bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency Reliability Sensitivity Analysis for Rotor System with Random Parameters
Authors: Meng Lei , Li Shuo , Li He , Guo Li Juan
Published: October 2014

The random factor method (RFM), an effective numerical simulation method, is employed to analyze the probabilistic characteristics and reliability sensitivity of uncertain structure system. The natural frequencies of the system can be expressed as the function of the random factors. By using the random variable’s algebra synthesis method, the expressions for the mean value and standard deviation of natural frequencies are derived from Rayleigh quotient. The reliability mode and the safety probability of random systems are defined, and then the frequency reliability sensitivity analysis method is presented. The formulas of failure probability sensitivity are derived when random variables are normally distributed. The reliability index is evaluated, and its sensitivity to mean values and variances are mathematically expressed, then the efficiency and accuracy of the proposed method are demonstrated by a numerical example.
Numerical Simulation Analysis of Tailings Dam Heightening Expansion Stability
Authors: Bing He
Published: October 2014

Xinchang tailings dam is used as an object and the software named Slide is utilized to operate numerical simulation, and then the three conditions (normal operating mode, flood conditions, the special conditions) of tailings dam are analyzed to determine the stability. The conclusions are as follows: tailings dam have been built to 80m height, both to meet regulatory requirements, so the dam is stable; but if continue to increase the height to 85m, tailings dam stability coefficient reduced to special conditions 1.032, less than the standard value 1.05, does not meet the national regulatory requirements, the maximum limit of a height of about 80m.
Acoustic Cloaking with Realizable Mass
Authors: Zhao Ai Guo , Chen Hong , Zhao Zhi Gao , Qian Jia Chang , Wang Lei
Published: October 2014

A nonideal acoustic cloak with realizable physical properties is proposed. The density and modulus of the designed acoustic cloak are in a reasonable range of material parameters. Full-wave simulations are performed to demonstrate the properties of the proposed cloak. Results on far-field sound pressure level show that the nonideal acoustic cloak decreases the scattering field intensity and the target strength (TS) of the scatterer. The nonideal acoustic cloak also has significant effect on suppressing internal radioactive noise. A comparison is made with the reduced cloak proposed by Chen.
Robust Design of Using MWCNTs in Minimum Quantity Lubrication
Authors: Huang Wei Tai , Wu Der Ho , Lin Shih Pin , Chen Jian Ting
Published: October 2014

This objective of this article is to present a new technique of nanofluids/MQL in high speed milling by using MWCNTs. In the past, studies have shown the MQL process can improve tool life and surface accuracy in high speed cutting. The purpose of using carbon nanotubes is to increase the thermal conductivity of cutting fluid and to reduce the temperature during the cutting and decrease the thermal wear of tool. The proposed study is to investigate the characterization of the MWCNTs/ nanofluids combined with MQL during the high speed milling of AISI 1050 and AISI P21 experimentally. The Taguchi robust design was also used to optimize the parameters of nozzle with respect to tool feed direction, such as spraying distance, angle of ejection, and relative locations for improving the MWCNTs/MQL cutting effect. Experimental results showed the MWCNTs/ nanofluid had the benefits of improving surface roughness and reducing wear of tool in high speed milling. The results were compared to dry cutting, and wet cutting in detail.
Coupling Vibration Research of a Turbine Blade-Disc System with Symmetric-Acyclic Structure
Authors: Zhang Yi , Zhou Pu , Zhang Qiang , Xie Yong Hui
Published: October 2014

The blade-disc in a turbine is characterized by symmetric-acyclic opening structure on the disc body. Four different numerical models with 3-D finite element method were established in the present investigation. The wave propagation technique was employed and the modal analysis of the blade disc was performed. The modal and vibration characteristics of different models in the same rotational speeds were compared in consideration of non-linear coupling/ interactions between blade and disc. The results indicate that in the modal analysis of symmetric-acyclic blade-disc system, the openings structure has low impact on the low-order mode frequency. Thus, cyclic symmetric model without the opening structure can help to get general frequency forecast to improve the analysis efficiency.
Comparative Studies of Multiferroic BiFeO3 Powders Prepared by Hydrothermal Method versus Sol-Gel Process
Authors: Zhang Xiao Yan , Qi Xi Wei , Yang Zhi Yuan , Zhong Rui Xia
Published: October 2014

Multiferroic BiFeO3 powders were synthesized by two methods: sol-gel process and hydrothermal method. The synthesized powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and particle size distribution analysis. The results obtained by XRD, which is consistent with 86-1518 JCPDS card, show that powders prepared by hydrothermal method are composed of the single phase with the trigonal structure (perovskite-type). It can be found by particle size distribution analysis that the particle size of the samples prepared by sol-gel process is finer and more uniform than that of the samples synthesized by the hydrothermal method. The SEM images of samples depicts that the synthesized BiFeO3 powders are united and the average grain size of hydrothermal processed samples is significantly large as compared to the sol-gel derived sample.
Study on Volumetric Tool Wear Measurement Using Image Processing
Authors: Liu Jian Cheng , Xiong Guang Xi
Published: October 2014

