bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis of Structural Reinforced Concrete Elements under Severe Impulsive Loads
Authors: Sun Wen Bin
Published: October 2010

The behavior and response of structural reinforced concrete elements under severe short duration dynamic loads was investigated numerically. The analytical approach utilized the Timoshenko beam theory for the analysis of reinforced concrete flexural elements, such as beams and one-way slabs. The differential equations of the Timoshenko beam theory were solved numerically by applying the finite difference method (FDM). The proposed FDM not only can account for both the shear and flexural deformations, but also can incorporate the strain rate effects on the strength of steel and concrete into the analysis. The results of this proposed FDM were compared with those obtained by using finite element method (FEM), were also compared with experimental data obtained by other investigators. The procedure of FDM in this paper was both fast-running and accurate and most suitable for design office application.
Investigation of the Tribological Properties of Si3N4 Ceramic Pair Lubricated by Emulsion with Different Functional Group
Authors: Wu Zhi Yuan , Wang S.H. , Tian Xin Li , Zhang S.
Published: October 2010

A series of experiment were performed to test the tribological properties of Si3N4 ceramic pair lubricated by emulsions of alcohol, acid and alkane. The experiment results showed that the function group can’t improve ceramic lubrication, which is reverse to metals. Under the condition of same carbon-chain, the lubrication by alkane is better than alcohol and acid. With the friction curve and wear scar diameter analysis, the paper studied the tribological properties of alcohol interfacial film. On the basis of above, hydrophilcity was involved to find the lubricating mechanism of emulsions.
A Peak Identification Method of Vibration Signal on Diesel Engine Cylinder Head in the Absence of TDC Signal
Authors: Zhu Zhao Qian , Zhang Wen Ming , Zhang Xiao Ming , Shi Yu Peng
Published: October 2010

This paper studied the time-domain waveform characteristics of diesel engine cylinder head vibration. The relative relationship between the various explosions of diesel engine were analyzed and compared. Seven criteria were proposed under which to achieve the time domain waveform peak identification in the absence of TDC signal. According to the criteria computer algorithms for the time domain waveform peak identification were given. The method can reduce the vibration diagnosis system using request such as can achieve misfire fault diagnosis in the absence of TDC signal.
Misfire Diagnosis of Diesel Engine Based on Short-Time Vibration Characters
Authors: Zhu Zhao Qian , Yang Jue , Zhang Xiao Ming , Li Xiao Lei
Published: October 2010

This paper studied misfire diagnosis of diesel engine based on short-time vibration characters. Misfire of diesel engine was simulated by the vibration monitoring test. Cylinder vibration signal and top center signal were collected under different states. The short-time vibration signal of each cylinder was intercepted according to the diesel combustion sequence, effective value was calculated, and BP Neural Network model built with this character was used to diagnose diesel misfire. The result shows that this method can locate the misfire cylinder effectively, and it is meaningful for guiding the detection and repair of vehicles.
The FNN Quilting Process Deformation Prediction Model
Authors: Tang Lu Xin , Bin Bin , Han Kun
Published: October 2010

It is easy to have deformation that non-rigid materials is on high-speed processing, so this paper introduces the fuzzy neural networks combine with computer vision measurement technology to control this process. Based on the traditional PID control, increasing a fuzzy neural network predictor for pre-processing of trajectory compensation. Established a fuzzy neural network deformation prediction model of the single needle quilting, and simulated. Experimental and simulation results show that: error compensation which based on fuzzy neural network, have a good real-time, allow fast and accurate automated processing of quilting.
Study on the Intelligent Controller of DTC System at Low Speed
Authors: Cui Wei Ping , Liu Yong , Qu Xi Long
Published: October 2010

This paper presents the way of how to reduce the torque and flux linkage ripples, and having better dynamic and static state performance. A new type of neural network resistance observer is developed, on basis of BP neural network, to measure the real time stator resistance of induction motor. Another improved method using fuzzy and adaptive principle can track the change of torque by regulating the duty ratio of the voltage space vector.
Evolutionary Optimization on Turning Linkage of Automobile in Simulated Annealing
Authors: Chen Feng , Zhu Jiang
Published: October 2010

The main function of turning linkage of automobile is to realize the ideal relations of turn angle of the internal and external wheels when vehicles steering. At present the main methods on design computing and verifying turning linkage have still been the planar graphing and analysis method, therefore it is very important to adopt optimization methods to design the steering linkage. Being satisfied with the Ackerman theory steering characteristics and boundary constraints, considering the ideal relationship of steering angles between external and internal wheels in steering linkage to ensure motion accuracy of automobile, optimization model of turning linkage is established. Then the objective function with penalty terms is built by penalty strategy with addition type, so the constrained optimization is transformed into the unconstrained optimization. The simulated annealing algorithm is adopted to optimize turning linkage of automobile, so that optimization process was simplified and the global optimal solution is ensured reliably.
Design and Experiment Research of a Non-Contact Optical Fiber F-P Ultrasound Sensor for Detecting Surface Defects
Authors: Shan Ning
Published: October 2010

