bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Discrete Multi-Freedom Modeling Method of Simple Supported Beam Based on MATLAB
Authors: Xu Han Bin , Zhao Wu Guang , Wu Fei , Wang Li Wei , Gao Rui
Published: October 2013

Vibration exists widely in people's life and production. Modal analysis for vibration system help to improve the running quality of the mechanical structure and prolong service life. This paper build a new discrete multi-freedom model to calculate the flexibility matrix of simple supported beam, and then use the flexibility matrix to calculate its modal parameters with matlab. In order to prove that the result is correct, this paper use classical continuous vibration theory to calculate the normal modal parameters, finding that the two results are basically the same and as the more discrete number, the result of discrete multi-freedom model more close to the result of continuous vibration theory. In view of this, the new discrete multi-freedom modeling method is proved to be true, and it also can provide the discrete modeling reference for modal analysis of complicated mechanisms.
Prediction of Forming Load for the Helical Gear Precision Forging by BP Neural Network
Authors: Feng Wei , Cao Ji Chang , Wu Shu Ting , Li Yang Fan
Published: October 2013

Precision forging of the helical gear is a complex metal forming process under coupled effects with multi-factors. The high forming load is required to fill the teeth corner, which significantly causes failure, plastic deformation and wear of dies. The maximum forming load during precision forging helical gear is calculated by the finite element method (FEM). Combining the FEM simulation results with the artificial neural networks (ANN), backward propagation (BP) neural network is trained using the data of FEM simulation as learning sample. The trained BP neural network is validated using test samples and used to predict the maximum forming load under the different deformation conditions. The results show that the predicted results agree well with the simulated ones, the differences of prediction results exhibit low value, the predicted precision satisfy the request of industry.
Innovative Design of a New Water-Saving Greenbelt Cleaning Device
Authors: Lu Qing Yi , Chen Li Qun , Kang Xiang
Published: October 2013

With respect to serious water waste and backward cleaning devices relevant to the cleaning of road greenbelts, this paper describes an independently-designed water-saving greenbelt cleaning device with performance of energy saving and emission reduction. After the device is developed, relevant cleaning experiments are conducted on the gardening vehicles. The results show that the new water-saving greenbelt cleaning device can improve the efficiency of water utilization significantly.
Fault Diagnosis of Rolling Bearing Based on Improved Independent Component Analysis and Cepstrum Theory
Authors: Zhu Pei Xin , Jin Guo Yong , Yan Yu Quan , Gao Si Yang
Published: October 2013

Based on the advantages of independent component analysis (ICA) and cepstrum, this paper adopts a novel feature extraction scheme for rolling bearing fault diagnosis utilizing improved independent component analysis and cepstrum analysis. Firstly, the fast fixed-point algorithm (FastICA) based on negative entropy was used here as the ICA approach to separate the mixed observation signals of rolling bearing vibration. Then, the largest spectral kurtosis value was used to confirm the characteristic separated signal associated with the Rolling bearing faults. Finally, cepstrum analysis was employed to deal with the selected signal to extract the original fault feature. The experimental results show that sensitive fault feature can be extracted prominently after the presented processing, and the proposed diagnostic method is effective for the fault diagnosis of rolling bearing. In addition, the proposed method provides an effective technical means for weak fault diagnosis.
Crankshaft Composite Lathe’s Tool Tip Trajectory Error Analysis and Simulation
Authors: Wang San Wu , Wu Jiang , Fan Yao Deng , Ma Shou , Gong Xi Bin
Published: October 2013

The crankshaft composite follow crankshaft turning lathes use the following tool system to complete the turning of crankshaft, when crankshaft machining is working, the turret mechanisms processing error and assembly errors will affect the crankshafts processing quality, So it is difficult to control the actual machining accuracy, or it may cause the waste of material. Therefore, in this paper, by analyzing the impact of the rod length errors on the trajectory of the tool tip, the tool tip trajectorys equations can be built. Using MATLAB tools, we can build the tip point trajectory modeling and solve the deviation between the actual tip point and the ideal trajectory, and finally can get the result of rod lengths error on the accuracy of the actual processing, which will provide basis for the design and analysis in future.
Optimal Control of Turbine Thermal Fatigue Life
Authors: Zheng Li Kun , Zhou Yan , Xie Dan Mei
Published: October 2013

As for turbine rotor, the simple stress on-line monitoring models of rotors temperature and thermal stress based on Greens function method are obtained. Using perturbation method, the models can deal with nonlinear problems resulting from temperature dependent properties. The working medium temperature change curve and the temperature rising rate curve during the period of startup or shutdown at shortest time for unit can be obtained to reduce fatigue wastage by analyzing the startup or shutdown process of a unit plant with the Pontryagin Maximum Principle of optimal control theory. The temperature rising rate curve thus obtained can be used not only as a guide for operation, but also as a programmable control signal for the startup and shutdown process of generating units, which will improve the economy of a power plant.
Research on the Structural Performance of Large-Tonnage Gantry Crane
Authors: Dong Jie , Cheng Wen Ming , Ren Yang Zhi , Wang Yu Pu
Published: October 2013

