens is as low as 10-2 or lower, the energy flow variation with the optical path difference is sinusoidal with period λ/2. Simulation is made via Matlab to verify the theoretical calculation and good agreement has been obtained between theoretical analysis and simulation. The parameters to be measured can be achieved via the record of the change in stripe energy flow, which is superior to the conventional method recording variation in stripe light intensity in good stability and strong anti-jam.
Research on Patch Near-Field Acoustic Holography
Authors: Zhu Hai Chao , Chen Zhi Min , Du Xiang Hua , Mao Rong Fu
Published: September 2011

Support vector regression is used to establish a kind of patch near-field acoustic holography. The regression functions are constructed by treating the measured data on the patch holography as training samples, and then the data outside the measurement aperture are extrapolated. The experimental results show that the extrapolation of the sound pressure outside the smaller initial hologram aperture may be realized easily and effectively, and the reconstruction accuracy is satisfactory.
Hydrodynamic Forces Measurement in Still Water Tank and Theoretical Validation of a Bio-Dorsal Fin Propulsive System
Authors: Du De Feng , Jiang Xiao Qin
Published: September 2011

The simulation level of prototypes mimicking torsional wave propulsion is low at present. A new prototype which uses a combination of crank and rocker mechanisms and pleated-skirt-pattern membrane is presented in this paper. The prototype’s dorsal fin is of high fidelity, the waveform looks pretty smooth and the wave amplitude can reach 85 degrees. In still pool, measurement of thrust and lateral force of dorsal fin were performed with a one-component balance. The experimental results show: 1. the thrust on the dorsal fin has periodic variation, and the frequency of thrust variation is twice the fin frequency. 2. The lateral force on the dorsal fin also has periodic variation, and the frequency of lateral force variation is the same as the fin frequency. 3. The periodic mean thrust on the dorsal fin is proportional to the square of fin frequency, and the influence of fin frequency on dorsal fin is stronger as wave number increases. 4. The computed results of large-amplitude EBT coincide qualitatively with experimental result, but our computed propulsive forces are quantitatively smaller. (This work was supported by the National Natural Science Foundation of China (10572151).)
Development and Application of Engineering Vehicle Transmission Load Test System
Authors: Xu Li Chao , Ge Ru Hai
Published: September 2011

Transmission load was one of the important parameters for engineering vehicle powertrain system, on the basis of calculating drive shaft torque values and ascertaining the measurement point positions, we selected resistance strain guages to design torque sensors and also chose a signal telemetry system, after using a self-made torque calibration bench to statically calibrate torque sensors, we developed a test system for loader drive shaft load. According to the given test program, we performed an actual loader experiment to measure torque at the loader drive shaft measurement points and analyzed the test waveforms. The results of bench calibration and actual loader test showed that the designed torque sensors had a high sensitivity and a good linearity, and the developed test system was correct and effective.
Improved TOPS about Direction of Arrival Estimation for Wideband Signals
Authors: He Bin
Published: September 2011

The study about the direction-of-arrival (DOA) estimation for wideband signals is a basic topic of Signal Processing. The method called test of orthogonality of projected subspaces (TOPS) does not require initial values to form focusing matrix compared with the coherent signal subspace method (CSSM), but it has poor performance for coherent wideband signals at low signal-to-noise ratio (SNR). Based on the lack of the conventional TOPS, this paper reconstructs a set of new matrices with the narrowband correlated matrices coming from the DFT decomposition of the array output and modifies the method frame of the conventional TOPS. So we get a set of reconstructed matrices with full rank corresponding to each frequency bin, and which have no array aperture loss. The improved TOPS can estimate the DOA for coherent wideband sources at low SNR, and enhances the performance of the conventional TOPS. Simulation results show that the improved TOPS is effective, and the total performance of which is similar to the rotational signal-subspace (RSS) method.
Frequency Response Analysis of Truss Spar by Considering the Viscous Damping
Authors: Zhai Gang Jun , Song Xiao Jie , Diao Wei , Li Bin Bin
Published: September 2011

A calculation model for Truss Spars motion response is established under the wave action by combing the potential flow theory and the modified Morison equation. The high order boundary element method is used to acquire the wave exciting force and the relevant hydrodynamic information. By numerical simulation, the surge, heave and pitch s are obtained, and the parameter analysis for influence of Morison drag coefficient on responses are conducted. The calculated results indicate that the surge and pitch motions are only sensitivity to the drag coefficient in the low frequency range, and consequently the viscous damping would play an important role when the platform undergoes 2nd order wave slow drift force. For the heave response, the heave plates installed on the Truss Spar provide large vertical viscous damping which distinctly affects the heave .
Study of the Manufacture about Piezoelectric Nanogenerator under Micro Vibration and its Performance
Authors: Sheng Jian Guo , Zeng Ping , Zhang Can Can
Published: September 2011