Laser ultrasound technology has many advantages such as being non-contact, nondestructive, fast, accurate and low cost. Therefore it is usually used as an effective way to detect and characterize small surface or subsurface breaking cracks. The optical fiber F-P sensor is adapted to laser ultrasound detection field because it can detect ultrasound signals non-contact. But the optical fiber F-P sensor deviates from working point easily because of machining error and external factors in practical applications. It leads to output signal attenuation and the decreasing of signal noise ratio. On this problem, an optical fiber F-P sensing system based on two wavelength quadrature-shifted demodulation technique is designed. The mathematical model of sensing system is established. Differential Evolution Algorithm is introduced to establish the optimal model of sensing system for the first time. The structure of sensing system is optimized designed. The non-contact laser ultrasound experimental devices based on optical fiber F-P senor are established for detecting surface defects. The experimental results show this sensor can detect surface defects effectively. It has higher sensitivity and larger signal-to-noise ratio.
Carbonation Test Study on Low Calcium Fly Ash Concrete
Authors: Xu Hui , Chen Zhan Qing , Li Su Bei , Huang Wei , Ma Dan
Published: October 2010

Making full use of fly ash (FA) is an important part of sustainable materials development in the word. This paper discussed the carbonation resistance of concrete with 10%, 20% and 25% fly ash replacement ratios(FA%). The process was accelerated in artificial carbonation laboratory by controlling 20% concentration of CO2, 10°C~30°C temperature and 50%~70% relative humidity(RH). The depth of carbonation could be observed by spraying phenolphthalein solution on the fresh broken concrete surface. The test results show that adding fly ash into concrete results in the decrease of cement consumption and calcium hydroxide, so carbonation rate increases. But with the increase of FA% and carbonization time, the drop speed of carbonation rate slower, the differences in the microstructure are detailed. In addition, the carbonation rate increases when the ambient temperature varies from 10°C to 30°C and ambient RH falls from 70% to 50%. It concludes that the 10°C ambient temperature and 70% ambient RH are superior to other environmental conditions for enhanceing concrete carbonation resistance, and mixing 10%~25% FA into concrete have little influence on carbonation resistance of concrete if have adequate curing time.
Analysis of Weld Formation Mechanism and Weld Pool Dynamic during Moving Laser-MIG Hybrid Welding
Authors: Gao Zhi Guo
Published: October 2010

In order to better understand heat transfer and fluid flow pattern in the weld pool of laser-metal inert gas (MIG) hybrid welding aluminum-alloy process, weld formation mechanism and weld pool dynamic behavior were analyzed by a three-dimensional mathematical model for moving laser- MIG hybrid welding. The temperature and velocity distribution of weld longitudinal section for laser-MIG moving hybrid welding at different moment were discussed to explain flow dynamic behavior in the weld pool. In addition, weld formation mechanism was illustrated by a transverse section heat history evolvement. Moreover, the effects of laser welding parameter and MIG welding parameter on important weld geometry characteristic were quantitatively studied using the mathematical model, and the simulated weld bead geometry parameters were in good agreement with experimental measurements.
Rolling Element Bearing Condition Monitoring and Diagnosis
Authors: Lin Hui Bin , Ding Kang
Published: October 2010

Bearing failure is one of the foremost causes of breakdown in rotating machinery. To date, Envelope detection is always used to identify faults occurring at the Bearing Characteristic Frequencies (BCF). However, because the impact vibration generated by a bearing fault has relatively low energy, it is often overwhelmed by background noise and difficult to identify. Combined the results of extensive experiments performed in a series of bearings with artificial damage, this research investigates the effect of many influencing factors, such as demodulation methods, sampling frequency, variable machine speed and the signals collected in different directions, on the effectiveness of demodulation and the implications for bearing fault detection. By understanding these effects, a more skillful application of the envelope detection in condition monitoring and diagnosis is achieved.
Researches into Influence of Process Parameters on FDM Parts Precision
Authors: Peng An Hua , Wang Zhi Ming
Published: October 2010

In the field of RPM( rapid prototyping manufacturing), accuracy and efficiency have become the bottleneck that slows down its development, so how to improve parts precision has been one of the hot research questions. A variety of factors are analyzed which have effect on parts precision , such as extrusion temperature, envelope temperature, extrusion velocity, filling velocity, slicing orientation, slicing thickness, filament-width compensation, and delay time, and then corresponding measures to improve parts precision is presented.
Co-Service Manufacturing System Integrated OPC UA/FDT for Complex Equipments & Field Devices
Authors: Shen Bin , Qi Dang Jin , Fan Liu Qun , Meier Horst
Published: October 2010

