bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-Helpingly Exchanging and Charging Batteries for EN-V
Authors: Chen Shu Ping , Zhang Qing Chun , Meng Xiang Fei , Pan Feng Hou , Liu Hong Lei , Cheng Fan Qiang
Published: January 2012

An idea of self-helpingly exchanging and charging batteries is proposed to solve some Battery Exchanging and Charging (BEC, for short) problems of Electric-Networked Vehicles (short for, EN-V). Large scale BEC stations occupy large working area and need high equipment cost; common charge piles have disadvantages of long charging time. As a result, a physical demonstration system, which encompasses intelligent vehicle system, BEC stake system and GPS (Global Positioning System) simulation system, is established to validate the feasibility of the idea.
Application of High-Speed Wind Tunnel Control Based on PID Neural Network
Authors: Li Ji , Wang Hong , Huang Hai Long
Published: January 2012

The traditional PID control in nonlinear system such as high-speed wind tunnel has limitations, and the range of using is limited. The BP neural network has been widely applied to the optimization of the PID controller parameter adjustment. The PID neural network control system is introduced in the conventional PID control, which has advantages such as simple structure, physical meaning clear parameters, but also has a neural network of parallel structure and the function of learning and memory and nonlinear mapping capability. The controller uses BP (error back propagation) algorithm to correct connection weights, through on-line training and learning and make objective function to achieve optimal value. This improvement scheme can not only improve algorithm in the training process, and the convergence speed in the wind tunnel, the control valve control system response speed, high precision, meet the steady-state real-time control requirements.
An Overview on Wafer Pre-Aligner
Authors: Zhuang Xian Wen , Zhang Peng , Hao Li Na , Huang Cheng Bao
Published: January 2012

Wafer pre-aligner plays an important role in wafer manufacture. Wafer pre-aligner positions wafers accurately before they are transferred onto exposure platform, and the positioning accuracy greatly affects the exposure accuracy of wafer and the work efficiency of the whole manufacture system. The paper makes an overview on wafer pre-aligner from the following aspects: working principle, mechanical structure, machine vision and the algorithm on the detection of wafer edge.
The Manipulator Cleared the Surface of Fluid Pipelines
Authors: Li Bin , Hong Jin Ping , Cao Zheng Feng
Published: January 2012

Manipulator cleared the surface of fluid pipelines is the necessary pipeline engineering construction equipment. Developing an advanced automatic robotic pipeline construction and making it industry can satisfy the needs of pipeline engineering in the country improve mechanization level and work efficiency and reduce labor intensity. According to the actual situation, the paper conform the principle of the robotic work. Analysis the work process of the manipulator, the design gives the optical detection system. This manipulator adopts automatic rotary and feeding, intelligent control and automatic detecting effects and feedback. The movement of the manipulator can been regulated and controlled timely by the photoelectric detection device of the manipulator. It is suitable for cleaning the surface of various pipelines in the complex condition field. This paper studies the revolution，feeding and feedback of the pipeline construction of the manipulator. Finally, study and design a stable running, flexible movement, accurate positioning, the effect is automatically detected and reliable intelligent robot which compatible with the subject. This manipulator can well meet the requirements of operation.
A Tolerance Analysis Approach Based on Robot Kinematics
Authors: Zhang Xiu Heng , Liu Hong Yi , Luo Zhong
Published: January 2012

This paper presents a tolerance modeling approach based on robot kinematics theory within CAD/CAM system. Based on the differential kinematics theories, each feature of characteristics including size tolerance and geometrical tolerance was established as a corresponding small displacement torsor. In order to express the relation between the small displacement of all functional features and the functional requirement, the final expression was represented to establish the projection of analysis of the tolerance chain. A mathematical expression was obtained by the mean instead of single points, and the constraints can be represented by interval using the standard deviation, not limit deviations. After having identified the unit components and the functional requirement from the tolerance chain, we obtained the percentage contribution of each unit feature to the functional requirement. A percentage contribution can help designer to decide which tolerance is tighten or loosen. The application of the tolerance analysis approach in a simple three-dimensional sample was also discussed in this paper.
Vibration Suppression of a 3-DOF Parallel Manipulator Based on Hybrid Negative Impulses Multi-Mode Input Shaping
Authors: Han Yan Yan , Li Bing , Wei Yu Lan , Zhu Shou Xin , Dai Ying Jun
Published: January 2012

The classic multi-mode negative impulses input shapers can suppress the residual vibration of the multi-mode system effectively. But when these several frequencies bandwidths and amplitudes of vibration modes are greatly different, the time delay and the suppression performances of input shapers are decreased. However, the hybrid multi-mode negative impulses input shapers can overcome the disadvantage. The hybrid double-mode negative impulses input shapers of a 3-DOF parallel manipulator and are constructed and compared with the classic multi-mode negative impulses input shapers. And the numerical simulations are shown out, for different frequencies bandwidths and amplitudes of vibration, and the hybrid multi-mode negative impulses input shapers can increase the total suppression performance of input shaper.
A Tetra-State Hopping Robot Driven by Shape Memory Alloy Spring
Authors: Liu Tian Qi , Chen Shu Ping , Guo Jiang Long , Dou Zhi Long , Liu Chun , Zhang Qing Chun
Published: January 2012

