bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical Solution of Elastic-Plastic Buckling of an H-Shaped Steel Column under Axial Compressive Load and Bending Moment
Authors: Niu Peng , Yang Gang , Gong Ben Qi , Jin Chun Fu
Published: October 2009

Based on Ježek method of computing the elastic-plastic buckling of the member under the axial compressive load and the bending moment, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the maximum moment of inertia for an H-shaped column are derived. By degenerated into the analytical expressions of the rectangular column and compared with the values of the finite element analysis (FEA) method, it shows that the analytical method in this paper is valid, which provides a new method of theoretical study for the elastic-plastic buckling of the member.
Damage Investigation and Design of Woven Composite Bonded Joint
Authors: Qin Tian Liang , Zhao Li Bin , Huang Hai
Published: October 2009

Non-plane joints, such as T-joints, L-joints and  shaped joint can bring enormous potential benefits from the reduction of the fastener and the part count, which lead to the dramatic decrease of assemble cost and primary structural weight in composite structures. To understand the mechanistic character of the  joint, a 3-D finite element analysis model is established by means of software ABAQUS. The stresses on ply level and the predictions on the damage onset of 3-D woven composite π joint under tensile load are obtained. Numerical results agree well with empirical data. The effects of structural geometry parameters, such as support length, support thickness and radius of the corner, are also discussed. Results illustrated that increasing the thickness of L preform or filler radius can improve the strength of woven composite π joint effectively.
Stochastic Characteristics of Fatigue Crack Propagation for TA15 Titanium Alloy
Authors: Bao Rui , Zhang Jian Yu , Yang Hong Qin , Fei Bin Jun
Published: October 2009

Crack propagation tests are conducted on TA15 titanium alloy in three stress levels to investigate the stochastic characteristics of FCG. A random variable probability FCG model, base on the Paris’ law, is used to characterize the stochastic performance. Distribution significance test has been done, which shows that the random variable X can be considered reasonably to follow log-normal distribution in all the three stress levels. The probability distribution of crack size at any specified loading cycle and the probability distribution of the random fatigue life at which a given crack size is reached are discussed. Variance analysis indicates that the standard deviations of the log fatigue crack growth rate (FCGR) under the three stress levels do not differ from each other significantly. The scatter of crack initiation life under the lowest stress level is the largest, however, the scatter for crack propagation life shows no significant difference in the three stress levels.
Modified Swift Criteria for Residual Strength of Multiple Site Damage Structure
Authors: Zhang Jian Yu , Bao Rui , Fei Bin Jun
Published: October 2009

As more aircrafts reach or exceed their design life, it is becoming very important to research multiple cracks damage, especially the multiple site damage (MSD) in order to re-evaluate their service life and damage tolerance/durability performance. The existing of MSD may remarkably reduce the residual strength of an aerospace structural component than those with a singe lead crack. This study investigated the residual strength of aluminum alloy sheet with MSD through three types of aluminum specimens test. Aluminum panels with bare collinear constant diameter holes were chosen as specimens. After some constant amplitude tension-tension load cycles, the MSD were found in these specimens since there were multiple fatigue cracks emanating from the saw cuts of holes. The residual strength was recorded as the maximum load when every specimen was subjected to monotonically increasing tensile load until failure occurred. In different failure prediction criteria that were often used in engineering in order to evaluate the accuracy of these criteria, Swift criterion (ligament yield) criterion got more accurate prediction results than other criteria. Although Swift criterion was more accurate than some other criteria, its error was still big for some specimens. Two modified approaches were proposed in order to get more accurate and appropriate failure criterion for MSD structure.
Yield Criteria for Pressure-Sensitive Materials Based on Meso-Mechanical Analysis
Authors: Tang Li Qiang , Yu Xue Mei , Zhang Xiao Ying
Published: October 2009

Investigation on mechanical properties of rock, soil and powder metallurgy is an important subject in study of damage constitutive models. These materials contain micro-voids (such as defects, inclusions and cracks) and perform pressure sensitivity. Unlike metal materials, hydrostatic pressure can influence plastic yield of these materials. Following the modified Gurson model in meso-mechanics and considering the meso-compressibility, this paper focuses on plastic limit analysis of micro-deformation mechanism of these materials. The two-independent-parameters criterion is taken as matrix yield function and spherical voids as the represent unit cell. The macroscopic stress and strain rate related to micro structure parameters are derived via upper-bound theorem. Then the macroscopic yield function (containing micro structure parameters) is established. Finally, the properties of macroscopic yield surfaces are studied by setting different values of these micro parameters. This paper provides theory foundations for materials damage and design.
Elastic-Plastic Analysis of the Interaction between Ice and Offshore Structures
Authors: Yu Tao , Yang Wei , Tang Li Qiang
Published: October 2009