With the development of science and technology, the smaller sizes generator, the more attention by people. The main purpose of this article is to manufacture piezoelectric nanogenerator under micro vibration and its working principle is introduced and its performance is studied. The results show that, using the present nanomaterials, piezoelectric materials can be prepared. When its wind in copper laps, under the situation of micro pulse vibration its can turn into electrical energy, thus yield piezoelectric nanogenerators. In ambient vibration condition, piezoelectric materials produce larger rated current and voltage. However, copper laps cutting magnetic line of force produce less rated current and voltage. So the piezoelectric nanogenerators can be separately used to supply power. If multiple piezoelectric nanogenerator in tandem may produce higher voltage, current and power, which possess commercial value.
2-D Numerical Analysis of Fin Efficiency on Straight Rectangular Fin with Combined Heat and Mass Transfer
Authors: Mao Jin Feng , Wang Bo , Geng Shi Bin , Sui Lu Yan
Published: September 2011

An analysis was carried out to study the efficiency of straight rectangular fin with combined heat and mass transfer. Numerical solutions are obtained for fin efficiency with SOR method when the fin surface is dry, fully wet and partially wet. The effect of fin parameters including the ratio of fin width and fin thickness to fin length as well as Bix on fin efficiency were also investigated. It is found that fin parameters shows impressive effect on 2-D fin efficiency, and the critical air relative humidity becomes closer to air saturated humidity when Bix increases.
Mechanical Performance Analysis of Petroleum Derrick Substructure
Authors: Pei Jun Feng , Deng Sheng Ying , Chen Guang Min , Zhang Jian
Published: September 2011

In recent years, the self-elevating derrick substructure which with the characteristics of easy to install、remove and transfer are gradually replacing layer box, box block substructure, etc. The three-dimensional finite element model of the MXD-701 jack-up derrick and substructure, which is used to analyze static properties of the petroleum substructure under the six different working loads are built by the ANSYS finite element software. Meanwhile, the wireless structural testing system（STS-WiFi）is testing at the MXD-701 petroleum substructure. Then comparing of the model results and testing results. Analysis results indicate that the stress of the substructure at the two beam table is greatest, the stress of the upper part of the guy column is much greater, and others are low, but in general, the overall substructure can fit the requirements of the strength and intensity. The compared results can accurately reflect the project structure of the stress and strain. Then, we can get the capacity of the substructure in order to provide evidence to the security situation of the substructure. It will have great significance to enrich and develop the mast base design and safety assessment theory.
Design of PID Controller Based on Compensation with Repetitive Control
Authors: Guo Hong Liang , Zhao Dong Jie , Zhao Ling , Wang Qing
Published: September 2011

Valve train is one of important mechanisms in internal combustion engine. The experiment is an important method to study the valve train. In the design of valve train experiment, the Permanent-Magnet Synchronous Motor (PMSM) is used as the driving force to drive the camshaft. PID controller based on compensation with repetitive control is designed to control the PMSM. It can eliminate all periodic errors in closed-loop control. And it has a virtue of nonparametric dependence on its control performance by combining with two control methods. An example has been given and simulation has been made. The simulation result shows that the controller apparently improves the position tracking precision and reduces the tracking error of servo system. So the PID control system based on compensation with repetitive control has a much higher accuracy than the PID control system has. It is fit for high-accuracy control of valve train.
Study on Optimal Algorithm for Shipping Route Automatic-Generation Based on Electronic Chart
Authors: Xu Jian Bo , Wang Zhi Kun , Song Li Sheng
Published: September 2011

For the traditional automatic-generation algorithm of electronic chart plan shipping route, it is difficult to achieve the shortest route and the least turning points at the same time. In this article, the optimal and planned shipping route automatic-generation method algorithm based on the rubber band algorithm was put forward. In this algorithm, the elasticity principle of rubber band was adopted to improve the original and basic path and the shortest path and the least turning points can be achieved at the same time. The experimental results showed that the algorithm can quickly and automatically generate an optimal and safe route with good stability and high searching efficiency and so it can be applied to shipping route planning in complicated and large sea area.
Application of MASW Method for Evaluating Dynamic Properties of Lu-Liao-His Earth Dam
Authors: Tsai Pei Hsun , Chen Kang Nan
Published: September 2011

In the paper the shear wave velocity and Poisson’s ratio profile are studied using the MASW test. Slant stacking was adopted in experimental dispersion curve constructing. Theoretical dispersion curve can be constructed by thin layer stiffness matrix method. A real-parameter genetic algorithm is required to minimize the error between the theoretical and experimental dispersion curves. Test results show that spectrum using slant stacking shows the fundamental mode of Rayleigh wave in the frequency range from 15 Hz to 50Hz. To reduce the error of experimental and theoretical dispersion curve using real-parameter genetic algorithm is feasible. The results also show that the strata of Lu-Liao-His Earth Dam can be modeled as 3 soil layers with an underlying half space.
Study of the Metal Crack Propagation by Acoustic Emission Testing
Authors: Zhang Wei Min , Liu Shu Xuan , Qiu Yong , Chen Cheng Feng
Published: September 2011

