bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Bauxite-Based Homogenized Mullite Grogs with Bauxite and Coal Gangue
Authors: Yang Zhong Zheng , Xing Zhen Xian , Gai Zhan Fang , Liu Huan Qiang
Published: February 2011

The sintering behavior, physical properties and heat processing changes of bauxite-based homogenized grogs prepared by homogenization process and high temperature sintering using bauxite as starting material were investigated. Results show that the bauxite-based mullite can be synthesized by the method, sintering temperature with and without MgO/CeO2sintering aids are 1600°C and 1700°C separately, the mullite with apparent porosity of＜1.0% and 2.5%, bulk density of ≥2.87g•cm-3and 2.75g•cm-3, Refracteriness-Under-Load(RUL) 1600°C and 1620С; changes in the heat processing is divided into three stages: dehydration stage(400°С~900°С ), primary mullitization stage(1000°С ~1200°С) and secondary mullitization stage(>1200°С).
Research on Flow Stress for 00Cr12Ti Stainless Steel
Authors: Fan Bai Lin , Guan Ke Zhi , Huang Gang Han
Published: February 2011

Flow stress of hot deformation about 00Cr12Ti stainless steel was experimentally studied by A Gleeble1500 thermo-mechanical simulator. The effects of deformed temperature, strain rate and strain to flow stress were analyzed .multiple Non-linear regression mathematical models of flow stress were proposed. 00Cr12Ti flow stress varies with temperature more slowly through 00Cr12Ti compared with 0Cr13Mn.
Microstructure and Anti-Corrosion Properties of Arc-Sprayed Aluminum Coating in Splash Zone
Authors: Zhu Qing Jun , Wang Kai
Published: February 2011

Aluminum coatings were developed by arc spray on mild carbon steel Q235. Scanning electron microscopy detection shows that the coatings have good bonding with the substrate and have low porosity. The corrosion behaviors of the coatings in splash zone were studied. The results show that free corrosion potentials of aluminum coatings are much lower than that of Q235. Potentiodynamic polarization measurements reveal that the curves of aluminum coatings have activity anodic dissolution zone, passivation zone and super-passivation zone. Corrosion morphology and energy dispersive spectrometers show that Cl- can penetrate into the coatings and some of the substrate has been corroded. The arc spray Al-coating develops a film of corrosion products on the coating surface, which tend to seal the pores in the coatings. Arc spray aluminum coatings can protect the substrate from corrosion in splash zone.
High Temperature Deformation Mechanical Model and Processing Map of Ti-6Al-2Zr-1Mo-1V Alloy
Authors: Wang Yao Ning , Zhao Xi Cheng , Ma Hong Zhou
Published: February 2011

Based on the high temperature compression simulation experiments, the mechanical behavior of Ti-6AI-2Zr-1Mo-1V alloy were studied over the range of temperature from 850°C to 1100°C , strain rate from 0.01 to 10s-1. The results show that the flow stress reduces with temperature increasing at the constant strain rate and increases rapidly with strain rate increasing at the constant temperature. The stress index n and deformation activation energy Q is respectively 7.0874 and 610.463 kJ/mol at 850-950°C . While at 950-1100°C , n is 4.7324 and Q is 238.030 kJ/mol. From the obtained processing map, it is found that two unstable regions present at the lower temperature or higher strain rate and two optimum regions in hot deformation process. The unstable zones are 850-950°C , 0.001-0.008s-1of strain rate, and 940-1030°C , 2-10s-1of strain rate respectively. In the optimum zone with the temperature range of 1060-1100°C , strain rate of 0.05-0.65s-1, and the peak efficiency of power dissipation of about 0.42; while in the other zone with the deformation temperature 890-940°C , strain rate of 0.06-0.18s-1, and the peak efficiency of power dissipation of about 0.33.
Research on Milling Stability Using CNC Small Size Tool
Authors: Luo Yong Xin , Shen Xiao Long , Long Hua , Zhang Lai Xi
Published: February 2011

In a larger-power CNC milling machine, the milling stability of CNC small size tool which is less than φ 25 diameters is restricted under a certain degree. Authors studied CNC milling chatter stability by the experiment and simulation; they had researched those influences of tool’s diameter, suspended length and craft of manufacturing system on chatter stability domain. Researches show that the larger diameter and shorter suspended length of the tool can improve the stability of milling, and also can improve critical axial cutting depth. The lobes of chatter stability domain can forecast effectively critical axial cutting depth and relevant to milling speed, can better mining machine cutting potential.
A Simplified Numerical Method to Determine the Loads Acting on the Cutterhead of a Compound Shield
Authors: He Fei Jiang , Zhang Qiang , Cai Zong Xi
Published: February 2011

In order to determine the loads acting on the cutterhead of a compound shield, this paper aims at the large-scale and fully coupled system of the excavation face. Firstly, a new model is proposed to calculate the loads acting on a single cutter, in which the earth pressure of the chamber is taken into consideration. Then, by transforming the large-scale nonlinear contact problem into a smaller one, we set up the governing equations only including the penetration depth of cutters in the approach of the sub-structure condensation, to calculate the loads acting on the cutterhead. Finally, the relationship between the penetration per revolution and the total thrust and total torque acting on the cutters of the cutterhead of a compound shield is investigated.
Catastrophe Analyses of Rock Cut by Helical Cutting Mechanism
Authors: Liu Song Yong , Gao Kui Dong , Du Chang Long , Fu Lin
Published: February 2011