In this paper, the mechanical properties of ice, which are affected by the existence of cavities and the different tensile-compression strength ratio, are analyzed in micromechanics view. Then the constitutive equation is established, and the distribution of stress field caused by the ice-structure interaction is constructed with the constitutive equation. Finally, the ultimate bearing capacity of ice is also discussed with different values of pressure sensitivity parameter and the tension-compression ratio. Thus, this paper provides the theoretical reference for offshore platforms design.
Analysis of the Three-Dimensional Delamination Behavior of Stretchable Electronics Applications
Authors: van der Sluis Olaf , Timmermans P.H.M. , van der Zanden E.J.L. , Hoefnagels J.P.M.
Published: October 2009

Stretchable electronics offer potential application areas in biological implants interacting with
human tissue, while also facilitating increased design freedom in electronics. A key requirement on these
products is the ability to withstand large deformations during usage without losing their integrity. Experimental
observations show that delamination between the metal conductor lines and the stretchable substrate
may eventually lead to short circuits while also the delaminated area could result in cohesive failure of the
metal lines. Interestingly, peel tests show that the rubber is severely lifted at the delamination front caused
by its high compliance. To quantify the interface in terms of cohesive zone properties, these parameters are
varied such that the experimental and numerical peel-force curve and rubber-lift geometry at the delamination
front match. The thus obtained interface properties are used to simulate the delamination behavior of
actual three-dimensional stretchable electronics samples loaded in tension.
The Ability of Current Models for Fatigue Life Prediction of Shot Peened Components
Authors: Cláudio Ricardo A. , Silva José M. , Branco Carlos M. , Byrne Jim
Published: October 2009

It is well known that shot peening has a marked benefit on fatigue life for the majority of applications. This effect is attributed mainly due to the compressive residual stress state at the component’s surface due to shot peening. The present paper evaluates the ability of several fatigue life prediction models, commonly used for general analyses, to predict the behaviour of components with compressive residual stress due to shot peening. Advanced elastic-plastic finite element analyses were carried out in order to obtain stress, strain, strain energy and fracture mechanics parameters for cracks within a compressive residual stress field. With these results several total fatigue life prediction models (including critical distance methods) and fracture mechanics based models were applied in order to predict fatigue life. Fatigue life predictions were compared with several experimental fatigue tests carried out on specimens, representative of a critical region of a compressor disc in a gas turbine aero engine. The results obtained showed that total fatigue life methods, even if combined with critical distance methods, give conservative results when shot peening is considered. Fatigue life was successfully predicted using the method proposed by Cameron and Smith, by adding initiation life to crack propagation life. This last method was also successfully applied for the prediction of non-propagating cracks that were observed during the experimental tests.
Study on Safety Evaluation of an Aged Steel Truss Bridge with Cracking Members
Authors: Jiang Lan Chao , Gao Ri
Published: October 2009

The safety of aged steel structures, especially those with cracking members, has aroused a great deal of attention. In this paper, the application of fracture mechanics for evaluating the ultimate load-carrying of steel material is proposed. Three-point bending tests of three specimens with the mode-I fracture are done to get the ultimate load-carrying capacity, when specimens are destroyed. Fracture ductility KIC, and the steel allowable stress [σ] with certain crack length are formulated. Magnetic method for measuring cracks of steel members is adopted for an aged steel truss bridge, and material composition of specimens is tested, and field nondestructive load test involved static and dynamic test are carried into execution. By comparing the results of the calculation and those of the field test, some conclusions are obtained, which are likely to contribute to safety evaluation of aged steel structures, or contribute to designing similar bridges.
Stochastic Damage Constitutive Model for Concrete Subjected to Uniaxial Tension Stress
Authors: Xie Ming , Zheng Shan Suo , Wang Bin , Li Lei , Wang Wei
Published: October 2009

A stochastic damage constitutive model is proposed based on Kelvin spring-damper model and Li Jie spring stochastic damage model. The model is made up by microscopic spring-slipper element. The slipper, parallel connected with spring, is introduced to consider the plasticity effect of concrete. Damage failure process of concrete subjected uniaxial tension is divided into spring broken state and slipper broken state to describe the elastic stage and plastic stage of damage respectively. In the light of energy conservation during the process of damage failure, stochastic damage constitutive equation of concrete material subjected to uniaxial tension stress is derived. Comparisons between test results and theoretical calculation results verify that the established constitutive damage equations are accord with the experimental situation, and the experimental data are observed undulated with theoretical curve in the range of variance. The research results can apply in the actual engineering.
Study on Seismic Damage Model with Double Variables of the SRHSHPC Composite Columns
Authors: Zheng Shan Suo , Zhang Liang , Wang Bin , Li Lei , Zeng Lei
Published: October 2009

