bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementation of Lean Manufacturing System in Bogie Assembly in Railway Coach Factory
Authors: Arunagiri P. , Gnanavelbabu A.
Published: December 2012

Elimination of the non-value added activities in the bogie assembly shop during bogie assembly process. The various non-value added activities are found in the assembly shop such as excess distance between each assembly stages, excess cost to flow of material from one stage to another stage, waste of time and non-flexibility of shop. These types of non-value added activities occur due to the improper arrangement of bogie assembly stages. Implementation of lean manufacturing systems through layout design by the conversion of existing layout of bogie assembly shop into proposed layout. Analysing the existing layout by using the CRAFT method to find out the best optimized layout .Interchanges are made between each stages that help to correct the present layout. Design calculation are done for various stages .Interchanging of stages of different section are considered by distant matrix and total cost calculations .Various cost of all the pair wise interchanged stages are estimated to find the best low cost interchange. As per the design calculation best interchange between the two stages are considered and that lead to the development of new proposed layout in which all the non-value added activities are eliminated
Intelligent Controller of Motion Assisting Robot Using Online Update of Vector Field
Authors: Xie Guang Hui , Jin Mi Na , Hashimoto Minoru , Zhu Zhi Yong
Published: December 2012

In order to synchronize motions between assisting robot and human, an intelligent controller using online update of vector field is proposed and applied to the research on assisting robot. Firstly, the polynomial expression approximation design is applied to endowing vector field of arbitrary attractor with self-oscillation characteristics. Secondly, input-output synchronization of the control system is realized by using online update design, and the degree of input-output synchronization can be modified by adjusting the oblivion parameter and load parameter in control system. Finally, the validity of the proposed method is examined by the simulation of motion assist system for human leg.
Research of Multi-Objective Optimization in Controlled Atmosphere Storage System
Authors: Huang Yue Jin , Xu Ming , Shen Xi , Gu Jiang Ping , Jin Hua Qiang
Published: December 2012

According to multi-objective optimization problem in controlled atmosphere storage system, a modified multi-objective particle swarm optimization algorithm based on maximin fitness function was proposed. This algorithm introduced normalization algorithm and the conception of ε-dominance to the computation of maximin fitness function value, which solved the skewed popularity of the particles in the flight process. A modified computation method and an alterable ε-dominance strategy were put forward, which effectively improved the convergence speed of the algorithm and the diversity of the particles. The modified multi-objective particle swarm optimization algorithm was applied to optimize parameters like fruits and vegetables type, gas content in the controlled atmosphere storage system. The experimental results showed that the convergent speed of the algorithm was fast and the algorithm was valid.
Gyroscopes and Accelerometers in the Robot Control
Authors: Božek Pavol , Pintér Tomáš
Published: December 2012

The paper deals with constructing the inertial navigation system (hereafter INS) which will be utilized for the calibration of a robotic workplace. The calibration is necessary for adapting the simulation of a production device model to real geometric conditions. The goal is to verify experimentally the proposed inertial navigation system in real conditions of the industrial robot operation.
Experimental Analysis of Static Stiffness for Vehicle Body in White
Authors: Chen Shu Ming , Song Xue Wei , Shen Chuan Liang , Wang Deng Feng , Li Wei
Published: December 2012

In order to know the static stiffness characteristics of the vehicle body in white, the bending stiffness and torsional stiffness of an automotive body in white were tested on a test bench of the static stiffness of an automotive BIW. The bending stiffness and bending deformation of the bottom of the BIW were determined. Also, the torsional stiffness and torsional deformation of the bottom of the BIW were obtained. The fitting curves and equations between loading torque and torsional angle were acquired at clockwise and counterclockwise loading, respectively.
Study on Vibration Fatigue Limits Test Method for Metallic Joint Pipe
Authors: Shao Chuang , Qiu Ming Xing , Li Yi Xuan
Published: December 2012

In order to determine the fatigue limits of two kinds of titanium alloy joint pipes connected by welding and rolling, the fatigue tests were carried out by test standard which defines the test method and failure rule. One cantilever-beam specimen was fixed on the shaker by the special fixture. The laser-displacement-sensor was fixed at the free end of pipe and the strain-gauge was adhesive at the root of the pipe. The first frequency of specimen was measured by these sensors. The first resonance frequency fell rapidly with the increment of the excitation loads of the shaker. The failure rule (1% drop of resonance frequency) of the standard was not same with the fatigue limit test of these connected pipes at the test beginning. In order to define the lives of two kinds of pipes, the stair method of sweep test was used to eliminate the effect of connection gap. Then the vibration fatigue of every specimen was tested at the last resonance frequency. And all the fatigue tests were finished using the failure rule which defines 1% drop of the steady resonance frequency.
Study of Thermal Gradient on Porosity Formation in A201 Aluminum Alloy Plate Castings
Authors: Kuo Yeong Sant
Published: December 2012

