bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Dynamic Stiffness of Machine Tool with Consideration of Friction Damping in Guide
Authors: Shinagawa Miki , Shamoto Eiji
Published: April 2012

The purpose of this study is to acquire design method of machine tools with higher dynamic stiffness and consequently higher chatter stability. This study focuses on stiffness of main structures and friction damping in guide of a machine tool, because stiffness and friction damping are considered to have major influence on the dynamic stiffness. A special testing machine with variable stiffness and friction was developed to clarify effects of the stiffness of main structures and the friction in guide on the dynamic stiffness and therefore the chatter stability. The stiffness of main structures and the friction in guide were changed experimentally, and it was clarified that the optimal friction force exists at every stiffness condition, and that higher stiffness does not always lead to higher stability.
Influence of Diameter and Number of Orifice on Static Characteristics of Radial-Thrust Aerostatic Bearing
Authors: Zhang Fei Hu , Wang Sheng Fei , Zhang Qiang , Fu Peng Qiang
Published: April 2012

The working performance of the spindle system is the most important factor to embody the overall performance of the machine tool. To ensure the advanced capabilities, besides the high-precision manufacturing technologies, it is mainly depending on the bearing module and the forces on the spindle. In this paper, a new strategy of the vertical spindle supporting system is presented to meet the high stiffness requirement for the aerostatic bearing. Based on the computational fluid dynamics and finite volume method, a fluid dynamic model and structure model of the large diameter incorporate radial-thrust aerostatic bearing is developed and simulated to find out the pressure distribution laws of the spindle supporting system. The grid subdivision in the direction of film thickness is paid more attentions when establishing the grid of the whole gas film. Simulation results show that this special structure of bearing module can supply enough load capacity and stiffness for the machine tool. The results also indicate that the static characteristics of the bearing are improved as the supply pressure increases and as the supply orifice diameter decreases.
Finite Elements Analysis and Multiobjective Optimization: A Way to Reduce Material and Manufacturing Cost
Authors: Sánchez-Caballero S. , Sellés M.A. , Plá-Ferrando Caballero R. , Seguí J.
Published: April 2012

The aim of this paper is to introduce a method to reduce the weight in structures which are subjected to multiple restrictions like deformation, max allowable stress, natural frequency, etc. The method is shown through the analysis of an aluminum bracket, whose maximum stress and deformation is well defined. The analysis is done using the Structural and Design of Experiments modules of Ansys Workbench v12.1. As result of the method a weight reduction of 50,2% is achieved.
Improvement of the Mechanical Properties of Formed Steel Cross Section Profile for Timber Upgrading
Authors: González-Bravo C. , Claver J. , Álvarez R. , Domingo Rosario
Published: April 2012

The main objective of this paper is to analyze the behaviour of cold formed steel cross section respect to mechanical characteristics, such as deflection, mainly. A cold formed steel profile with thickness of 1 mm regards is studied to determine its viability as reinforcement of timber upgrading. Thus, temperatures, stresses and strains have been analysed during the manufacturing process of these profiles, and also, the deflection supported, comparing between unreinforced and reinforce pieces. The analysis has been carried out by means of Finite Element Method, using DEFORM 2D software, during the simulation of manufacturing process and COPRA software during the final static computations. Results provide information about the integrity and good behavior of these profiles for timber upgrading.
Laser Tracker Based Volumetric Verification of Machine Tools
Authors: Aguado S. , Samper David , Santolaria J. , Aguilar-Martín Juan-José
Published: April 2012

Different techniques of volumetric verification for long range machines are presented in this paper. Its working principle is based on captured points that can be distributed or not, through laser tracker (LT) or a measurement instrument that is generally of large scale. The developed model allows us to characterize the different errors in the machine tool to study, depending on its kinematics and geometry. Obtaining the transformation matrices that define the kinematics of the machine tool (MT) including the measurement system in the kinematic model, it is possible to relate the coordinates of the tool with the coordinates of LT. The best combination of parameters, techniques and models were obtained through the realization of a large number of synthetic tests based on non linear optimisation techniques
Machining Control of Surface Roughness by Measuring Cutting Forces
Authors: García Plaza Eustaquio , Núñez López Pedro Jose , Mata Francisco , Sanz A.
Published: April 2012