To research the change law of the load of the helical cutting mechanism cutting into the rock, the cutting experiment was done basing on the constructed rock. The constitutive model of the cutting load was build according to the experiment load, and the mechanical model of the rock was build too. Simultaneously, the mechanical model of the helical cutting mechanism cutting into the rock was build according to the actual working condition underground; and the cusp catastrophe model of the cutting process was build basing on the catastrophe analysis, the stiffness condition and the energy condition of the helical cutting mechanism cutting into the rock were acquired. Research results indicate that: the stiffness of the haulage system of the helical cutting mechanism must be smaller than the resistance stiffness of the rock, otherwise the strong vibration will be caused, and the helical cutting mechanism and the transmission system will be damaged too; the energy release rate of the helical cutting mechanism must be bigger than the required energy of the rock broken, or else the helical cutting mechanism will be lockout, even the cutting motor is damaged.
Kinetics Performance of a Linkage with Dynamic State Balance and Small Fluctuation Features
Authors: Ren Tao
Published: February 2011

A linkage with dynamic-state balance and small fluctuation load features on its crankshaft would both enhance a motor’s efficiency and load rate and reduce its input power by ensuring that the motor is driving as uniform load as possible. It could then be widely applicable to the saving of energy in oil pumping equipment. This paper presents a new model of oscillating block six-bar linkages in which the net crankshaft torque is reduced to a small fluctuation in load by adding the counterweights to the crank and rocking bar. The kinematics and kinetics models of this linkage under the counterbalance were therefore established. Factors influencing the net crankshaft torque fluctuations were analyzed. All parameters of design scheme were optimized using the MATLAB optimization toolbox. Analyses contrasting the effects of energy saving were performed under the actual load conditions.
Research on the Construction Method of Intermittent Transmission Function and its Application
Authors: Cao Yan Ke , Guo Pei Quan , Zhao Hao Dong
Published: February 2011

Construction method of transmission function was presented based on intermittent transmission characteristic of indexing cam mechanism. The transmission function with continuous acceleration has been deduced by an example, and verification method of transmission function was presented based on the virtual prototype technology. A model of parallel indexing cam mechanism was established using the constructed transmission function, and theoretical derivation was verified correctly through simulation.
Study on Minimum Teeth without Undercutting of Standard Involute Gears
Authors: He Jia Ning , Zhang Wei , Zhang Hai Bin , Ma Wu Xing , Chen Si , Li Qiang , Gao Yong
Published: February 2011

In textbooks of mechanical engineering, rack has been mistakenly regarded as rack cutter so that minimum teeth without undercutting have been deduced, which has made people misunderstand undercut phenomenon more than 65 years. Theoretical research and computer simulation about undercut phenomenon are presented in this paper. Firstly, the theoretical analysis and calculation on minimum teeth without undercutting have been carried out, the rack cutter is used to infer minimum teeth without undercutting of standard involute gears, and correct minimum teeth without undercutting are get; And then computer simulation is applied to verify validity results of theoretical calculations, which not only corrects the long-standing mistakes about the traditional undercut phenomenon, but also provides the correct theoretical guidance for gears’ manufacturing.
Experiments and Modeling of a Rotatable-Direction-Valve in Bionic Undulating Propeller
Authors: Xu Hai Jun , Pan Cun Yun , Li Qiang , Gao Fu Dong
Published: February 2011

Motions of natural creatures appear flexible and rhythmical characteristics. The bionic undulating propeller imitates undulating motion of a fish’s flexible long fin, and its propelling efficiencies are affected by bionic units’ characteristics. In order to improve the flexibilities of both structure and bionic motion, the paper designed a bionic undulating propeller driven by hydraulic system, and then carried out some modeling work on the rotatable direction valve. At last, some experiments are brought forward on a prototype of bionic undulating propeller. In the experiments, rotatable-direction-valve could control fluid flowing through all the oil orifices periodically and in sequence, so as to drive the bionic units swinging rhythmically. Under the control of rotatable-direction-valve, the prototype gains flexible starting and stopping processes, as well as self-resume character of bionic undulating wave, which are coincident to nature fish. The results show that application of hydraulic system in bionic undulating propeller is feasible, and theoretic model of rotatable direction valve is correct.
Innovation Synthesis of Basic Configurationof Epicyclic Gear Trains with Three-Degrees of Freedom
Authors: Ren Heng Bin , Huang Mao Lin
Published: February 2011