This study is to with system change the riser size and the casting geometry to find out the relation between thermal gradient and porosity formation in A201 aluminum alloy plate casting, which is discussed in this study. The results show that the porosity content was found to be relevant to the thermal gradient and riser system. The larger the thermal gradient (G), the lower the porosity content was found in this study.
Buffeting Prediction of a Square Cylinder with Inflow Turbulence
Authors: Liu Zhe
Published: December 2012

It is known that the fluctuating structural load is caused by turbulent eddies flowing past or impinging upon the structure in case of turbulence buffeting. The prediction of the response of a structure to turbulence buffeting may be very important. In this paper the buffeting response of square cylinder with constant damping ratio (5%) based on FSI theory proposed by Zhe Liu [6] is simulated. And the movement of bluff body is controlled in the across-flow direction, and two types of inlet boundary conditions are considered to compare the different influence of them on the flow around the square cylinder, one is the steady inlet boundary and the other is the unsteady one.
Estimation of Ultimate Limit Statefor Stiffened-Plates Structures: Applying for a Very Large Ore Carrier Structures Designed by IACS Common Structural Rules
Authors: Do Hung Chien , Jiang Wei , Jin Jian Xin
Published: December 2012

In advanced marine industry, the reduction in weight of hull structures for a very large object ship plays an important role as the economic efficiency is the most significant aspect. In this paper, we investigate the ultimate strength of structural ship stiffened-plates designed by International Association of Classification Societies (IACS) Common Structural Rules (CSR) methods of collapse state, by applying for ANSYS nonlinear finite element analysis (FEA). Specifically, the ultimate limit assessment methods for the outer bottom of ship structures, which have drawn a significant attention from industrial marine and offshore structures, are proposed to reduce the weight of ship structures. To solve this, we study the structures of a hypothetical Very Large Ore Carrier (VLOC) designed by pre-CSR and CSR methods. In particular, the stiffened-plates under the biaxial compression and lateral pressure loads with simply supported or/and clamped boundary condition(s), the results ultimate limit state assessment performance of Nonlinear FEA methods are shown and compared to various states.
Study of Civil-Plane High-Lift Model Using Omni-Tree Cartesian Grids
Authors: Xi Chao , Sang Wei Min
Published: December 2012

We developed a CFD code applies the omni-tree Cartesian grid to simulate the flow fields around one civil-plane high-lift model using the multi-zone technique. With a face-to-face algorithm, the flow control equations are solved numerically, in combination with the cell-center finite volume method and dual-time stepping scheme. The computed results are in good agreement with the experimental data and show preliminarily that numerical method is effective.
Mutation Instability Model of Perilous Rock and Calculation Methods for Corresponding Dynamic Parameters
Authors: Chen Hong Kai , Tang Lan , Zhang Rui Gang , Tang Hong Mei , Wu Reng Jie
Published: December 2012

Failure mechanism of perilous rock and its corresponding dynamic parameters is one of the basic theoretical questions for the security alert implement about collapse disaster. Focusing on the dominant fissure of perilous rock, it is divided into linking patch and locked patch, and the constitutive model of dominant fissure is proposed. Based on the energy principle, it proposes the deformation energy formula of perilous rock with dominant fissure’s creeping displacement. On the mutation theory, it establishes the failure cusp mutation model of perilous rock, and the calculating formulas of creeping displacement on failure starting point and end point and the controlling factors of dynamic instability are gained. With scientific theory, elastic energy releases and transforms to the elastic and impulsive kinetic energy at the moment of dynamic instability, and a method to calculate the violent-slide velocity and acceleration on collapse mass at that moment is proposed. Practical examples indicate that this method is useful in engineering practice.
Structure Analysis of Microbe-Repaired Concrete Using Scanning Electron Micrographs
Authors: Chen How Ji , Yang Ming Der , Lin Shu-Ken , Huang Chung Ho
Published: December 2012

As one of the most popular materials used in construction, concrete is prone to superficial flaws, such as crack, due to the load-bearing and external environment. This research manually made cracks of 2 mm with 100 mm length and 30 mm depth on concrete vessels as specimens. Subsequently, bacteria, specifically B. pasteurii, was used in crack rehabilitation to enhance the compression strength of the repaired concrete. The mixture of microbes, urea medium, and urea-CaCl2 medium was added to a sludge and fine aggregate with a weight ratio of 0.6:1:1 to be the repairing material for crack rehabilitation. Crack rehabilitation was conducted by injected the mixture into the test samples after 90 days curing in saturated lime solution. In addition to the traditional test – compression test, scanning electron microscope (SEM) was used to examine the structure composition of the microbe-repaired concrete for calcium carbonate crystal formation. Various rectangular and polygonal crystals were observed in the SEM photographs of the microbe-repaired concrete samples with high bacterial concentrations demonstrated that bacteria can induce calcium carbonate precipitation to complete crack rehabilitation. The results prove that high concentration of bacterial broth induced a great amount of calcium carbonate precipitate and improved the concrete strength of the microbe-repaired samples.
Numerical Analysis of Anti-Impact Performances of the Reinforced Concrete Slab
Authors: Ma Qian , Wu Dan , Shi Xu Dong , Jiang Xiu Gen
Published: December 2012