The seismic performance and seismic damage model for steel reinforced high strength and high performance concrete (SRHSHPC) composite frame columns subjected to constant axial load and cyclically variety flexural loading was investigated experimentally. The main influencing parameters, including shear span ratio, axial compression ratio, stirrup ratio and concrete strength, on the seismic performance and seismic damage of the SRHSHPC frame columns is studied. From the test results, the failure mechanism is analyzed and damage quantization criterion is obtained. Several existing seismic damage models are comparatively analyzed. And then, the variation history of accumulated hysteretic energy of the specimens under different loading cycle indexes is figured out, and influence of different test parameters on it is also discussed. Finally, the damage index of the SRHSHPC columns is compared to the existing seismic damage models, and the double variables seismic damage model adapted for the SRHSHPC structure is established by statistical regression theory. The rule of damage evolvement for the specimens is proposed employing variation history of the damage index under different loading cycle indexes. The analytical results indicate that the seismic performance of the SRHSHPC composite column is good, and the double variables damage model could give a quantitative description for damaging process of the samples, which is a reference for seismic damage design of the SRHSHPC structure.
Fatigue Crack Initiation and Propagation in Thick Multilayer Metallic Laminates
Authors: Sharif-Khodaei Z. , Baiz P.M. , M.H.Aliabadi Ferri
Published: October 2009

The objective of this study is to investigate and develop a methodology to predict fatigue
crack initiation and propagation in metallic laminate structures. The fatigue crack initiation is based
on strain-life approach. After a crack has initiated, Stress Intensity Factors (SIF) are obtained and
the subsequent propagation is described following Paris law type equations (NASGRO). Detailed
Stress-Strain distribution in each layer is obtained from FE models, including the effect of the
transition from flat to slant cracks on the fatigue crack growth.
Water Jet Peening of 39NiCrMo3 Steel by Means of a Standard Water Jet Cutting Machine
Authors: Annoni Massimiliano , Arleo F. , Guagliano Mario
Published: October 2009

This work investigates the possibility to perform Water Jet Peening (WJP) by means of a standard Water Jet (WJ) cutting plant. The experimentation is carried out on 39NiCrMo3 specimens with the aim to find out the best working conditions of two different methods: the in air-WJP and the submerged-WJP. Comparisons between the two methods and to previous experimentations in the reference literature are also presented.
Theoretical Research on the Dynamic Crack Propagation Velocity Based on Nonlocal Field Theories
Authors: Liu Cai Ping , Duan Qing Quan , Zuo Jian Ping
Published: October 2009

The purpose of this paper is to discuss the nonlocal effect on dynamic crack propagation velocity. Some experimental phenomena in dynamic fracture and simulative results using molecular & atom dynamics were analyzed and discussed in this paper. The authors found that there were still some disagreements on the dynamic crack propagation velocity. Based on these researches, we introduced nonlocal field theories into the estimation of dynamic crack propagation velocity. The dynamic crack propagation velocity is affected not only by the crack instability, but by characteristic length of material. A nonlocal characteristic length parameter M is defined through a double pile-up dislocation model. According to the Mott’s research method for crack velocity in dynamic fracture and the nonlocal field theories, an approximate theoretical dynamic propagation velocity is obtained. And we conclude that the velocity is related to the combined activity of the nonlocal characteristic length parameter M, the velocity of longitudinal wave, constant k, crack length and Poisson’s ratio.
Evaluation of Interaction Effect of Two Surface Cracks by Fatigue
Authors: Kikuchi Masanori , Wada Yoshitaka , Li Yu Long
Published: October 2009

Fatigue crack growth under mixed mode loading conditions is simulated using S-version FEM. By using S-FEM technique, only local mesh should be re-meshed for new crack configuration, and it becomes easy to simulate crack growth. By combining with auto-meshing technique, local mesh easily re-meshed and curved crack path is modeled easily. Fully automatic crack growth simulation system in 3-dimensional problem is developed. Using this system, several kinds of plural surface cracks problems are simulated. It is shown that intereaction effect between two surface cracks appear in complicated manner depending on intial distances between two cracks.
Early-Age Autogenous Shrinkage of High-Performance Concrete Columns by Embedded Fiber Bragg-Grating Sensor
Authors: Yun Ying Wei , Jang Ii Young , Kim Seong Kyum , Park Seung Min
Published: October 2009

High-performance concrete (HPC) as a promising construction material has been widely used in infrastructures and high-rise buildings etc. However, its pretty high autogenous shrinkage (AS) especially in its early age becomes one of the key problems endangering long-time durability of HPC structures. This paper carried out the early age AS research of large scaled HPC column specimens by embedded Fiber Bragg-Grating (FBG) strain sensor. Temperature compensation for FBG strain sensor by thermocouple was also attempted in this paper, and the results were reasonable and acceptable comparing with the result compensated by FBG temperature sensor. Reinforcement influence, size effect and temperature effect on HPC AS were also analyzed respectively in this paper.
Foundation Structure Design and Analysis for Offshore Wind Turbine
Authors: Zhang Liang , Zhao Jing , Zhang Jian Hua , Hao Jun
Published: October 2009

Offshore Wind Turbine (OWT) is a device to extract and convert offshore wind energy into useful electrical power. The typical concept design of monopile foundation structure for 1.5MW OWT is raised in this paper. The arrangement of the monopile and related accessorial facilities are especially considered during design. Mechanical characters of the foundation structure are emphatically analyzed, including static analysis, dynamic analysis, fatigue analysis and bucking analysis. The time domain approach is preferable for the dynamic response of foundation under the condition of earthquake and wave. Based on the analysis results, the reliability of the structure is proved to be satisfied with the requirements .The paper provides the reference for the design of OWT.
Research on Obtaining Functional Periodicity by Using Su-Field
Authors: Zhang Peng , Li Na , Liu Fang , Tan Run Hua
Published: October 2009