This paper presents a method of measuring the volumetric tool wear by use of the image processing technique. A single CCD camera based stereo vision system is built to acquire the image pair. The crater wear’s boundary of the cutting tool is then detected, and then the 3D volumetric shape of the worn region on the rake face is reconstructed through the developed image matching algorithms, and the crater’s volume and depth is estimated. A Matlab software system is developed to perform image acquisition, calibration, image rectification, image adjustment, stereo matching, crater’s depth estimation, and the representation of the volumetric tool wear. The feasibility of the proposed method is verified through experiments.
High Permittivity and Varistor Properties of SnO2-Zn2SnO4 Composite Ceramics
Authors: Liu Huan Huan , Li Li Ben , Zang Guo Zhong , Cao Jing Xiao , Li Yong
Published: October 2014

(1-x)SnO2-xZn2SnO4composite ceramics were prepared by traditional ceramic processing and the varistor, dielectric properties were investigated. With increasing Zn2SnO4content, the breakdown electrical fieldEBand nonlinear coefficientαreaches the minimum of 6.9 V/mm and 2.5 at x=0.206, respectively. In the dielectric spectra, the relative dielectric constantεrexhibits strong frequency dependent character and at 40 Hz,εrfor the sample of x=0.206 reaches a maximum as high as 3×104. In the frequency region lower than 1 kHz, accompanied by the sharp increase of dielectric loss at 40 Hz,εris depressed and a dielectric peak is presented in the spectra with increasing bias voltage. In the low electrical current range of 1.37-20 μA, The barrier heightφBabout 1.0 eV are obtained and it is found thatφBdecreases with increasing measuring current for each sample. Based on the results, the varistor behavior with high dielectric constant is explained by the Schottky barriers at grain boundaries.
The Study on Broad Directivity Characteristic of Piston Transducer with Finite Baffle
Authors: Qin Lei , Gu Chuan Xin , Wang Li Kun , Zhong Chao , Liu Jing Jing , Zhang Bin , Long Dan
Published: October 2014

Transducer with large directivity and high transmitting sensitivity is designed and fabricated. It is a sandwich transducer with composite horn and it has a finite baffle. A novel model considering the dimension of baffle is deduced, the directivity of transducers are calculated under different conditions. The computations of models agree with the experimental data well. The maximum transmitting voltage response level of the sandwich transducer is 143dB (1V/μPa) and the directivity is up to 99°(-3dB) at the resonance frequency of 75.6kHz.
Uncertainty Analysis for Static Balance Measurement of Hollow Be Rotor
Authors: Cheng Xiang Wen , Shi Nan
Published: October 2014

The hollow Be rotor is grinded by the four-shaft-ball lapping machine, it has been repeated grinded to reach the accuracy requirement. The eccentric distance of rotor is measured by gas floating method. Actual measurements found that repeated measurement of the balancing cycle change a little during the rough finish and semi finishing stage while it changes a lot in the finish machining stage. This paper established the rotor balance equation of gas floating that is solved by Matlab software, and draw the curve of motion of the rotor changing along with time, analyze the motion curve to draw a conclusion that the starting conditions of finish machining stage have large influence on balancing cycle.
An Effective Independence-Improved Modal Strain Energy Method for Optimal Sensor Placement of Bridge Structures
Authors: Zhan Jie Zi , Yu Ling
Published: October 2014

In this study, an effective independence-improved modal strain energy (EI-IMSE) method is proposed for the optimal sensor placement (OSP) problem in the field of the structural health monitoring and moving force identification. The improved modal strain energy (IMSE) is used to modify optimal sensor placement results obtained by the effective independence (EI) method. The EI-IMSE OSP method is verified by some numerical simulations on a 2D planar truss bridge model. Based on the criteria of modal assurance criterion (MAC), trace of fisher matrix, matrix condition number, and the least mean square error, the EI-IMSE OSP method is assessed through comparing with those of EI, EI-driving point residue (EI-DPR), EI-average driving DOF velocity (EI-ADDOFV), and EI-average acceleration amplitude (EI-AAA). The illustrated results show that the proposed EI-IMSE OSP method is feasible with a higher accuracy.
Autonomous Underwater Vehicle Motion Planning via Sampling Based Model Predictive Control
Authors: Wang Lin Lin , Wang Hong Jian , Pan Li Xin
Published: October 2014

In order to improve the ability of independent planning for AUV (Autonomous Underwater Vehicle), a new method of motion planning based on SBMPC (Sampling Based Model Predictive Control) is proposed, which is combined with model predictive control theory. Input sampling is directly made in control variable space, and sampling data is substituted into the predictive model of AUV motion. Then surge velocity and yaw angular rate in next sampling time are obtained through calculations. If predictive states are evaluated according to the performance index previously defined, optimal prediction of AUV states in next sampling can be used to realize motion planning optimization. Effects of three sampling methods (viz. uniform sampling, Halton sampling and CVT sampling) on motion planning performance are also compared in simulations. Statistical analysis demonstrates that CVT sampling points has the most uniform coverage in two-dimensional plane when amount of sampling points is the same for three methods. Simulation results show that it is effective and feasible to plan a route for AUV by using CVT sampling and rolling optimization of MPC (Model Predictive Control).
Development of a Piezoelectric Micropump with Novel Separable Design
Authors: Luo Wen Fu , Ma Hsiao Kang
Published: October 2014