The influence of the structure parameters on the anti-impact performances of the reinforced concrete slab is studied in the article. The reinforced concrete model is established by using ANSYS 13.0/LS-DYNA and nonlinear finite element theory and the parameterized modeling is achieved. The results show that the increase of the thickness of the slab and the steel bar diameter result in the enhancement of impact resistant capability of the slab; a appropriate quantity of reinforcement is significant; Increasing the concrete strength has a distinct impact on the slab’s impact resistance when using relatively low strength concrete. However the influence becomes weak after the concrete strength comes to C60 and higher. The fruits are useful to the designing of reinforced concrete slabs.
Numerical Simulation of the Rock Fragmentation Process Induced by TBM Cutters
Authors: Li Gang , Wang Bo , Chen Ya Dong , Wang Wan Shan
Published: December 2012

The rock fragmentation process is the interaction process between TBM and rock mass, which is affected by TBM specifications, such as thrust force, cutter tip width and profile, cutter spacing, RPM, and torque, and rock mass properties mainly including rock material strength, rock brittleness, joint spacing and orientation. In this study, based on the systematic study of the existed rock constitutive model achievements and introduction of rock breaking mechanism, main failure mode of rock in the breaking process of disc cutter is added and revised in order to meet the actual situation. The method of establishing numerical model of disc cutter breaking process is introduced. After the dynamic simulation, we can obtain that geotechnical interface disturbance insulted by disc cutter. Based on plenty of experiments, it confirms reliability of numerical methods and provides a method to study cutting performance for different geological conditions.
Nonlinear Probabilistic Analysis of the Reinforced Concrete Structure Failure of a Nuclear Power Plant Considering Degradation Effects
Authors: Králik Eng Juraj
Published: December 2012

This paper describes the reliability analysis of a concrete containment for VVER 440 under a high internal overpressure considering nonlinear behavior of reinforced concrete structure. The probabilistic safety assessment (PSA) aims at an assessment of the probability of the concrete structure failure under the excessive overpressure. The non-linear analysis of the concrete structures was taken. The uncertainties of the loads level (long-time temperature and dead loads), the material model (concrete cracking and crushing, behavior of the reinforcement and liner), degradation effects and other influences following from the inaccuracy of the calculated model and numerical methods were taken into account in the response surface method (RSM). The results of the reliability analysis of the NPP structures are presented.
On Problems of Mechanical Properties of Structural Steel in Load-Carrying Structure of Historical Building Construction
Authors: Karmazínová Marcela , Melcher Jindrich
Published: December 2012

The paper is focused on the problems of the mechanical properties of steel used for load-carrying structures of civil engineering constructions, especially from the viewpoint of properties of old steels used in historical constructions in comparison with current steels. Chemical composition and physical-mechanical properties of historical steels can be important, for example, in the case of reconstructions, when for the static assessment and evaluation of existing constructions subjected to new (higher) loading actions, material properties of load-carrying structure must be known. In the case of constructions aged about 100 years, usually no project documentation and no information about used material and its properties exist. Then, the properties must be determined using material tests carried-out on the test specimens taken from the real existing structure. But here the sampling of test specimens is limited by the possibilities of existing structural system and by the dimension of particular members from which the specimens are taken, so that the test specimen dimensions and number are limited. Thus, the evaluation of material properties for obtaining representative design values can be more difficult and less reliable than in the case of the large test number. But the main problem is to determine the usable design values of material properties (design yield and ultimate strength) to utilize them for the reliable static re-design of existing structure under actual loading actions. Some problems indicated above have been shown on the example of the material analysis of steel load-carrying structure of slaughterhouse aged more than 100 years. This analysis has been performed recently within the framework of the construction exploration in connection with the intended revitalization of historical “industrial zone” in the city of Brno, Czech Republic.
Evidence Theory and Differential Evolution for Uncertainty Quantification of Structures
Authors: Deng Li Xin , Tang He Sheng , Hu Chang Yuan , Xue Song Tao
Published: December 2012

Due to lack of knowledge or incomplete, inaccurate, unclear information in the modeling, simulation, measurement and reliability assessment and design optimization, there are limitations in using only one framework (probability theory) to quantify the uncertainty in a system because of the impreciseness of data or knowledge. In this paper, evidence theory is proposed as an alternative to the classical probability theory to handle the imprecise data situation. In order to alleviate the computational difficulties in the evidence theory based uncertainty quantification (UQ) analysis, a differential evolution based interval optimization for computing bounds method is developed. A typical truss structure with the aleatory and epistemic uncertainties is investigated to demonstrate accuracy and efficiency of the proposed method.
The Application of an Immune Clonal Selection Algorithm Based on the Information Entropy in Truss Structure Multi-Objective Optimization
Authors: Hu Chang Yuan , Tang He Sheng , Deng Li Xin , Xue Song Tao
Published: December 2012