Internet gives the manufacturing a new way to confront the challenges from the protean market. Applications including web techniques such as XML, Web Services, and the industrial techniques OPC UA & FDT/DTM, contribute to the reforming of the manufacturing. It leads to a new revolution and orients the manufacture to network manufacturing, cooperative manufacturing and even so-called the cloud manufacturing (the integration of the manufacturing and cloud computing) based on SOA in order to outrival other companies in the drastic competitions. This paper describes a new type of the co-service supporting based on SOA for Complex Equipments & Field Devices following a lead system which has been built in the frame of the project “Sino-German cooperation to advance the technique’s advantages: co-service supporting of the complex devices“.
Microstructure and Properties of Super Plastic Diffusion Bonded 00Cr25Ni7Mo3N Duplex Stainless Steel Joint
Authors: Chen Xiao Hui , Jiang Chun Xian , Ren Xue Ping , Hou Hong Liang , Li He Jun
Published: October 2010

The super plastic diffusion bonding behavior of 00Cr25Ni7Mo3N duplex stainless steel was performed on Gleeble-1500 hot simulator. The microstructure of the bonding interface region was studied by using optical microscope (OM), scanning electron microscope (SEM). The mechanical property of the joint was characterized by tensile strength tests. The results indicate that the strength of joint was improved with the increase of the bonding temperature, the applied pressure and the hold time. The suitable bonding temperature is higher about 100°C than its super plastic temperature. The initial bonding boundary were disappeared and the voids were closed by hot plastic deformation under the bonding condition like T=1323K, P=20MPa, t=12min. At the same condition, the grain grew up across the interface by atomic diffusion and the interfacial migration, and the strength of joints was high as 440MPa.
Thermal Cracking Meso-Characteristic of LuHui Granite
Authors: Zhang Yuan , Zhao Yang Sheng
Published: October 2010

Rock macro mechanic character is decided by rock composite and meso configuration. LuHui granite minerals composite, micro configuration and the rock thermal cracking in differ temperature are observed by micro-photometer in meso. LuHui granite is composited by kinds of minerals, and its minerals’ inhomogeneity is visible, the change of cementation among rock crystal grains, dislocation and micro cracking in crystal is produced in crystal grains under temperature. By means of experiment, the development of granite micro cracks and interior configuration, and change laws of micro cracks were observed. The quantitative analysis of the micro mechanism and laws of granite thermal crack was made, granite cracks number increases acutely in 240-260 degree C after a narrow range fluctuation in 80 degree C. Finally, the thermal cracks threshold of granite was determined primarily.
Study on Simulation Reliability Test of Machining Center
Authors: Zhang Xiang Po , Shang Jian Zhong , Wang Zhuo
Published: October 2010

Reliability research on machining center has great significance for the quality improvement of the machining center and its mechanical products. The long cycle and insufficient accuracy of collecting data is the main problem of the current reliability research on machining center. By means of building a test-bed and simulating the environment and running conditions of live using in the specialized laboratory, the simulation reliability tests, accelerated and enhancement tests are carried out. This paper aims to solve the above mentioned limitations and offer a more effective method for reliability tests on machining center.
Element Characterization of AlZnO by Laser Induced Breakdown Spectroscopy (LIBS)
Authors: Yuan Dong Qing , Zhou Ming , Xu Jian Ting
Published: October 2010

We calculate the temperature of excited plasma, found that will be enhanced with pulse energy increased. The delay time and the pulse energy were very important to the LIBS signal and define the -0.5μs was very suitable to this experiment, determined the intensity of emission spectra was linear to the pulse energy when the delay time was fixed. By change the delay time, got the emission of bivalence ionization of Zn was just less than 500ns.At last, we had researched the effect of element concentration and the thickness of film on signal intensity. When the concentration of Al being increased from 2.5% to 5%, the intensity of signal enhanced double. At the same time the content of Zn being decreased from 78% to 76%, the intensity of signal had just no change.
Geometrically Nonlinear Analysis of Long Span Composite Girder Cable-Stayed Bridge with Three Towers under Live Load
Authors: Liu Mu Yu , Wang Feng
Published: October 2010

A comparison on geometrically nonlinear analysis of composite girder cable-stayed bridge is presented. The spatial nonlinear analysis model named double-girder is established, the geometrically nonlinear behavior of whole bridge is analyzed under dead load plus live load in normal service stage, the nonlinear analysis involves cable sag, large displacement and beam-column, the three nonlinear factors effect on internal force and deformation of side tower, main girder are investigated. The results show that the effect of geometric nonlinearity is small on bending moment and deformation of side tower, and also small on vertical deflection of main girders, but nonlinear effect is large on bending moment of main girders. Results obtained in this research and conclusions made provide valuable insight and guidelines for the design of composite girder cable-stayed bridge with three towers.
Numerical Investigation on Aerodynamic Performance for Guiding VAWT with Combined Blades
Authors: Wang Qi Kun
Published: October 2010