The primary aim of this study was to design and develop an on-line control system of finished surfaces in automated machining process by CNC turning. The control system consisted of two basic phases: during the first phase, surface roughness was monitored through cutting force signals; the second phase involved a closed-loop adaptive control system based on data obtained during the monitoring of the cutting process. The system ensures that surfaces roughness is maintained at optimum values by adjusting the feed rate through communication with the PLC of the CNC machine. A monitoring and adaptive control system has been developed that enables the real-time monitoring of surface roughness during CNC turning operations. The system detects and prevents faults in automated turning processes, and applies corrective measures during the cutting process that raise quality and reliability reducing the need for quality control.
Roundness and Cylindricity Verification of Cylindrical Workpieces of Magnesium Alloys Obtained by Intermittent Dry Machining
Authors: de Agustina B. , Clavijo N. , Villeta M. , Rubio E.M.
Published: April 2012

Magnesium is the lightest metal used in industry, above all for aerospace and automotive applications where weight reduction allows an improvement in the fuel efficiency and reducing CO2 emission. In this work, an experimental study was carried out in order to determine with which machining process, turning or milling, are obtained cylindrical bars of magnesium alloy UNS M11917 by intermittent dry cut with improved roundness and cylindricity finish.
Application of Laser Texturization to Increase the Depth of AA5083 Welds
Authors: Sánchez-Amaya J.M. , Boukha Z. , González-Rovira L. , Amaya-Vázquez M.R. , Botana Francisco Javier
Published: April 2012

The application of laser beam welding to aluminium alloys has some complications, mainly due to their high reflectivity, high thermal conductivity and low viscosity. In order to increase the laser absorption of aluminium alloys, some surface treatments has been applied in the literature, such as the application of dark coatings or sandblasting. However, these conventional superficial treatments have some drawbacks, such as the low weld penetration, the possibility to undergo magnesium evaporation and the impossibility to control and/or change the superficial properties of the treated samples. In the present contribution, laser texturization treatments have been performed with a fibber laser for the first time on aluminium alloys to increase their absorption and weld penetration. The texturised samples leaded to deeper bead welds than the reference sandblasted samples.
Economical Assembly of Aluminium Parts with Composite Materials in Automotive Competitive Industry
Authors: Reina José M. Arenas , García Cristina Alía , Prieto Julián J. Narbón , López Rosa Ocaña , Recio M.M.
Published: April 2012

At the present time, in the automotive competitive industry, new materials are investigated for to satisfy relative requirements to the design and manufacturing of structures more slight and resistant that allows bigger speed with smaller energy consumption (compound materials, aluminum alloys, etc.). Structural adhesives can use for joint compounds materials with aluminum and they will provide, front traditional methods and among other advantages, a smaller weight, uniform distribution of stress, tightness and elimination of the galvanic corrosion. Present work analyzes viable technically structural adhesives and, by means the application of Value Analysis, to select the adhesive and surface treatment that have the best mechanical benefits/cost ratio.
Evaluation of On-Line Signals for Roundness Monitoring
Authors: García Plaza Eustaquio , Núñez López Pedro Jose , Martin A.R.
Published: April 2012

The cutting forces, mechanical vibration and acoustic emission signals obtained using dynamometer, accelerometer, and acoustic emissions sensors have been extensively used to monitor several aspects of the cutting processes in automated machining operations. This study assesses the significance of these on-line signals for the real-time monitoring and diagnosis of the roundness error in automated cylindrical turning processes. The system developed is based on predictive models obtained by regression techniques employing the orthogonal components of the cutting forces, mechanical vibration and acoustic emissions, and combines all three types of sensors into one system. This monitoring system enables the on-line monitoring and diagnosis of roundness error by registering, visualizing, and characterizing the signals obtained during the machining process.
The Electrochemical Performance of Carboxymethyl Cellulose with Different DS as a Binding Material in Lithium Batteries
Authors: Hao Hong Ying , Shao Zi Qiang
Published: April 2012

The carboxymethyl cellulose (CMC) with the different degree of substitution, which was synthesized in the mixed agent system of isopropanol and ethanol and water, was used in rechargeable Lithium batteries. The electrochemical performance of the 9,10-anthracenedione (AQ) electrodes with different binders were investigated by galvanostatic discharge/charge, cyclic voltammetry and electrochemical impedance spectroscopy techniques. Tested as the binding material in a lithium cell at room temperature, the CMC electrode showed better electrochemical performance compared to a PVDF electrode. It exhibited a specific capacity of up to 214 mAh.g-1at the initial discharge, and its speciﬁc capacity was maintained at 62 mAh.g-1after 50 cycles. In addition, it had better stability during the charge and discharge processes. Furthermore, the electrochemical performance of the CMC with lower degree of substitution(DS) was better.
Approach of Selecting Profile Modifications Curves for Spur Gears
Authors: Yuan Zhe , Guo Yu
Published: April 2012