Functional periodicity is one of the important concepts of the complexity theory. Obtaining functional periodicity is the key of time-dependent complexity elimination. However, how to obtain functional periodicity is not mentioned in the complexity theory. This paper proposes a method which combines the complexity theory with su-field analysis. It can help the designers to obtain the functional periodicity of the system. A case study shows the application of the method.
Research on Dynamics of Rotor Systems in Large Centrifugal Compressor
Authors: Ma Hui , Ren Zhao Hui , Dai Ji Shuang , Wen Bang Chun
Published: October 2009

It is important to study system vibration characteristics for improving product quality and ensuring safety operation of units. In this paper, some dynamics of rotor systems are studied in large centrifugal compressor. The models of diaphragm coupling and tilting pad bearing are established by appropriate simplification. The finite element model of rotors with bearing and coupling is set up by taking interrelation of these subsystems into account. The unbalance responses of journal are computed based on the relative standard. The effect of bearing parameters (length-diameter ratio, clearance ratio and lubricating oil number) to journal vibration of rotor systems is analyzed. Finally test results and theoretical results are compared and errors are analyzed. The research results will provide theoretical basis for improving the bearing design of compressor rotor systems.
Research on Loading Method of High-Speed Closed Power Flow Test System
Authors: Wang Li Quan , An Yong Dong , Sun Rong Hua , An Shao Jun
Published: October 2009

In this paper, a new type of shaft end torque loadling device is studied for the closed power flow test system of the high-power marine reducer, and it illustrates the structure of the load device, makes the principle of analysis and power calculation of the loading device; and analyses the test system power flow conditions and anti-way self-locking of the installation, Finally, the loading devices of the test system is designed to the order of 100000 magnitude reducer, verify the feasibility of this loading method.
An Immune Particle Swarm Optimization Algorithm for Solving Permutation Flowshop Problem
Authors: Qiu Chang Hua , Wang Can
Published: October 2009

To solve the permutation flowshop problem more effectively, a novel artificial immune particle swarm optimization (PSO) algorithm has been proposed. The new algorithm combined the biology immune system theory with particle swarm algorithm by the following phases. Firstly, the scheduling objective and constrain condition were served as antibodies while solutions was served as antigens. Secondly, the particles were encoded as workpiece processing sequence. Furthermore, a concentration selection strategy was adopted to maintain the particle diversity. Finally, comparing with genetic algorithm and PSO, case results showed that immune PSO algorithm not only optimized results and convergence velocity but also had a small fluctuation.
A Subjective Evaluation Method for Man-Machine Interface Based on Grey Interval Relational Analysis
Authors: Yan Sheng Yuan , Xia Chun Yan , Yu Kun , Xu Wei Bo
Published: October 2009

The quality of man-machine interface (MMI) directly affects efficiency, safety and comfort of the man-machine system. Therefore, it is significant to study an appropriate evaluation technology for MMI. The method of grey relational analysis based on interval numbers is put forward in the field of MMI evaluation in this paper, based on human thinking having the grey and fuzzy characteristic. In this method, interval numbers are employed as a mean to reflect the rating of indexes instead of real numbers, which offer uncertain information. By judging the correlative degree between the evaluation criterion and the design schemes, the optimal scheme can be found. Based on the proposed method, a novel subjective evaluation model of MMI is set up and applied in the subjective evaluation on the digital control system console of the power plant. Results of the evaluation example prove that the proposed method for MMI evaluation is reasonable and applicable.
Simulation Research on Temperature Field of Circular Cavity Hydrostatic Thrust Bearing
Authors: Yu Xiao Dong , Meng Xiu Li , Wu Bo , Shao Jun Peng , Zhang Yan Qin , Shi Zhi Min
Published: October 2009

In order to solve the thermal deformation of the hydrostatic thrust bearing in the heavy equipment, a simulation research concerning temperature field of multi-pad hydrostatic thrust bearing having circular cavities was described. The Finite Volume Method of Fluent has been used to compute three-dimensional temperature field of gap fluid between the rotation worktable and base. This study theoretically analyzes the influence of cavity radius and cavity depth on the bearing temperature performance according to computational fluid dynamics and lubricating theory. It has revealed its temperature distribution law. The simulation results indicate that an improved characteristic can be gotten from a circular cavity hydrostatic thrust bearing, oil cavity temperature decreases by gradually with cavity radius enhancing, oil cavity temperature decreases by gradually with cavity depth. Through this method, the safety of a hydrostatic thrust bearing having circular cavities multi-pad can be forecasted, and the optimal design of such products can be achieved, so it can provide reasonable data for design and lubrication and experience and thermal deformation computation for hydrostatic thrust bearing in the heavy equipment.
Fault Diagnosis and Analysis for Marine Planetary Gearbox
Authors: Jiang Li Dong , Chang Shan , Dai Guang Hao , Zhu Zhen Rong
Published: October 2009