In this study, partially disposable piezoelectric micropumps with separable design have been developed and discussed. The actuator, a rectangular piezo-plate, can be separated and be used repeatedly while the pump chamber is single-use to prevent infection. Thus, a low cost and waste solution for biomedical uses is achieved. Central bossed design of diaphragm was used to achieve self-return in supply mode. More, pump chambers with different depths and diameters have been made. The maximum flow rate, 15.03 ml/min, is reached under 60V actuated voltage.
Study of Wind Farm Power Output Predicting Model Based on Nonlinear Time Series
Authors: Teng Yun , An Zhi Yao , Yu Xin , Wang Zhen Hao , Zhang Yong Gang
Published: October 2014

To solve the problem of the variancy of the wind power when wind farm connect with the power grid, a wind power predicting model of wind farm based on double ANNs is proposed in the paper. Wind velocity and wind direction on wind farm are the key of wind power predicting, and other circumstance conditions such as temperature, humidity, atmospheric pressure, are also great influence on it. The observed values of these five circumstance conditions can be treated as a nonlinear time series and be analyzed by the nonlinear time series ANNs model. The wind power predicting model consists of double artificial neural networks. The first is consisted of five artificial neural networks which is used to prediction the circumstance conditions time series, the second is employed to prediction the power of wind farm use predicting value of the five conditions. A series of simulation show that the results of the predicting model is acceptable in engineering application.
Preparation of the Carbon Fiber/Cu Alloy Matrix Self-Lubricating Composite Materials
Authors: Chen Sui Yuan , Li Xin Rong , Bi Yu Ning , Wellburn Daniel , Liang Jing , Liu Chang Sheng
Published: October 2014

Using 663-tin bronze, Ni, W, nanoAl2O3, MoS2, graphite, CaF2, and Ni coated graphite as the matrix alloy powder, in which copper-coated carbon fiber of 5%, 7%, 9%, 11% and 13% in volume fraction were added as the reinforcing phase, a novel type carbon fiber/copper-matrix self-lubricating composite materials was prepared by means of powder metallurgy. The results indicate that the mechanical properties of the composite materials are improved after adding copper-coated carbon fibers. The composite materials reach optimal overall mechanical performance under testing when the volume fraction of the added copper-coated carbon fibers is 11%.: with a hardness of 57.8 HV and a compressive strength of 222 MPa. The addition of carbon fiber also improved the friction and wear properties of the composite materials. Increasing the volume fraction of fiber, was found to increase the wear resistance and improve self-lubricating performance. A volume fraction of 11% gave a friction coefficient of 0.09 and abrasion loss of 4mg.
Study on Transverse Shear Behavior of CFRP Sandwich Structure with M-Pattern Folded Core
Authors: Cong Li Xin , Sun Yu Guo
Published: October 2014

In order to solve the problem of the face/core bonding performance of the sandwich structure, this paper proposed a M - pattern folded sandwich structure. Structural performance in direct (pure) shear was investigated for sandwich structure. FE-Analytical of sandwich structure strength under shear loading condition was presented for possible failure modes. Panels with core of different thickness were tested for different failure modes and the mechanical properties. In general, the measured failure loads showed good agreement with the FE-analytical predictions.The results shown that failure modes of the sandwich structure with low relative density were shear buckling and fracture of thin-walled of cores, respectively. For the sandwich structure with high relative density, the dominant failure mode was interfacial debonding of face/cores, and the initiating failure along the ends of the specimens.
The Outdoor Aging Properties of Polypropylene/Mica Composite
Authors: Wu Yu Jiao , Yang Chun Ping
Published: October 2014

In this paper, In this paper, polypropylene / mica composites were prepared by blending, using polypropylene (PP) as matrix, mica as filler. In order to study the anti-aging properties of polypropylene / mica composite materials, the above polypropylene / mica composite materials were placed outside to study the influence of natural aging time on the anti-aging properties and to explore the natural aging mechanism of polypropylene / mica composites. Natural aging research results show that:with the extension of the natural aging time the surface of materials will appear cracks and sheddings. The trends of tensile strength reduce at first, then increase and then decrease; the notched impact toughness values show fluctuating in the early aging, then an increase following and then decreasing.The increase of mica content are good for maintaining the mechanical properties of PP / mica composite, PP-g-MAH helps to maintain the tensile strength, while toughening POE-g-MAH will weaken the anti-aging properties of polypropylene / mica composite materials.
Effect of Heat Treatment Process on the Preparation of Foamed Glass Ceramic from Red Mud and Fly Ash
Authors: Guo Yu Xi , Zhang Yi He , Huang Hong Wei , Hu Pan
Published: October 2014

Lightweight glass ceramic foams have been prepared from a mixture of solid wastes, namely 40 wt-% red mud and 60 wt-% fly ash. In this work, we illustrate the effects of variables in heat treatment process, including the sintering temperature and the holding time, on the quality of the foams. The reduction of sintering temperature as well as the holding time, was found to limit the coalescence and improve the apparent density and the compressive strength.
Polymerization of Maleic Anhydride Induced by Non-Equilibrium Atmospheric Pressure Argon Plasma
Authors: Yan Jun , Hosoi Katsuhiko , Kuroda Shin-ichi
Published: October 2014