According to the characteristics of jumping locomotion, a solution of Tetra-state Hopping Robot (for short: THR) actuated by Shape Memory Alloy Spring (for short: SMAS) is presented in this paper. This article establishes a mechanical model of the jumping robot and analyzes the kinematics and the dynamics of the mechanical model. Lagrange method is applied to analyze the dynamics the mechanical model. Meanwhile, a preliminary explanation of the THR flipping phenomenon during the take-off and flight process is conducted from the perspective of momentum moment.
Research on EEG-Based Control of Prosthetic Hand
Authors: Li Chun Sheng , Zhao Hai Bin , Wang Hong
Published: January 2012

The wireless control method is implemented between NEU BCI-II brain-computer interface and DR05 humanoid hand in this paper. A user interface with a set of real-time analysis and control methods is developed based on Lab VIEW platform. Wavelet analysis method is embedded in this framework, which extracts the character of alpha rhythm. 86.7% correct rate is achieved by using this framework to make humanoid hand do six gestures. Electronic disturbance of finger motor is eliminated by adopting wireless method.
Twin Channel of Speed Control System Based on DSP
Authors: Li Bin , Cao Zheng Feng , Hong Jin Ping
Published: January 2012

A microprocessor as the core of the digital controller has become one of the major features AC speed regulation system in modern. Based on DSP as the core of the speed control system，it can realize complex algorithm. At the same time, it can achieve the diagnosis of system’s fault, and the self-setting of parameters controlled, etc. Thus it can make the motor speed control system have higher performance. This paper introduces the motor speed control system which consists of three DSP. This system is able to adjust two Frequency conversion motor. Division of work to the DSP is according to the function of DSP. Inter-DSP makes use of dual-port RAM to exchange data and communicate. They work together to achieve and improve the performance of the control system.
Research on the Planetary Gear Deceleration Machine Design of a Novel Rapidly-Opening/Closing Actuator of Manual Valve
Authors: Shi Bin , Wang Feng , Wang Hua Qing , Chen Ya Jun , Chen Cun Yin
Published: January 2012

Failing to promptly close the valve whose circuits have been burnt out is one of the important causes leading to an amount of oil leakage after the Dalian oil pipeline explosion. Moreover, the opening/closing torque of the manual valves will be bigger due to no actions for a long time, corrosion, rust, etc. And the operators will stay in a dangerous environment for a long time and thus they will have life problems when there are abnormal conditions or accident conditions. This paper proposes a design idea of a novel rapidly-opening/closing actuator of a manual valve, in order to resolve the problem that how to open/close a manual valve rapidly. The research on the rapidly-opening/closing actuator of a manual valve should include the calculation of the opening/closing torque of the manual valve and the designs of the deceleration machine and the chuck. The output shaft of the deceleration machine connects with a chuck, while the chuck connects with the wheel of the valve. The work principle of the actuator is that a motor drives the rotation movement of the deceleration machine so as to realize the rapid opening/ closing of the valve. This paper mainly focuses on the design of the deceleration machine, wherein the structure of planetary gear is designed through the theoretical calculation and the computer-aided design method. The research of the method provides the design method and the technical support for the design of the rapidly-opening/closing actuator of the manual valve. The actuator could be employed to the safety prevention departments of the chemical industries after the successful design of the device. The device can be utilized to cope with the problem that how to open/close a manual valve with more rotating laps or in emergency conditions rapidly. Moreover, the accident rescue ability of the chemical industries will be further improved, and the loss of the accidents will be reduced.
User-Oriented Web Service Search Technique for Mobile Mashup
Authors: Hizen Kazuki , Koita Takahiro
Published: January 2012

This paper presents the basic design of a new web service search technique for mobile mashup. Web service search means searching web APIs to build a new mobile mashup service. The technique is based on user-oriented profiling and can be easily used on mobile devices. For web service search, a user must know the details of a web service in advance. However, conventional service search cannot provide such information on whether the web service can be used for the mashup. This study discusses a user-oriented web service search technique for mobile mashup. Its key feature is that users can easily search for web services that use mashup on mobile phones without knowing the details.
Tail Deviation’s Predictive Control of the Tandem Rolling Strip Based on Manifold Learning
Authors: Wang Guang Bin , Kong Y.Q. , Wang Ke
Published: January 2012

In the rolling process, serious deviation will cause product quality drop and rolling equipment fault. This reserch propose tail deviation’s predictive control method of the tandem rolling strip based on manifold learning. Based on real deviation data in the rolling production site,tail deviation patterns are divided according to deviation’s value. Using manifold learning method to deviation data in middle rolling stage , tail deviation pattern and scope are obtained. According to regression model between the control variable and deviation, predictive control strategy of the tandem rolling strip may be implemented. Experiment shows this method may control tail deviation in preconcerted permission range.
Cast Shadow Detection for Surveillance System Based on Tricolor Attenuation Model
Authors: Zhu Lin Lin , Tian Jian Dong , Tang Yan Dong , Han Jian Da
Published: January 2012