In order to solve the conflict multi-objective optimization of truss structures between the structure minimum weight and safety redundancy, the immune clonal selection algorithm based on information entropy was adopted in this paper. Based on the immunology theory, the non-dominated neighbor-based selection, proportional cloning and elitism strategy were introduced in the multi-objective immune clonal selection algorithm (MOICSA) to enhance the diversity, the uniformity and the convergence of the obtained solution. Mathematical models for truss multi-objective optimization design are constructed, in which the information entropy value of bar stress is taken as one of objective functions, and penalty function method was used to deal with violated constraints. Several classical problems are solved using the MOICSA algorithm, and the results compared with other optimization methods. The simulation results show that the method can achieve the effect of multiple-objective optimization successfully.
Real-Time Identification and Tracking of Infrared Markers Based on Kalman Filter
Authors: Xing Qiao Na , Yan Da Yuan , Hu Xiao Ming , Lin Jun Qin , Yang Bo
Published: December 2012

Automatic equipmenttransportation in the wild complex terrain circumstances is very important in rescue or military. In this paper, an accompanying system based on the identification and tracking of infrared LEDmarkers is proposed. This system avoidsthe defect that visible-light identification method has. In addition, this paper presents a Kalman filter to predict where infraredmarkers may appear in the nextframe imageto reduce the searchingarea of infrared markers, which remarkablyimproves the identificationspeed of infrared markers. The experimental results show that the algorithm proposed in this paper is effective and feasible.
Significant Factors Identification for Particle Swarm Optimization Algorithm to Solving the Design Optimization Problem of a Four-Bar Linkage for Path Generation
Authors: Lee Cheng Kang , Cheng Yung Chang
Published: December 2012

Particle swarm optimization (PSO) is a well-known population-based searching algorithm to solving optimization problems. This paper aims at identifying significant control factors for PSO to solving the design optimization problem of a four-bar linkage for path generation. Control factors considered herein are inertial weight, acceleration coefficients, breeding operation, and the number of population. A full factorial design of experiments is used to construct a set of experiments. Experimental results are analyzed with the analysis of variance method. According to the results obtained in this paper, breeding operation and the interaction between breeding operation and acceleration coefficients are significant. Inertial weight, acceleration coefficients, the number of population, and the other interactions are not significant. For the design optimization problem discussed herein, it is suggested to adopt breeding operation strategy and apply constant acceleration coefficients to increase significantly PSO’s performance and robustness. Type of inertial weight and the number of population do not affect PSO’s performance and robustness significantly.
Stability Analysis for Discrete-Time Markov Jump System
Authors: Li Ming Wei , Chen Yi , Zhang Xiao Han
Published: December 2012

Network control systems (NCSs) where the problems of data packet dropout induced by communication channel is studied in this paper. We model the data packet dropout a Markov Jump Linear systems and introduce a freedom matrix. Our goal is to find a controller such that the Markov Jump Linear systems mean square stable. According to linear matrix inequalities (LMI), we can get the sufficient condition on the mean square stabilization of NCSs. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approach.
Optical-Tracker-Based 3D Reconstruction for Endoscopic Environment
Authors: Yang Bo , Zhou Ya , Hu Xiao Ming , Lin Jun Qin , Xing Qiao Na
Published: December 2012

Endoscopic surgery is increasing for minimally invasive treatment in recent years.But the conventional two-dimensional endoscope technique cannot provide three-dimensional information for surgeon. Lacking depth and other 3D information often made doctorshave to carry out the surgery depending heavily clinical experience.In response to the above described issues,this paper proposed a method based on improved SIFT algorithmto recover 3D structure information of the endoscopic environment, with the help of an optical tracking system which can provide the orientation of the camera in real time. The proposed approach is evaluated on sequence digital images gotten from an 1394 camera and the experimental results show that the proposed approach iseffective.
Cloning of the High Alkaline Endoglucanase Gene from Bacillus pumilus AC-4 and Expressed in E.coli
Authors: Lin Yuan , Li Xin Zhou , Gao Ji Wei , Xu Jing , Du Chao
Published: December 2012

The genomic DNA of Bacillus pumilus AC-4 strain, which were separated by our laboratory, was used as the DNA template. The β-1,4-endoglucanase gene fragment was amplified by PCR (Polymerase Chain Reaction). The PCR product was recovered and cloned into plasmid pMD-19T. The DNA sequence analysis showed that the length of the amplified fragment is 1898bp, which has 95% similarities to the β-1,4-endoglucanase gene sequence from other Bacillus strains. Sub-cloned the recombinant plasmid which containing β-1,4-endoglucanase and digested with BamHI and EcoRI. And then linked with the expression plasmid pGEX-4T-1 and transferred into the competent E. coli BL21 for expression. The result of protein electrophoresis showed that there has expressed protein whose molecular weight is about 70 kDa. Measured the enzyme activity of the expression protein of recombinant strains is 0.92 IU/mL, which is 1.52 times as the start strains.
The Evolution Equation for Wave Processes of the Shift Deformation
Authors: Ivanova Yulia E. , Ragozina Victoria E.
Published: December 2012