The tooth profile modification can generally choose straight line modification, parabolic modification and arc modification. In order to accurately determine the tooth profile modification curves, basing on analysis of the vibration that effected by transmission error, a pair of gears meshing process is simulated with FEM approach. Aiming at reducing the fluctuation of transmission error, the transmission error curves of straight line modification, parabolic modification and arc modification with the same modification parameters are plotted, and the best modifications curve is obtained. The research shows that the approach is accurate to choose the best modification curve, and reduce the fluctuation of transmission error greatly. The approach illustrated in this paper provides a new way for designing the noiseless gears.
Finite Element Analysis for Homogeneous Earth Dam of Heisonglin Reservoir
Authors: Ma Wen Liang , Li Xiao Fen
Published: April 2012

In this paper, finite element analysis is proceeded for homogeneous earth dam of Heisonglin reservoir. Deducing variation law of the dam’s stress and displacement in construction process and operational process. The analytic results are shown：homogeneous earth dam of Heisonglin reservoir is reasonable structure, and every index meets the requirements for design.
Effects of Ball Milling Time on the Microwave Properties of Mg4Nb2O9 Ceramics by the Solid-State Process
Authors: Wu Hai Tao , Jiang Yi Shan , Wang Ying Zi , Chen Ya Ming , Yue Yun Long
Published: April 2012

Corundum-type magnesium niobate (Mg4Nb2O9) ceramics were synthesized by the conventional solid-state method, the effect of ball milling time on microwave properties was studied in detail. Xrd results showed that the major phase was identified as the ordered corundum structure Mg4Nb2O9with minor secondary phase of orthorhombic-symmetry Mg5Nb4O15. The morphology was obviously affected by ball milling times at sintering process, and then the relationships between the morphology and microwave properties were discussed. The results indicated that ball milling times at sintering process could obviously affect the microstructure and microwave properties of Mg4Nb2O9ceramics. When ball milling time was 10h, the Mg4Nb2O9ceramics were prepared with the conditions of calcination at 1100°C for 2h and sintered at 1350°C for 6h, and the optimal microwave properties were εr~13, Q·ƒ~120,000GHz and ƒ~-60ppm/°C.
The Optimization Design of Certain FRP Sluice Gate
Authors: He Jun , Yang Yong Xin , Wang Ming Sen
Published: April 2012

In order to optimization design a FRP sluice, four parameters(plate thickness、web number,web thickness,web height) are analyzed on two integrated performance(maximum deflection and volume fraction) by the ANSYS software. The results show that the plate thickness has a great effect on the volume fraction and the web height has a great effect on the maximum deflection. The web height is the controlling factor in the optimization design .After determining other three parameters, the web height controls the maximum deflection. This research result provides a reference optimization method for designer.
Effects of Holding Time on Microwave Properties of Mg4Nb2O9 Ceramics by the Solid-State Process
Authors: Wu Hai Tao , Jiang Yi Shan , Wang Ying Zi , Chen Ya Ming , Yue Yun Long
Published: April 2012

Corundum-type magnesium niobate (Mg4Nb2O9) ceramics were synthesized by the conventional solid-state method, the effect of holding time during calcination and sintering process on microwave properties was studied in detail. The xrd results showed that the major phases were identified as the ordered corundum structure Mg4Nb2O9with minor secondary phases of orthorhombic-symmetry Mg5Nb4O15. The morphology was obviously affected by holding times at sintering process and the relationships between the morphology and microwave properties were discussed. The results indicated that holding time at calcination process had negligible effect on the microstructure and microwave properties, while holding time at sintering process could obviously affect the microstructure and microwave properties of Mg4Nb2O9. When calcination at 1100°C for 2h and sintered at 1350°Cfor 6h, the optimal microwave properties were εr~13, Q·ƒ~130,000GHz and τf~-50 ppm/°C.
Motion Trajectory Analysis of Potting Knife in Pot-Making Mechanism Based on Pro/E
Authors: Yin Wei Da , Gao Yu Zhi , Zhou Ping
Published: April 2012

This paper first analyzes the working principle and the working process of the pot-making mechanism. Then the modeling design for the parts of the pot-making mechanism is taken using the basic modeling module of Pro/E. According to the dynamics requirements of the pot-making mechanism, the modeled parts are assembled. Considering the actual working situation, these assembled parts are connected each other according to the motion patterns, thus completing the assembly of the pot-making mechanism. At last, with the help of the mechanism module of Pro/E, the dynamic trajectory of the potting knife is simulated, and the simulation results are analyzed.
The Finite Element Simulation of Milling Based on Orthogonal Cutting Model
Authors: Gao Ai Hua , Wang Fu Rong , Zhang Jian Xin
Published: April 2012