In this paper, the reason was analyzed that the aerodynamic efficiency of the traditional vertical axis wind turbine (VAWT) was always low, and a new type of VAWT—Guiding VAWT was introduced. On that basis, a new blade shape called as combined blade for Guiding VAWT was proposed and numerical investigation was complemented on its aerodynamic performance by CFD (Computational Fluid Dynamics) technique. This Guiding VAWT includes two components: guiding impeller and rotating impeller, which are both combined blade in shape. The guiding blade is combined by three sections: inlet radial section, middle arc section and outlet linear section. The wind blade is combined by two sections, inlet arc section and outlet linear section. The combined guiding blade may not only avoid the wind impeller from the direct impact by the coming flow on its convex surface of the blade so as to decrease the drag torque but also improve the effective impact by the coming flow on the concave surface of the blade, both of which contribute the enhancement for the driving torque of the wind turbine. Results indicate: This new type of Guiding VAWT with combined blade has a wider operating range, higher aerodynamic efficiency than the traditional VAWTs. And more, this paper introduced the airfoil blade into this new type of VAWT and numerically validated that even though the flow inside VAWT was a large separated flow with variable attack angles, the aerodynamic advantage of the airfoil blade could still be shown to some extent, which hoped to further enhance the aerodynamic efficiency of the VAWT. Additionally, this new type of VAWT has a two dimensional structure for convenient manufacture, which has the latent energy to be popularized.
Elasto-Plastic Cellular Automaton Simulation of Fracturing Process in Single Pre-Fractured Rocks under Uniaxial Compression
Authors: Yao Hua Yan , Pan Peng Zhi
Published: October 2010

Rock is a natural heterogeneous material and presents complicated behaviors in the fracturing process. It is prevail to study the basic failure mechanism of rocks via numerical simulation. Based on the elasto-plastic cellular automaton (EPCA) model, this paper simulates single pre-fractured rock fracturing process with consideration of rock heterogeneity on the meso-scale. In this model, the Weibull’s distribution, which characterizes heterogeneity with the homogeneous index m and the random seed parameter s, is adopted to describe the distribution of mechanical parameters of rock specimens such as cohesive strength, Young’s modulus, etc. Pre-existing crack rock specimens with different homogeneous index or the different random seed are simulated by EPCA under uniaxial compression. Numerical results show that heterogeneity has great influence on pre-fractured rock failure process, final failure modes, and the uniaxial compressive strength.
Reliability Analysis of Supply Chain Based on GO Methodology
Authors: Ren Xian Lin , Zhang Gen Bao
Published: October 2010

To study the accurate calculation and failure mode diagnosis of supply chain, the idea that GO methodology is introduced into the reliability analysis of supply chain system is brought forward. Through analyzing detailedly every important factor leading to success of supply chain system and taking three-tier supply chain as the object, The GO model of reliability analysis of supply chain is found, which is universal. It can not only calculate reliability of supply chain system in detail, but also diagnose its failure mode and calculate its importance, which provides a way for improving and optimizing supply chain system. The example is presented to prove the method’s feasibility and validity.
An Elastic Dynamic Analysis of a Nonhomogeneous Moderately Thick Plate Using the Meshless Local Petrov-Galerkin Method
Authors: Xia Ping , Mao Wen Gui , Hu Wei Jun
Published: October 2010

A meshless local Petrov-Galerkin method for the elastic dynamic analysis of a nonhomogeneous moderately thick plate is presented in this paper. The discretized system equation of the moderately thick plate is obtained using a locally weighted residual method. It uses a radial basis function coupled with a quadratic polynomial basis function as a trial function and a quartic spline function as a test function of the weighted residual method. The shape function has the Kronecker delta function properties, and no additional treatment to impose essential boundary conditions. In computational procedures, variations of material properties in the considered domain are modelled by adopting proper material parameters at Gauss points in integrations. Examples show that the presented method can give quite accurate results to elastic dynamic problems of the nonhomogeneous moderately thick plate.
Crashworthiness Optimization Using Response Surface Method Based on Uniform Design
Authors: Yoshino Tatsuo , Xu Tao , Xu Tian Shuang , Cheng Peng
Published: October 2010

The crash box of vehicle plays an important role in absorbing energy during collision. However, the crashworthiness optimization problem is nonlinear which means the relationship between the response and design variables is implicit. This paper constructed a response surface model instead of original model. Meanwhile, uniform design has been taken to select sampling points uniformly. Then PSO method was used to optimize the approximate model with high precision. Finally, the optimization results show that the crashworthiness of structure has enhanced and provide a guide for practical application of crashworthiness design.
Research of Simplified B Pillar Model for Roof Crashworthiness
Authors: Xu Tao , Hao Liang , Li Yi Wen , Li Qiang
Published: October 2010

The B pillar structure, which affects automotive roof crashworthiness, must have a perfect surrogate model to satisfy the early design demands. This work aims to explore the proper approach of simplified model construction. To create the simplified B pillar, the collapse theories of thin-walled hexagonal and channel beams under bending collapse are reviewed and applied to simulate the deforming behavior. Meanwhile, the simplified model is constructed from parallel connection of curved hexagonal and channel section beams. After distributing different rotational nonlinear springs, the same crashworthiness analyses are performed on both simplified and initial FE models to verify the simplified effects. The results demonstrate the potential of the approach and process proposed in developing the simplified model for the concept design of autobody.
Investigations on Twisted Blade for Axial Microfan
Authors: Wang Qi Kun
Published: October 2010