Crack propagation is the main reason which leads to the invalidity of the metal components. A set of detecting equipment based on the acoustic emission method was designed, and it was mainly composed of acoustic emission sensor, signal operating circuits and signal acquisition system. Specimens of 16MnR material were manufactured and the static axial tension test of them was carried on. Acoustic emission signals from the specimen were detected by acoustic emission equipment by using piezoelectric ceramic sensor. Signal datum were acquired and operated by the acquisition system, as well as the acquisition program written for it. The final results has demonstrated that acoustic emission equipment designed for the test performed well in acquiring the signals induced by the metal crack propagation.
Buckling Behavior of Through-Plates under Gravity Loads
Authors: Samimi Razieh , Mirghaderi Seyed Rasoul
Published: September 2011

Due to the development in the construction and building industry in recent years, numerous methods for safer, easier and more economical design of structures have been studied.Because of the high bi-axial bending capacity and high compressive strength of hollow structural sections, these sections are considered as a popular alternative by designers. Supporting the panel zone demands in the columns and occurring the moment hinge at the ends of beam are too available in column with hollow section. One of the major problems in the way of using these sections is lack of appropriate load path to connect beams to them, which ends up using through-plates. Through-plates are plates that pass through column and beams connect to them at their webs. Consequently these plates should have sufficient stiffness in order to provide enough strength. This paper proceeds to study the buckling behavior of through-plates in moment beam to column connections under gravity loads.
Research on the Application of High Speed on Off Valve in the Hydraulic Cylinder Speed Control System
Authors: Gao Qin He , Song Hai Zhou , Yang Zhi Yong , Liu Bo , Guan Wen Liang
Published: September 2011

An application of high speed on-off valve which is connected between rod cavity and no-stem cavity of hydraulic cylinder was designed to study the speed control problem when the motion state of hydraulic cylinder is transformed. Research result shows that HSV can reduce the maximum starting acceleration and the final velocity effectively, and can realize the speed control when the motion state of hydraulic cylinder is transformed.
Comparison between Two ANSYS Finite Element Modeling Methods of Multistage Centrifugal Pump Rotor
Authors: Tian Ya Bin , Qi Xue Yi , Hu Jia Xin
Published: September 2011

In the last decades, many methods of ANSYS finite element modeling have been proposed. By comparing the two different methods of beam element modeling and entity unit modeling for multistage centrifugal pump rotor, we find that although both methods are insensitive to torsional vibration model, to some extent they affect other vibration models and result in certain deviation in calculation results. Using beam element modeling not only improves the calculation precision, but also saves computing resources. The Appropriate selection of the element type will reduce the amount of input data and computation time.
Modal Analysis of Mechanical System Containing Nonlinear Joint
Authors: Poruba Zdenek , Szweda Jan
Published: September 2011

The paper describes modal analysis of lifting platform usually used in theatre technologies. The platform itself consists of several components mutually connected by joints. The behavior of particular joints can be linear or nonlinear. The connection of two main parts - tables and pillars of lifting platform-must be considered as nonlinear because the force transfer between these parts can occur only in one direction. Since standard modal analysis is in principle linear, the method of linear description of nonlinear behavior has to be proposed. The contribution presents such method using application of three different boundary conditions which allow describing the nonlinear behavior of system by tools of linear analysis. Consequently, the modal analysis of the entire system is performed for all three types of boundary conditions. On the base of mode shapes visualization the proper mode shapes are extracted which satisfy the real behavior of the lifting platform.
Performance Research of a Novel Spiral Piezoelectric Harvester
Authors: Zhou Yong , Li Shi , Tang Jian
Published: September 2011

Piezoelectric materials generate electricity when they are subjected to mechanical strain. This paper presents an innovative design platform of piezoelectric energy harvester with variable curvatures and sections. Firstly, the effects of the proof mass position on the spiral laminated beam with PZT-5H bonded on the surface are analyzed. Secondly, the dynamical performances of the piezoelectric harvester with different shape are investigated. The results, which are gotten through ANSYS software, show that the first three order natural frequencies increase linearly while the distance from the free end increases. The voltage distribution variates acutely because of the coupling of the bending and twisting actions in the beam. The simulation data will provide a theory analysis foundation for the engineering, design and application of harvester.
Experimental Investigation on Natural Characteristics and Forced Response of Bladed Disks
Authors: Zhao Zhi Bin , He Er Ming , Wang Hong Jian
Published: September 2011