Shadows bring some undesirable problems in computer vision, such as object detecting in outdoor scenes. In this paper, we propose a novel method for cast shadow detecting for moving target in surveillance system. This measure is based on tricolor attenuation model, which describes the relationship of three color channel’s attenuation in image when shadow happens. According to this relationship, the cast shadow is removed from the detected moving area, only the target area is left. Some experiments were done, and their results validate the performance of our method.
The Effect of Initial Cooling Temperature on Deformation of U75V Heavy Rail after Cooling
Authors: Gao Ming Xin , Jia Hao , Jiang Juan Juan , Wang Pei Long , Song Hua , Yuan Si Yu , Wang Zhong Qiang
Published: January 2012

The initial cooling temperature has important effect on the bending change and section size of rolled heavy rail, when rolled heavy rail is on the cooling bed for natural cooling. In the paper, the heat-stress couple method is adopted to carry on numerical simulation to cooling process of 60kg/m U75V heavy rail, and we has obtained the bending change value and section size of rolled heavy rail in different initial cooling temperature. The study is of great reference value on the design of cooling bed which is for hundred-meter high speed heavy rail and the formulation of cooling technological parameters.
Effect of Draw Blank Velocity on Steel Fluid Flow Field in Blank Continuous Caster Crystallizer
Authors: Xu Ze Ning , Liu Hong Yu , Lu Yan Ping , Liu Lei Gang
Published: January 2012

As the heart of continuous caster, crystallizer is the cradle of most surface deficiencies and inside quality problems in steel blank. Steel blank surface quality, nonmetal impurity content and relevant distribution rely on the steel fluid solidification behavior namely steel fluid flow field distribution on great extent. For the high temperature steel fluid has big kinetic energy, so, the immixture dregs, solidification heat conduction, temperature field distribution in crystallizer, solidification blank shell thickness distribution and continuous caster blank quality were influenced by steel fluid flow. The numerical simulation analysis on flow field and temperature field in crystallizer were conducted in this paper. Three dimensions turbulent flow model was adopted to computate flow field. The heat conduction was ignored on draw blank direction in temperature field. The conjugate heat conduction model of ANSYS CFX was adopted to analyze temperature field, which can consider heat conduction in solid layer and convection heat conduction between solid shell face and fluid simultaneity. The draw blank velocity was found by setting crystallizer water gap insertion depth and crystallizer water gap angle, which can obtain reasonable flow field in blank crystallizer.
Mathematical Modeling of Control Systems Based on Output Feedback Decoupling, Curve Fitting and Spline Interpolation
Authors: Zhang Chi , Wang Hong , Lian Xiao Fei
Published: January 2012

In this paper, based on the output feedback decoupling, curve fitting and spline interpolation method, a mathematical model is presented for nonlinear dynamical system wherein only system inputs and outputs are known.
Research on Periodic Motion Stability of Rotor-Bearing System with Dual-Unbalances
Authors: Li Chao Feng , Liu Guang Chao , Li Qin Liang , Wen Bang Chun
Published: January 2012

Multiple freedom degrees model of rotor-bearing system taking many factors into account is established, the Newmark-β and shooting method are combined during the stability analysis of periodic motion in such system. The paper focused on the influence law of two eccentric phase difference on the instability speed of rotor-bearing system. The results have shown that the instability speed rises constantly with the eccentric phase difference angle increasing in small eccentricity system. When the two unbalance be in opposite direction, the system reached its maximum instability speed. However, the unstable bifurcation generates mutation phenomenon for large eccentricity system with the eccentric phase difference angle increasing. In summary, the larger initial phase angle can inhibit system instability partly. The conclusions have provided a theoretical reference for vibration control and stability design of the more complex rotor-bearing system.
Damage Process Simulation of Damping Coating of Thin Plate
Authors: Zhai Jing Yu , Li Hui , Han Qing Kai
Published: January 2012

In this paper, the element birth and death technique is used to simulate the damping stripping process of damping coating, and the interface of substrate and damping coating is simulated by contact elements or interface elements. The stress intensity factors and crack length are also calculated based on finite element method under different thicknesses and elastic modulus The simulation could provide reference for the design and optimize of damping coating.
Research on Characteristics of Chaotic Motion Based on the Wavelet Ridge
Authors: Li He , Wen Ji Dan , Zhang Jie , Wen Bang Chun
Published: January 2012