Because of the huge lifting weight and complex structure of large-tonnage gantry crane and in order to effectively design and review it, this paper aims to carry out a research on its structural performance based on the method of theoretical calculation and finite element analysis. During the early period of design, the method of theoretical calculations is adopted, and after specific design it comes the finite element analysis, so as to get the results of analysis under a variety of operating conditions, which illustrates that the structural design and review of large-tonnage gantry crane based on theoretical calculations and finite element are feasible, and also verifies that the method of finite element is an effective way to find a real dangerous cross-section, thus providing the basis for the design and manufacture of the crane structure.
Study on Control Strategy of Nonlinear Systems with Hysteresis Inverse Model Feed-Forward Compensation Based on Preisach
Authors: Zong Xiao Ping , Zhang Na , Wang Pei Guang
Published: October 2013

In order to reduce the effect of hysteresis of piezoelectric ceramic pressure on the system, designed the feedforward compensation adaptive sliding mode control based on Preisach inverse model. The inverse model feed-forward compensation does not depend on the precision of the Preisach model which weakens the hysteresis characteristics, and also can obtain the compensation voltage that combined with adaptive sliding mode controller. This paper proves that the controller can make the system to achieve global asymptotic stability. Simulation in Matlab. The simulation results show that the system can track the desired output, and can get good control effect.
Multiresolution Representation of a Geometric Model for Free-Form Surfaces Turning Based on Mesh Simplification
Authors: Zou Qing , Lu Jian Feng , Gao Yu Jiang , Wang Tao , Yao Jian Ning , Jia Dong Ming
Published: October 2013

In this paper, a new multi-resolution representation (MRR) of a series of intermediate shape models for FTS diamond turning based on mesh simplification is proposed. In this MRR, geometric relations between each resolution model can be controlled so as to avoid overcut and to level the cutting loads. The new control method for MRR is based on an improved Edge Collapse Algorithm with consideration of the curvature factor. In addition, the calculation method of machining allowance and tool path generation method are proposed to support the machining process. The effectiveness of the MRR has been verified through simulation.
System Identification of Unmanned Planning Boat Rolling Motion Mode
Authors: Yang Wang Lin , Xu Hai Tong , Yang Song Lin , Zhang Sheng
Published: October 2013

In this paper, the author took an unmanned planning boat as the object of study and carried out a series of rolling decay ship model test by changing the draft. The author established nine kinds of mathematical model of rolling decay motion model system identification by using different damping and righting moment and established the optimization calculation of the objective function based on the principle of system identification. Then the author adapted the genetic algorithm of system identification program which is based on the Visual Basic 6.0 and got 15 kinds of identification programs. By doing research on the first three cycles of the series of rolling angular velocity curve and identifying respectively the resulting 15 kinds of identification programs, the author confirmed the feasibility of the adapted program. Comparing different drafts and the initial roll angle identification results, the author found a reasonable hydrostatic roll motion equation of the unmanned planning boat in the case of different drafts and the initial roll angle, and made a preliminary analysis.
A New Feed Brace System in Single Reflector Compact Antenna Test Rang
Authors: Luo Hong Yu , Tan Long Qing , Li Dong Sheng
Published: October 2013

To solve problems of the traditional feed brace in single reflector compact antenna test rang, such as difficulty in position adjustment and the feed polarization manual switching, mechanical structure and position adjustment mechanism of feed brace system are designed, based on principle of feed positioning. The new feed brace system weight is lightened with same intensity. Function of precision rotation around axis of feed horn is realized. Control system software is developed. Two control modes, onsite and remote, are provided. Laser tracker is used to locate feed phase center in high-precision when feed brace system is installed on site. The new feed brace system has been applied in some single reflector compact antenna test range and its precision meets the requirements.
The Design of Ship Dynamic Positioning Controller Based on Piecewise Control Method
Authors: Li Hong Sheng , Miao Qing , Zhou Rui Min
Published: October 2013

In this paper, by establishing a mathematical model of ship dynamic positioning system, and considering the force and torque of environment disturbance such as wind, wave and flow, a piecewise controller was designed after the study of ship steering motion on three degrees of freedom, in order to improve control accuracy. The model of fuzzy controller and piecewise controller were respectively simulated using MATLAB in x axis direction. The results of simulation show that the piecewise control method improves the dynamic and static performance of the system, and the system acquires a better control performance.
The Intelligent Control System Design of High-Rise Residential Building Lighting Based on PLC
Authors: Li Du
Published: October 2013

The high-rise residential building lighting intelligent control system is designed in this essay. There are two kinds of high-rise residential lighting which are normal life lighting and emergent lighting. The design for normal life lighting by using of PLC enable lighting be more energy saving and convenient. The power supply control and open control design for emergent lighting enable lighting be more liability and ensure the work and evacuate process be more safe.
Accuracy Analysis of Sensor Array Direction-Finding Crossing for the Sound Location of Burst Point
Authors: Zong Jun Jun , Cui Xun Xue , Yang Hui , Yu Kai Ping , Wu Yan , Lv Cao Fang , Hou Zhi Bin
Published: October 2013