The non-equilibrium atmospheric pressure Ar plasma was applied for the polymerization of maleic anhydride (MA). The deposited films were analyzed by using Fourier transform infrared spectroscopy (FT-IR) proving the monomer was successfully polymerized with retaining the functional groups. The intensity of optical emission spectroscopy (OES) of the plasma jet was found to become weaker when the monomer was introduced into the jet. This was interpreted as the result of the energy transfer from the metastable Ar to the monomer. It was proposed that the excited MA changed into π-π* transition state to produce dimer biradicals which initiate the polymerization.
Research on Efficient Polymer Dissolving Technology for Hydrophobically Associating Polymer Flooding on Offshore Platform
Authors: Zhu Yue Jun , Zhang Jian , Zhao Wen Sen , Wang Shan Shan , Jing Bo , Meng Fan Xue , Zhang Hong
Published: October 2014

In order to apply the technique of polymer flooding to the offshore oilfield, some contraventions (the large well spacing, the high salinity formation water, the narrow production platform space, the limited load capacity, the slow dissolution of hydrophobically associating polymer, the voluminous existing polymer injection equipment) must be faced. In order to resolve the problems, a study on the efficient polymer dissolving technology for hydrophobically associating polymer flooding on offshore platform was conducted. The principle of polymer rapid dissolution was analyzed on its restrictive factors. By comprehensive utilization of multi-disciplinary angle of studying from polymer materials, fluid mechanics, et al, the efficient polymer dissolving technology was formed by means of compulsory stretching and water logging for polymer molecular chains, and break through the "bottlenecks" of polymer rapid dissolution. The designed dispersing & dissolving equipment cut down the polymer dissolution time from 60 min to 40 min. Meanwhile, the auto-unloading device, metering device, curing system, injection system, and automatic control system were optimized. Compared with the original equipment, the novel one’s occupied area and operating weight decreased by 21% and 37%, respectively. The efficient injection allocation technology was applied to the polymer flooding pilot testing in Bohai bay so as to provide key technology and equipment support for cumulative incremental oil 395×104 m3 (up to June, 2014), incremental output value 12 billion yuan (estimated by the barrel oil price $90).
Technical Research for Oil Well Variable Frequency Electromagnetic Field Paraffin Prevention
Authors: He Ya Wei
Published: October 2014

Oil well paraffin is one problem that often occurs in oil production; it will seriously affect or even suspend production. There are many kinds of paraffin prevention technologies, but limited to particular conditions or other factors, there are still shortcomings and insufficiency of all these technologies. In order to make this process environmental, efficient and energy saving, we propose the technique of variable frequency electromagnetic field paraffin. According to the principle of Maxwell's electromagnetic theory, the reciprocal transformation of electromagnetic field and magnetic field intensity are determined by diameter of coil, current intensity, as well as the turn number of coils. The optimal parameter for paraffin prevention is defined by the selection of the current intensity and frequency of the conversion electromagnetic field in the laboratory so as to achieve optimum efficiency of paraffin prevention. Judging from the practice in three wells in site, this technology can extend flushing period, increase oil production, reduce power consumption and improve efficiency of oil well production, so the application of this technology has a very broad and bright prospect.
Hot Deformation Behavior and Microstructure Evolution of Extruded 6069 Al Alloy under Tension
Authors: Wu Horng Yu , Lin Ming Chieh , Zhu Feng Jun , Wu Cheng Tao , Liao Ching Hao , Chiu Chui Hung
Published: October 2014

The flow behavior and associated microstructural changes of wrought 6069 Al alloy deformed in tension were analyzed in this work. Tensile tests were conducted on an extruded tube with a thickness of 1.6 mm in the temperature range of 300–500 oC, with initial strain rates from 0.001 to 0.1 s-1. The true stress–true strain curves exhibited a peak stress at a critical strain. The overall level of the flow curve increased when the strain rate was increased and/or the temperature was decreased. The flow curves exhibited a typical flow behavior with dynamic softening and showed that the softening degree after reaching the peak stress was dependent on the deformation conditions. This could be related to the softening mechanism. The main softening mechanism of the alloy was dynamic recovery (DRV) at low temperatures; dynamic recrystallization (DRX) occurred as deformed at high temperatures.
Cutting Tool Run out Considered Cutting Force Estimation in Micro Milling Processes
Authors: Liu Jian Cheng , Su Yu Long , Dong Zhi Guo , Ya Gang
Published: October 2014

This paper presents a method of estimating cutting forces of the tool by taking the tool’s run out into account during micro milling processes. The thickness of uncut chip is modelled based on the trochoidal trajectory synthesized from the rotational motion, the feed motion, and the run out of rotational micro tools. The strain gradient plasticity theory is then used in conjunction with the Johnson–Cook constitutive equation to calculate flow stresses, where the influence of the plough shear on the rake face and the elastic recovery on the flank face is considered. The calculated cutting forces using the proposed method for micro milling processes show a satisfactory agreement with existing experimental results.
Surrogate Modeling and Optimizing for CCP Etch Process
Authors: Duan Wen Rui , Tian Ling
Published: October 2014