The wavelet ridge method to analyze chaos is described, and the wavelet ridge method is applied to analysis of the nonlinear vibration of blooming mill which exists chaos. The results show that the wavelet ridge can tell the periodic motion, quasi-periodic motion or chaotic motion by analysising the time history of one component of the system state variables. Compared to the other researching methods, such as the Poincaré sections or the phase diagram, we can find the wavelet ridge is more suitable to high dimensional chaotic systems and the clutter of instantaneous frequency which is represented by the wavelet ridge can distinguish between strong and week chaos motion. And it can provide more accurate partial details and features of chaotic motion.
FEM Analysis on the Frame of Cross Roll Straightener for Steel Pipes
Authors: Wang Li Ping , Piao Jing Wei , Xu Ze Ning , Jiang Chang Hua , Bi Xin
Published: January 2012

The intensity and rigidity of cross-roll pipe straightener frame are analyzed with the Finite Element Method (FEM) and the stress of the frame is tested. The FEM results are compared with experimental results and the accuracy and rationality of FEA results are verified. The analysis results have significant guidance to design and transformation the structural type of cross roll straightener and its frame.
Nonlinear Response of Graphite-Epoxy Composite Thin-Walled Structure under Elevated Thermal Environment
Authors: Sha Yun Dong , Xu Fei , Gao Zhi Jun
Published: January 2012

Composite materials thin-walled structures are widely used as skin panel in flight vehicles in recent years. These structures will encounter severe complex loading conditions, which may be a combination of mechanical, aerodynamic, thermal and acoustic loads. Thin-walled structures subjected to this kind of loadings will exhibit nonlinear response; as a result, fatigue failure will occur. High temperature may cause large thermal deflection and stress, for some special conditions, may cause thermal buckling. Once the thermal buckling appears, the stiffness will change correspondingly, it will cause significant influence on the dynamic response and fatigue failure. Accordingly, it is important to research the nonlinear response of this kind of structures under elevated thermal environment. Nonlinear response and thermal pre-buckling/post-buckling behavior of a Graphite-Epoxy composite plate subjected to server thermal loading is numerically investigated in this paper. A composite laminated plate with clamped-clamped boundary conditions is chosen as simulated body, nonlinear finite element model is developed using the first-order shear deformable plate theory, Von Karman strain-displacement relations, and the principle of virtual work. The thermal load is assumed to be a steady-state with different predefined temperature distribution. The thermal strain is stated as an integral quantity of the thermal expansion coefficient with respect to temperature. Then the modes of the plate are analyzed, the nature frequencies and modal shapes are obtained. The critical temperature of buckling is calculated. The static nonlinear equations of motions are solved by the Newton-Raphson iteration technique to obtain the thermal post-buckling deflection. The Riks method is used to analyze static post-buckling behavior. In the numerical examples, four types of situations are studied, which include i) the buckling behaviors for different initial imperfections, ii) the buckling behaviors for different thickness to width ratios, and iii) The buckling behaviors for different width to length ratios; The critical temperature, the static thermal post-buckling deflection and the load to displacement relation are presented respectively. The influences of different boundary conditions on the buckling behaviors of the plate are achieved as well. The simulation method and results presented in this paper can be valuable references for further analysis of the nonlinear responses of thin-walled structures under complex loading conditions.
Influence of Thermal Loading on the Dynamic Response of Thin-Walled Structure under Thermo-Acoustic Loading
Authors: Sha Yun Dong , Gao Zhi Jun , Xu Fei , Li Ji Yong
Published: January 2012

Future flight vehicle structures will encounter severe loading conditions, a combination of aerodynamic, thermal, acoustic and mechanical loads. Although the analysis methods for responses of structures under acoustic loads have been developed to some extent, but with thermal loads considered, the responses show fundamental differences, which complicate the analysis immensely. It was reported that hypersonic flight may give rise to surface temperature as high as and intense noise whose overall sound pressure level (OSPL) may reach 180dB. Thin-walled structures subjected to such loadings will exhibit nonlinear responses. Large temperature increments may cause thermal buckling, large thermal deflections and large thermal stresses superimposed on dynamic stresses, coupled with changes in material properties. Both the geometry change by thermal buckling and stiffness change by thermal stress account for the changes of natural frequencies and mode shapes. When the acoustic loading increases to a high enough level, the post-buckled structures will exhibit snap-through motion, a large amplitude nonlinear vibration between different equilibrium positions, which will introduce extra large mean stress. As a result, thermo-acoustic fatigue may be caused, which will reduce the structure's fatigue life dramatically. Therefore it is an urgent need to estimate the influences of thermal loads on the nonlinear response of structures. A numerical investigation of the influences of thermal loads on the dynamic response of thin-walled structure under thermo-acoustic loadings is implemented. With clamped-clamped thin flat plate selected, the response characteristics related to temperature are investigated by changing thermal loads. The thermal load is considered as constant both on the surface and across the thickness. The acoustic load is simulated using stationary Gaussian white noise. Firstly, a thermal buckling analysis is proceeded to obtain critical buckling temperatures, followed by modal analysis under different thermal loads. The pre-buckled and post-buckled mode frequencies and shapes are obtained. Then three types of snap-though motions are predicted: i) vibration around one post-buckled equilibrium position, ii) intermittent snap-through, and iii) persistent snap-through. The relations between thermal loads and the occurrence of snap-though is obtained together with results about the statistics characteristic of dynamic response and their relations with thermal loads, which include critical thermal buckling loads, natural frequencies and mode shapes, RMS response and snap-through frequency. Good agreements have been achieved with previous analytical solutions, which demonstrate the effectiveness and reliability of the method employed.
Multi-Channel Active Noise Control System Designs with Fuzzy Logic Stabilized Algorithms
Authors: Ahn Dong Jun , Kim Keun Sik , Nam Hyun Do , Shin Eun Woo
Published: January 2012