With development of the short time interval measurement technology, array direction-finding technique for burst point localization has been applied to the actual. In this paper we conduct in the following order: the basic positioning principle will be elaborated at first. Then the precision estimation formula of the positioning will be deduced. Finally we perform the simulation experiment. The simulation results show that, if you want to improve the burst positioning accuracy, you need to decrease the measurement error of single station, and choose reasonable arrangement mode and the appropriate baseline length as far as possible.
Fuzzy Neural Network Controller Based on Hybrid GA-BP Algorithm
Authors: Chen Yin Ping , Wu Hong Xia
Published: October 2013

This paper presents a hybrid GA-BP algorithm for fuzzy neural network controller (FNNC). BP algorithm is a method to monitor learning, easily realized and with good local searching ability. But it depends too much on the the initial states of the network. Genetic algorithm is a random search algorithm which has strong global searching ability. The hybrid GA-BP algorithm ensure the global convergence of learning by genetic algorithm, overcomes the BP algorithms dependency on the initial states on the one hand. On the other hand, combined with the BP algorithm overcome the simple genetic algorithms randomness, improve the searching efficiency. The simulations on the inverted pendulun problem show good performance and robustness of the proposed fuzzy neural network controller based on hybrid GA-BP algorithm.
The Design of Low Power Consumption Walkie-Talkie
Authors: Wei Wan Hua , Fang Hao
Published: October 2013

Communication is very common today, this document introduces a design of high frequency walkie-talkie for communication, and the design of the circuit is low power consumption. The circuit has transmitting circuit, receiving circuit, control circuit and so on, mainly includes mixer, filter, amplifier, frequency modulation (FM), demodulation, microcontroller unit (MCU), liquid crystal display (LCD), keymatrix and so on. This system not only can realise voice communication, but also can transmit short messages. Through the choice of ICs in the circuit, that makes the system to be a low power consumption system. So this system can be used in various conditions.
Design of Detection and Control of Oil Mist Lubricating System
Authors: Yuan Zhi Xian , Xue Yan Lin
Published: October 2013

In order to well lubricate the industrial machine and decrease the consumption of lubricating oil, it is necessary to develop a system to monitor and control the density of oil mist. This paper introduces such a system based on LPC2214 of ARM7. The system can monitor 10 parameters, give an alarm to the status of factors which affect the quality of the oil mist and store the relative information into high capacity SD card through I2C bus and SPI bus. All the status information can be shown on LCD so that the operator can realize the system in real-time. System supplies input interface which can set some parameters and display other information on LCD, including history status information of system.Keywords: LPC2214, Oil mist, SD card, LCD
The Analysis of Mechanical-Hydraulic Governor of Diesel Based on the Multi-Body Dynamics with Rigid-Flexible Integration
Authors: Zhang Wei Dong , Wang Hong Dong , Liu Zhen Ming , Ouyang Guang Yao
Published: October 2013

The multi-body dynamics model with rigid-flexible integration of the mechanicalhydraulic governor of diesel was set up based on the theory of computational dynamics of multi-body system. The initial conditions and boundary conditions were analyzed and added correctly to the components of the model. Then the working process of the mechanicalhydraulic governor was simulated, and the dynamic characteristics were analyzed. The results show that the model and the solving process are correct and credible. These pave the way for the further study about structure and capability optimum of the speed governing system. The whole analysis process provides a simple and feasible approach which can be used in other mechanical and hydraulic system.
LQG Control of Across-Wind Response of a Tall Building
Authors: Kim Young Moon , You Ki Pyo , You Jang Youl
Published: October 2013

Modern tall buildings using high strength and lighter construction materials are more flexible so could be excessive wind-induced vibrations resulting in occupant discomfort and structural unsafety . Recently, many studies have been advanced in using actuator force as an active control force based on the linear quadratic optimum control theory. It needs to predict the wind-induced response and the optimum control force to reduce the excessive wind-induced vibration. It takes a lot of time and cost to do wind tunnel test needed it, so numerical simulation approach instead of that is recommended sometimes. Simulating wind load in the time domain using known spectra data of fluctuating wind load is particularly useful for some prediction of windinduced vibration which is more or less narrow banded process such as across-wind response of a tall building. The simulation procedure is taken from Deodatis. In this study, fluctuating across-wind load acting on a tall building was simulated numerically in the time domain using the across-wind load spectra proposed by A.Kareem in1982. And using this simulated across-wind load estimated the reduced across-wind vibration response of a tall building using the linear quadratic Gaussian (LQG) control method.
Globally Optimal Weighted Fusion White Noise Deconvolution Estimator
Authors: Sun Xiao Jun
Published: October 2013

White noise deconvolution or input white noise estimation has a wide range of applications including oil seismic exploration, communication, signal processing, and state estimation. A globally optimal weighted fusion white noise deconvolution estimator is presented for the multisensor linear discrete systems using the Kalman filtering method. It is derived from the centralized fusion white noise deconvolution estimator so that it is identical to the centralized fuser, i.e. it has the global optimality. Compared with the existing globally suboptimal distributed fusion white noise estimators, the proposed white noise fuser is given based on the local Kalman predictors, and the computation of complex covariance matrices is avoided. A simulation for the Bernoulli-Gaussian input white noise shows the effectiveness of the proposed results.
Wavelet Algorithm in Rotating Machinery Fault Feature Extraction
Authors: Luo Dong Song , Fan Zheng
Published: October 2013