The results of an experimental investigations on the natural characteristics of tuned bladed disk and forced dynamic responses of mistuned bladed disks are reported. Three experimental bladed disks are discussed: a tuned specimen of periodic symmetry with 12-blades which are nominally identical, and two mistuned specimens, which feature small blade-to-blade variations by adding slight blocks to blade tips. All the specimens are subject to travelling wave excitation produced by piezo-electric actuators sticking on the root of blades. The primary objective of this experiment is to observe the natural characteristics of tuned bladed disk, and to research the impact of mistuning on the forced response blade amplitude magnification. Analytical predictions about the blade amplitude magnification factor are verified by the experimental results.
An Analysis of Forming Limit in Micro Deep Drawing of the Square Cup for Anisotropic Foil
Authors: Yeh Fung Huei , Li Ching Lun , Tsay Kun Nan
Published: September 2011

This paper presents an explicit dynamic finite element method (FEM) in conjunction with the forming limit diagram (FLD) to analyze the forming limit for the SPCC foil in micro deep drawing of square cup. In the present study, the tensile, anisotropic and friction test are performed to obtain the material parameters of the alloy foil according to the ASTM standards. Importing these properties, the numerical analysis is conducted by the explicit dynamic FEM. The FLD in numerical simulation is used as the criterion of the forming limit in micro deep drawing of the square cup. The forming limit, punch load-stroke relationship, deformed shape and thickness distribution of square cup, are discussed and compared with the experimental results. It shows that a good agreement is achieved from comparison between simulated and experimental results. The limit drawing ratio in micro deep drawing of square cup is 2.08 in this paper. From this investigation, the results of this paper can be used as reference in the relative researches and applications of micro forming.
Experimental Analysis and CAE Optimization for Exhaust Noise of the Diesel
Authors: Zhang Yuan Yuan , Li Shun Ming , Hu Yi Xian , Hu Guo You , Lu Wen Feng , Wang Xing Xing
Published: September 2011

Based on compute analysis engineering (CAE), the performances of acoustic and fluent for muffler comprehensively were analyzed and optimized in the paper. First, aiming at the heavy exhaust noise of diesel engine, bench experiments of measuring independently were designed and carried out, the frequency spectrum of exhaust noise was achieved, combining with simulation analysis of the finite element, acoustic and fluid performances of the original muffler and respective muffling cavities were analyzed, whose shortage such as transmission loss, pressure loss and flow regeneration noise were achieved, the muffler would be re-designed by CAE. Simulation shows the performances of improved mufflers were better than the original one. Eventually, insertion loss of experiment for new muffler is more 10dB(A) above than the original one, and power loss met requirement.
Elastic Energy Change Rate Method Research Using Energy Catastrophe Theory
Authors: Liu Shuang , Ren Qing Wen
Published: September 2011

The state before and after structural failure is quite different, which leads to some sudden changes to its corresponding energy. According to energy catastrophe theory, each phenomenon that reflect system state mutations can regarded as the criterion of instability. Based on the energy catastrophe theory, the problem of concrete structure failure is dealt with various energy calculation methods. Moreover, the energy change rate method is put forward to search the omen point of structure deformation and failure. By comparing with structure total strain energy and plastic strain energy, it is shown that the elastic energy change rate can determine the omen point of structure failure more easily, directly and precisely. Finally, it is found that the stress-strain relationship of many materials in engineering are quite similar, which shows that using elastic energy change rate method to determine the omen point of structure failure has some certain universality in engineering.
Optimization of Contact Problem by Genetic Algorithm Method
Authors: Szweda Jan , Poruba Zdenek
Published: September 2011

In this paper is discussed the way of suitable numerical solution of contact shape optimization problem. The first part of the paper is focused on method of global optimization field among which the genetic algorithm is chosen for computer processing and for application on contact problem optimization. The brief description of this method is done with emphasis of its characteristic features. The experiment performed on plane structural problem validates the ability of genetic algorithm in search the area of the global optimum. On the base of the research described in this work, it is possible to recommend optimization technique of genetic algorithm to use for shape optimization of engineering contact problems in which it is possible for any shape to achieve successful convergence of contact task solution.
Research on Seismic Isolated Floor Slab with Damper and Rolling Base
Authors: Ge Hai Jie , Wang Hui , Gao Dong Qi
Published: September 2011

Earthquake is one of the major threats towards building and non-building structure and various seismic isolation technologies have gained a good development all-round the world. Based on such a condition, a new form of seismic isolation technology is raised, which combine rolling bases and dampers to isolate floor slabs from quake wave. Analysis towards scaled model dynamic test shows that this seismic isolation technology for floor slabs can effectively reduce response acceleration of floor slabs, especially when frequency of input acceleration is high. While frequency of input acceleration is low, it has to be assured that when slab hits damper, the hitting should be soft so that the response acceleration can be controlled at a low level.
Structure Noise Prediction of Submarine by Propeller Excitation
Authors: Wei Ying San , Wang Yong Sheng
Published: September 2011