By ‘Radial Equilibrium’ principle, an equation was derived to describe the radial distribution of the throughflow velocity, by which a design approach was proposed for the twisted blade of axial microfan. This approach can take into consideration the influence of the radial gradient for the throughflow velocity at the impeller’s outlet, which is different from the traditional design approach for large fans assuming the throughflow velocity remains radially unchangeable. By this design approach, attempt was made on the design for an axial microfan by choosing different twisted powers so as to obtain different shapes of twisted blades and their respective aerodynamic performance was numerically investigated. Compared to the corresponding straight blade and the twisted blade designed by the traditional approach, this new twisted blade can not only enlarge the stable operating range but also improve the flow pressure, which contributes to the improvement of the blade’s aerodynamic performance.
Optimization of Generator Structure and Additional Anode Access Method of MDAM System
Authors: Tian X. Li , Yang J.F. , Zhang Bao Guo , Guo Fang , Mao Ya Tao , Yu Ai Bing
Published: October 2010

MDAM technology is a brand-new and low-cost machining technology. Based on the brief introduction of MDAM system, the generator structure and additional anode access method are in-depth studied. The results show that the cost of consumable parts can be reduced to a minimum of only 10.9% of the original design for optimized generator based on cost reduction, but have the problems of lifespan reduction and frequently replacement. Cost and efficiency are considered comprehensively in the design of final optimized generator, which not only extends the lifespan of consumable pieces about 4 times and improves machining efficiency, but also reduces the cost to only 36.4% of the original design. So it is adopted by the system. On the choice of additional anode access methods, through comprehensive comparison, the method of additional anode attaching with the nozzle directly is ascertained, which is simple and easy realized, and reduces the damage to the surface and sub-surface during the machining of ceramics and other brittle materials. The results lay a solid foundation for further technology promotion.
Dynamic Properties Analysis of Electromagnetic Gear Driving System
Authors: Chen Hai Hong , Chen Jun
Published: October 2010

Electromagnetic gear realize non-touching driving technology, which is non-friction and non- lubrication. Based on the FEM static analysis, creating torsional vibration dynamic model for the electromagnetic gear system with the theory and method of mechanical vibration to makes research on the dynamic performance parameter. The system makes motion stimulation by utilizing the Simulink module of MATLAB. Then, a conclusion is made through the theoretical analysis. The analysis provides some reference for the futher study of the dynamic characteristics of the magnetic gear driving system.
The Interaction between a Dislocation and Circular Inhomogeneity in 1D Hexagonal Quasicrystals
Authors: Hu Ya Qun , Xia Ping , Wei Ke Xiang
Published: October 2010

The interaction between a dislocation and circular inhomogeneity in 1D hexagonal quasicrystals is investigated. By using the complex potential method, explicit solutions of complex potentials are obtained. The image force acting on the dislocation are also derived. The results show that the interface attracts the dislocation inside both the matrix and the inhomogeneity under most condition. The attraction increase with the increase of the elastic constant of phason field and the phonon-phason coupling elastic constant.
Thermal Paints Color-Temperature Intelligent Interpretation
Authors: Ma Chun Wu
Published: October 2010

Thermal paints, as a kind of temperature sensor, provided a non-intrusive method for surface temperature measurement. Based on chromaticity theory, the system described in this paper realized thermal paints temperature intelligent interpretation with digital image processing and database technology. The system overcome the effects of subjective interpretation, environment light and human color discrimination ability and made the analysis more accurate and consistent than manual interpretation.
The digital image acquisition system was described in detail. Cubic spline interpolation algorithm was adopted to process the data in the L*a*b* color space. The system had been applied to measure the surface temperature of aero-engine combustor. The results showed that the system can greatly improve the accuracy of temperature-recognition.
Numerical Analysis for Dynamic Characteristics of New Launcher with Coupled Rigid and Flexible Motion
Authors: Wang Ying Ze
Published: October 2010

This paper is concerned with an analysis of the dynamic characteristics of the high performance launcher—rarefaction wave gun(RAVEN) by numerical simulation. Based on its launch mechanism and launch structure, a rigid-flexible coupling dynamic model which considered the coupling effect between the flexible virbation of the launch barrel and the motion behaviors of the other parts of the RAVEN is established via a subsystems method. The actual motion of the projectile and inertial breech during the lauching are described by the interior ballistic equations of the RAVEN. The dynamic characterisitcs of RAVEN is illustrated by the numerical simulation about a small caliber launcher, and the interaction between launch barrel and the other parts is also studied.
Discharge Flow Ripple of Axial Piston Pump with Conical Cylinder Block
Authors: Li Lei , Ke Jian , Xu Jia , Yong Wang
Published: October 2010

The discharge flow ripple is a crucial criterion for evaluating the piston pump. This research examines the discharge flow ripple of axial piston pump with conical cylinder block by developing a comprehensive mathematical model based upon the Bernoulli equation and the continuity equation. The novel aspect of this research is that it includes the analysis of cylinder block cone angle. From the results of this research, it can be concluded that cylinder block cone angle has a significant impact on the discharge flow ripple, and utilizing a conical cylinder block design is more feasible than cylindrical cylinder block from a flow ripple point of view. This conclusion can be used to guide the up-front design for the variable displacement pump.
Chaotic Calculation and Prediction on Volume Deformation of MgO Concrete Based on Lyapunov Exponent
Authors: Song Jun Wei , Cai Xiao Ping
Published: October 2010