A method of Rotating Machinery fault feature extraction based on wavelet transform and Hilbert demodulation is been studied. On the basis of rotating machinery fault mechanism and spectral characteristics, wavelet transform is used to be decompose the vibration acceleration signals of bearing faults into different frequency bands, Which is then used to achieve accurate fault information by Hilbert demodulation. The result shows the method can effectively improve the frequency resolution and realize accurate extraction of fault feature, and it has certain practical value for industrial production of rotating machinery faults diagnosis when applied to the production industry.
Key words: Rotating Machinery; bearings; Wavelet algorithm; Hilbert demodulation
Study on Continuous Measurement of Material Level Based on Dusty Environment such as Ash Storage
Authors: Wu Hong Xia , Chen Yin Ping
Published: October 2013

The ash storage is indispensable equipment in the coal-fired power plant, it used to store coal ash. The accurate measurement of coal ash level in the storage can ensure the boiler ash discharge smoothly. But the ash level measurement problems with dust, low dielectric constant, negative / positive pressure and long measuring distance (up to 70 m) etc., resulting in material level measurement becomes a major difficulty in level measurement technology. This paper puts forward a kind of mechanical measurement methodHeavy hammer-level meter detection based on investigation and research around the Hubei power plant. Practice has proved that this measurement method has the advantage of high measuring accuracy, little maintenance, great economic value and it can reduce the maintenance cost of power plant. At the same time this paper also provides some basis for the other studies on continuous measurement of material level.
Design of the Monitoring and Control System for Ozone Production Based on ZigBee Technology
Authors: Zhang Hai Chuan , Wang Huan , Li Yue
Published: October 2013

The monitoring and control system for ozone production based on ZigBee wireless communication technology is designed in this paper. With the JN5139 module of Jennic company that includes the microcontroller and ZigBee wireless transceiver as the core, the field node of the monitoring and control system is set up to measure and control the production parameters. The master control terminal is designed to measure the input power of ozone production and to perform the functions, such as data processing, alarming and human-computer interaction etc., based on the PC104. The wireless monitoring and control can be implemented for important parameters of ozone production. The ZigBee wireless network makes the system more compact, flexible and practical.
AC-DC Isolation of EIS Impedance Test System for Li-Ion Battery Packs
Authors: Xie Chang Jun , Liu Jiang Bo , Zhao Heng Bing
Published: October 2013

Impedance test is very critical for estimating the SOC and SOH of Li-ion battery. In this paper, a novel AC-DC isolation method applied in the impedance test is proposed based on Electrochemical Impedance Spectroscopy (EIS) with the technique of dynamic frequency scanning. Specifically, we analyze the presented AC-DC isolation methods and design an isolation module with the inverting superposition of Root Mean Square (RMS), which is compared with passive filtering and active filtering via the simulation and experimental test. The results show that the proposed isolation module can meet the performance requirement determined by the EIS test system, without the bandwidth limit, the phase shift and the DC bias.
Study on Accuracy of Wind-Power Caused Flicker Estimation
Authors: Wang Miao , Yin Zhong Dong
Published: October 2013

Intermittent and volatility of wind energy makes wind power generation output power characterized by its instability make adverse impact on grid power quality , will give a rise to serious problems of voltage fluctuation and flicker. It is very important to calculate the flicker emission when analysis the power quality. However, flicker level is hard to predict and the way given by IEC61400-21 has been verified to be lack of accuracy. This paper analyzes a constant speed wind turbines caused grid voltage fluctuation and flicker on the mechanism. Illustrates the two way to measure flickers caused by voltage fluctuation. Improves the on-site calculation of flicker by considering the impact of tower shadow and wind shear. Finally, verified the feasibility of the improved methodology by comparing the results of the three calculation.
Reverse Engineering and the Application of Reverse Engineering in Mould Design and Manufacture
Authors: Chen Zhuo , Zhao Chong , Zhang Hong , Chen Yang Yang , Tang Ping
Published: October 2013

Reverse engineering, as the advanced absorption technique, playing a vital role in shortening the design time of products and providing technological guarantee for modeling design of products, is the latest hotspot in the present technological field. The application principle of this technology is to turn the primary physical modeling into design modeling through the transformative platform. It serves as both the technological foundation in intensifying the engineering quality and the information for accurate analysis of modeling design data and processing of modeling profile. Coupled with modernized design concept and improved creativity , reverse engineering capitalize fully on CAE/CAM/CAD technology to integrate the current resources for information supply of manufacturing accurate modeling. The practice of reverse engineering could be conducive to bring the preference of measuring equipment into full play so as to improve the data processing ratio in CAD/CAM system and advance the level of industrial design for the purpose of manufacturing automation.
Research of Reentry Corridor and Guidance Technology for Hypersonic Vehicle
Authors: Wang Xin Min , Zhang Peng , Yao Cong Chao
Published: October 2013