One-dimensional process of formation and the subsequent motion of a plane transverse shock wave is studied on the basis of solutions of the corresponding nonlinear evolutionary equation. This equation defines behaviour of the solution in front area of wave process and follows from inner series of a matched asymptotic expansions method. A comparative analysis of the volume deformation and forming processes will be carried out and their basic differences are specified. In the capacity of model examples solutions of some concrete boundary value problems of a dynamic shear deformation are observed.
Structural Damage Detection by Integrating Non-Negative Matrix Factorization and Relevance Vector Machines
Authors: Zhou Shu Mei , Bao Yue Quan
Published: December 2012

This paper proposes a structural damage detection method based on wavelet packet decomposition, non-negative matrix factorization (NMF) and a relevance vector machine (RVM). First, vibration data at multiple points are used to calculate the wavelet packet node energies and construct a non-negative damage feature matrix. Second, to increase the damage detection accuracy, the NMF technique is employed to obtain the reduced dimensional representation of the non-negative damage feature matrix and extract the underlying features. Last, the RVM, a powerful tool for classification and regression, that can obtain the probability estimation for classification, is used to determine the relationship between features extracted with NMF and the corresponding damage patterns by considering the measurement noise. The trained RVMs are then used to perform damage pattern identification and classification of an unknown state structure. Numerical study on the Binzhou Yellow River Highway Bridge is carried out to validate the ability of the proposed method in damage detection. The results show that the RVM can achieve a high accuracy in damage pattern identification accuracy using the features extracted by NMF.
Tilt Error Analysis and Compensation for Two-Position North Determining Scheme in FOG North-Seeker
Authors: Pei Ren Zhong , Li Deng Hua , Duan Ke Ke
Published: December 2012

Two-position north determining scheme for FOG north seeker can effectively eliminate the impact of drift, and can be easily implemented. But the angle between the base and the horizontal plane will induce tilt error and reduce the north seeking accuracy. In order to eliminate the tilt error and to improve the north seeking accuracy, the corresponding tilt compensation scheme is designed in this paper. A tilt sensor is used to measure the angle between the base and the horizontal plane, and the DSP is used to collect the output of the tilt sensor and solve real-time compensation. North seeking experiments proved that this tilt compensation scheme can compensate the base plane tilt error, and improve the north seeking accuracy effectively.
Locomotive Characteristics of Body and Limb in a Terrestrial Vertebrates
Authors: Park Sung Ho , Hong Dong Pyo
Published: December 2012

Locomotion of many living creatures remains infinitely more advanced and elegant than that of present-day legged walking robots. However, the principles of existing systems are based more on technical rather than on biological concepts, yielding unstable locomotion with low speed. In order to apply those advanced biological phenomena to the design of a Quadruped, the structural and locomotive characteristics of several selected animals are studied. Also, the four-legged walking machine, covering all existing leg arrangements and locomotion patterns, is modeled by a rigid multi-body system, consisting of 13 links and 12 joints. As a time variable, the model is simulated to prove the optimal conditions, which satisfy the principle of minimum energy expenditure.
Numerical and Experimental Investigation on the Weighing System of an Incubator Shaker
Authors: Gu Ye Jing , Feng Zhi Hua , Tang Yin Ping , Wang Zhen Ming , Pan Xiao Ping
Published: December 2012

In order to solve the weighing problem of a type of incubator shakers, a new weighing method, combined with numerical analysis and experimental verification, is proposed. The numerical analysis based on the software of ANSYS Workbench indicates that the sum of the two-point strain in the mechanism is found to be constant and there is a fine linearity relationship between the sum of the two-point strain and the weight of load, so as to offer a measurement method for indirect measurement of the loading weight and this measuring method has been verified by experiment.
Density-Based Distributed Elliptical Anomaly Detection in Wireless Sensor Networks
Authors: Ma Shu Hua , Wang Jin Kuan , Liu Zhi Gang , Jiang Hou Yan
Published: December 2012

Data measured and collected by WSNs is often unreliable and a big amount of anomaly data exist. Detecting these anomaly in energy-constrained situations is an important challenge in managing these types of networks. To detect anomalies induced by the decrease of battery power, we use HyCARCE algorithm but it has the problem of low detection rate and high false positive rate when the input space consists of a mixture of dense and sparse regions which make the anomalies form clusters. The paper presents a density-based algorithm to separate the normal cluster from all clusters. The performance of this algorithm is tested on a subset of the data gathered from a real sensor network deployed at the Intel Berkeley Research Laboratory in the USA and this density-based method has a better detection performance than HyCARCE algorithm.
An Efficient Model for Trust Force Dynamic Analysis in Drilling of CFRP/AL Stack
Authors: Cheng Hui , Li Yuan , Zhang Kai Fu , Luo Bin
Published: December 2012