The abnormal noise was found in a marine planetary gearbox during the experiment. Then, the load test of the gearbox was done on a gearbox test rig and the vibration signal was measured and collected. The fault of the gearbox was analyzed by the time domain and frequency domain analysis. The trouble part was diagnosed and treated. The method used in this paper combined the theory analysis with engineering application. Simultaneously, it has provided a properly feasible method and valuable reference for the fault diagnosis of planetary gearbox.
Generalized Variational Principles of Quasi-Static Electro-Magneto-Thermo-Elasticity
Authors: Song Hai Yan , Zhou Zhen Gong , Liang Li Fu , Liu Zong Min
Published: October 2009

Finite element method is an approximate computational method which is widely used and continuously developed. Variational principles are the foundation of finite element method. In this paper, the generalized variational principles of quasi-static electro-magneto-thermo-elasticity are established using variational integral method. And these variational principles can be degenerated to be variational principles of simple coupling properties materials, which offer theoretical support for finite element method of coupling problems of electro-magneto-thermo-elastic.
An Outlier Detection Method Based on Fuzzy C-Means Clustering
Authors: Li Qiang , Zhang Jian Pei , Feng Guang Sheng
Published: October 2009

Both fuzzy c-means (FCM) clustering and outlier detection are useful data mining techniques in real applications. In this paper, we show that the task of outlier detection could be achieved as by-product of fuzzy c-means clustering. The proposed strategy consists of two stages. The first stage consists of purely fuzzy c-means process, while the second stage identifies exceptional objects according to a novel metric based on the entropy of membership values. We provide experimental results to demonstrate the effectiveness of our technique.
Simulation Research on Dynamic Characteristics of Mooring System for Double Body Working Ship
Authors: Xue Kai , Wang Wen Bin , Wang Wei Yuan
Published: October 2009

The purpose of this paper is to solve the positioning problem of a double body working ship. Dynamic characteristics of mooring system are analyzed with the effect of wind, wave and current. According to the dynamic equations of the system in the horizontal plane, longitudinal force coefficient, lateral force coefficient and yawing moment coefficient are obtained by towing test. The wind lord, wave load, current load and chain force can be calculated by empirical formulas. The motions of a mooring system are simulated in MATLAB. The results show that yawing motion would be occurred for the mooring system with single anchor at one point. The motions of the system have similar forms under the same amplitude of external loads. The results are agreed well with the observation data from documents about this relation. It is also can be point out that single point mooring system has poor stability and can not control the motion accurately. Thus dynamic positioning/mooring system should be developed for anchored working ships. This research in this paper provides the theoretical support and the analysis foundation for the further studies.
Kinematical Analysis of Manipulators Interfacing
Authors: Li Guang Jun , Luo A Ni , Liu He Ping , Wang Lin
Published: October 2009

Underwater interfacing device of flexible manipulators is designed in order to avoid blindness and fatalness of direct interfacing and fit the condition of low visibility and large leaning swing. At initial stage of interfacing, velocity expression of single manipulator is obtained. According to position relation of interfacing device and aim circle, coordinate transforming matrix is obtained through analysis. Considering limiting relation of harmony movement, the method of Denavit- Hartenberg is adopted to get velocity expressions of two opposite manipulator ends. At pulling down state, reverse kinematical solutions of parallel mechanism are solved to obtain lengths of manipulators.
A Dispatching Rule Study of a LED Sorting System
Authors: Shiang Wei Jung , Lin Yu Hsin , Rau Hsin
Published: October 2009

The scheduling problem of LED chip sorting workstation is a multiprocessor open shop scheduling problem. In practice, this problem is usually solved with finding a dispatching rule to achieve certain performance indexes. Experimental design was applied to find a proper rule, and dispatching rule, wafer quantity, wafer mix type, and bottleneck location were chosen as independent variables. Maximum make-span and average queuing time were selected as dependent variables. Five dispatching rules were considered in the dispatching rule factor. Experimental results showed that all independent variables are significant on all dependent variables. While make-span as the performance index, three dispatching rules common in applying LPT in bottleneck machines obtained better results. A dispatching rule with applying SPT in non-bottleneck machines has least average queuing time among those three, and this rule is recommended for practical application.
The Structural Design and Optimization for the Inner-Frame of Subsea Flange Connection Tool
Authors: Li Zhi Gang , Lin Qiu Hong , Zhao Dong Yan , Wang Li Quan
Published: October 2009

Subsea Flange Connection Tool (SFCT) is a remote apparatus for connecting underwater bolted flanges, especially applied in the offshore pipeline laying. As a pivotal unit construction of SFCT, Inner-frame enables the Bolt Handling Tool and Nut Handling Tool to move separately in axial direction and together in circumferential direction with the reference of the pipe’s axes. This paper presents the Inner-frame’s structural concept and builds its kinematics-equivalent mechanism models, carrying on the kinematics analysis of Inner-frame; to improve the energy efficiency, models the Inner-frame’s rotation-mechanism parametrically and establishes an objective with the minimum power consumption, which generates the optimal positions for the hinged-hydraulic cylinder’s joints with Box and Pendulum.
Design and Experimental Research on Ester Ferrofluid Seal for Stern
Authors: Yang En Xia , Liu He Ping , Yi Chuan Bo , Dong Yan
Published: October 2009