During the time that a hypersonic vehicle experiences the reentry segment, the environment changes dramatically. This paper analyzes all kinds of constraint conditions of the reentry process, then designs the reentry corridor in both the D-V plane and the H-V plane, and analyzes the influence of various factors on the reentry corridor according to that. Based on the constraint conditions, the reentry segment is divided into the initial descent phase, angle of attack recovery phase, overload hold phase and angle of attack transition phase. Meanwhile the rationality of the design is verified by simulation.
Research on Hydrogen Absorption Mechanism Modeling of the NdFeB Hydrogen Decrepitation Process
Authors: Li Qi , Shang Wen Bin , Zhu Lin , Zhao Jian Min
Published: October 2013

The behavior of hydrogen absorption in the NdFeB Hydrogen Decrepitation process is affected by the shape of the NdFeB alloy, pressure and temperature curves of the reaction process, which makes the reaction process with characteristics of nonlinear, time-varying parameters and coupling. In this study, we proposed a state space modeling method to describe the dynamic mechanism model of the hydrogen decrepitation process, and determine the main parameters of the model according to the mass balance, energy balance and kinetic equations. Then implemented the simulation model of the hydrogen absorption dynamic mechanism model using the matlab language. The simulation results were compared with the measured data, which verified the correctness of the model.
Analysis of Rehabilitation Data by Multi-Dimensional Principal Component Analysis Method Using the Statistical Software R
Authors: Ishida Akio , Aibara Ukyo , Murakami Jun , Yamamoto Naoki , Saito Satoko , Izumi Takeshi , Kano Nozomi
Published: October 2013

The multi-dimensional principal component analysis (MPCA), which is an extension of the well-known principal component analysis (PCA), is proposed to reduce the dimension and to extract the feature of the multi-dimensional data. We have analyzed the rehabilitation data, which is known as the Functional Independence Measure (FIM), routinely measured from inpatients of a hospital by using MPCA. This time, we implemented the MPCA program by the statistical software R, and carried out the analysis of that data with changed configuration from the previous works in the environment of the R statistical system. From the results, the usefulness and the effectiveness of MPCA analysis in the R environment are confirmed.
A Dynamic Film Thickness Control System Based on Automatic Wind Ring
Authors: Cai Li , Tan Yue Gang
Published: October 2013

Film thickness is one of the important parameters in the plastic film production process.A dynamic film thickness control system ,gradually adjusting the opening degree of the wind ring, is utilized for real-time control film thickness, enabling the film thickness to meet the requirements.This paper proposes a dynamic film thickness control system based on automatic wind ring ,consisting of industrial control computer, capacitance detection module, wing ring device , motor drives and so on.Then it further states the method of controlling the opening degree of wind ring by a series of stepper motors. The method can make the film thickness uniformity better,combining the traditional film production line with an idea of controlling automatic wind ring .
Analysis on the Application of Pro/E in Die Designing and Die Making
Authors: Chen Yang Yang , Zhang Hong , Chen Zhuo , Tang Ping
Published: October 2013

Recently, the market share of die making in our country is increasing day by day, which can be attributed to the development of processing and manufacturing industry as well as the deepening of reform and opening-up. At current, die making has been applied in these practices such as manufacturing of electronic connector and producing of workpieces of dashboard. With the arrival of computer age, the die making technology based on Pro/E is becoming increasingly common. With specific cases, this text carry out discussions on the die making which is based on Pro/E.
Analysis of Human-Machine Design of Hand-Grasp Apparatus
Authors: Zhang Jiu Mei
Published: October 2013

Hand-held tools for the main object of study, start with the classification of the analysis of hand tools, specifically talking about the hand-held tools, human-machine design factors, including the two major aspects:1.Starting from the perspective of the"human" and point out that the hand structure of the human body, including muscle and bone structure is hand tools most closely the human-machine design factors. 2.From the "Tools" point of view, pointed out that product-related factors include the size and shape is the most important human-machine design factors of hand-held tool. Finally, hand tools must be designed to transfer to the center of the design and products of common concern, human-centered design will bring new design ideas and methods to hand-held tool designed. So ergonomics in the design of handheld products have broad application prospects.
Synthesis and Electrochemical Properties of Cu-Doped LiMnPO4/C Nanorods as Cathode Materials of Lithium-Ion Batteries
Authors: Yuan Lin Feng , Ge Lan Lan , Shen Yu Hua , Zhang Hui , Wang Cui Ping , Xie An Jian
Published: October 2013

LiCuxMn1-xPO4/C nanorods are successfully prepared by a simple solvothermal process followed by calcination of the precursor LiCuxMn1-xPO4 and sucrose. The effects of dopant and carbon coating on the physical and chemical characteristics of LiMnPO4 are investigated. The results show that Cu successfully entered into the lattice of LiMnPO4, and induced a decrease in the lattice parameters. A thin layer of carbon coating with an average thickness of 20 nm is formed on the surface of LiCuxMn1-xPO4 particle. We also observe that the LiCuxMn1-xPO4/C nanorods have higher electronic conductivity (5.5139×10-4S cm-1) and initial discharge capacity (87.5 mAh g-1 at 0.5C) compared with pristine LiMnPO4. Based on the results above, the developed nanocomposites could have potential applications in lithium-ion batteries.
Sol-Gel Synthesized Copper-Substituted Cobalt Ferrite Nanoparticles for Biomedical Applications
Authors: Sanpo Noppakun , Wang James , Berndt Christopher C.
Published: October 2013