The paper make the service life of relieving formed milling cutter as the optimization objective, proceed the simulation study on the mechanical degree of cutter, cutting data. The concrete method is that the orthogonal milling model is established to simulate the simulation milling process, some basic parameters which are obtained in the machining process are analyzed and discussed. The results indicate that the finite element simulation of the metal cutting processing can analyze quantitatively some physical properties, such as the cutting force, stress, strain and so on, the traditional way of qualitative analysis is changed. The state of machining is in favour of grasping in the theory, the theory and technology are provided to establish the proper processing technology strategy.
Theory Analysis of FBG Characteristics under 3D Homogeneous Stress Field
Authors: Wu Zhao Xia , Zhang Hui Fang , Wang Jun Wei , Wang Li Fu
Published: April 2012

FBG sensing characteristics and model under three-dimensional stress are studyed in this paper. Theory analysis indicates that the reflection spectra of FBG is gradually splitted into two resonance peaks with the increase of the load and the two resonance peaks have a linear relation to the load. The difference of the wavelength sensitivity of the two directions of FBG is much less than the conditions of FBG only under transverse force, that is to say, the axial force plays a leading role in the shift amount of center wavelength.
Fabrication of C/Cu Composites by Mechanical Activation and Spark Plasma Sintering
Authors: Liu Xue Ran , Liu Y. B. , Sun Y. , Su G.H.
Published: April 2012

C/Cu self-lubricating composites were a kind of potentially functional materials. Nanostructured C/Cu composites were prepared by the new technology of mechanical activation-spark plasma sintering (MA-SPS). Microstructures of the as-milled powder and the as-sintered simple were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. These investigations indicated that in Cu-C immiscible system, the nanostructured supersaturated solid solution of carbon in copper was formed at atomic level after milling for 24 h. Microstructures of SPS sintered C/Cu composites still kept the nanostructure. In addition, Cu-C interface bonding was good. It was ascribed to a double activation mechanism in the MA-SPS process, which improved the sintering activity of C/Cu powders. Nanostructured C/Cu composites were obtained by SPS sintered at 600 °C for 3 min.
A Numerical Analysis for Cracks Emanating from a Quarter-Spherical Cavity on the Edge of an Elastic Body
Authors: Yan Long Hai , Liu Bao Liang
Published: April 2012

This note is specifically concerned with cracks emanating from a quarter-spherical cavity on the edge in an elastic body (see Fig.1) by using finite element method. The numerical results show that the existence of the cavity has a shielding effect of the corner crack. In addition, it is found that the effect of boundaries parallel to the crack on the SIFs is obvious when.H/R≤3
Application Research on Fault Diagnosis Based on Improved Wavelet Neural Network
Authors: Li Jie Jia , Li Jie , Qu Rui , Li Ying
Published: April 2012

Aluminum electrolysis is a nonlinear, multi-couplings, time-variable and large time-delay industrial process system. The paper puts forward the fault diagnoisis method of improved wavelet Elman neural network, which firstly simplifies the input of network with the method of principal component analysis, secondly, the weights, as well as scale factor and shift factor of the wavelet function are optimized by use of the wavelet Elman network which is optimized by improved particle swarm algorithm. Then it is verified by the simulation. The simulation results show that the method can precisely forecast the aluminium electrolysis equipment faults and improve the production and quality of aluminum.
Earthquake Response of Asymmetric Structure Considering Soil-Structure Interaction in Time Domain
Authors: Wang Mei Li , Lan Jiao Xia , Yang Xiao Rong
Published: April 2012

A study is carried out on lateral-torsional coupling response considering soil-structure interaction in time domain. Acoording to lateral-torsional coupling vibration equations of soil-asymmetric structure system, the direct integral MATLAB program in time domain were made used method. The parametric research on elastic dynamic response of soil-asymmetric interaction system in time domain was done by directed integral program. By comparing the parameter influence rule in time domain with the result in frequency domain, it verified the feasibility of using time history method to do parametric research. This conclusion can supply references to study the laws how the parameters influence the inelastic seismic response.
Simulation of Cavitation Erosion in Different Throttling Pipelines
Authors: Zhu Bin , Su Yong , Li Zhi Gang
Published: April 2012