For the measured deformation time series of concrete engineering, linear and nonlinear chaotic prediction methods are represented for the autogenously volume deformation of concrete on basis of phase space reconstruction. Thus，the chaotic analytic method is set up for the prediction of the measured deformation time series of concrete engineering. At first，the autogenously volume deformation of RCC mixed with MgO are simply presented. Then，for the measured convergent deformation time series of RCC mixed with MgO，the interpolation method is adopted and an equal interval deformation time series is obtained. The results show that the largest Lyapunov exponent is 0.02 based on phase space reconstruction. Finally，it is separately predicted by the method of equidistance in near neighbor and that of the largest Lyapunov exponent prediction，and the predicted deformation values are ideal compared with the measured deformation values.
Modeling and Simulation of PCB Assembly under Board-Level Drop Impact
Authors: Liu Fang , Meng Guang
Published: October 2010

Finite element (FE) method is an efficient and power tool, and is adopted to analyze dynamic response of printed circuit board (PCB) assembly. First, FE model of PCB assembly was established. Second, the dynamic behaviors of ball gird array (BGA) lead-free solder joint were obtained when the PCB assembly was subjected to a half-sine acceleration pulse. Results show that the maximum tensile stresses occur at solder joints located at the four outermost corners of BGA and solder joints at outermost corners are the most vulnerable to crack. In addition, it can be found during FE analysis that the solder joint reliability can be enhanced as the PCB damping increases and input acceleration level reduces.
Defect Detection in Seven-Wire Steel Strands Using Single Magnetostrictive Transducer with Two-Layer Coil
Authors: Liu Zeng Hua , Zhao Ji Chen , Wu Bin , He Cun Fu
Published: October 2010

In order to achieve active health monitoring of seven-wire steel strands, single magnetostrictive transducer with two-layer coil is developed and applied for the excitation and reception of ultrasonic longitudinal guided waves simultaneously. The transducer can be conveniently fixed at any single one position on the helical surface of these structures. The inner and outer layers of its coil are used for excitation and reception respectively with the help of same axisymmetric permanent magnets. Experimental results show that chosen ultrasonic longitudinal guided wave mode, L(0,1) at 140kHz, can be excited and received with high signal-to-noise ratio in steel strands by using the developed magnetostrictive transducer. Furthermore, to identify the performance of the transducer, the detection of an artificial defect is also conducted.
Artificial Neural Network Analysis Method of Concrete Performance Based on Virtual Data Samples
Authors: Song Jun Wei , Shi Yan
Published: October 2010

The relationship between concrete performance and influence factors is uncertain and nonlinear. Accordingly, present BP neural network and virtual samples are presented to predict concrete performance in this paper. At first neural network and matters which need attention are introduced, And frost resistance forecasting model and impermeability model are built up, which are three-tier BP neural network of 6-13-2,4-9-1.The results show that the predicted values are ideal, and artificial neural network as one of the methods to forecast performance of concrete is appropriate.
Study on Bifurcation of Rigid Rotor Roller Bearings System Considering Nonlinear Dynamic Behavior
Authors: Cui Li , Zheng Jian Rong
Published: October 2010

Rigid rotor roller bearing system displays complicated nonlinear dynamic behavior due to nonlinear Hertzian force of bearing. Nonlinear bearing forces of roller bearing and dynamic equations of rotor bearing system are established. The bifurcation and stability of the periodic motion of the system in radial clearance-rotating speed and ellipticity-rotating speed parametric domains are studied by use of continuation-shooting algorithm for periodic solutions of nonlinear non-autonomous dynamics system. Results show that the parameters of rotor bearing system should be designed carefully in order to obtain period-1 motion.
A Novel 3-D Topography Model for Micro-Manufacturing Process Simulations
Authors: Xu Dong Liang , Zhang Jian
Published: October 2010

This paper presents a novel 3-D topography model for micro-manufacturing process simulations, which uses unit vector of the parametric surface as an important parameter to achieve the surface evolution algorithm. According to various physical models of given fabrications, it can be applied to simulations of isotropic/anisotropic etching, deposition, and other processes with surface evolution direction dependence. The simulation results of this model are 3-D visible of variable perspective. Furthermore, simplification is introduced in some special case to reduce memory requirement and calculation time. Some isotropic etching simulations are performed as examples, and the results indicate the accurate simulated surface.
Behavior-Based Fuzzy Control of Obstacle Avoidance for Indoor Mobile Robot
Authors: Chen De Hai , Liang Yu Ming
Published: October 2010