Copper-substituted cobalt ferrite nanoparticles were prepared via a sol-gel route using citric acid as a chelating agent. The influence of copper concentration on the microstructure, crystal structure and antibacterial property of copper-substituted cobalt ferrite nanoparticles against E. coli and S. aureus has been systematically investigated. The results indicate that the substitution of copper influences strongly the microstructure, crystal structure, particle diameter and antibacterial property of cobalt ferrite nanoparticles.
Creating a Monocrystalline Membrane via Etching and Sealing of Nanoholes Considering its Sealing Behavior
Authors: Ebschke S. , Poloczek R.R. , Kallis Klaus T. , Fiedler H.L.
Published: October 2013

Based on silicon on insulator (SOI) technology [, a monocrystalline membrane is fabricated, in which a buried silicon dioxide layer in the silicon material is the sacrifice layer for the cavity. The membrane is a monocrystalline silicon top layer which contains nanoholes for creating the cavity in the buried oxide (BOX). To encapsulate the cavity the holes are sealed by using different techniques like non-stressed plasma-enhanced chemical vapour deposited (PECVD)-nitride and-oxide, thermal oxidation and evaporation of aluminum. To determine the sticking behavior of the membrane different sizes of membranes are fabricated and compared due to their sticking behavior.
The experimental result shows that a membrane, having the size of 25 μm × 25 μm or below, has a perfect non-sticking behavior and can be used for further fabrication (cf. Fig. 8). For comparison, Figure 9 shows a membrane which delivers sticking behavior.
The knowledge of this work can be widely used for several applications that need a cavity with a monocrystalline membrane like an absolute pressure sensor with a fully integrated CMOS-circuit on top of it [. This delivers a large variety of possibilities for novelty MEMS devices in different fields of research.
Structural and Morphological Changes in Ag:TiN Nanocomposite Films Promoted by In-Vacuum Annealing
Authors: Machado D. , Pedrosa P. , Fonseca C. , Martin N. , Vaz F.
Published: October 2013

Thin films composed of titanium nitride doped with silver were deposited by DC reactive sputtering, with Ag contents varying between 0 and 50 at.%. The as-deposited samples were subjected to vacuum annealing treatments, with a range of temperatures varying from 200 to 500 °C, in order to study the morphological and structural changes that may occur. The as-deposited samples showed three main zones of basic characteristics, which differ both in terms of morphology and structural features. By increasing the annealing temperature, the thermodynamic stability is accelerated, giving rise to (i) a uniform dispersion of silver particles at 200 °C; (ii) the start of segregation at 300 °C; (iii) at 400 °C the coalescence of the segregated Ag particles takes place and finally (iv) at 500 °C the formation of large Ag clusters is evident, particularly within the zone that comprises the samples with higher Ag content. In addition to corroborate the presence of free Ag in Ag:TiN thin films, the increasing annealing temperature promotes the improvement of the coatings crystallinity, as well as Ag grain growth.
Electrochemical Anodizing, Structural and Mechanical Characterization of Nanoporous Alumina Templates
Authors: Samantilleke A.P. , Carneiro J.O. , Azevedo S. , Thuy T. , Teixeira V.
Published: October 2013

Highly ordered Anodic Aluminum Oxide (AAO) structures produced from aluminum by using an electrochemical anodizing method were developed towards its application for the next generation of micro/nanomedical and energy devices. In addition of analyzing the anodizing current profile, the surface morphology was characterized by using Scanning Electron Microscopy (SEM), the crystalline structure by X-Ray Diffraction (XRD) and the mechanical properties by nanoindentation experiments. The anodizing time and applied potential determines the nanopores regularity and their size, although the effect of the potential is more pronounced than the effect of temperature in the transformation from crystalline alumina to amorphous alumina. Optimum pore growth was achieved with an applied potential of 17 V which led to a pore fraction - P(f) - of about 17.5%. The experimental Berkovich nanoindentation method was used to determine the AAO hardness as a function of the indenter depth, during the loading stage, using mechanical response and deformation behaviour of the nanopores structure. From the experimental data of the load-displacement curves, this method allows the calculation of the indenter contact depth at each reloading point, thus leading to the estimation of the materials hardness. The results reveal that the hardness depends on the processing conditions used for the production of the AAO samples that also strongly influences the organization and pore size uniformity.
Simulation of High Speed Milling of SiCp/Al Metal Matrix Composites Based on Deform
Authors: Jiao Ke Ru , Huang Shu Tao , Xu Li Fu , Zhou Li
Published: October 2013