Epicyclical gear trains with three-degrees of freedom have found its wide application as the development of new technique. Currently, nearly all domestic researches on epicyclical gear trains with three or more degrees of freedom are aimed at the practical application, and scare works systematically investigate basic configuration and synthesis of the train system. An innovation synthesis method is proposed based on the compound joint kinematic chain and the substitution of low pair with high pair for epicyclical gear trains with three-degrees of freedom, and the possible independent basic configurations of epicyclical gear trains with three-degrees of freedom are obtained by applying the proposed method and the utilization of the method is also discussed. The method provides not only a new approach for innovation synthesis of epicyclical gear trains but also a few basic configurations of epicyclical gear trains with three-degrees of freedom for practice design.
Natural Properties Analysis of an Idler Gear System of a New NC Power Turret
Authors: Xu Li Jiao , Chen Nan
Published: February 2011

This work develops a dynamics analytical model for an idler gear system of a power turret to analyze its vibration modal frequencies and modes. The idler gear system has four gears and each gear of the idler gear system has been defined as a rigid body which has the two translational and one rotational freedom. An ADAMS simulation model for whole idler gear system is built also. The calculated result by the analytical model accord with the ADAMS model’s well.
Computation for Output Torque of Electromechanical Integrated Toroidal Transmission
Authors: Cai Yi , Xu Li Zhong
Published: February 2011

The mechanics models of electromechanical integrated toroidal drive in magnetic meshing between stator and planet or between worm and planet are established on the base of electromagnetic theory in this paper. Equivalent current model of permanent magnetic body of planet tooth is founded too. The calculated formulas for magnetic field force between stator and planet or between worm and planet are deduced. And the calculated formulas of output torque of electromechanical integrated toroidal drive are obtained too. The output torque of drive is calculated and analyzed, summarized the influence factors and regulars of output torque, which is the base of design.
Transmission Efficiency Analysis of pin-Cycloid Planetary Gearing Reducer Applying Two-Stage Speed Reduction Used in Propeller Pitch Variator
Authors: He Wei Dong , Lu Qi
Published: February 2011

This paper introduces a pin-cycloid planetary gearing reducer in two teeth difference applied in propeller pitch variator. To be considered, the main factors are pin-cycloid gear meshing efficiency, bearing efficiency and output mechanism efficiency. Finally, the transmission efficiency of this new-type reducer is calculated by the inverted mechanism method, which is the foundation of prototype test in future.
Low-Speed Dynamic Characteristics of Hydraulic Clinder Based on Nonlinear Coupling- Force
Authors: Lin Rong Chuan , Guo Yin Biao , Li Yan Ping
Published: February 2011

The mechanism and producing condition of instsbility in low velocity of hydraulic clinder was analyzed based on dynamic model and test ,Nonlinear coupled force combined with hydraulic spring and Self-excited vibration were though the key factor that could effect instability in low angular velocity, The mathematic model was established to obtain the change rule of speed & instantaneous acceleration of the hydraulic clinder A simulation analysisis then created for dynamic characteristics of hydraulic clinder with Simulink to analyze the effect of friction torque, leakage and compressibility of oil and liquid on low-speed stability of hydraulic motor, The test shows that fluctuation was the negative characteristics of friction in the self-excited vibration conditions .Some measures were proposed to improve the low-speed stability of hydraulic clinder.
Nickel Deposition on Pre-Electroless Plated Ni-P-B Coating on Quartz Optical Fiber in a Lanthanide Oxide-Added Watt Electroplating Bath
Authors: Jiang Bo Quan , Zeng Jiang Nan , Liu Yu De , Liu Xiao Hong
Published: February 2011

Lanthanide oxide was added into the common Watt bath to make a thick nickel on the Ni-P-B coating on the quartz optical fiber surface by response surface method. The experiment showed the optimum concentrations of NiSO4•6H2O, CH3（CH2）11OSO3Na and La2O3 as well as current density were separately 220g/L, 0.08g/L, 0.9g/L and 1.0 A/m2 under which the deposition rate reached 24.2μm/h. The established model had an agreement with the experimental values and can be used to predict the deposition rate within the experimental range. The experiment also showed that the deposition rate, structure and other physical properties of the Ni coating prepared with addition of La2O3(0.9g/L) were greatly improved compared with the sample prepared without addition of La2O3 under same conditions.
Structural Design and Analysis on Reducer with Traveling Wave Driving Principle
Authors: Song Rui Yin , Wang Xian Cheng , Zhang Mei Qin
Published: February 2011

A new type of reducer based on traveling wave driver principle was put forward. The initial structure of the reducer was designed and the theoretical model was built up. An initial reducer was manufactured and some performances were tested. The experiment results illustrated that the new type reducer has a feature of large ratio, and the testing results accord with the theoretical model through adjusting some test parameters.
Study of Reliability Modeling for Process System
Authors: Zhang Kun Lun , Guo Bo , Jiang Ping
Published: February 2011

The definition of process system reliability was provided. The study focused on the process reliability model with the quality parameter as index. Taking into account the effect of error propagation in working procedures on the whole process, it proposed the calculating methods of working procedures and process system reliability, which can effectively evaluate the ability of process subsystem in fulfilling design requirement.
Study the Equipment Based on Fast Flood Discharge
Authors: Xu Yue Zeng , Jiang Fan
Published: February 2011