This paper describes indoor mobile robot covering path to avoid obstacle based on behavior fuzzy controller. The robot measures the distance to obstacle with ultrasonic sensors and infrared range sensors, and the distance is the input parameter of the behavior-based fuzzy controller. The behavior architecture has three levels behaviors: emergency behavior, obstacle avoidance behavior, and task oriented behavior. The task oriented behavior is the highest level behavior, and has two subtasks: wall following and path covering. The middle level behavior is obstacle avoidance. The lowest level is an emergency behavior, which is the highest priority behavior. The simulation result demonstrates that each behavior works correctly.
Intelligent Fault Diagnosis Method Based on Reliability Analysis
Authors: Duan Rong Xing , Tu Ji Liang , Dong De Cun
Published: October 2010

This paper presents a novel fault diagnosis method which overcomes the shortcomings of traditional approaches. It uses dynamic fault tree model for reliability analysis. All minimal cut sequences are generated via a new modular method, while the diagnostic importance factor (DIF) of components and minimal cut sequences are calculated using discrete-time Bayesian network. Also, we introduce the cost of diagnostic importance factor (CDIF) for components to evaluate the influences of the test costs, and combine it with minimal cut sequences’ DIF to determine the order of the system diagnosis. Finally, an example is given to demonstrate the effectiveness of this method.
Study on Discharge Characteristics of Piezoelectric Self-Adaptive Micro-EDM System
Authors: Zhu Yu Jie , Zhang Qin He , Fu Xiu Zhuo , Bao Guang Hua
Published: October 2010

A new technology of piezoelectric self-adaptive micro electrical discharge machining has been developed in this paper according to the characteristics of micro-EDM. Its working principle and the discharge characteristics are introduced, and it has been proved that the new technology can achieve micro machining. Using piezoelectric actuator as micro-feed mechanism, this new technology is simple in structure and can improve the discharging gap effectively. The discharge frequency and effective pulse utilization rate of the power supply is enhanced in machining. Experimental results show that this new technology can achieve good results.
A Fast Collision Detection Algorithm in Virtual NC Machine Tool
Authors: Tian Juan Xiu , Liao Zhi , Xiao Lei
Published: October 2010

Efficient and exact collision detection is important to improve reality and enhance immersion of virtual environment of NC(numerical control) lathe system. We introduce two techniques to improve efficiency and speed up the collision detection process. First, we adopt a spatial partitioning system and bounding volumes hierarchies to reduce the number of potential colliding polygons. Octree structure has been adopted to describe the partitioned object. Second, according to the feature of NC lathe system ,we exploit cylinders to simulate the workpieces. The experiments testify that the algorithm accelerates the velocity of collision detection and ensures the real_time requirement of collision detection in virtual dynamic processing environment.
Optimal Design of Drive System in Wind Power Generation Acceleration Gearbox Based on Matlab
Authors: Yang Shao Bo , Zhang Jun Fu , Wang Jin Ge , Deng Xing Qiao
Published: October 2010

Performance of gearbox drive system has a great impact on the working life of the whole drive mechanism, especially in wind power generation systems. Using the power split differencial drive system, the objective function of speed up Gearbox optimal design is built adopting the nonlinear constrant minimum function Fmincon from Matlab, the constraints are settled and the relevant parameters of the gearbox with the minimum volume while satisfying the transmission ratio are finally obtained. Then the optimised results is verified with single factor method. The results show that the overall volume of the gearbox is reduced by 9.13% after optimization.
Optimization of Maximum Entropy Model of Bayesian Prior Distribution Based on HPSO
Authors: Wang Zhong Min , Dai Yi
Published: October 2010

A hybrid particle swarm optimization (HPSO) approach is proposed to solve the optimization problem of the maximum entropy model oriented to Bayesian prior distribution. HPSO introduces chaos mechanism to create better initial species population, and the power-function carrier is adopted to improve the ergodicity and the sufficiency of the chaos mechanism. Then HPSO uses an inertia weight, which can balance global and local searching capability and fasten convergence speed. A nonlinear constrained optimization model of prior distribution based on the principle of maximum entropy is set up. By using Lagrange multiplier this constrained optimization problem is transformed to a non-constrained optimal one, which is solved by PSO and HPSO algorithm. The simulation example shows that HPSO not only has a better performance at the aspect of solution precision but also converges more quickly.
Modeling and Estimating Thermal Error in Precision Machine Spindles
Authors: Han Jian , Wang Li Ping , Yu Lian Qing
Published: October 2010

Thermal induced errors are significant factors that affect machine tool accuracy. The deformation of spindle is the main contributor to thermal error. In this paper, the thermal characteristics of the spindle system are investigated. Taking into account the coupling of elastic deformation and temperature, the heat conduction of the spindle system is modeled. The heat of bearings and heat transfer coefficient, and boundary conditions of the spindle are determined. Based on the numerical results, an iterative model of spindle's temperature and thermal deformation are acquired under the actions of thermal loads using the finite element method. Taking the spindle of precision boring machine with some reasonable assumptions and simplicities as an example, the finite element analysis model of spindle thermal characteristics is analyzed with virtual prototyping, and the static/transient temperature field and thermal-structure field are calculated using ABAQUS software. The characteristics of heat flow and thermal deformation within the spindle are analyzed according to the simulation results. The research results provide a theoretical foundation for reasonable arrangement and optimal design to reduce radial and axial deformation of the spindle head, temperature controlling, and the error compensation to the precision machining tool.
A New Vehicle Speed Estimation Method Based on the Longest Radial Crack on Windshield
Authors: Xu Jun , Zhu Meng Yi , Liu Bo Han , Sun Yue Ting , Li Yi Bing
Published: October 2010