By 3D finite element simulation for temperature field and tool wear of SiCp/Al metal matrix composites under the condition of high speed milling, we draw a conclusion that the most significant influence on cutting temperature is cutting speed, less is feed rates, the minimum is cutting depth, which is exactly the same as the influence law of ordinary metal cutting. In the course of high-speed milling SiCp/Al by PCD tools, the higher the cutting speed is, the bigger wearing depth of tools is. When v=300m/min, ap=0.5 mm, f=0.3 mm/r, the transient temperature in the milling would reach to 619°C. Such a high temperature can cause graphitizing wear of the PCD tools. Because of the effectiveness of the simulation’s conclusion, it is vital significance to the reasonable options of cutting parameters and the prolongation of tool life.
Three-Dimensional Finite Element Simulation Analysis of Cutting Force of SiCp/Al Composite Thin-Walled Parts
Authors: Liu Yu Nan , Huang Shu Tao , Zhou Li , Xu Li Fu
Published: October 2013

In milling process, cutting force is the main cause of machining deformation, and in machining of thin-walled parts, machining deformation is the major factor for machining error. In this paper, through finite element analysis software ABAQUS, three-dimensional simulation analysis on the machining of SiCp/Al composite thin-walled parts with a polycrystalline diamond tool have been carried out. It reveals the influence of radial depth of cut, cutting speed, and feed per tooth on cutting force. Analysis results show that: higher speed, small radial depth of cut and moderate feed per tooth can effectively reduce cutting force and inhibit deformation. In addition, a comparison is made between analysis results of milling force and high accuracy milling force prediction model, results from the two methods are similar.
A Fractal Analysis of Cutting Force in Simulation and Experiment
Authors: Zheng Guang Ming , Zhao Jun , Song Xin Yu , Cheng Xiang
Published: October 2013

A 3D finite element model (FEM) of metal cutting was constructed based on the thermal-mechanical coupling theory. The cutting process of Sialon ceramic tools turning Inconel 718 was simulated and experimented. The effect of cutting speed, feed rate and depth of cut on the cutting force was analyzed. According to the correlation characteristics between the data points, the fractal characteristics of cutting forces in the cutting process were also investigated. The results showed that the cutting speed had a great effect on the fractal dimension of cutting force. The simulation results were in good agreement with the experimental findings. It was concluded that the minimum fractal dimension of cutting force was obtained at v=230 m/min under these experiment conditions. The fractal analysis is a simple and powerful tool for quantifying the stability of cutting process. The finding of this research is valuable for future practical implementation.
Characteristic Study of Milling Force in Cut-In Process of Hard Milling Die Steel
Authors: Ma Jing , Liu Xian Li , Yue Cai Xu , Liu Fei , Wang Guang Yue
Published: October 2013

This article takes common material Cr12MoV for automobile panel die as research object, aiming at difficulties when tool cutting in workpiece which are caused by high material hardness in maching, based on simulation software DEFORM-3D, a high precision simulation model of cut-in process in hard milling die steel is established, and the accuracy of the model is verified by tests, the milling force cut-in process in hard milling die steel is studied, the influence law of different cutting parameters and cut-in angles on milling force in milling cutter cutting in workpiece is analyzed, and the optimized cut-in angles are obtained, this study provides a reference for further optimization of cut-in conditions, reducing tool early damage and improving processing efficiency.
Effect of Drills with Different Drill Bits on Delamination in Drilling Composite Materials
Authors: Wei Ying Ying , Xu Jin Yang , Cai Xiao Jiang , An Qing Long , Chen Ming
Published: October 2013

Drilling is frequently used in machining of carbon fiber reinforced materials. Twist drill is mostly used in drilling composite materials and some other drills with special drill bits are also needed. Drilling induced delamination is considered one of the most serious problems during machining while drilling force plays a decisive role in delamination. This paper presents the analysis of critical thrust force with special drill bit theoretically. The method of simulation to study the critical thrust force is also introduced. In addition, effect of cutting parameters on delamination by comparing experimental results and mathematical model of twist drill is studied.
An Experimental Study on the Cutting Tool Performance during Milling of Carbon Fiber Reinforced Polymer
Authors: Han Shu , Gong You Hong , Yang Ni Hong , Han Sheng Chao
Published: October 2013

Carbon Fiber Reinforced Plastic (CFRP) is widely used in aerospace field as an advanced composite material. Recently, more and more studies are focused on milling of CFRP with its increasing applications. In this paper, three different milling tools were chosen, and a systematic analysis on cutting force, surface quality and tool wear has been carried out to evaluate the tools. Experimental results indicate that the multi-flute tool with diamond coating has a better performance than the double spiral compression tool and the multi-tooth tool with AlTiN coating, with a lower cutting force, a better surface quality and a higher tool life than others, which would be a better tool for cutting of CFRP.
The Research of Effect of Cutting Parameters on Machined Surface Defects in High-Speed Milling of SiCp/Al Composites
Authors: Dong Guo Jun , Zhang Yuan Jing , Zhou Ming , Wang Yang Jun
Published: October 2013