The design of the fast flood discharge equipment structure with displacement reached 0.5×104m3/h is given, which is based on the researchs of elimination methods for floods which happen in each kind of small reservoir in the flood season. This paper analyzes the equipment’s performance characteristic and application in the emergency on the spot. It indicates that its structure is reasonable and the performance is good.
Stochastic Finite Element Method Using Polynomial Chaos Expansion
Authors: Zhao Wei , Liu Ji Ke
Published: February 2011

We present a new response surface based stochastic finite element method to obtain solutions for general random uncertainty problems using the polynomial chaos expansion. The approach is general but here a typical elastostatics example only with the random field of Young's modulus is presented to illustrate the stress analysis, and computational comparison with the traditional polynomial expansion approach is also performed. It shows that the results of the polynomial chaos expansion are improved compared with that of the second polynomial expansion method.
Research on Complex Structures Reliability Analysis Using Improved Response Surface Method
Authors: Cheng Ye , Zhou Cui Ying , Xie Jin Rong , Huang Lin Chong , Wen Jian Hua
Published: February 2011

Response surface methods are often used to solve reliability analysis problems of complex engineering structure. But the solved reliability index of these methods is mostly geometric reliability. Some errors exist in geometric reliability index compared with the reliability in practical engineering which need to be improved. The importance sampling method in V-space was lead into this paper to transform the basic random variable space to V-space by Rosenblatt transformation and linear orthogonal transformation basing on the designed checking points and its nearby response surface, the complex structure reliability value was solved out by using Monte Carlo importance sampling method. The comparative analysis of several numerical examples’ results have showed that the method put forward in this paper is of high precision and suitable for the reliability solution of complex structures with strong nonlinear performance function.
Supercritical CO2 Anhydrous Dyeing Equipment and the Static Stress Analysis of Key Components
Authors: Sun Ying , Zheng Huan Da , Zheng Lai Jiu
Published: February 2011

In anhydrous dyeing research process, a set of self-developed supercritical CO2fluid dyeing equipment was manufactured. With computer control system, temperature and pressure was controlled accurately in dyeing process. As key components of the supercritical dyeing equipment, the coloring matter kettle and the segregator had a close relationship with the dyeing process. The finite element analysis software ANSYS was used to analyze the static stress of supercritical dyeing equipment. The model of the coloring matter kettle and the segregator were established, and the static stress analysis result of the coloring matter kettle and the segregator were obtained. These models not only confirmed the safety of the dyeing equipment, but also offered related parameters and provided the methods for improving the efficiency of dyeing equipment design.
Application of Bayesian Method in Assessing Reliability Parameters of Mechanical Product
Authors: Cui Yu Lian , Wu Wei
Published: February 2011

When assessing the reliability parameters, the traditional method is to deal with a large quantity of data obtained through test and to get the result with high confidence. But small sample size and the lack of test data of mechanical items make the traditional method have weakness. If the Bayesian method can be used properly, accurate assessment will be derived even if it is lack of data. What is discussed in this paper are: 1) determination of prior distribution, 2) reliability assessment based on pass/fail data with Beta distribution, Gamma distribution and cut-tail normal distribution as prior distribution, and 3) reliability assessment based on time-to-failure with Weibull distribution and normal distribution as prior distribution.
Stress Analysis of Rail for an Electromagnetic Launcher due to Projectile Movement
Authors: Geng Yan Bo , Xu Li Zhong
Published: February 2011

The principle of electromagnetic launch is introduced. The equation of electromagnetic load applied on rails is given. Based on the calculated result of electromagnetic pressure, the equation for calculating bending stress of rail on the elastic foundation is deduced using superposition principle. The stress distribution in rail with the armature in different positions is analyzed. Compared with results considering the force on the rail as uniformed load, the calculating results of stress distribution are more accuracy and useful for intensity and rigidity design of electromagnetic launch. The study may provide a theoretical basis for further analysis of systemic mechanical properties.
Research on Preventing Deflection Mechanism of the Auger Mining Machine
Authors: Du Chang Long , Gao Kui Dong , Liu Song Yong , Fu Lin
Published: February 2011

Auger mining machine which is used in thin coal seam gets coal by drilling. Its drilling distance always is dozens of meters. Because of the long Drilling distance, the deflection of the drilling tool was produced by deviating force . In order to improve auger mining machine’s preventing deflection character and scope of application, the research on preventing deflection mechanism of auger mining machine combining theoretical analysis and experimental research was carried out on the basis of a simplified drilling tool structure. The studies we have performed showed that: increasing the drilling assembly bending rigidity or the drill pipe weight can prevent deflection; reducing the distance between the drilling stabilizer and drill is another method to reduce amount of deflection.
Experimental Study on Lubrication Performance of Slide Bearing with Groove on All Pads
Authors: Guo Yong , Zhao Wei Jun , Yang Ling , Yuan Xiao Yang
Published: February 2011