When boundary element (BE) was coarse, the general Gauss quadrature of Helmholtz integral equation (HIE) on it was not accurate. A mesh-less refined integral algorithm (RIA) of BEM was used to overcome this problem. Then RIA coupled with FEM/CFD was applied to predict submarine propeller excited hull underwater noise. The thrust and torque excitations of propeller simulated via CFD were loaded on to submarine respectively to calculate the acoustic response, and the sound power and main peak frequencies were obtained. Results show that, thrust mainly excites submarine axial mode and high sound area appears at the two conical-type ends, and torque mainly excites circumferential mode and high sound area appears at the broadside of cylindrical section, but with rather smaller sound power and radiation efficiency than the former. So, main attention should be focused on thrust excitation when perform the sound radiation reduction of submarine that propeller excited. Keywords: Submarine, Propeller excitation, Refined integral algorithm, Vibro-acoustic, CFD/FEM.
Dynamic Analysis of Flexible Rotor-Ball Bearings System with Unbalance-Misalignment-Rubbing Coupling Faults
Authors: Zhang Jun Hong , Ma Liang , Lin Jie Wei , Zhang Gui Chang
Published: September 2011

Dynamic responses of flexi rotor-ball-bearing system under unbalance misalignment rubbing coupling faults are studied. Coupling faults dynamic control model of flexi-multi-system of rotor-ball-bearing system is established, based on finite element analysis and numerical integral combined simulate method. Then nonlinear bearing force and rub-impact force models are programmed in MATLAB. Analysis and compare vibration characteristics of system while under faults-free, unbalance and rub-impact faults. The result demonstrates that when system under unbalance faults, vibration frequency brought by eccentric mass is agreed with rotating speed frequency, its fundamental frequency wave add high frequency component, can show the characteristics of unbalance-rubbing faults efficiently; when system under misalignment faults, with frequency double vibration and high harmonics; when system under unbalance-misalignment-rubbing coupling faults, support force of shafting of rotor system appears high frequency responses like saw tooth based on sine wave, causing aggravation of rub-impact faults.
Dynamics Analysis of a Sinking Winch Mechanism
Authors: Shao Xing Guo , Zhu Zhen Cai , Cao Guo Hua , Li Yi Lei
Published: September 2011

This paper investigates the dynamics of a sinking winch mechanism in the framework of non-smooth dynamics. The previous works ignored the unilateral property of the cable (it can only pull the platform but can’t push it), which is specially taken into consideration in this paper. We propose the set-valued tension law to model the unilateral constraints of the cables. The equations of motion are derived by use of the Lagrange multiplier method. The dynamics model of the mechanism is obtained by combining the equations of motion and the set-valued tension law. Its solution is solved by the Moreau midpoint method. We present a numerical simulation study to demonstrate that the non-smooth dynamics framework is effective and suitable for the dynamic analysis of the sinking winch mechanism.
Analysis of the Arresting Dynamic Loads of Aircraft’s Landing Gear
Authors: Jia Zhong Hu , Han Wei , Zheng Xiao Hong , Tao Yang
Published: September 2011

The arresting landing of carrier aircraft is especial dynamic problem. During this process,the gear would bear the very big dynamic load,which does the biggest harm to gear .In this paper,it analyzed the landing gear shock strut in carrier aircraft arresting landing,and aiming at the runout of shock strut and the flexibility of the landing gear by using the Lagrange equation.Then it concluded the chaging of landing gear shock strut with symmetrical and straight arresting,3m of off-center distance arresting and 2°of rolling angle arresting after simulating.The conclusion showed that the landing gear shock strut would be stable after a short time concussion;rolling and unsymmetrical affected the shock strutmore severe than off-center and symmetrical arresting,and the qualities of concussion also being more acute.
Research and Analysis of Dynamic Behaviour in the Mathematical Models of the 6-Axle Locomotive
Authors: Mai Van Tham , Wu Shi Jing , Wang Xiao Sun , Chen Jie , Jafri S. A. K. S.
Published: September 2011

With the aiming of mathematically modeling dynamic behavior in latitudinal and vertical movements of the 6-axle locomotive, this paper introduces the Kalker’s Wheel-Rail Rolling Contact Theories and their implementation in multibody codes. This paper also highlights methodology for solving inhomogeneous linear second-order differential equations with MATLAB computer software aided. The calculation has reported that the dynamic behaviors of Diesel-Electric 6-axle locomotive are significantly demonstrated. The calculation has reported that the dynamic behaviors of Diesel-Electric 6-axle locomotive are significantly demonstrated the requirements on Rolling stock Dynamic behaviors of Vietnam Railways.
Dynamic Characteristics Analysis of a Combined Gantry Milling Machine
Authors: Shi Duan Wei , Liu Can Pei , Wang Zhi Yuan , Zhang Yan , Sun Xiao Qing
Published: September 2011