The silicon carbide reinforced aluminum matrix composites (SiCp/Al) are widely used for its high specific stiffness and high specific strength. However, the poor surface quality and machined surface defects limit its further application. The aim of this paper is to investigate the effect of cutting parameters on the machined surface defects in high-speed milling of SiCp/Al composites. The tests were performed on a high precision computerized numerical control (CNC) precision milling machine using a polycrystalline diamond (PCD) tool, and the machined surfaces were measured by the scanning electron microscope (SEM).It was found that cutting parameters have a great influence on the depth of big pits. A high feed rate and a low cutting speed correspond with a big cutting force, and result in a large depth of big pits.
Study on Grinding Crack of Premium Thread Gauge Material 9Mn2V
Authors: Chen Ming , Dong Da Peng , Guo Guo Qiang , An Qing Long
Published: October 2013

This paper investigates the surface integrity of premium thread gauge material 9Mn2V in reciprocating surface grinding using SG abrasive, which includes metallographic structure for grinding crack, specific grinding energy and surface residual stress. The specific grinding energy and the surface residual stress can be reduced after the workpiece gets tempered, so small grinding depth can lead to the generation of cracks when the workpiece is not tempered. Otherwise, the depth of heat affected zone increases with the increase of grinding depth, but not increases proportionally. After 9Mn2V is tempered, the occurrence of grinding burn and grinding cracks can be improved.
Experimental Analysis on Delamination Damage by Acoustic Emission in High Speed Drilling of Carbon Fiber Reinforced Plastics
Authors: Cai Xiao Jiang , Qin Sheng , An Qing Long , Zhang Hong Zhou , Han Shu , Chen Ming
Published: October 2013

Carbon fiber reinforced plastics (CFRP) has increasing applications in aerospace and other fields, due to low density, high strength, high stiffness, great resistance to corrosion, etc. Although, delamination damages in drilling holes for assembly influence the final characteristics of CFRP components. This paper presents an experimental investigation to analyze delamination damage, in which acoustic emission and thrust force are monitored during drilling CFRP laminates to clarify the relationship between AE signals and delamination damages. The results show that delamination damage has close correlation with thrust force and acoustic emission energy. AE root mean square (rms) is recommended to be selected as AE signal parameter. Abrupt peak feature of AE rms can be used as a dependable trigger for delamination monitoring. The number of abrupt pulses of AE rms can be counted online to predict the degree of delamination damages, based on which delaminations can be monitored and controlled online.
Research on Stress Intensity Factor of the Interface Crack in the Hard Cladding Material Structure under Mechanical Impact Load
Authors: Yang Jun Ru , Zhu Ran , Chen Gong Ling , Zhang Yue Kan
Published: October 2013

In the paper, the crack parallel to and lying on the interface in the hard cladding material structure is regarded as the research object, theoretical model of the stress intensity factor (SIF) of the interface crack under the mechanical impact load is built. Based on it, the SIF of the crack parallel to and lying on the interface in the cermet cladding material structure under the mechanical impact load is investigated by using finite element analysis method. The influences of the cladding thickness ratio and mechanical impact stress amplitude on the interface SIF are investigated. The research results show that, at a certain moment, the interface SIFs decrease with increasing cladding thickness ratio when the mechanical impact stress amplitude is a constant and increase as the mechanical impact stress amplitude increases when the cladding thickness ratio is a constant.
Study on the Mechanical Properties of DLC Thin Films Doped with Cu
Authors: Ren Ni , Zhao Dong Cai , Ma Zhan Ji , Xiao Geng Jie , Wu Sheng Hu
Published: October 2013

Samples of DLC thin films with different Cu concentration were prepared by using a Cu target and different number of graphite target，or adding a grid before the Cu target. The results show that the hardness and stress decreases with an increase of Cu concentration (below 6.3 at.%). When Cu concentration increases from 6.3 at.% to 17.8 at.%, the hardness and stress keep almost constant, and the friction coefficient increases gradually and slowly, as well as the wear loss.
Study on the Machining Parameters in Polishing Single-Crystal SiC Wafers with SG Films
Authors: Du Zhi , Lu Jing , Fang Cong Fu , Huang Hui , Xu Xi Peng
Published: October 2013

In this paper, diamond abrasive SG films were prepared by means of sol-gel technology for polishing single-crystal SiC wafers. The effects of machining parameters on processing quality including pressure, rotating speed and polishing time were investigated, respectively. The results indicated that the surface roughness decreased with increasing polishing time. While for pressure and rotating speed, there were inflections existing. Polishing SiC wafer under optimized machining parameters, an ultra smooth surface with the roughness of 3.7 nm could be achieved using 40 μm diamond grits.
Indentation and Scratching Experimental Research on Brittle-Ductile Transition of Optical Glass SF6
Authors: Jia Peng
Published: October 2013

In diamond cutting of optical glasses, the magnitude of critical depth of cut for brittle-ductile transition is an important factor affecting the machinability of the work material in terms of production rate and surface quality. In this work, scratching tests with increasing depths of cut were conducted on glass BK7 to evaluate the influence of the cutting fluid properties on the critical depth of cut. Boric acid solutions of different concentrations were selected as cutting fluids in the tests. The resulting scratches were examined utilizing a white light interferometer and the values of the critical depth of cut were determined based on the observations of the micro-morphology of the scratch surfaces produced. Experimental results indicated that compared with the process without cutting fluid action, the critical depth of cut in diamond cutting of glass BK7 can be increased by using boric acid solution as the cutting fluid.