This paper reports a case of lubricating property test of bearing. In order to seize the performance and the reasonable work condition of Ф480mm elliptical bearing with groove on all pads for 1000MW steam turbine, an experimental method that load is on the rotor was adopted in this paper. And the test focused on the bearing characteristics which is most concerned by designers such as power loses, temperature, flow, and flow state, etc. The influence on power loses, temperature rise, flow by the temperature and pressure of inlet oil, load, speed was studied in this test. The results show that the flow state in this bearing is changed from laminar to turbulent in the speed range 2000rpm~2200rpm and in the Reynolds number range 1325.8~1556.5. The specific pressure for the bearing with groove on the down pad is proper between 1.57MPa and 1.96MPa.
A New Method to Realize Unsteady Calculation of Flow in Labyrinth Seals
Authors: Liu Zhen Ping , Liu Shu Lian , Zheng Shui Ying
Published: February 2011

As non-contact seal, labyrinth seal is widely used in rotor system of high speed. However, with the development of turbo-machinery toward high performance and huge capacity, gas excitation vibration within the labyrinth seal becomes the main reason threatening safe operating of machinery sets. Recently three dimensional computational fluid dynamic was applied to analyse inside flow in labyrinth seal. These researches, while greatly improve rotordynamic prediction of labyrinth seals, are mostly focused in steady calculation. In fact, rotor inside the seal is whirling in a nonlinear behaviour, which makes the flow unstable. In an effort to analyse the non-linear behaviour of flow in labyrinth seal, this paper utilizes an improved dynamic mesh technology to realize unsteady calculation. The Reynolds Averaged Navier Stokes equations is solved by a commercial CFD program, FLUENT. Steady calculations are firstly done to determine mesh density and turbulence model, then an unsteady analysis is used to study gas excitation force. The influence of initial condition to the unsteady analysis is discussed. This method allows modeling of rotor orbit around the eccentric position and gives prediction of nolinear gas excitation force.
Preparation of Electroless Ni-P Composite Coating and its Tribological Properties
Authors: Yan Yu Tao , Huo Yu Qiu , Sun Zhi Li , Xu Zhen Xing
Published: February 2011

The Ni-P composite coatings onto 4043 aluminum alloy were prepared by electroless plating with nickel sulfate and sodium hypoposphite as raw material. The Ni-P composite coatings were heat-treated for 1 hour at 200°C, 300°C, 400°C, 500°C and 600°C, respectively. The tribological behaviour of the coatings was investigated on a vertical universal friction/wear tester under dry friction. The morphology and phase structure of the composite coatings were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), and the microhardness of the composite coatings were measured by Vickers diamond indenter. The results showed that the as-deposited coatings had smooth cellular pattern and amorphous structure, and the microhardness of the coatings reached the maximum at 400°C heat treatment, the reason is the formation of Ni3P alloy phase with increasing of the heat treatment temperature. The friction coefficient of coatings annealed at 400°C is the lowest. The wear loss was found to increase with corresponding increase in load and sliding speed. It was found that the wear mechanism of the as-deposited Ni-P composite coatings was dominated by adhesive wear and scuffing under the experimental conditions, but the wear mechanism of the coatings annealed at 400°C was scuffing.
A GAFCM Clustering Analysis Model for Diesel Engine Faulty Diagnosis
Authors: Chen Xiao Guo
Published: February 2011

A general fuzzy clustering analysis theory method is introduced at first, then a GAFCM algorithm and its implement steps are given. The diagnosis types of the test samples are judged by getting across the most of the Euclid pressing close degree choosing approximately principle. Practice proves that this method can be used to diagnose the diesel engine vibration faulty.
Finite Element Analysis of the Static Performance of a Self-Slot-Compensating Aerostatic Bearing
Authors: Zuo Xiao Bo , Wang Jian Min , Guan Chao Liang , Li Juan
Published: February 2011

The static performance of an aerostatic bearing with angled surface self-slot-compensation is analyzed. The consistent condition was applied to unitize the Reynolds equation of different forms and the finite element method (FEM) was used to solve the equation. The load carrying capacity (LCC) and the stiffness of the bearing was obtained and the influence of the geometric parameters was discussed. It is concluded that this self-compensating aerostatic bearing can achieve a good performance; the geometric parameters of the gap are interactive, and should be rationally matched.
The Application of Fuzzy Mathematics in Shearer Malfunction Diagnosis
Authors: Fu Jun Wei , Fu Bao Wei
Published: February 2011

The subject relationship between the AM500 Shearer malfunction omen and reason is fuzzy, therefore, in the thesis we draw fuzzy mathematic method into Shearer malfunction diagnosis, bring forward setting up the fuzzy membership grade method which is based on the history data and expert preferential ordinal number, found the fuzzy diagnostic model, carry out the fuzzy diagnosis on AM500 Shearer malfunction in computer.
Torsional-Vibration Action Research on the Diesel Engine Crankshaft
Authors: Tian Xiao Qing , Liu Shi Ying , Ding Guo Dong
Published: February 2011

Abuse conditions of torsion and vibration occurred on crankshaft should be eliminated or diminished during the engine design process. 3D model of the crankshaft is set up by means of the simplified crankshaft system, using the concentrated quality method. FEA software was used for analyzing the different vibration amplitude orders. Two models with absorber and without absorber were compared and tested. The results of torsional vibration amplitudes-speed and so on are benefit to the new product development for eliminating the potential mechanical harm.
Study on V-Shaped Linear Ultrasonic Motor and its Experiments
Authors: Li Zhi Rong , Wang Hong Bing , Xu Hai , Chen Chao
Published: February 2011