In active noise control filter, IIR filter structure which used for control filter assures the stability property. The stability characteristics of IIR filter structure is mainly determined by pole location of control filter within unit disc, so stable selection of the value of control filter coefficient is very important. In this paper, we proposed novel adaptive stabilized Filtered_U LMS algorithms with IIR filter structure which has better convergence speed and less computational burden than conventional FIR structures, for multi-channel active noise control with vehicle enclosure signal case. For better convergence speed in adaptive algorithms, fuzzy LMS algorithms where convergence coefficient computed by a fuzzy PI type controller was proposed.
DEM Simulation of Spin Vibration Screening Process
Authors: Li Dong Sheng , Du Yi Qiong
Published: January 2012

This paper focus on the motion simulation and visualization of the material particles in the operation of the spin vibration screening using DEM(Discrete Element Method). Based on analysis of the simulation results, some conclusions are made which provide the theory basis in order to design the screen parameters reasonably. Finally some experiments are carried out in order to verify the correctness of the simulation.
The Design and Simulation of HPLC’s Structure
Authors: Xu Ze Ning , Wang Xiao Xia , Hou Liang , Liu Lei Gang
Published: January 2012

As an important part of chromatography instruments, chromatographic column plays an important role in the progress of science and the development of production. In order to avoid the traditional process ,design - processing- test - Fixed design - re-processing and effectively shorting the design cycle save a lot of manpower, material and financial resources. This paper offers to watch the changes of flow profile within the column by the application of simulation software ANSYS CFX .Besides, according to the distribution of flow profile, the traditional column has been done a lot of dynamic simulation, especially the stigma part of the column. From a fluid Machinery perspective, we simulated and designed the structure, and then found out the best separation efficiency of the column structure.
Analysis of Moment Transmitted by Universal Joint in Varying Operating Condition
Authors: Feng Chang Lin , Wang De Shi , Zhu Yong Yong
Published: January 2012

The moments transmitted by a universal joint in varying operating condition was investigated. A model of shaft system driven by a universal joint which consists of a driving shaft, a driven shaft and a cross piece is chose. Both structure misalignment and error misalignment between the two shafts at the universal joint was considered, and the study was based on the assumption that friction, inertia and elastic forces of the cross piece were disregarded. Two pairs of Euler angles were introduced to denote structure misalignment and error misalignment respectively, sets of reference frames were built up on the driving shaft, driven shaft and cross piece. Using direction cosine matrixes to describe the relation between different frames, then the expressions of components of the transmitted moment acting on the driven shaft were obtained via method of vector projection. Based on engineering fact, the transmitted moment model was simplified with respect to different misalignment conditions, such as only structure misalignment or only error misalignment is considered. Then for different misalignment situations, the lateral and torsional components of the transmitted moment acting on the driven shaft were simulated through numerical examples. It turns out that both the lateral moment and torque components will fluctuate based on the import torque, and that due to accelerating of the driving shaft, the fluctuation of transmitted moment will be more distinct, consequently, more complicated nonlinear dynamics behavior will arise.
Performance and Analysis of Concrete in Sewer Environment: Anisotropy of Damage
Authors: Oualit Mehena , Jauberthie Raoul , Melinge Yannick , Abadlia Tahar
Published: January 2012

The costs associated with the provision and maintenance of drinking water and wastewater infrastructure represents a signiﬁcant ﬁnancial demand worldwide. Maintenance costs are disproportionately high, indicating a lack of adequate durability. The aim of this paper is to study the degradation mode and the responsible factors of deterioration concrete pipe, used in the sewage’s city of Rennes (France). Thus, samples taken from different areas of the pipe (Raft, medium and roof) were analyzed using investigation methods in order to illustrate the internal and external rate of damage, caused by effluents and ground. In addition, chemical and mineralogical changes recorded were identified using scanning electron micrographs (SEM). In this research program, chemical and mechanical studies were performed by measuring the compressive and splitting tensile strengths. A phenolphthalein indicator solution is applied to a concrete specimen on a fresh fracture surface to determine the corrosion of steel reinforcement and the diseases advancement (pathologies depth). This study clearly shows the important anisotropy of both, internal and external damage. Finally, recommendations are proposed in line with the environment and possible approaches to sustainability assessment are also imposed.
Design and Finite Element Modal Analysis of 48m Composite Wind Turbine Blade
Authors: Tarfaoui M. , Khadimallah H. , Imad Abdellatif , Pradillon J.Y.
Published: January 2012