There often exists cavitation erosion, large energy loss and big noise in throttling pipelines. In this study, the three-dimensional (3D) model of the secondary throttling pipeline was constructed according to the actual structure and parameters. Adopting the finite element method (FEM) for flow field calculation, the secondary and ordinary throttling pipelines have been calculated respectively under different working conditions, and the distribution maps of velocity and pressure fields in the pipelines have been constructed. The analyzed results demonstrate the applicability of the calculating model. It has also been shown that the cavitation erosion resistance of the secondary throttling pipeline is better than that of the ordinary throttling pipeline. Cavitations first appear at the entrance of throttling pipelines, and as the pressure difference between the two ends increases, the cavitations appears inwards. This result is significant for choosing and designing the throttling pipelines.
Study on the Deformation and Fracture of Bolted Roadway with Infrared Characteristics
Authors: Yan Ru Ling , Zhang Yong Jun , An Li Qian , Mao Ling Tao
Published: April 2012

The thermal infrared (TIR) radiation in the deformation and progressive failure of coal roadway and the mechanism of thermo-mechanical coupling were investigated. The experimental achievement showed that the surface TIR temperature (TIRT) rose non-uniformly with the load increase before the stress peak and TIR radiation caused by stress concentration, shear band and bolted area, was much stronger and higher than that caused by stress relaxation, week friction and tensile fracturing. The bolted ranges were determined from the change ratios of TIR temperature of the different areas of the bolted surrounding rocks. The infrared thermal image anomaly appeared with the macro-cracks development in the progressive failure of bolted roadways, which reflected the spatial and temporal features of infrared precursor respectively. The infrared thermal image precursors were classified as TIRT increment region and TIRT constant region to disclosure the damage evolution and localization behaviors of bolted roadways.
Application of Finite Element Method in Structure Analysis for Inclined Clay-Core Wall Earth Dam
Authors: Zhang Jian Hua
Published: April 2012

This paper adopts universal finite element calculation software to carry out simulation analysis for inclined clay-core wall earth dam of Hongxing reservoir, computer is applied in design and analysis of inclined clay-core wall earth dam. Variation law of inclined clay-core wall earth dam’s stress and displacement in construction process and operational process is researched. The research results are shown: inclined clay-core wall earth dam of Hongxing reservoir is economic and reasonable, structure is safe and reliable, and every index meets the requirements for design.
Dynamic Inverse Model for Multi-Sensor Measurement System Based on Wavelet Neural Network
Authors: Zhang Dong Zhi , Xia Bo Kai , Wang Kai , Tong Jun , Yang Nian Zhen
Published: April 2012

As traditional measuring method based on dielectric coefficients shows cross-sensitivity for multi-factor in the measurement of oil/water mixture, it can not meet the requirements of digital oilfield construction. Therefore, this paper presents an inverse model of wavelet neural network (WNN) combining with multi-sensing technology for achieving high-accuracy measurement of water content in crude oil. The simulation and experimental results demonstrate that the proposed method is available to eliminate the cross-coupling effects of multi-factors. The method has higher measurement accuracy and stronger generalization than the model built by BP-NN, and opens a versatile approach in nonlinear error calibration for multi-factors measuring system.
A New Numerical Analysis for Inclined Crack in an Infinite Plate
Authors: Liu Bao Liang , Yan Long Hai
Published: April 2012

This paper presents a numerical approach for modeling multiple crack fatigue growth in a plane elastic infinite plate. It involves a generation of Bueckner’s principle, In the numerical simulation, for each increment of crack extension, remeshing of existing boundaries is not necessary. Crack extension is modeled conveniently by adding new boundary elements on the incremental crack extension to the previous crack boundaries. At the same time, the element characters of some related elements are adjusted according to the manner in which the boundary element method is implemented. Fatigue growth of an inclined crack in a infinite plate under cyclic load is modeled to illustrate the effectiveness of the numerical approach.
Analysis and Evaluation on Detectability of Characteristic Index for Coal Property
Authors: Cheng Gang , Zhang Hong Liang , Fu Qiang , Su Wei
Published: April 2012

Through capability comparison activity on fuel laboratories of 30 thermal power plants, evaluate the capability of ash content in coal conducted in each laboratory by │Z│value, possible uncertain factors that may occur in the determination process of the project has been assessed fully, and technical measures to control quality detection level in fuel laboratory have been proposed.
Research on Distribution for Soot Remain Different Height in Smoldering Fire
Authors: Chu Yan Yan , Li Ying Yu , Dong Liang
Published: April 2012