The FE model of a combined gantry milling machine was constructed. The joint stiffness of bolt fastening, ball screw, and roller guideway were calculated. The static analysis, modal analysis and harmonic analysis of the whole machine were carried out. The results indicated that the static stiffness and minimum dynamic stiffness of the spindle could satisfy the accuracy requirements of milling, but the stiffness of the X-axis feed system was comparatively low, while the stiffness of the rest and the cross-beam could be relatively abundant. The result of “considering joint stiffness” modal analysis was more accurate than “unconsidering joint stiffness”, especially the 5th-order natural frequency had a difference of up to 52.2%. The harmonic analysis result showed that the response amplitude of the spindle center was comparatively large in three directions when the 1st-order and the 17th-order natural frequency were working, so the frequencies should be avoided while working.
Computation of Guidance Electrimagnetic Force for High-Speed Maglev Train Negotiating the Curve
Authors: Zhao Chun Xia , She Long Hua , Chang Wen Sen
Published: September 2011

This paper first derives the accurate computational formula of guidance electromagnetic force, when guidance magnet has the movement of the lateral excursion and yawing relative to the curved guideway. Firstly, the gap distribution characteristics between the guidance magnet and the curved guideway have been analyzed and simplified. Secondly, the theoretical formula of electro- magnetic force for singled magnetic pole has been derived by the air-gap magnetic permeance and flux tube methods. Then, the numerical calculations have been done by Ansoft Maxwell, and according to the numerical results, the theoretical formula has been modified accurately. Finally, the formulas of electromagnetic resultant force and resultant moment for guidance magnet have been represented, and the variation curves of electromagnetic force changing with maglev line indicate that gap changes caused by curved guideway should not be neglected. The formulas acquired in this paper are in favor of dynamics modeling and controller design for guidance system, and analyzing the running states of magnet and the curved form of guideway influencing on guidance system.
Temperature Influence Compensation for Lamb Wave Damage Detection
Authors: Qu Wen Zhong , Inman D.J.
Published: September 2011

Among structural health monitoring (SHM) techniques, Lamb waves is frequently used as diagnostic tools to detect damage in plate-like structures. Temperature variation can cause significant changes in guided-wave propagation and transduction for SHM. In this paper, controlled experiments examine changes in Lamb wave propagation and transduction using PZT-5A piezoelectric wafers under quasi-statically varying temperature (from 5°C to 60°C). The baseline selection method and baseline signal stretch method are used to compensate the temperature influence on Lamb wave propagation. The results of the experiments demonstrate the effectiveness of the temperature compensation approach and the simulated damage on the plate can be detected effectively under elevated temperatures environment.
Study on Health Evaluation System for Coal Mine Speed Reducer Based on Embedded System
Authors: Yin Xian De , Liu Ai Guo , Dong Xin Min , Hao Wang Shen
Published: September 2011

To meet the requirement that continuous monitoring the mine special gear box, an embedded health evaluation system was designed in this paper. The software and hardware components of the system were described. The reasoning mechanism of expert systems used in the system was proposed. The system can report the whole machine health status based on crest factor, kurtosis and various bands. And the system is helpful for guiding equipment management, maintenance and maximizing efficiency of assents.
Study on Data Structure of Excavation Monitoring System
Authors: Tu Jie Nan , Ma Ping , Pan Xiao Hua
Published: September 2011

With the C# language and Access database, Building Foundation Pit Monitoring Information System (BFPMIS) was developed. At the process of developing the excavation monitoring system, the design of the system data structures and the data types are discussed. The excavation monitoring system contains main data structure and assistant data structure. The data structure, data element and data type of projects, bids, sections, monitoring point types, point property, alert values, bore information, pile information and beam information are analyzed emphatically. The application of the tree structure in the main data structure is introduced. And the monitoring points are classified according to the monitoring objects to describe and store the monitoring data. The system set orange alarm and red alarm to every monitoring point.
The Damage Boundary Curve of the Suspension Packaging System under Rectangular Pulse
Authors: Wang Lei , Chen An Jun
Published: September 2011

The geometric nonlinear dimensionless dynamical equations of suspension spring cushioning packaging system were established and a new concept of damage boundary curves of the system was developed under the action of rectangular pulse. Considering the angle of the suspension spring ,a three-dimension damage boundary curve is obtained.The mathematic results of the equation are calculated by using the four steps Runge-Kutta method. Studies have shown that the dimensionless pulse peak, the angle of suspension spring and the damping ratio of the system can affect the safe region, and that increasing damping can enlarge the safe region of the system. The shock of the packed product can reduce by adjusting the parameters of the system properly. These results have important application value in design of the suspension cushioning system.
Research on Horizontal Cracks in Web Plates of Rail Girder under High Frequency Impulsive Loads
Authors: Dong Da Shan , Mei Xiao , Liu Long
Published: September 2011