We currently notice a substantial growth in the wind energy sector worldwide. This growth is expected to be even faster in the coming years. This means that a massive number of wind turbine blades will be produced in the forthcoming years. There is a large potential for materials savings in these blades. The analysis of designed blade is done in dynamic loading. Five types of spars cross-section are taken in this work. The blade and spar are of composite material. The Finite element modal analysis of designed blade is done in ABAQUS. The scope of the present work is to investigate the structural modal analysis of full-scale 48m fiberglass composite wind turbine blades for 5MW horizontal axis wind turbine and through this to assess the potential for materials savings and consequent reductions of the rotor weight. The entire wind turbine can benefit from such weight reductions through decreased dynamics loads and thus leave room for further optimization. A numerical work has been used to address the most adequate spar shape and to get an understanding of the complex structural behavior of wind turbine blades. Five different types of structural reinforcements helping to prevent undesired structural elastic mechanisms are presented. Comparisons of the eigenfrequencies observed in the full-scale tests are presented and conclusions are drawn based on the mechanisms found.
Optimizing Residual Stress Profile Induced by Laser Shock Peening Using DOE Technique
Authors: Frija Mounir , Sghaier R. Ben , Bouraoui Chokri , Fathallah Raouf
Published: January 2012

The control of residual stress is crucial in ensuring the integrity of engineering components and Laser Shock Peening (LSP) process can be used to good effect to introduce the beneficial compressive residual stress levels required. It is, however, difficult to use normal laser peening control systems to establish the ideal peening conditions that will result in the best component performance. This paper presents results from a study to optimise the laser peening parameters for a typical titanium super alloy used in high performance turbine blade by investigating how the main peening process parameters influence residual stress profiles resulted by numerical simulations. Statistical Design of Experiments (DoE) was used to limit the number of experiments required for optimisation to be possible. Using this technique and numerical depth profiling methods for residual stress analysis, the maximum compressive residual stresses in Ti-6Al-4V were measured for a range of peening conditions. The results of the detailed process characterisation investigations have shown that, by using careful DoE, it is possible to fully optimise the laser shock peening process to obtain greater benefits than would be possible with traditional control processes.
Toward Optimal Updating Time Inspection Based on Reliability Approach of Fatigue Crack Propagation
Authors: Eltaief M. , Hassine T. , Bouraoui Chokri , Riahi H. , Chateauneuf A. , Bressolette Ph.
Published: January 2012

t is well-established that fatigue crack growth process is one of the main process which can produce failure of structures and mechanical components. The aim of this work is to develop a model predicting an updating inspection time model for structural fatigue crack growth life based on updating reliability analysis taking into account the additional information generated by the previous inspection results. First order reliability method (FORM) and Surface response method are used to evaluate the reliability. The uncertainties such as material parameters and geometrical parameters which affect the lifespan of the structure were regarded as random variables. Updating reliability assessment based on Bayesian approach was introduced to determine the updating inspection time for target reliability. The method was illustrated through an application to a plate with an emergent rectilinear crack loaded with a constant amplitude cyclic stress. The results of the application are in a good agreement with the physical results and show that the proposed method is proved to be feasible and applicable in the general complex fatigue loading and able to give accurate updating framework for scheduling inspections. Furthermore the proposed approach leads to determine the optimal Inspection time strategy based upon cost-minimization by considering a single type or multiple types of inspections.
Singular Perturbation Method for Solving Non-Linear Vibration of Stay Cable (II) - Engineering Application
Authors: Ran Zhi Hong , Qu Jun Tong , He Fei , Miao Sheng
Published: January 2012

According to vibration characteristic of cable in cable-stayed bridges, the non-linear dynamic model of cables was set up. The vibration differential equation is deduced using the singular perturbation method. The stiffness and coupling boundary conditions of simple and fixed are introduced in the cable force analysis. The useful formulation of measuring techniques for cable force using frequency method is advanced. Results of analyses indicate that the formulation is high in accuracy and convenient in practice. The formulation was used to the cable-stayed construction control of Nanjing Yangtze River No.3 Bridge. The cable force was calculated with test data of vibration, and compared to cable force of design and pressure sensor. The method can be widely used for field of measurement during the construction of cable system structures.
Double Non-Linear Mechanical Characteristics of Transmission Tower Structure Based on Model Amendment
Authors: Xue Jia Zhu , Zhi Xiang Cao , Chi Yv Zhang
Published: January 2012