Soot remains different locations from fire source have the same characteristics of fire remains different combustion time. This study discusses the soot formation process from the time theory view and soot disposition rule from the space theory view. By GC/MS, through the analysis of the histograms of every composition percentages of smoke remain different height and the molecular structure of the primary ingredient of smoke remain, the characteristics information of different combustion stages retained in soot different height can perfomance the process of soot formation, Which may be used to analyze of the primary ingredients generated by smoldering fire and may help the fire investigation in smoldering fire.
Numerical Simulation of Three-Component Induction Resistivity Log
Authors: Luo Shui Liang , Li Lin Xiang , Cui Yong , Ma Qing Bo , Liao Xun Ping
Published: April 2012

This paper shows enumerated electrical field is divided into primary field and secondary field according to two Maxwell circuitation equations combined with fact of induction resistivity log, and the primary field can be solved by analytic geometry method, the secondary field can be solved by finite difference Crisscross grid method. Finite difference Crisscross grid method is precise and advisable by means of comparing with analytic geometry method. Some formation factors such as relationship of log response and formation thickness, formation nonisotropy, formation penetration and measurement factors such as transmitter frequency, coil arrangement, coil span are simulated by finite difference Crisscross grid method.
Microstructure and Mechanical Properties of Mg-6Al-0.3Mn-0.9Y Alloy
Authors: Su G.H. , Cao Zhan Yi , Liu Xue Ran , Sun Y.
Published: April 2012

Mg-6Al-0.3Mn-0.9Y (mass fraction, %) magnesium alloy was prepared by metal mould casting. The as-cast ingot was homogenized, and then hot-rolled with total thickness reduction of 70%. Further annealing treatment was carried out on the hot-rolled sample. Microstructure and mechanical properties of the studied alloy in as-cast, hot rolled and annealed states were investigated. Results showed that main phases of the as-cast sample were composed of α-Mg, Mg17Al12 and Al2Y. Average grain size was about 9 μm after hot rolling and annealing treatment. It is found that the optimal annealed parameters for the Mg-6Al-0.3Mn-0.9Y alloy should be 350 °C for annealed temperature and 30 min for the corresponding time, respectively. Tensile test results showed that ultimate tensile strength, yield strength and elongation of the annealed sample were 261 MPa, 149 MPa and 32%, respectively. Compared with those of the as-cast sample, they were enhanced by 36%, 140% and 146% correspondingly.
Development of Data Recording and Analysis System for Urban Rail Vehicle
Authors: Zhang Fu Jing , Zhou Ping , Li Li Gong
Published: April 2012

A data recording and analyzing system for urban rail vehicle is proposed and developed in this paper. This system can record the vehicle running information with the help of the installed data recording equipments, and offline analyze the recorded vehicle running data and the fault data. By using the proposed recording and analyzing system, the vehicle maintainers can quickly investigate the vehicle running status, so as to diagnose the fault working condition and make the reasonable measures; The vehicle debugging person can easily find out the debug problems and the direction of improvement; The vehicle administrator can effectively obtain the vehicle’s overall operating status so as to make the appropriate management strategies. The developed system has already been used in some urban rail lines successfully, and has achieved good results.
Gear Transmission Fault Tree Analysis Based on Bayesian Network
Authors: Zhou Zhen , Zhang Jin Biao , Ma De Zhong , Qin Yong , Zhang Bo
Published: April 2012

As a kind of important mechanical drive forms, the reliability level of gear transmission directly haves an effect on the performance of mechanical products. At present, the analysis method of main gear transmission failure is the fault tree analysis, which has several limits in describing multi-state events. Bayesian network which is very suitable to express multi-state events and uncertain logical relationships has been successfully applied to fault diagnosis field. Therefore, Bayesian network is researched in this paper in order to improve gear transmission fault tree, solve limits of the fault tree out and make the failure analysis results more objective and accurate.
Perfluoropolyether Modified Waterborne Shape Memory Polyurethaneurea Ionomers for Potential Medical Implant Application
Authors: Li Qun Xia , Hou Zhong Yu
Published: April 2012

A series of cross-linked fluorinated waterborne shape memory polyurethaneurea (PUU) ionomers were synthesized from polycaprolactone diol, perfluoropolyether diol (PFPE), dimethylolproionic acid, isophorone diisocyanate, ethylenediamine (EDA) and diethylenetriamine (DETA). The effect of PFPE content in the soft segment and the degree of cross-linking on the molecular structure and the properties of for these PUU films was examined and studied. Differential scanning calorimetry showed that the transition temperature for these Tm type shape memory PUU could be facially tuned by PFPE weight percentage and EDA/DETA ratio in the range between 30°C to 50°C, in the vicinity of body temperature. The dependence of their properties on hydrogen-bonds evaluated by FT-IR was also discussed.
Size Effect of Expandable Graphite
Authors: Lu Yan
Published: April 2012