Nowadays, bridge cranes have a tendency to be designed for big lifting capacity, wide span with high operating speed. Several long horizontal cracks have been found in web plates of the rail girder, which is terrible threat to crane’s safety. Firstly, the local stress distribution of web plates is illustrated in a semicircle form based on the elastic-plastic contact theory. Then the cyclical variation of shear stress is analyzed due to high frequency and impulsive moving wheel loads. Finally, a fatigue crack propagation model is proposed according to the strain energy density law. It is found that the shear stress and welding residual stress give rise to the fatigue horizontal crack near welding seam.
Blind Separation of Excavator Noise Signals in Frequency Domain
Authors: Liao Li Da , He Qing Hua , Hu Zhong Lin
Published: September 2011

In order to identify noise sources of an excavator in non-library environment, a complex-valued algorithm in frequency domain was applied. Firstly, an acoustic camera was used to acquire excavator’s noise signals, which were convolutive mixtures in time domain interfered by echo. Secondly, signals in time domain transformed into frequency domain by FT, turned to be complex-valued mixtures. Then, independent components of noise signals were obtained through separation of complex-valued mixtures using complex-valued algorithm based on independent component analysis. Finally, according to noise of diesel with muffler was mainly consist of surface noise, the relationship between principal frequencies and structrual parts was founded by comparing frequency-amplitude spectra and modal analysis in Ansys. Research shows that complex-valued algorithm based on fast fixed-point independent component analysis can effectively separate noise signals from an excavator in time domain, and noise sources can be well ascertained by comparing the modal analysis with blind separation components.
An Evaluation of Damage Features Extraction from Attractors in Structural Health Monitoring
Authors: Xu Chao , Wang Dong
Published: September 2011

Structural health monitoring provides accurate information about structure’s safety and integrity. The vibration-based structural health monitoring involves extracting a feature which robustly quantifies damage induced change to the structure. Recent work has focused on damage features extracted from the state space attractor of the structural response. Some of these features involve prediction error and local variance ratio. In the present paper, a five degree of freedom spring damper system forced by a Lorenz excitation is used to evaluate these two typical damage features. Their ability of identification damage level and location is characterized and compared.
Study of Earth-Fault Location Method for Distribution Network Based on Transient Signal
Authors: Huang Zhi Chao , Zhong Yi , Li Cai Lin , Liu Mu , Yang Sheng Zhen
Published: September 2011

According to the generating process and propagation characteristics of earth-fault transient signal, an earth-fault location method for distribution network based on transient signal is presented. In the method, in order to change line characteristic impedance, a resonant filter circuit is paralleled in line segment border, so that it could cause transient current energy differences in feature frequency band on both sides of detection device. The location method achieves earth-fault area location through comparing transient current energy and energy attenuation coefficient in feature frequency band. The simulation test result shows that the method isn't influenced by distribution system grounded style, operation style and other factors and which could detect the earth-fault area rapidly and reliably in distribution network and has a high project application value.
Integrated Analysis for Gearbox Fault Based on Autocorrelation and Spectrum Analysis
Authors: Wan Shu Ting , Wang Cong , Zhang Yu , Zhang Jing
Published: September 2011

The advantages and disadvantages of traditional gearbox fault diagnosis method based on autocorrelation, spectrum-zoom, Hilbert demodulation and cepstrum analysis are respectively analyzed. Then a gearbox fault diagnosis method is presented, which integrates autocorrelation, spectrum-zoom, Hilbert demodulation and cepstrum analysis. Finally, vibration data of the pitting gear is measured by using QPZZ-II rotating-machinery fault simulating system. The result shows that the improved method proposed in this paper is effective for the fault diagnosis of the pitting gear.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications.. The best is to read these instructions and follow the outline of this text.
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Wheel-Rail Lateral Force Continuous Measurement Based on Rail Web Bending Moment Difference Method
Authors: Li Yi Fan , Liu Jian Xin , Lin Jian Hui
Published: September 2011

According to the wheel-rail interaction characteristics and the restriction condition of track, a wheel-rail lateral force continuous measurement method is researched. This paper validates the feasibility of rail web bending moment difference methodthough simulation calculationand field measurement. The results shows that this method is absolutely capable of achieve continuous measurement of wheel-rail lateral force.
The Dynamic Responses of RC Columns Subjected to Blast Loading
Authors: Kuang Zhi Ping , Xie Lei , Yang Qiu Hua , Dong Yi Ling
Published: September 2011