A V-shaped linear ultrasonic motor with a stator and a slider has been developed. The stator consists of two orthogonal Langevin actuators which is joined together in their ends. The Langevin actuators are symmetrical and have same first order longitudinal mode. A linear motion of the slider is generated by friction between the stator and the slider when the two first order longitudinal modes are combined. In this paper, structural dynamic design on the stator is completed with Finite Element Method(FEM). The prototype motor is manufactured based on the design results. The operation modes of the stator and the output performances of the motor are tested. The diameter and length of the Langevin actuator are 20mm and 58mm, respectively. The mass of the stator is 290g. The first order longitudinal frequency of the Langevin actuator is 27.47 kHz (FEM simulating result) and 27.36 kHz (expermental result), respectively. The maximum driving force of the motor approaches 40N. The maximum velocity of the motor is about 100 mm/s. So the stator’s operation modes are consistent with the design results, and the motor output properties have characteristics of slower velocity and stronger force.
Analysis and Design of Stator of Traveling Wave Type Rotary Ultrasonic Motor
Authors: Chen Chao , Chen Ru Juan
Published: February 2011

Due to its compact sizing, fast response and good control performance traveling wave type rotary ultrasonic motor (TRUM) has significant potentials for applications in robot actuation. In order to considering the complex geometries, this paper presents modeling approach for micro-TRUM stator. First piezoelectric composite stator is partitioned into three substructures, two of which are modeled as several continuous annular plates by semi-analytical method. Without losing the complex geometries, the stator teeth as another substructure are modeled by means of finite element (FE) approach. Based on both component-mode synthesis and dynamic reduction, the coupled method for continuous plate and FE discretized teeth is presented in order to consider dynamic behavior of composite stator with good accuracy and short computation time. It allows combination of the continuous parameters and FE discretized substructures, and the mathematical model representing the complete stator is derived. Finally the prototype is manufactured according to the presented method. The validation of the analysis and design method is attained through the experiments for the manufactured stator. It is pointed that radial friction can be capable to increase s for the ultrasonic motor with smaller dimension. It explains why micro-TRUM has a fast heat output at the contact interface.
Vibration Response Analysis of a Stepped Beam with Crack Using Composite Element Method
Authors: Lu Xu Bin , Lv Zhong Rong , Liu Ji Ke
Published: February 2011

The composite element method is utilized to discretise a stepped Euler-Bernoulli beam with a crack. The local stiffness reduction due to the crack is introduced by using a simplified crack model. The finite element equation for the forced vibration analysis is obtained using the composite element method (CEM). The forced vibration response of the cracked stepped beam is numerically calculated using Newmark integration method. Numerical results indicate that the position and depth of a crack affects the low and high natural frequencies and modes of a cantilever beam, respectively. And the position of the crack has significant effects on the dynamic responses of the beam.
Identification of Excitation Source Number Using Principal Component Analysis
Authors: Dong Jian Chao , Yang Tie Jun , Li Xin Hui , Shuai Zhi Jun , Xiao You Hong
Published: February 2011

Principal component analysis (PCA), serving as one of the basic blind signal processing techniques, is extensively employed in all forms of analysis for extracting relevant information from confusing data sets. The principle of PCA is explained in this paper firstly, then the simulation and experiment are carried out to a simply supported beam rig, and PCA is used in frequency domain to identify sources number of several cases. Meanwhile principal components (PCs) contribution coefficient and signal to noise ratio between neighboring PCs (neighboring SNR) are introduced to cutoff minor components quantificationally. The results show that when observation number is equal to or larger than source number and additive noise is feebleness, accurate prediction of the number of uncorrelated excitation sources in a multiple input multiple output system could be obtained by principal component analysis.
The Vibration Characteristics of a Large Flexible Vibration Isolation Structure with Finite Element Analysis and Modal Test
Authors: Zhou Liu Bin , Yang Tie Jun , Yuan Wan Peng , Shi Hui , Liu Zhi Gang
Published: February 2011

A large flexible vibration isolation structure is presented in this thesis, and experimental modal test based on the finite element analysis is carried out in order to find out the vibration characteristics of it. Results show that the natural frequencies and mode shapes calculated by finite element method basically conform to those measured from experimental modal test. Some suggestion to vibration active control in further research is also provided.
Dynamic Analysis of 64-Type Rush-Repair Steel Girder under the Moving Train Loads
Authors: Zhang Yao Hui , Wang Hai Long
Published: February 2011

In China, the 64-type rush-repair steel girder developed in 1964 has played a huge role in the railway and highway transportation engineering construction. When it is used as a temporary railway bridge, the original biggest design traffic speed only is 30 km/h. With the rapid development of domestic railway, the dynamic performance of the 64-type rush-repair steel girder must be studied in detail in order to make clear what it can adapt the current technical requirements. In the paper, the structure and technical characteristics of the 64-type rush-repair steel girder are introduced and the dynamic responses of the 64-type rush-repair steel girder are calculated using the train-bridge coupling vibration theory. The main objects of study in paper are the 24m-span and 32m-span girders. The vibration-related laws of the 64-type rush-repair steel girder versus the different train speeds are revealed, and the proposals about the largest reasonable traffic safety speed are given.
Investigation of Self-adaptive Vibration Suppression for a Flexible Plate with Imbedded Fluid
Authors: Ma Ning , Xu Hui , Wang Jian Wei
Published: February 2011