CFRP/AL stacks are widely used in modern aircraft manufacturing industry. Thrust force is the most important element which will cause delamination in the drilling of stack. This paper developed a thrust force dynamic analysis model for drilling of CFRP/AL stack, by firstly, representing the drilling process into a five-stage model. Secondly, the dynamic thrust force is decomposed into two parts (sub models for CFRP and AL drilling). Thirdly, the thrust force components on both tool major cutting edge and chisel edge is developed according to the analysis on infinitesimal cutting unit in both sub models for CFRP and AL drilling. Lastly, several experiments are performed to compare the result of thrust force analysis, which proves that the purposed model can analyze the dynamic thrust force in drilling of CFRP well.
An Optimal Selection Model of the Satellite Lurk Orbit
Authors: Zhang Xiao Kun , Gong Ying Kui , Qu Jiang Hua
Published: December 2012

An optimal selection model of the lurk orbit on which a satellite will park waiting for instructions aiming at a non-cooperative space target is presented. The model uses factors including orbit maneuver satisfaction degree in special cases and orbit utilization value in ordinary uses taking into account orbit maintenance cost, orbit availability and the resulting elusiveness. These factors are derived from dynamics characteristics of the space target orbit and the optional lurk orbits. The model is employed to select the optimal lurk orbit from several optional orbits for a satellite taking aim at a non-cooperative space target so as to secure ordinary utilization and effective respond when receiving instruction to perform tasks concerning the space target. In the presented work, lurk orbit selection processes in an application example are analyzed using the model. It is seen that the optimal selection model effectively solves lurk orbit selection
Thermodynamic Performance Analysis of Ammonia-Water Rankine Cycles Using Heat Sources of High and Low Temperatures
Authors: Kim Kyoung Hoon , Ko Hyung Jong , Kim Se Woong
Published: December 2012

In this study, thermodynamic performances of ammonia-water Rankine (AWR) cycle and regenerative Rankine (AWRR) cycle are comparatively investigated. Special attention is focused on the effects of ammonia concentration and turbine inlet pressure on the performance of system using heat sources of high temperature of 300 oC and low temperature of 150 oC. The behavior of important system variables including mass flow ratio of working fluid, net work production, and thermal efficiency are closely examined. Results show that performance characteristics for heat sources of high and low temperatures are quite different each other. For the high-temperature source, the thermal efficiency has a minimum in AWR system while it has a maximum in AWRR with respect to ammonia concentration in the range of 65% to 75%. For low-temperature source, however, the thermal efficiency decreases with ammonia concentration in the range of ammonia concentration higher than 95% for both AWR system and AWRR system and the effect of regenerator is negligible.
Research of Dynamics Simulation of a Six-DOF Segment Erector for Tunnel Boring Machine
Authors: Li Gang , Wang Bo , Chen Ya Dong , Wang Wan Shan
Published: December 2012

In order to solve the problems such as more restriction conditions, complicated interference and longer design periods in the design process of segment erector for Tunnel Boring Machine, it is necessary to study on the dynamics simulation of TBM segment erector. The 3D virtual assembling model of a tunnel segment erector is built based on Pro/E software according to its design parameters such as structure and size. The model is simplified and optimized reasonably and various constraints are applied under variety working conditions. The dynamics characteristics of drives and the forces of each part are obtained and they will provide a boundary condition for strength check and basis for the power system design which is important for the further optimal design. The simulation results also provide an important reference for the mechanism design and type selection design for the power system of segment erector and design cycle is shortened for TBM segment erector.
Kinematic Model of Mobile-Cylinder Engine
Authors: Fedorenko Stanislav , Nikiforov Aleksey , Fedorov Vladimir
Published: December 2012

A kinematic model of mobile-cylinder engine is suggested. Analysis of motion equation solutions reveals periodic pulsations of rotational frequency in the system which leads to non-uniform rotation of a crank shaft. The amplitude and pulsation phase depend essentially on geometric and kinematic parameters of the model. Discussed are possible ways of the model optimization so as to damp the amplitude of rotational frequency pulsations.
Slip-Slope Estimation of Mutative Road Friction Coefficient Based on Unscented Particle Filter
Authors: Lin Fen , Huang Chao
Published: December 2012

The accurate information of road friction coefficient allows the control algorithm in vehicle activity system to adapt to external driving conditions. This paper developed a slip-slope friction coefficient estimation method based on Unscented Particle Filter. A 7-DOF non-linear vehicle dynamic model was established. The normal force of tire was approximately calculated from the vehicle dynamic model; the slip and longitudinal force of tire were estimated through a combination of tire mechanical model and UPF(Unscented Particle Filter) method. Finally slip-slopes of different adhesion level roads was obtained. Through virtual test environment in ADAMS/Car, the estimation method proposed was verified to be effective and reliable under various road condition. From the method the relationships between the slip-slope and road friction coefficient are achieved.
The Refined Equations of Special Orthotropic Piezoelectric Plate-I: Anti-Symmetrical Transverse Surface Loadings
Authors: Zhao Bao Sheng , Wu Di
Published: December 2012