A special seal is required at stern shaft, since it must serve the purposes of preventing both leakage of lubricating oil and seawater entering the stern shaft system. Improper design might cause leakage of fuel and pollution to the environment. Besides, the safety of machinery operation will also be affected. Ferrofluid seal is superior in terms of features such as long life, zero leakage, structure simplicity, fitting purposes of high-speed rotation, making it a new technology of sealing the stern shaft. In the following text, magnetic particles of Fe3O4 and solution of glyceride are made through proper chemical reactions, after which they are mixed as ferrofluid sealing liquid, and the performance of the liquid is studied experimentally. The experimental result indicates that magnetization intensity of the ferrofluid is increased as the intensity of outside magnetic field increases. Experimental instruments are designed for the purpose of research on ester magnetic fluid seal for stern. Through the experiment, performance of pressure resistance of esterified Fe3O4 ferrofliud is studied; also, main factors influencing pressure resistance of the studied ferrofliud are analyzed. The results indicate: pressure resistance decreases with increasing seal clearance or shaft rotation speed; whereby it is increased with the enhancement of saturated magnetic intensity of the ferrofliud.
Study on Shell-Solid Coupling Method of Trunk Structure for Efficient FE Analysis
Authors: Xue Kai , Li Yong Xin , Shi Dong Yan , Maharjan Sanjeev , Zhang Lei
Published: October 2009

The FE modeling of complex trunk structure often needs shell and solid elements. Different commercial software adopts different shell-solid coupling techniques. A simple, robust method has been demonstrated for shell–solid coupling by fictitious perpendicular shell. Systemic study on the method is performed through the FE analysis of T-trunk model to ensure the displacement compatibility and stress equilibrium. Modal analysis of gearbox is executed to observe the reliability and efficiency of the coupling method. Parametrical conclusions and practical suggestions are presented finally.
The Design for Twelve-Accelerometer Gravity Gradiometer
Authors: Zhao Lin , Liu Feng Ming , Yuan Hai Jing , Zhao Hong Bin
Published: October 2009

The design and manufacture for GGI are different and only several countries have the ability to produce it. Devising the feasible scheme for gravity gradiometer is the primary question.In this paper, a new type of GGI is designed using twelve accelerometers. First, the mathematical relationship between the accelerometer and GGI is derived and the method to separate the angular velocity and gravity gradient is disscussed. Second, the model of twelve-accelerometer gravity gradiometer is provided. Third, the estimation of angular velocity is analyzed when the GGI is installed in the form of strapdown or stabilized state. Finally, it is concluded that a new type of inertial navigation system using gravity gradiometers will be configured when it becomes possible to precisely measure gravity gradient.
Development of a Magneto-Rheological Fluid Tension Control Device
Authors: Li Gang , Sun Yu , Du Cheng Bin
Published: October 2009

Based on the characteristics of magneto-rheological fluid, a new type of transmission device has been developed in this paper, in which output torque can be controlled accurately by adjusting electric current. It can be applied to replace magnetic particle clutch widely used at present to achieve tension control in some small-sized winders. A structure design of prototype has been proposed. By using the Bingham plastic constitutive model, the output torque of the device has been derived. Electromagnetic finite element analysis has been employed to simulate the magnetic circuit of this magneto-rheological fluid tension control device. It is shown that this magneto-rheological fluid tension control transmission has its significant advantages comparing with traditional magnetic particle clutch. The new one can produce higher controllable torques, and may be applied widely in the future.
Kinematics Research on Blade Control Mechanism of Variable Vector Propeller
Authors: Kong Fan Kai , Huang Sheng , Chang Xin
Published: October 2009

With structure small and weight light, Variable Vector Propeller (VVP) can provide moving to any direction. In this paper, the mechanical and kinematical character is analyzed with taking disc-rod adjustment mechanism of VVP developed by Harbin Engineering University as an example. Combining the work environment of VVP, the kinematical model is established according to spatial mechanism knowledge. Several typical movement forms’ results are obtained. The study lays the foundation for the further research on kinematical simulation, system control algorithm and trajectory planning.
Parallel Horizontal Sealing Mechanism Design and Experimental Research about Heat Sealing Parameters
Authors: Hu Sheng Hai , Zhao Xiao Li , Deng Kun Xiu , Dong Xin
Published: October 2009

The heat sealing process of Al/PE film mechanism based on diffusion theory is investigated in this paper. Parallel horizontal sealing mechanism is designed and heat sealing strength test is conducted. Considering the sealing performance of Al/PE film as the objective function, establish ternary quadratic mathematical sealing strength model about the heat sealing temperature, dwell time and film thickness three factors. Through analyzing the impact of heat sealing process parameters on sealing performance, the optimization heat sealing process parameters are determined. All the work provides a practical guidance and theoretical basis for heat sealing packaging machine design and parameters determination.
Methods of Assigning Attribute Weights Based on Rough Set and D-S Evidential Theory
Authors: Li Ling Ling , Wang Ming Hui , Zheng Fei , Duanmu Yong Guang
Published: October 2009