Using three natural graphites with different particle size, 35, 50 and 80 mesh, as raw materials, expandable graphites were prepared by intercalating, water-washing and drying the natural graphites. The products were characterized by X-ray diffraction, Infrared spectroscopy, scanning electron microscope and Raman spectroscopy. Results show that the structure of expandable graphite is affected strongly by the particle size of natural graphite. With increasing the particle size of natural graphite, for expandable graphite, the expansion degree of graphite flakes along the c-axis and the relative ratio of intercalating agents increase, while the structural disorder increases.
Size-Dependent Young's Modulus of the FCC Metallic Films
Authors: Li Ming , Su G.H.
Published: April 2012

Young's modulus is one of the most fundamental parameter to depict the elasticity of a given material. It determines the basic elastic deformation capacity of a structure under a bear load. When the diameter of nanocrystals is in the scale of several nanometers, the Young's modulus is quite different from that of bulk. In order to determine elastic deformation capacity of nanocrystals, it is necessary to study the size dependent Young's modulus. Based on above consideration, a simple thermodynamic model is developed for size dependent Young's modulus of nanocrystals according to the “universal” binding energy curve and Laplace-Young equation. According to this model, the Young's modulus of several FCC metallic films is predicted and the Young's modulus increases with the size reduction. The prediction is agreed with computer simulation results.
Synthesis and Characterization of Novel PCA-PEG-PCA Triblock Copolymer
Authors: Chang Jun , Li Cheng Wu , Li Gang
Published: April 2012

Using chloroacetic acid(CA) and polyethylene glycol(PEG) as raw material, polyacetic acid-polyethylene glycol-polyacetic acid(PCA-PEG-PCA) triblock copolymer was synthesized by solution polycondensation. The triblock copolymer was characterized by FT-IR spectroscopy、X-Ray Diffraction and DSC. The structure of copolymer was confirmed by FT-IR. The crystallinity of compolymer was 51.24% investigated by XRD, and the result of DSC showed the PCA and PEG was homogeneous with a good compatibility.
A Study of Cutting Forces in High-Speed Dry Milling of Inconel 718
Authors: Li Huai Zhong , Wang Jun
Published: April 2012

nconel 718 is one of the most commercially important superalloys but with very poor machinability. It has a very high yield stress and a high tendency to adhesion and work-hardening. A recent trend of improving the machining processes of difficult-to-cut materials is to move towards dry cutting operations. This paper presents an experimental study of the cutting forces in high speed dry milling of Inconel 718 using a milling cutter with coated carbide inserts. It is found that the peak cutting forces increase with an increase in chip load in a nonlinear way, but cutting speed does not show a significant influence on the cutting force for the range of cutting speeds tested in this study.
Tool Wear in Ball-End Milling of Cr12MoV Die Steel Using an Indexable Cutter with the Asymmetric Inserts
Authors: Zou Bin , Huang Chuan Zhen , Liu Zi Ye , Zhuang Xin Qiang , Wang Jun
Published: April 2012

Tool wear was investigated at the different cutting conditions in rough ball-end milling of Cr12MoV die steel using an indexable cutter with asymmetric inserts. The wear patterns on rake face and flank face of major insert and minor insert, and chip patterns were observed by VHX-600E large depth-of-view 3-D scanner. The relationships of tool wear and cutting conditions, and their mechanisms were discussed. The tool life was determined by the flank wear at No. 1 cutting condition. At Nos. 2-8 cutting conditions, the life of major inset and minor insert were determined by the wear of their rake faces and flank faces respectively. At No. 8 cutting condition, the tool wear was dominated by boundary wear, adhesion and diffusion wear, and the slight chipping. Both type and color of chips identified the cutting stability at the different cutting conditions.
Influence of Inclination Angle on Machined Surface Hardness in High Speed Ball End Milling
Authors: Han Shi Guo , Zhao Jun , Chen Xiao Xiao , Li Yue En , Cao Qing Yuan , Dong Yong Wang
Published: April 2012