The deformation field and stress states of special orthotropic piezoelectric plate are analyzed. Based on elastic theory, the refined equations of bending thick plate are derived by using Elliott-Lodge’s general solution and Lur’e method without ad hoc assumptions. At first, expressions were obtained for all the displacements and stress components of a piezoelectric plate. Based on boundary conditions, the refined equations for the plate with anti-symmetrical transverse surface loading are obtained.
Analysis of Contacting Mechanical Characters Based on Cyclical Symmetrical Theory
Authors: Zhao Da
Published: December 2012

Based on cyclical symmetrical theory, static stress analysis of assembly body is achieved, then obtains the distribution of maximal and minimum stress. Cyclical symmetrical dynamic analysis of structure is also achieved, and works out the contacting status, frictional stress, siding distance, penetration, gap and contacting pressure under cyclical analysis. Contrast to the traditional ensemble analysis methods, it turns to be more efficient and more precise, and all the parameters are better distributed, finally testifies the scientificity and feasibility of wheel-axle contacting analysis methods based on cyclical symmetrical theory.
Research on Fatigue Life of Autofrettaged Thick-Walled Cylinder in Probabilistic Fracture Mechanics
Authors: Chen Ai Jun , Cha Zi Chu , Wang Zhi Qun
Published: December 2012

Based on the theory of probabilistic fracture mechanics and Monte Carlo simulation, reliability analysis method for fatigue life of autofrettaged thick-walled cylinder was given. The forms of fatigue cracks in bore of autofrettaged thick-walled cylinder were considered as semi-elliptical cracks. The autofrettage residual stress solution was suitable for the thick-walled cylinder made of steel with strain hardening and Bauschinger effect. The stress intensity factors of thick-walled cylinder were calculated according to weight function method. The analysis of the examples showed that lognormal distribution is the best fit for fatigue life. Finally, the fatigue life of autofrettaged thick-walled on the condition of different reliabilities and confidences were presented.
Characteristics of Self-Synchronization of Dual-Rotors System
Authors: Zhang Nan
Published: December 2012

The characteristics of the self-synchronization in the offset self-synchronous system are put forward. In the paper, based on Lagrange principle, a dynamic model is derived to give its electromechanical-coupling model, which is provided with many variable no-linear characters. A serious of the practical phenomena in the transition process of the system is reasonably explained using the numerical solution simulation, and the variations rules of each parameter in the system are discussed at several types of the typical status. Finally the characteristics of the self-synchronization in the system are generated under the action of the electromechanical coupling. The visually processes are shown in the simulation results, for which the conventional mechanic models are unavailable to explain quantitatively, in which the vibration machines implement fully the transition from asynchronous to synchronous state or from one type of synchronous state to other type. It is fully verified that the system is with the self-healing synchronous ability, and the synchronous movement rules in the electromechanical coupling system are also revealed. For its research not only it is useful to explore the electromechanical coupling model of the offset self-synchronous system, but also it is in-depth to study synchronous motion rules of the self-synchronous system, and it is of the theoretical and practical importance.
Design Method of the Advanced Actuator
Authors: Zou Chang Ping , Feng Jian Qiong
Published: December 2012

The advanced actuator is a kind of swaying mechanism being an ingenious combination of high pressure oil cylinder and ball helical transmission, has lots of advantages, such as the torque produced by its unit weight is the greatest, dimension is little, weight is light, mechanical efficiency is efficient, service life is long, reliability is high, etc, it may be widely applied to varied occasions which need swaying mechanisms with low rotational speed and great torque.This paper firstly introduces mechanism composition and working principle of the advanced actuator.Then gives ascertaining methods on such key parameters as helical lift angle,pitch diameter,ball diameter,oil pressure and internal diameter of oil cylinder, etc.Next summarizes the analyzing and designing methods of the advanced actuator in a systematic way.Lastly points out three problems requiring thorough study.Successful development of the advanced actuator is an example of fulfilling major project by adopting modern method of design.Its systematic methods on analyzing and designing make further advances on the theories of ball helical transmission.
Large Eddy Simulation of Two-Phase Mixing Layer Flows in the Scramjet
Authors: Ren Zhao Xin , Wang Bing , Zhang Hui Qiang
Published: December 2012

To study the dispersion of fuel droplets in the supersonic flow and reveal the momentum and heat exchanges between two phases, a large eddy simulation (LES) and particle Lagrangian tracking model were employed to numerically simulate two-phase mixing layer flows, using the one-way coupling method. The velocity fluctuation disturbances were added to inspire the flow instabilities. The motions of droplets in different diameters and droplets’ response to the large scale eddies were analyzed. The results indicated that droplets of 1micro diameter below are corresponded with the motions of coherent vortexes in the mixing layer. The more intense momentum and heat exchange are performed with decreasing the droplet’s diameter. The well mixing of fuel droplets in turbulence would make the combustion preparedness more sufficient. The research conclusions are of important academic value for further analyzing the two-phase dynamics in the scramjet.
Identification and Reconstruction of Cracks in Ultrasonic Infrared Thermography
Authors: Feng Fu Zhou , Zhang Chao Sheng , Min Qing Xu , Jiang Peng Cheng
Published: December 2012