Using the concept of support degree in rough set theory for reference, two new concepts, namely dominant support degree and recessive support degree were proposed in this paper. By utilizing these new concepts, two simple weight assignment methods by which dominant weight and recessive weight of attributes could be obtained. Nonetheless both the methods had drawbacks. Hence a further method was developed below. The first step was to construct two items of evidence by deploying dominant weights vector and recessive weights vector of the attribute set and then assigned weights for the evidence to construct weighted evidence. Next was to combine the two items of weighted evidence in reference to the D-S evidential theory. Finally the weight assignments for the attributes could be procured after further processing the combination result. Furthermore, the concept of joint dominant weight of multiple attributes and related methods to assign weights for attributes in some particular situations were proposed. The rationality and wide scope of application of above methods were proven.
A Research on the Concepts and Estimate Methods of Remanufacturing Rate of Engine
Authors: Liu Bo Hai , Xu Bin Shi , Yang Shan Lin , Shi Pei Jing , Xue Shun Li
Published: October 2009

Based on total life cycle assessment (TLCA) and a research project on auto engine remanufacturing, this article look forward to make certain what is "Remanufacturing Rate" of engine remanufacturing and how to express it on the occasions of OEMs, independent remanufacturers and subcontracted remanufacturers in China. The concepts of ‘Remanufacturing rate’ of engine are put forward at first, and then the estimate methods are studied based on remanufacturing environment of China.
An Approach for Module Partition of Product
Authors: Teng Xiao Yan , Kong Fan Kai , Zhang Jia Tai
Published: October 2009

. Modular design technology is one of the ways to realize the product variety. It has been widely used in increasing fields. Module partition which has been the hot spot in and around the world is the key part of modular technology. In this paper, the combination of system clustering and the fuzzy ISODATA algorithm is used to achieve the rough-to-fine division according to the principles of module partition. Finally, the automobile security system has been taken as a case to justify the validity of the method and the result of the division accorded with the function of it.
Design and Analysis of a Cylindrical Traveling Wave Ultrasonic Motor Using Orthogonal Longitudinal Composite Transducer
Authors: Liu Ying Xiang , Liu Jun Kao , Chen Wei Shan , Shi Sheng Jun
Published: October 2009

A cylindrical type traveling wave ultrasonic motor using orthogonal longitudinal composite transducer is proposed. The composite transducer contains two longitudinal transducers, which are located orthogonal to each other. Each longitudinal transducer includes one exponential horn located on leading end, and the horns insect with each other at tip ends. The composite transducer is attached to the cylinder on its outer surface to excite two degenerate flexural vibration modes spatially and temporally orthogonal to each other in the cylinder. Thus, a flexural traveling wave in the cylinder could be excited. The working principle of proposed motor is analyzed. The stator is designed with FEM. The vibration modals of stator are degenerated. Transient analysis is developed to gain the vibration characteristics of stator, and results indicate that the motion trajectories of nodes on the teeth are ellipses. The results of this paper verify the theoretical feasibility and provide instructions for the development of proposed motor.
Study of Flat Belt Drive Mechanics
Authors: Zheng Da Yu , Guan Xiang Yi , Chen Xin , Zhang Zhong Lin
Published: October 2009

The Mechanics between belt and pulley in flat belt drive running is complicated. Since no inertial force or only partial inertial force was taken into account before, it is necessary to add in the inertial affection fully for more accurate dynamic analysis modeling of the flat belt drive. In the assumption that belt material is deformed in linear elasticity and the flat belt drive is running in steady state, the dynamic equilibrium equations of radial and tangent directions are presented and simplified through the belt infinitesimal element processing and the equations associated with mechanical coefficients and dimensions are also derived. After building up the relations of constitutive equations and geometric boundary equations, the solutions to the dynamic differential equations have been found. The sample flat belt drive is introduced for performing method application and obtained adequate calculation results. It is concluded that the presented method calculation results make the maximum transmission momentum tends to be smaller and the slip angle tends to be bigger than the traditional one. And the fluctuation range is mainly depending on the belt speed and the belt stiffness. This method is valuable for dynamic analysis and the design methodology of belt drive.
Mechanism Research on the Waviness Excitation of Ball Bearings
Authors: Wu Yun Peng , Zhang Wen Ping , Li Hong Mei
Published: October 2009

. The paper used spline function fitting the curve of the waviness and its derivative throught measuring vibration and waviness measurement to samples of the bearing, and analysised the nature of the curve of the effects on the bearings vibration. Simulation calculation be done in accordance with the established model of ball bearing vibration. Conclusion have a major role for studying the mechanism of bearing vibration and noise and improving the quality of bearing.
A 3D Virtual FEM and SA Method to Determining the Optimization Clearance for a Punching Die
Authors: Lin Jui Chang , Lin W.S. , Lee King Sun
Published: October 2009