Transmission tower, being of evident nonlinear characteristic, is a complex space structure. Linear theory is generally adopted in the process of designing, which results in a waste of resource and disaster. Starting from the problems exiting in the process of transmission tower designing, the space beam element is adopted in the thesis, which reduces material nonlinearity through the rod end of the plastic method, and the geometric large deformation problem is involved by considering the amendment of the element stiffness matrix. Arc-length method of iterative computation is adopted as the solution method. On the premise of clarifying the process of dual non-linear solution, this thesis combines specific project example through self-organizing the finite element programming to calculate displacement - load curve, and the results show that the transmission tower structural system possesses obvious nonlinear characteristics. The research lays a foundation for improving the accuracy of space truss structure and developing the large specific finite element software.
Reliability Assessment of Fatigue Life of Hangers in Large-Span Suspension Bridges
Authors: Zeng Yong , Tan Hong Mei
Published: January 2012

Hangers are very important components for suspension bridges, which link main cables and stiffening girders. When in service, hangers are much vulnerable to fatigue loads due to kinds of traffic flows, which may reduce the remaining life of the hangers and increase the risk of losing public confidence in cable supported bridges. In order to quantify the reliability of hangers under vehicle loads, fatigue reliability formula of hangers is proposed in this paper. Based on the accurate analysis of vehicle load spectrum, the time history of hangers is simulated and maintenance strategy is proposed.
Maintenance Strategies of Main Cable for Large Span Suspension Bridges Considering Different Scales
Authors: Zeng Yong , Tan Hong Mei
Published: January 2012

Like all other civil engineering structures, suspension bridge is subjected to long-term formidable environment, such as fatigue and corrosion. After its open to traffic, degradation and damage of its components appear in suspension bridges, which cause the reduction of bearing capacity and reliability of suspension bridges. Therefore, the service safety of suspension bridges is a topic of importance, particularly for its managers. This paper provides maintenance strategies for managing and maintaining the structural safety of suspension bridge in a life cycle framework in order to rationalize maintenance actions, economically.
Explosive Compaction of Sand Foundation: In Situ Trails
Authors: Qu Jun Tong , Ran Zhi Hong , Miao Sheng
Published: January 2012

It is necessary to find a more economical soil improvement technique to densification the reclamation by bumping filling foundation. As a soil improvement technique, blasting-densification of sand is a viable and efficient method, which offers several advantages compared to other soil densification methods. Although Explosive Compaction (EC) has been used effectively for compaction loose, non-cohesive soils for more than 70 years, it has not attained widespread acceptance in China. In-situ trials of Explosive Compaction were carried out to determining appropriate and feasible of Explosive Compaction for improvement sand foundation.
Comparison between Generated Data by Different Markov Chain Methods in the Mola Sany Station of the Karun River in Iran
Authors: Adib Arash , Sohldoost Soheil , Labibzadeh Mojtaba , Vaghefi Mohammad , Ghanbarzadeh Afshin
Published: January 2012

For programming and management of water resources, access to hydrometric data is necessary. Unfortunately, the quantity and quality of hydrometric data are not suitable in developing countries. These data can not show drought periods and wet periods correctly. Prediction of wet periods is an important problem for flood control while forecasting of drought periods is very vital for water supply in critical conditions. In this research, two hydrometric stations on the Karun River were considered (Ahvaz and Mola Sany hydrometric stations). The data of Ahvaz hydrometric stations are more exact than of their Mola Sany hydrometric stations. For generation of synthetic hydrometric data in Mola Sany hydrometric station, two methods were applied: 1- Generation of yearly hydrometric data by yearly Markov chain method and monthly hydrometric data by monthly Markov chain method in Mola Sany hydrometric station 2- Generation of yearly and monthly hydrometric data by multi spatial Markov chain method and generated yearly and monthly hydrometric data by yearly and monthly Markov chain method in Ahvaz hydrometric station By comparison results of two methods, it is observed that multi spatial Markov chain method can produce data of wet and drought periods better than yearly and monthly Markov chain method while the results of yearly and monthly Markov chain method and observed data have more fitness. Two methods can predict the length of time of wet and drought periods exactly too.
Evaluation of Undrained Shear Strength of Converting Dredged Material to Agricultural Soil
Authors: Gui Yue , Cao Jing , Song Zhi Gang , Zhang Qing
Published: January 2012

In order to keep the river and harbor clear, the dredging activity need to be done continuously which has generated millions of cubic meters of dredged material (DM) every year in China. It is an economical and environment-friendly alternative of DM disposal to convert the dredged material to agricultural soil (CDMTAS) by adding admixture and/or dewatering. However, the corresponding evaluation criteria has not been reported so far to determine whether these treated DM are available for using as agricultural soils or not. 145 groups of data composed of weight and the shoes size of the adult was obtained by surveying in China, and a safety factor was given during the statistical analysis of the foot plantar pressure on the ground of adults, and 50 kPa is recommended for human agriculture activity loading on CDMTAS whose process could be regarded as undrained shear. Moreover, 16 kPa is recommended for the least undrained shear strength of CDMTAS that is required for bearing the human agriculture activity.
Numerical Simulation of Random Wind-Excited Response Analysis of Henan TV Tower
Authors: Zeng Yong , Tan Hong Mei
Published: January 2012