In order to analyze performance of the Capacitively Coupled Plasma (CCP) etcher, commercial software like OPTIMUS can be applied to approximate etch process model by Response Surface Method (RSM) or Radial Basis Functions (RBF). Multi-factor parameters are concerned in etch process, like frequencies of the dual Radio Frequency system (RF) and flow rate and flow ratio of the process gas. When facing the multi-dimensional problem, the algorithms would turned to be inefficiency and the optimization process may be trapped in local minimum area or cannot converge because of oscillation. To improve surrogate modeling for the CCP etcher, a self-optimizing RBF (SO-RBF) algorithm is proposed and a process modeling tool is developed. Experiments on a state-of-art dual station CCP etcher shows that based on the global approximation model generated by this algorithm, process parameter optimization can be easily implemented with less error than OPTIMUS.
A Study on Solving the Seepage Flow Model of Three-Area Composite Reservoir
Authors: Dong Xiao Xu , Li Shun Chu , Gui Dong Dong , Zhang Feng Jiu
Published: October 2014

This paper studies the seepage flow mathematical model of three-area composite reservoir under three kinds of outer boundary conditions (infinite boundary, constant pressure boundary and closed boundary), in which influences of well-bore storage and skin factor are not taken into consideration. On the basic of theory of similar structure of solution of boundary value problem of differential equation, this paper obtain the solution of the seepage flow model of three-area composite reservoir. The study is not only conducive to further analyze the inherent law of the solution and solve corresponding application problems, but also easy to compile corresponding analysis software.
Sliding Mode Control for Spacecraft Large Angel Attitude Control with Fuel Sloshing
Authors: Song Xiao Juan , Yue Bao Zeng
Published: October 2014

This paper presents the analysis of the spacecraft with fuel sloshing during attitude maneuver. The fuzzy sliding mode controller is designed for a simplified model of the spacecraft. The controller includes an equivalent control term, a sliding controller, and an optimal controller by adaptive fuzzy algorithm for perturbation parameters. Extensively numerical simulations are carried to verify effect of the control method in this paper and the numerical results show the good performance and better effectiveness for the fuel-filled spacecraft large attitude maneuver.
The Establishment of Ninety Degree Gas Elbow Pipes Internal Pressure Distribution Model
Authors: Lu Xiao Yang , Zhou Yong , Chen Shi Ying , Li Xin Guang , Zhu Hong Liang
Published: October 2014

According to the principle of harmonious dimensions, the qualitative distribution model of the internal pressure on elbow pipes were determined; Through FLUENT numerical simulation, the internal pressure were given under 96 kinds of gas fluid conditions; By analyzing the variation of the internal pressure with flow and geometrical parameters, the variation of the internal pressure distribution within the elbow pipes has been studied; By means of 1stOpt nonlinear fitting package, the formula of three-dimensional internal pressure distribution was determined; Compared with the numerical results, the maximum relative error is 0.012%. The formula provides theoretical bases for strength check, the transport pipeline and wall thickness design of the high pressure, high velocity elbow.
Typical Solid State and Wet Chemistry Methods to Prepare Nano-Sized Nickel Ferrite Particles
Authors: Qu Hui , Liu Shi Quan
Published: October 2014

Different ways to prepare nanosized nickel ferrite particles have been developed. Typical solid state reaction routes including high temperature sintering, mechanical alloying, self-propagating high temperature synthesis and wet chemistry methods including co-precipitation, sol-gel, hydrothermal synthesis are briefly reviewed and compared by focusing on the particle size control.
Modified Wavelet-Based Multilevel Discrete-Continual Finite Element Method for Local Structural Analysis - Part 1: Continual and Discrete-Continual Formulations of the Problems
Authors: Akimov Pavel A. , Mozgaleva Marina L. , Aslami Mojtaba , Negrozov Oleg A.
Published: October 2014

The distinctive paper is devoted to wavelet-based discrete-continual finite element method (WDCFEM) of structural analysis. Two-dimensional and three-dimensional problems of analysis of structures with piecewise constant physical and geometrical parameters along so-called “basic” direction are under consideration. High-accuracy solution of the corresponding problems at all points of the model is not required normally, it is necessary to find only the most accurate solution in some pre-known local domains. Wavelet analysis is a powerful and effective tool for corresponding researches. Initial continual and discrete-continual formulations of multipoint boundary problems of two-dimensional and three-dimensional structural analysis are presented.
Numerical Simulation for Flow over Two Circular Cylinders in Micro Channel with Lattice Boltzmann Method
Authors: Gong Zhi Jun , Yang Jiao , Wu Wen Fei
Published: October 2014

For indepth study on flow characteristics for fluid bypass obstacles in micro-channel, the Lattice Boltzmann Method (LBM) was used to simulate fluid flow over two circular cylinders in side-by-side arrangement of a micro-channel. The velocity distribution and recirculation zone length under different Reynolds numbers (Re = 0~100) and different spacing ratio (H/D= 0~2.0) were obtained. The results show that the pattern of flow and the size of recirculation zone in the micro-channel depend on the combined effect of Re and H/D.
The Segment Loading Static Finite Element Analysis on the Mobile Refuge Chamber
Authors: Zhang An Ning , Gu Yu Ming
Published: October 2014