Ultrasonic infrared thermography is a novel nondestructive detection technique, which combines a short ultrasonic pulse excitation and infrared imaging to detect defects, such as crack, in materials and structures. A simplified one-dimension heat-conduction model excited by ultrasonic pulses is put forward in this paper. Based on this model, a serial of image processing methods for recognition and reconstruction of cracks were presented. Results obtained show that the proposed method is creditable and applicable.
The Control of Hydrogen Flow in Keeping with Load Changing at the PEMFC
Authors: Jung Young Guan , Hwang Chul Min , Park Dea Heum , Kim Kyoung Hoon , Han Chul Ho
Published: December 2012

The performance of a proton exchange membrane fuel cell (PEMFC) under the fuel control system was investigated experimentally using dry hydrogen and oxygen gas. In this study, experiments have been carried out on the unit cell with the active area of 25cm2. Both sides of outflow lines were closed by valves. This investigation focuses on the low-power system which has a fuel flow control unit. The change of internal pressure in fuel cell and the checked system load were used as the control conditions for the solenoid valve. As the system loads were changed unexpectedly, the on/off control of fuel line was proposed as the way to supply hydrogen gas efficiently into the fuel cell. As a result, it was shown that the proposed procedures can display the load variation and increase the power request. Furthermore, this study could be beneficial for the fuel saving and the safety of fuel cell system.
A Novel Shape Memory Alloy Damper and its Application in the Vibration Control of Transmission Towers
Authors: Liang Feng Chao , Chen Hua Ling , Wang Yong Quan , Liu Chao Qun , Qiang Jun Hua
Published: December 2012

This paper presents the design of a novel shape memory alloys (SMAs) damper, and its application in the vibration control of transmission towers. Firstly, based on a brief introduction for the essential properties of SMAs, a kind of constitutive model, i.e., the Brinson model is established to describe the unique behaviors of the material, combined with the experiments results. And then, a novel SMA damper, with the functions of displacement amplification and re-centering, is specifically designed by utilizing SMAs’ damping capacity. To verify and evaluate the device’s performance, the FEM model of an actual transmission tower is subsequently built in ANSYS, and by embedding the theoretical model of the damper into its analysis process, the responses of the tower subjected to the natural wind are numerically calculated. The results show that under the reasonable installations, the proposed SMA damper has a good effect on the wind-induced response control of the transmission tower.
Analysis of Ring Compression Test for Determination of Friction Circumstances in Forging Process
Authors: Dehghan Mojtaba , Qods Fathallah , Gerdooei Mahdi , Doai Javad
Published: December 2012

Friction is a major factor in determining the characteristics ofmetals as they are forged.Regularand efficient lubrication is one of the best ways in controlling friction and wear in this process.One of the best ways of testing the lubricant is the ringCompression test. In this research the effect of mixed graphite in water and also the effect of the amount of graphite in the lubricant in the reduction of friction between the sample-die are calculated using the ring test. Friction behavior is changed fromsticking friction to sliding frictionby using the lubricant; but the changes in the amount of graphite in water didnot have a great effect on the reduction of the friction coefficient. Furthermore, after viewing differences in the friction coefficients calculated by the means of FE analysis and the friction calibration curves, it is concluded that the sole calibration curves could not be used for hot working conditions.
Thermal Analysis of Cold Plate for Motor Controller Based on Fluent
Authors: Lin Gui Lin , Xu Guo Qing , Li Wei Min , Liu Bin Bin
Published: December 2012

Electronics cooling research has been largely focused on high heat flux removal from computer chips in the recent years. However, the equally important field of high-power electronic devices has been experiencing a major paradigm shift from air cooling to liquid cooling over the last decade. For example, multiple insulated-gate bipolar transistors (IGBT) used in a power drive for motor used in electric vehicle. Motor drive system plays an important impact on electric vehicle’ performance, so thermal design should be considered in the early stages during the motor controller design and layout of the devices. In this paper, a new type of water-cooled cold plate for motor controller was designed, and its cooling ability was analyzed by using different material base on Fluent. The results provide reference on the optimization design of cold plate.
The Optimum Windshield-Defog and Passenger-Comfort Methods of a Vehicle in all Seasons
Authors: Wong King Leung , Chen Wen Li , Li Yung Chang
Published: December 2012

The knowledge and principles of air conditioning as well as numerical analyses and experiments are applied to obtain the various defog guides depending on extreme wet-conditions and the various outside air temperatures in all seasons. The defog guides can be listed as a leaflet to let the drivers know how to operate their air-conditioning control panel properly to defog the windshield with suitable air to obtain the safe and comfortable driving.