Based on wind velocity spectrum generated by CAWS method, the dynamic response of tower is computed by Ansys software. The wind-reduced displacement response, force response and acceleration response are acquired. At the same time, wind load factor based on displacement equivalence and force equivalence is acquired.
The Sustainable Indoor Environment Research and Design of Earth Buildings for Rural People
Authors: Tan Liang Bin
Published: January 2012

The earth building is a building type with enormous quantity and widely being used in rural section of south-western part. It will dominate for a long time. The environment of traditional earth buildings is very poor because of out-dated ideological limitations and construction mode, it can’t meet the needs of increasingly demanding of local people. So these buildings must recur to modern technologies to integrate fine parts in tradition and form new appropriate technologies. This paper took Yi minority’s houses in Yongren as an example to look for a road opening to rural buildings’ sustainable development.
Study of Fuzzy Control for Turbofan Engine Based on Improved Genetic Algorithms Optimization
Authors: Hu Yu , Yang Yue Cheng , Zhang Shi Ying , Yu Xi Xing
Published: January 2012

In the paper, the fuzzy control algorithm was studied in turbofan engine. The turbofan engine models of “little deflection” model and “large deflection” model were built based on component level model. Then, a fuzzy controller, including the fuzzy-integral mixed controller, smith forecast and compensation, was designed with the fuzzy rules were optimized by improved genetic algorithm. The simulation results show that the designed control system responds fast, has no overshoot or oscillation, and the control precision is high. The controller can effectively solve time delay influence with a great control effect for “little deflection” model and acceleration model.
A Micromechanical Model for Debonding Process in Composite Solid Propellants
Authors: Li Gao Chun , Wang Yu Feng , Jiang Ai Min , Liu Xiang Yi
Published: January 2012

The random distribution packing models of particles in the binder of solid propellant were generated based on the Molecular Dynamics method. The generated packing models were then analyzed by finite element method combined with the analytical method. A cohesive interface model was incorporated to capture the debonding process taking place along particles binder interface. The results show that the FEM analyses with cohesive interface can predict the complex heterogeneous stress and strain fields and the progress of debonding of particles from binder. Particles interaction significantly influences the interfacial damage evolution of propellant.
Energy and Exergy Analysis for Three Type 500MW Steam Power Plants
Authors: Li Zhi , Li Zhong Min , Yan Zhan Liang
Published: January 2012

The paper shows the comparison of energy and exergy analysis of thermal power plants based on advanced steam parameters in China climatic conditions. The research contains coal-based thermal power plants using sub-critical, super-critical, and ultra-supercritical steam conditions. The design configurations of 500 MW unit size were considered. The research contains the effect of condenser pressure on plant and exergy efficiency. The effect of high grade coal on performance parameters as compared to typical China low grade coal was also studied. The major exergy loss took place in coal combustion followed by the steam generator. Due to condenser pressure limitation, the maximum possible overall energy efficiency was found to be about 44.4% with the ultra-supercritical power plant. Installing coal-based thermal power plants based on advanced steam parameters in China will be a prospective option aiding energy self-sufficiency.
Analysis and Research on the Performance of the Ground Source Heat Pump System in Different Areas of China
Authors: Qi Zi Shu , Gao Qing , Liu Yan , Yan Y.Y. , Spitler Jeffrey D.
Published: January 2012

In the paper, it is to describe the performance of the vertical ground heat exchangers (GHE) in different areas of China. The energy consumption of ground source heat pump (GSHP) system is based on the instantaneous fluid temperature at the heat pump inlet. This temperature defines the GSHP coefficient of performance and hence the electricity consumption required in order to fulfill the energy demands of the building. A mathematical model for simulation of vertical ground heat exchanger system is built based on long time-step theory. The design methodology is based on a simulation that predicts the temperature response of the ground heat exchanger to hourly heating and cooling loads demand in 20 years. This paper presents GSHP system can achieve energy performance in buildings that heating and cooling loads all the year round in different areas.
Study on Electro-Pneumatic Clutch for Automatic Mechanical Transmission
Authors: Zhang Wu Chao , Zhai Yong
Published: January 2012

The clutch control is one of the cores and most difficult issues in the development of an AMT system. In this paper the pneumatic clutch engagement characteristic is analyzed. Thereto, a simulation model of an automotive powertrain comprises a diesel engine, drivetrain and wheels driving a vehicle through tire-road adhesion are built using Matlab/Simulink. In the simulation, a refined control law of constant engine speed in part process is proposed and tested. The engaging speed and displacement of the clutch vary with the accelerate paddle opening, engine speed, clutch driven plate speed and gears according the control law. Field experiment results show that the control strategy fulfills the system requirements.
The Collection System of Relay Electrical Endurance Based on LabVIEW
Authors: Huang Xian Ge , Jing Zhan Rong
Published: January 2012

Electrical-endurance of relay is great important work .In this paper, the composition of relay collection system and using ni_7811R achieve fpga contact collection technology based on Labview platform are introduced .This paper make contact information can be collected real- timely and transferred rapidly through dma module . It has positive significance to enhance relay quality and reliability.