This paper studied the difference between the segment loading static analysis method and the uniform loading static analysis method on the mobile refuge chamber. The structure strength static analysis of the mobile refuge chamber was made in the uniform and segment loading ways by the finite element software SolidWorks Simulation. The stress cloud charts and the displacement cloud charts were obtained. The comparison result indicates that the results of the segment loads method are less than those of the uniform loading method and is closer to those of the dynamic analysis method. Therefore the segment loading static analysis method is better than the uniform loading one.
A Dynamic Simulation Design of a Ladder Fire Truck Based on ADAMS
Authors: Cui Qun Feng
Published: October 2014

This paper completed the virtual prototype design for a ladder fire truck in ADAMS.After add the joints and motion functions,a dynamic simulation and analysis to the virtual prototype had been carried out.It approved the ladder fire truck could achieve the intended motion with comparatively steady space.The simulation provided a theoretical basis for the further design,which is a reference for the next imporving design.
Redesign of a Reverse Shoulder Prosthesis: Kinematic and Mechanical Study
Authors: Tumino Davide , Ingrassia Tommaso , Nigrelli Vincenzo , Trinca Giovan Battista
Published: October 2014

In this work a commercial reverse shoulder prosthesis has been redesigned to improve performances in terms of range of movements of the implant and stability to dislocation. A kinematic and mechanic study has been performed using a realistic solid model of the prothesised shoulder: in particular, all the components of the prosthesis have been acquired via a 3D laser scanner and inserted in a virtual humerus-glenoid system by reproducing the common surgical procedure. The final model has been used to measure the maximum angles of abduction and rotation of the arm and the shear forces that cause dislocation. Modifications proposed to the commercial prosthesis are: a different orientation of the cutting plane of the glenoid component and the interposition of a spacer to move the center of rotation of the arm.
The Performance Analysis and Parallel Optimization of the OpenFOAM-Based Viscoelastic Solver for Heterogeneous HPC Platforms
Authors: Zou Shun , Lin Yu Fei , Chen Juan , Wang Qian , Cao Yu
Published: October 2014

The scalability and the efficiency of the OpenFOAM-based parallel viscoelastic solver are greatly restricted by MPI operations. In this work, we proposed a comprehensive strategy of the computation and communication overlap and the hybrid parallelization with MPI and OpenMP to optimize the parallel viscoelastic solver on HPC platforms. Critical simulations based upon 3D contraction benchmark flow show that the efficiency of the parallel viscoelastic solver could be considerably improved, and an extra speedup of 2.20 could be obtained with 8 threads upon 2 MPI processes.
Study on the Ground Settlement Regularity Caused by Deep Caving Method
Authors: Wei Shu Xiang , Wang Yun Yong , Jin Chang Yu , Dong Long Bin , Liu Dong
Published: October 2014

With the increase of mining depth, rock mechanics conditions become complicates. So the surface subsidence law caused by deep mining is different from the shallow. Based on the finite difference method and rock mechanics theory, the surface subsidence law cased by deep caving mining was studied, the strata movement rule and characteristics of stress distribution of different excavation stage was analyzed systematically. The results of the study can provide certain reference significance for the deep mining to confirm the displacement angle and range of surface subsidence.
Design Analysis of Dock Apron Skidway Blocks
Authors: Liu Quan Gang , Jiang Li Qun , Li Ling Zhu , Song Guang Xing
Published: October 2014

As for jacket dragging load-out foundations, the concrete skidway blocks were prone to be sheared and wrecked, especially the outer blocks, for they generally swung with the tugboat. This paper takes dragging load-out of LS36-1 jacket on 3# skidway for example, and proposes a design analysis for dock apron skidway blocks. The design philosophy is replacing original concrete blocks with steel blocks, and the new steel blocks not only have good shear strength and compressive strength, but they are also easier to connect and fix with skidway. In addition, some essential strengthen measures are adopted, reformed 3# skidway blocks are ready for much heavier modules and jackets dragging load-out works.
Design of Sealing Structure and Analysis of the Flow Field in Micro Internal Combustion Swing Engine
Authors: Sun Meng , Zhang Zhen Yu , Kong Wen Jun
Published: October 2014

A multistage groove sealing structure in Micro Internal Combustion Swing Engine (MICSE) was designed. By machining several grooves on the center-swing, it provides non-contacting control of internal leakage. The sealing principle of this structure may be described as follows. Gas at high pressure enters through the clearance of adjacent grooves to accelerate, then expands isentropically in the grooves. Once crossing several such grooves, gas emerges at the other end of the sealing structure at significantly reduced pressure. Numerical simulations were utilized to analyze the influences of pressure ratio and groove depth on leakage characteristics. The results demonstrate that at pressure ratio smaller than 2.0, turbulence eddy dissipation process in grooves cannot dissipate kinetic energy obtained during the throttling process completely, which results in poor sealing effect, at pressure ratio lager than 2.5, the two processes reach dynamic balance and sealing effect no longer changes. There is an optimal value in groove depth, undersize or oversize may lead to imperfect throttling effect or turbulence eddy dissipation process.
Micro-Scale Manufacture of 3D Printing
Authors: Chen Yi Ping , Yang Ming Der
Published: October 2014