A new method of vibration suppression, interior inlay viscous fluid unit (IVFU), has been proposed and investigated in this paper. Experimental results show the inherent characteristics of interior inlaid fluid subsystem in suppressing the plate vibration. A numerical simulation is carried out using software FLUENT. The original liquid-solid coupling model is rationally simplified to an approximate hydrokinetic model by constructing the fluid dynamic boundary conditions. A criterion of energy dissipation is proposed. Simulation results show that under the first principal vibration, the damping effect of 1/2 volume water is better than that of 2/3 volume, and under the second principal vibration, the latter behaves a self-adaptive characteristic more than the former. Simulation results clearly illustrate the inherent mechanism of suppressing vibration and the characteristic of fluid movement in closed cavity on different situations.
A Method of Signal-Noise Separation from Measured Vibration Response Signals
Authors: Bao Xing Xian , Li Cui Lin
Published: February 2011

Measured vibration response signals are inevitably contaminated with noise originating from test environment as well as electronic devices. This situation often leads to serious difficulties in many applications as they require high-quality measured data. This paper presents a signal-noise separation method for measured impulsive response functions (IRFs) based on structured low rank approximation (SLRA). The proposed method was tested with a steel cantilever beam, which was subjected to impulsive excitation. Gabor transform was also employed to process measured signals. The results show that this method can give a reliable separation of signal and noise, which will enhance the accuracy of various applications that rely on measured signals.
Vibration Analysis and Optimal Design for Cab’s Isolation System of Vibratory Roller
Authors: Quynh Le Van , Zhang Jian Run , Jiao Guo Wang , Liu Xiao Bo , Wang Yuan
Published: February 2011

In recent years, vibration roller market has required increasingly not only on working capacity but also ride comfort. Thus, in order to reduce the effect of vibration to operators, identification and elimination of vibration sources are the most important tasks to achieve optimum design. In this paper, the attention is paid to cab’s low-frequency sloshing analysis and optimal design for cab’s isolation system of vibratory roller. When working, it often exists the problem of cab’s low-frequency sloshing in the direction of forward motion. In order to solve this problem, the dynamic test and simulations analysis are carried out; and the main reasons causing cab’s low-frequency sloshing are found out. The optimization model according to the two points response amplitude in the direction of forward motion on the cab to reach the minimum value in the low frequency range is proposed in this paper. And also, the auxiliary vibrations isolator for solving the low-frequency sloshing in the direction of forward motion is designed.
Dynamic Analysis for a Subsurface Elastic Cylindrical Inclusion with a Semi- Cylindrical Hill Impacted by SH-Wave
Authors: Lv Xiao Lang , Liu Dian Kui
Published: February 2011

An analytic method is developed for dynamic stress concentration of a subsurface elastic cylindrical inclusion below a semi-cylindrical hill under SH-wave. And the dynamic stress concentration factor (DSCF) is given by complex variable function. During the solution, a standing wave and scattered wave displacement functions are constructed in different parts respectively. All of these displacement functions should satisfy the boundary conditions of each part. Employed to the boundary conditions around the elastic cylindrical inclusion, a series of infinite algebraic equations about the problem can be obtained. The calculating results of DSCF around the elastic cylindrical inclusion are plotted to show the effects of some parameters on DSCF.
Separate Control Characteristics of Electro-Hydraulic Vibrator Using a Parallel Mechanism
Authors: Ren Yan , Ruan Jian , Yi Ji Yan
Published: February 2011

A scheme of the separate control technique of electro-hydraulic vibrator is proposed, in which symmetrical hydraulic cylinder is controlled by a parallel mechanism of a two-dimensional valve (named as 2D valve) and a parallel servo valve. The working frequency and vibration amplitude of the electro-hydraulic vibrator are dominated by the rotary speed and the sliding displacement of the spool of the 2D valve respectively, and the vibration central piston is controlled by the sliding displacement of the spool of the parallel servo valve. This paper analyzes the relationship between vibration characteristic values and control parameters using the analytic method based on the hydrodynamic control theory. The experimental system is built to verify that the theoretical analysis is consistent with measured results.
Numerical Modeling and Simulation of Random Road Surface Using IFFT Method
Authors: Hu Zhi Gang , Zhang Yong Lin , Ye Jian Ping , Song Shao Yun , Chen Li Ping
Published: February 2011