The blast-resistant performance of columns which are the most important component in the whole structure is a crucial factor which influences the safety of the structures subjected to the blast loads. Studying dynamic responses of RC columns under the blast loading and improving the blast-resistant performance can prevent the structure from progressive collapse due to the damage of the columns in the blast loading, and give people more time to escape from the building in a dangerous situation. Then the same parameters are used to analyze the dynamic responses of RC columns under three typical blast loads. Conclusion can be used for structure blast-resistant design.
Limiting Buckling Moment Design for Singly Symmetric Girders
Authors: Hsu Wei Ting , Lue Dung Myau , Liao Cheng Yen
Published: September 2011

Girders with singly symmetric sections are more efficient and economical then the double symmetric sections. However, the theoretical moment calculations for singly symmetric sections are not an easy task. The difficulty comes from some of the evaluation of torsion properties. Current AISC specifications [1, 2] are not provided the theoretical formulas for the critical moment curves of singly symmetric girders. In AISC specification [1], which revisions the residual stress design to influence the limiting buckling moment strength. This study introduces the singly symmetric girders design methods with theoretical and design manual, and compared the limiting buckling moment with the specification of AISC [1, 2]. It will enable practicing engineers to perform more in-depth evaluation in their routine deigns.
Acoustical Design and Measurement of 316 Classroom in TYUT
Authors: Lu Feng Hua , Wang Xin Xing , Li Miao Bo
Published: September 2011

This paper involves the acoustical design and measurement of sound quality in the new 316 classroom in TYUT. Based on the “Code for design of sound insulation of civil buildings” GBJ118-2010， this paper deals with the acoustical design of the frequency characteristics of reverberation time in the new 316 classroom in TYUT. Before the acoustical design in new 316 Classroom, the measurement of reverberation time (T20, T30, EDT) with frequency 500-1000Hz in empty room are 3.86-4.72s; After the acoustical design that the perforated wooden sound absorption tablet wall within glass wool sound absorption and the gypsum -slab mineral wool board ceiling are mounted in new 316 Classroom in TYUT, the measurement of reverberation time (T20, T30, EDT) with frequency 500-1000Hz in empty room are 0.72-0.82s.Through the checking of the testing data and the evaluation of the users, the acoustical design of the new 316 classroom in TYUT is in accordance with the requirements of Code for design of sound insulation of civil buildings GBJ118-2010.
Practical Constitutive Model in the Application of Arch Dam Shape Design Calculation
Authors: Wang Hong , Jin Chong , Xia Xiao Zhou , Yuan Hong
Published: September 2011

A fitting curve of stress-strain relation given is applied in numerical analyzing based on Legendre orthogonal polynomial and least square method. The nonlinear constitutive model is employed to examine the shape of an arch dam. For the asymmetries and high water pressure, the safety of High Arch Dam is one of key issues in the design and construction of High Arch Dam. The simulation results show that the basic mechanical performance index is symmetrical distribution. The dam mainly bears pressure and no obvious tensile stress exists in the dam when water level is normal. Material yields in dam heel when 1.4 times overloading is considered. It can be concluded that the dam is reliable and the safety margin is satisfactory.
Dynamic Elasto-Plastic Analysis on the Steel Spatial Arch Truss with 120 m Span and 0.4 Rise-Span Ratio
Authors: Li Hai Wang , Ma Yu , Liu Jing
Published: September 2011

In this paper, the elasto-plastic dynamic analysis on the steel spatial arch truss with 120 m span and 0.4 rise-span ratio is carried out under earthquake EL-Centro wave with SAP2000 about pin-connected model and rigid truss model. The geometric and material nonlinear effects are considered simultaneously based on the plastic-hinge theory. The study shows that the vertical stiffness of the two models is smaller than horizontal stiffness; the failure mode of the pin-connected truss model under the earthquake action is elasto-plastic dynamic buckling, and the failure mode of the rigid truss model under the earthquake action is between the elasto-plastic dynamic buckling and the strength failure.In order to improve the ductility of the truss, we should enhance the design of joint stiffness in actual structures.
Effects of Materials on Cracking of Pumping Concrete
Authors: Cao Xiu Li , Xia Bing Qing , Liu Zheng Bao
Published: September 2011

The constituents of concrete have a crucial effect on early age cracks of pumping concrete. Based on early age cracking mechanism of pumping concrete, the influence of raw materials, which includes cement, coarse and fine aggregates, mix ratio, admixtures, mineral additives and fibers on cracks are analyzed. The results show that the extent of early age cracking varies with constituents of concrete. It is advised that the appropriate concrete materials should be selected in terms of specific engineering features, not only by the requirements of strength and slump. With regards to the projects that are required crack control strictly, the characteristics of pump construction should be considered and the appropriate composition of concrete, especially the types and dosage of admixtures, mineral additives and fibers, should be determined by experiments.