3D printing as additive manufacturing enables to give concept proposers and designers a great possibility of producing physical parts and concept models at acceptable cost during a short time. Such technology is quite distinct from traditional machining techniques adopting subtractive process. The purpose of this study is to briefly describe new micro-scale manufacture utilizing a series of process of 3D printing, including 3D modeling, 3D model slicing, printing, and products. Especially, 3D modeling is one of major components in 3D printing process and becomes a barrier to entry the business of micro-scale manufacture for everyone with a 3-D printer. This paper introduces two low-cost approaches to generate 3D models, including active and passive approaches. 3D scanning as an active approach allows the replication of real objects without the need of moulding techniques. On the other hand, image-based modeling as a passive is an alternative of un-touch model reconstruction without a threat of destructive impact to the modeled object. Also, a statue in gypsum was made by a 3D printer based on a digital 3D model generated through the low-cost active approach for demonstration.
Research on Hardness for Low-Alloy Steel after Fire Damage
Authors: Chen Wang , Jin Chen , Wang Yin Pei
Published: October 2014

In chemical processing plants and petroleum refineries, the pressure vessels and pipelines suffered often from fire accidents and thus resulted in the metal materials were in overheating state. Elevated temperature could cause the changes in metallographic structure and have unfavorable effects on material mechanical properties. In order to understand better the influence laws of overheating on metallographic structures and material mechanical properties, the methods of theoretical analysis and experimental research were used and the effects of thermal exposure temperature, duration time and cooling rate on microstructure and mechanical properties of low-alloy steel 12MnNiVR, were studied systematically. In the paper, mechanical testing (hardness test) are carried out to understand changes in the mechanical properties that would be observed in the metal exposed to elevated temperatures during a fire accident. The study can provide basis data for the material properties database of metal material suffered from fire accident, and afford technical supports in the key technologies on fire damage FFS (Fitness-For-Service) integrity assessment.
Design and Manufacture of Composite CNG Cylinders
Authors: Gao Long Shi
Published: October 2014

The design of filament-wound composite Compressed Natural Gas (CNG) cylinders was reviewed, including the liner and filament-wound reinforcement part. The domestic and abroad standards are discussed here. It is of great significance to improving composite CNG cylinders safely. The focus of future research is summarized finally.
A Reflective Display Technology Based on Electrofluidics
Authors: Duan Ming Zheng , Hayes Robert A. , Zhang Xiao , Zhou Guo Fu
Published: October 2014

In this paper we describe the design, driving and electro-optical behavior of an electrofluidic, or electrowetting, display panel. Electrofluidic displays involve the movement of a colored oil water interface as a result of polarizing the interface between water and a hydrophobic surface under the influence of external electric field. The proposed direct-segment drive approach successfully drives the display panel based on electrofluidic. The electro-optical behavior of electrofluidic display samples are measured and analyzed. The tonand toffof the pixel is 16 ms and 8 ms, respectively, which demonstrates that electrofluidic display panels have the capability to show video content.
A Distribution Network Reconfiguration Method Considering Weather Conditions
Authors: Wu Ying Jun , Yao Ying Bei , Cao Bei
Published: October 2014

A distribution network reconfiguration method with the considerations of time-varying weather conditions is proposed. The aim of distribution network reconfiguration is to minimize the outage risk. The effects of weather condition in evaluating the outage risk are considered. Finally, simulations on the 33-node test system validate the proposed method.
Controller Parameters Optimization of PWM Converter Based DFIG
Authors: Zhu He , Xu Da Tian , Zhao Hao Ran
Published: October 2014

Based on the mathematical model of the PWM converter, control strategy of the grid-side converter directed by the grid voltage and control strategy of the rotor-side converter directed by the stator flux were established combining the vector control theory. The method using the nonlinear simplex algorithm to optimize the PI control parameters of the DFIG unit was first proposed, optimization results proved that this method had good practicality and robustness.
Experimental Investigation of Using Solar Chimney to Induce Natural Ventilation
Authors: Hao Cai Xia , Zhang Hai Ping , Hao Min Xia
Published: October 2014

The vertical panels of solar chimney have internal dimensions of 2000mm height、1000mm length. Under the condition of heat flux and chimney gap variety, we research chimney interior velocity field. Experimental Results show that airflow increased with chimney gap augmentation, the airflow and air velocity augment with the increase of solar radiant intensity, and air velocity decreases with the increase of solar chimney gap. Air velocity is higher near the heated surfaces than it in the middle chimney. Meanwhile velocity boundary layers form near the heated surface.
Experimental Analysis and Engineering Design of Laser Removing Technology for Extra Matters on Overhead Lines
Authors: Chen Guang , Liu Yang , Ma Yong , Chen Jie , Zhou Zhi Cheng , Li Hong Ze
Published: October 2014