Based on the power spectral density (PSD) function of stochastic irregularities of the standard grade road and by means of inverse fast Fouerier transform (IFFT) based on discretized PSD sampling, an equivalent sample of stochastic road surface model in time domain was built. A one-dimensional model of stochastic road was developed into a 2D model of stochastic road surface. Through computer simulation practice based on the MATlab, a 2D sample of stochastic road surface in time domain was regenerated. Furthermore, given the sample data, the PSD was estimated and then compared with the theoretical 2D PSD Equation deduced from the one-dimensional PSD expreesion so as to prove the effectiveness and accuracy of the time-domain model regeneration of 2D stochastic road surface by means of IFFT method. The 2D stochastic road surface model directly provided basic road excitation input data for virtual prototyping (VP) and virtual proving ground (VPG) technology.
Task Scheduling of Product Development Process Based on Complex Features of Web
Authors: Li Xiao Juan , Yuan Yi Ping
Published: February 2011

Multi-task scheduling networkis extended based on the complex network theory, from new angles and perspectives to study the multi-task scheduling. The description of method and related mathematical models of complex and multi-task directed network aregiven. Combined with topology of the product development process and their own characteristics,the evaluation model and algorithmto describe the importance of the event node are presented. It can assess the nature ofdifferent nodes effectively, including the key nodes, at the same time,the scheduling algorithm based on the importance of active nodes hasbeen proposed.The study has a certain significance toarrange the execution of tasksin complex product development process reasonably and realize optimal allocation of manufacturing resources.
Single-Machine Scheduling to Minimize Absolute Value in Maximum Lateness with Deteriorating Jobs
Authors: Wang Ji Bo , Yang Dar Li , Hsu Chou Jung
Published: February 2011

In this paper, a single-machine scheduling problem with simple linear deterioration was explored. By simple linear deterioration, we mean that the processing time of a job is a simple linear function of its execution starting time and its deterioration rate. The objective of this study was to find a schedule that minimizes the absolute value of maximum lateness, where the due date of jobs are a common due date. Given that the cases of common due date is a given constant and variable, we showed that the problem can be solved in polynomial time, respectively. Some extensions of the problem were also delineated.
Using a Hybrid Genetic Algorithm to Minimize the Number of Tardy Jobs in the Flow Shop
Authors: Wu Jing Jing
Published: February 2011

Numerous real-world problems relating to flow shops scheduling are complex. The main problem is that the solution space is very large and therefore the set of feasible solutions cannot be enumerated one by one. Current approaches to solve these problems are metaheuristics techniques, which fall in two categories: population-based search and trajectory-based search. Because of their complexity, recent research has turned to genetic algorithms to address such problems. In this paper we present an effective hybrid approach based on genetic algorithm (GA) for minimizing the number of tardy jobs in a flow shop consisting of m machines. Jobs with processing times and due dates randomly arrive to the system. We assume that job arrival or release dates are not known in advance. The objective is to minimize the number of tardy jobs. Although genetic algorithms have been proven to facilitate the entire space search, they lack in fine-tuning capability for obtaining the global optimum. Therefore the proposed approach incorporates a fitness functions and a population trained by a local improvement search based on tabu search with a candidate list strategy into GA for the problem which belongs to NP-hard class. Experimentation results show that the number of cells and the crossover strategy adapted affect the number of tardy jobs found. The results also indicate that hybrid genetic algorithm approach improves the solution quality drastically.
Finite Element Analysis on Structural Stress of 8×8 InSb Infrared Focal Plane Array with Underfill
Authors: Meng Qing Duan , Sun Li Gong , Pu Jie Xin
Published: February 2011

Based on viscoplastic Anand’s model, the structural stress of 8×8 InSb infrared focal plane array (IRFPA) detector is systemically analyzed by finite element method, and the impacts of design parameters including indium bump diameters, heights and InSb chip thicknesses on both Von Mises stress and its distribution are discussed in this manuscript. Simulation results show that the maximum stress existing in InSb chip reaches minimum with indium bump diameter 32μm. Under this condition, for the fixed indium height, as the InSb chip thickness reduces from 21µm to 9µm in step of 3µm, Von Mises stress maximum values of InSb chip seems increases gradually, and when the indium bump height reduces from 21µm to 9µm in step of 3µm, its maximum Von Mises stress increase at random increment, do not show certain rules, and indium bump height seems to have a comparable effect on stress value with InSb chip thickness. When indium diameter, height and InSb chip thickness are set to 32µm, 15µm, and 12µm, respectively, the maximal Von Mises value existing in InSb chip reaches minimal value 628MPa, simultaneously the stress distribution at the contacts areas is uniform and concentrated, and this structure is promising to avoid device invalidation.
Simulation-Based Genetic Algorithm for Cross-Docking Center Operation Optimization under Supply Disruptions
Authors: Wu Yi Fan
Published: February 2011

Practical performance optimization of a cross-docking center has been rare in the literature so far. The measures representing operation efficiency are average inventory level and transportation cost rate, while average backorder level represents the customer service level. In this paper, a simulation optimization problem is considered and a solution framework has been developed by integrating simulation, genetic algorithm (GA) and smart computing budget allocation (SCBA) to find an optimized solution. Moreover, supply disruptions are considered in the simulation model. This problem has huge search space even for medium-sized problem scenarios. To address this difficulty, the framework employs simulation to estimate the performance measures, GA to search for better design and SCBA to efficiently allocate the simulation budget.