Pedestrian-vehicle accident without road marks has long been a headache to accident investigators. This paper suggested a new method with the application of fracture mechanics to estimate impact speed in pedestrian-vehicle. Firstly, a windshield crack propagation model based on the crack initiation model put forward by Freund [1] is established. In the model, crack bluntness coefficient is an unknown parameter, depending on various factors, so speed domain is then divided into five intervals and sample real-world accident cases are employed to the calibrate crack bluntness coefficient in different speed intervals. Further, fourth-order Runge Kutta’s method is used to solve the differential equation. Five additional real-world accident cases are then employed to verify the accuracy of the model. Results show good agreement between the model results and the real impact speeds. Finally, the advantages and limitations of this method are discussed.
Study on an Integrated Child Safety Seat
Authors: Cao Li Bo , Chen Huan , Ren Xi Juan , Ou Yang Zhi Gao
Published: October 2010

A new integrated child safety seat is presented in this paper. The seat is a two-mode seat for a motor vehicle cooperable with an adult seat belt assembly to provide two modes operation including an adult seat mode and a child seat mode. The seat locates in the center of the rear seat. The structure of the seat was designed in detail. The height of the booster of the seat can be adjusted continuously according to the seated shoulder height of the child passenger. The depth of booster cushion also can be changed according to the size of the passenger. The sled test with the seat was conducted. The seat simulation models with different booster heights were developed using MADYMO software and validated. Then, these models were used to study the performance of the seat in frontal impact. Some key parameters of the seat were studied in simulation test. The results of the test and simulation show that the seat can provide effective protection for the children aged from 3 to 10 years in frontal impact.
Modeling and Simulition of Hydraulic AGC System for 1100mm Cold Rolling Mill
Authors: Gao Qi Ming , Li Jun Fu , Zhao Guo Qing
Published: October 2010

Regarding 1100mm rolling mill hydraulic AGC system as the research object, on the basis of considering the pipeline dynamic characteristics and adopting position-pressure compound control method, the mathematical model of the hydraulic system is established. This paper analyzes the system dynamic characteristics in different conditions and studies the various static and dynamic error compensation methods.
Measures for Improving Reliability of the Machining Center
Authors: Zhang Xiang Po , Shang Jian Zhong , Wang Zhuo
Published: October 2010

Improving reliability of the machining center (MC) has great significance for raising the manufacturing level of machine building industry and enhancing the international competitiveness of products. Based on the current situation of researches on the reliability of machining center, this paper presents a systematic discussion of MC from the perspectives of the reliability design, the test and assessment and reliability management respectively, aiming to improving reliability of the MC. Relevant methods and approaches, which form a theoretical system of reliability researches on the MC and serve as a scientific and systematic reference basis for them, are proposed. The study of it has an active meaning to raising the level of researches on the reliability of MC.
Experimental Investigation on Dynamic Characteristics of a FEAD System: Affected by Serpentine Belt Length
Authors: Zeng Xiang Kun , Shangguan Wen Bin
Published: October 2010

Serpentine belt is widely used in the front end accessory drive (FEAD) system of automotive engine. Experimental setup and dynamic behaviors of a FEAD system are demonstrated in this paper. Some dynamic characteristics are investigated, subjected to multifrequency excitations and different crankshaft (CRK) loads. Experimental results show that the parametric instability of belt transverse vibration occurs mainly in the frequency regions of secondary resonance, and the instability regions are shifted to lower frequencies according to the increasing of CRK speed. With the same CRK load and speed, the rotational angle of tensioner arm, the hubload of tensioner pulley and the slip rate of ALT pulley in the short-belt system are smaller than that in the long-belt system. But with the increase of CRK loads, the parametric instability of belt transverse vibration in the short-belt system is stronger than that in the long-belt system, the higher CRK speed, the greater belt transverse displacement.
The Application of Pseudo-Excitation Method to the Ride Comfort Research of Wheel-Loader
Authors: Chi Chun Yan , Qin Si Cheng , Yu Ding Wen , Zhang Wei Jun
Published: October 2010

The wheel-loader is modeled as a linear 12-DOF system in this paper for researching its ride comfort under typical working situations. The pseudo-excitation method is introduced for vibration analysis, which accuracy has been validated. By using this method and taking a certain type of wheel-loader as a representative example, the spectral density of real response of wheel-loader such as the vertical acceleration of driver, the for-and-aft angular acceleration of bucket and the wheel relative dynamic force due to different carrying capacity, speed and the road surface level are obtained. The results offer the theoretical evidence for the farther wheel-loader vibration reduction research.