This paper proposes a convenient and safe method for removing extra matters on overhead lines by distantly irradiating the extra matters with high-energy laser beam. Theoretical study and field experiments on the feasibility of this method were carried out according to the thermal properties of the main components of overhead lines and common extra matters on them. Results show that infrared laser is a better choice to be used to remove the extra matters than ultraviolet and visible laser lights. Experimental results also indicate that there is a large feasible scope of laser power density in which common extra matters can be efficiently removed while the conductors and grounding lines get no harm. Moreover, preliminary design of the laser removing system is given in this paper for practical application.
Electric Load Forecasting of Electric Vehicles in Charging
Authors: Liu Wei , Wei Tao , Zhao Ming Xin , Xu Dan , Gao Chao
Published: October 2014

This paper forecast the electric load of the mass electric cars connected to the electric grid in charging and discharging; considered the inventory forecast of electric vehicles; comprehensive analyzed the charge and discharge characteristics of the electric cars’ charging infrastructures and the impact factors such as users’ behaviors as well as the using frequency, which lead to different load distribution at different times. It calculated the total load of electric vehicles into the load curve and the load curve of the characteristics under different regions (industrial, commercial and residential). Concludes that the mass electric cars connected to the electricity grid will increase the peak load of power grid, and lay the foundation for the subsequent market management and optimization control.
Energy Harvesting Shock Absorbers for Vehicles: Design, Modeling and Simulation
Authors: Chen Wei Wu , Zhang Zu Tao
Published: October 2014

Energy harvesting shock absorber is used for harvesting the kinetic energy in the vehicle suspension vibration. In this paper, we present design, modeling, and simulation of a novel energy harvesting shock absorber based on rack and pinion mechanism. The shock absorber consists of three main components: the mechanical vibration input, the transmission module, and the micro-generator module. The shock absorber is installed between the vehicle frame and chassis to obtain a relative linear motion acting as mechanical vibration input. The function of transmission mechanism module is to convert the relative linear motion to a unidirectional rotation for the input shaft of micro-generator. The micro-generator will produce electricity due to the input shaft rotating in one direction. This shock absorber was tested in simulation condition, and the last performance evaluation demonstrates the validity of the proposed energy harvesting shock absorber.
Research on the Optimum Continuous Mileages under the Pure Electric Mode of Plug-In Hybrid Electric Vehicles
Authors: Bu De Ming , Zhu Cheng
Published: October 2014

Plug-in hybrid vehicles (PHEVs) combine the motor and traditional internal combustion engine with their full advantages, they have great advantages in practical application, are an important direction to develop the energy saving and emission reduction vehicles. The PHEVs’ capacity of battery pack determines the continuous mileages under the pure electric mode, the larger the capacity of battery pack is, the higher the PHEVs’ cost is. But the continuous mileages under the pure electric mode are longer, the fuel cost of consumers is lower. For ordinary consumers, economy and utility are two important factors to purchase PHEVs. Considering different consumers, city forms and people use habits, the PHEVs’ optimum continuous mileages under the pure electric mode for suitable promotion were presented, to make they have the optimum consumer ownership cost, have the important practical significance to promote the development of PHEVs in different area.
The Optimization Model of Planning Electric Vehicle Charging Station
Authors: Zhao Shu Qiang , Li Zhi Wie
Published: October 2014

Aiming at the problem of electric vehicle charging station planning, the clients of fast charging stations is analyzed. The optimal mathematical model about siting of electric vehicle charging stations is proposed based on the city's geographic information. We obtain the optimal location of charging stations by charging convenient factor as a constraint. And divide the load area which is served by each charging station by the Voronoi. According to the load which is served by each charging station, this paper designs the optimal battery charger number of each charging station with the Queuing Theory. Finally, optimize the charging convenient factor using the total cost as objective function. The analysis of examples verifies the effectiveness and the practicability of the proposed planning approach.
Advanced Progress in Diagnosing the Reliability of Electrical Equipments by Infrared Thermography
Authors: Wang Feng , Shi Jing , Jun Liu , Zhang Rui , Tian Hao
Published: October 2014

Infrared thermography was obtained more attention and accepted as an effective method in electrical preventive maintenance in account of high precision and sensitivity image features. This review elaborates the application of infrared thermography for diagnosing electrical equipment, both of the thermal anomalies and methods of measurement. Developments of the inspection techniques are remarkable for purpose of investigate the reliability of electrical equipments due to the effect of the environmental factors and equipment condition. Due to the complex analysis, various automatic diagnostic systems are proposed for faster and more accurate detection. Recent technologies of typical engineering solutions are introduced to raise the level of infrared thermography inspection.
Research on Reliability Evaluation Methods of Distribution System
Authors: Ou Yu Qiang , Cheng Le Feng , Wen Jian Zhong , Qiu Xuan Yu , Yu Tao
Published: October 2014

Research on reliability of distribution network has very important meaning and function to ensure the quality of power supply. This paper introduces some basic concepts of reliability in distribution network, including distribution network reliability definition, task and index. The classical reliability evaluation method was reviewed, and focused on specific distribution network, an example analysis was given, and specific reliability evaluation indexes were calculated. Finally, the future development of distribution network reliability evaluation was made a simple prospect.
Optimization of Parameters of Heat Exchangers of Air Heating Systems
Authors: Melekhin Andrei , Melekhin Aleksandr
Published: October 2014

This article is devoted to the complex research method based on mathematical modeling and visualization of thermal fields, which allowed one to obtain the optimal parameters of heat transfer elements of the spacecraft systems of air heating of buildings.