This study is subject to 3D virtual simulation and experiment design method application in the optimal clearance design in the 3D shell punched processing. During the simulation stage, the PAM-CRASH and 3D-CAD (Pro/E) system are used to model the punching processing. The results of the punching maximum punched burr from the 3D virtual punching simulation were input to a neural network to establish a model corresponding to the 3D shell punched variables. Once the metal punching control parameters, such as punch/die radius, punch/die clearance, punch cutting angle and different material thickness, were given, the punching processing performance (the punching maximum burr and maximum stress) can be accurately predicted by this developed network. Therefore, in this research, a satisfactory result based on the simulation verification is established.
X-Ray Image Reconstruction of Solder Joints by Using Several Algebraic Reconstruction Techniques
Authors: Shaw Dein , Hsu Po Yen , Chen Shih Liang
Published: October 2009

In this study, several Algebraic Reconstruction Technique (ART) algorithms are used to construct the 3 D sliced images from several transparent X-ray images. The speed and quality of image reconstruction are two important requirements when doing the inspection in a printed circuit board (PCB) assembly line. . To fulfill the requirements, several methodologies are discussed. The image qualities of regular ART method, binary ART method and Mixed ART method are developed and compared. The binary ART method uses the property of x-ray absorb rate of metal, silicon and other non- metal material are extremely different. The absorb rates of non-metal part are assumed to be zero and metal parts are assumed to be a single value. By using this method the quality of image reconstruction is improved. The mixed ART method is the combination of the tradition ART method and binary ART. Due to the X-ray sensor’s framing time, a method to improve the image reconstruction quality due to effect of X-ray sensor framing time is also discussed. Finally, the best solution algorithm is found to be mixed binary steering ART when consider the signal noise of X-ray detector.
Computational Analysis of Multibody Dynamic Systems Using Nonlinear Recursive Formulation
Authors: Hwang Yunn Lin , Hwang Shen Jenn , Huang Zi Gui , Lin Ming Tzong , Mao Yen Chien , Wang Pei Yu
Published: October 2009

. In this paper the computer implementation of the nonlinear recursive formulation in multibody dynamics systems is described. The organization of the computer algorithm which is used to automatically construct and numerically solve the system of loosely coupled dynamic equations expressed in terms of the absolute and joint coordinates is discussed. The inertia projection schemes used in most existing recursive formulations for the dynamic analysis of deformable mechanisms lead to dense coefficient matrices in the equations of motion. Consequently, there are strong dynamic couplings between the joint and elastic coordinates. By using the inertia matrix structure of deformable mechanical systems and the fact that the joint reaction forces associated with the elastic coordinates do represent independent variables, a reduced system of equations whose dimension is dependent of the number of elastic degrees of freedom is obtained. This system can be solved for the joint accelerations as well as the joint reaction forces. The multibody flexible four-bar system is used as an example to demonstrate the use of the procedure discussed in this paper.
Stress Analysis of a Resin Pocket Embedded in Laminated Composites for an Optical Fiber Sensor
Authors: Her Shiuh Chuan , Yao Bo Ren , Lan Shien Chin , Liu Chun Yen
Published: October 2009

Optical fiber sensors have a number of advantages over conventional electronic sensors such as light weight, small diameter and immunity to electromagnetic interference. Despite all the advantages of optical sensors, one must recognize that optical fibers are foreign entities to the host structure, therefore will induce stress concentration in the vicinity of the embedded sensor. As an optical sensor is embedded between plies, a lenticular resin pocket exists in the composite plies. The resin pocket acts as a crack-like region, and can form the site of the initiation of the delamination under mechanical loads. In this investigation, the geometry of the lenticular resin pocket around the optical sensor is derived basing on the principal of minimum potential energy. It shows that the geometry of the resin pocket is dependent on the stiffness of the plies, the stacking sequence, the diameter of the optical fiber and the curing pressure. The stress distributions in the resin pocket and in the laminated composites are obtained by using the finite element method. The numerical results demonstrate that the stress increases rapidly in the vicinity of the optical fiber sensor, causing a high stress concentration factor. The high stress field may produce delamination and fracture in the composite.
Numerical Simulation of Quasi-Brittle Fracture in UHPFRC I-Beam as a Linear Complementarity Problem
Authors: Han Sang Mook , Guo Yi Hong , Wu Xiang Guo , Guo Qing Yong
Published: October 2009

This paper presents a numerical simulation of quasi-brittle fracture in UHPFRC I-beam as a linear complementarity problem. Based on the investigation of Tin-Loi and Attard, the simulation of quasi-brittle fracture in concrete has been extended to model UHPFRC I-beam by including a tensile hardening. Fracture is simulated through a hardening-softening fracture constitutive law in tension and a softening fracture constitutive law in shear at the boundary nodes, with the material within the triangular unit remaining linear elastic. LCP is used to formulate the path-dependent hardening-softening behavior in non-holonomic rate form. The good matching of test results and numerical results indicates the effectivity of this method.