In this paper, the effects of the variational combinations of cutter inclination angle in feed direction and the feed per tooth on the machined surface hardness were mainly concerned. The cutting forces transformed from the measured cutting forces in OXYZ and the SEM microstructures of the surface layer were analyzed to explore the generation condition of the hardness. Variations of the surface hardness are not apparent with the increment of feed per tooth with the identical other cutting parameters. Inclination angles in feed direction of approximately ranging from 10° to 15° and from 25° to 30°, which correspond to high surface hardness, are suggested to be applied in cutting process when high abrasive resistance is expected. While values of inclination angle approximately equal to 0° and 45° are prior to be chosen when high shock resistance performance is firstly expected. Optimization of the cutting parameters, which could offer guidance to the machining of sculptured surface concerning cutter inclination angle, was presented.
A Comparison of Dry and Wet Machining of SiC Particle-Reinforced Aluminum Metal Matrix Composites
Authors: Li Jian Guang , Du Jin Guang , Yao Ying Xue
Published: April 2012

This paper explains and demonstrates the machinability of dry and wet machining of SiC particle-reinforced aluminum metal matrix composites based on the experiments. The plunge surface experiments with mill-grinding method under wheel peripheral speed of up to 14.13m/s, feed rate 80mm/min and depth of cutting 50μm were carried out on a vertical CNC milling machine. The comparisons of dry and wet machining on the force composites and surface roughness (Ra) versus material removal volume were studied. The material removal volume was gained with the same machining parameters after an equal period of time. In most cases, the tangential mill-grinding force values are greater in wet machining condition than that in dry condition. But for normal mill-grinding force, the Fn values are much greater in dry machining condition than that in wet condition. And the normal mill-grinding force in wet machining increased quickly with increasing material removal volume. A better surface finish can be produced in dry machining than that produced by wet machining. The surface roughness decreased slowly with the increasing material removal volume and the surface roughness shows an insignificant decreasing trend in wet machining.
High Speed Face Milling Cutters Dynamic Response with Deformation
Authors: Tao Fu Chun , Chen Guang Chao , Jiang Bin , Chen Bo , Ding Yan
Published: April 2012

Based on the field research, we found that in the course of high-speed face milling aluminum, Cutters components prone to deformation as the role of load such as Centrifugal force, Cutting force and Preload. The deformation will directly affect the the dynamic performance of the cutter. So its necessary to reveal the dynamic response of the deformation cutter. We base on the Dynamic model and the modal analysis model, Obtained the deformation cutters dynamic simulation which the cutters deformation is come from the ANSYS. At last we got the method of identifying cutters deflection deformation by vibration signal. With the method we can effectively identifying milling distortion In the cutting process.
Influence Characteristics of Cutting-Contact Stress on the Wear of Milling Cutter in High Speed Ball-End Milling Hardened Steel
Authors: Jiang Bin , Zhao Pei Yi , Wang Yong Zhong , Fan Yi Hang
Published: April 2012

Adopted the cutting-contact model of high speed ball-end milling hardened steel surfaces, researched distribution characteristics of cutting-contact stress; by researching the influence of the distribution of this stress on cutter wear, clarified the influence theory of milling pattern and cutting parameters on initial wear of milling cutter. By using the method of climbing, conventional milling alternating and changing cutting parameters, verified the influence of milling pattern and cutting parameters on initial wear pattern. The result showed that, initial wear mechanism of high speed milling hardened steel is an interaction of multiple wear mechanisms under the effect of friction and alternating pressure stress, by using conventional milling can significantly reduce concave curvature radius of hardened steel, the contact stress of blade area and front, rear flank, inhibit crushing and wear rate of the milling cutter surfaces. Under this condition, by increasing rotation speed and reducing the feed per blade, will further increase the strength of this effect, and achieve the purpose of reducing the initial wear, inhibiting the wear rate and extending the cutters life.
Model of Intrinsic/Extrinsic about the Safety for High Speed Milling Tools on Mesoscale
Authors: Jiang Bin , Song Ji Guang , Wang Song Tao , Chen Bo , Liu Xuan Chi
Published: April 2012

The article is about the safety for high speed milling tools between macroscopic and mesoscale, making some analysis about the relationship between damage of cutting tools and its components and mesoscale movement, the damage of cutting tools and its components is known. With the boundary conditions of material force damage, using the material design software named MAPS to do molecular dynamics simulation, the simulation is about mesoscale state in different stress, Make sure the various mesoscale movement on stress response rate, the model of intrinsic/extrinsic about the safety for high speed milling tools on a mesoscale is established. Clear the value of intrinsic/extrinsic parameters and mesoscale movement on stress response rate. The regular pattern between damage of cutting tools and its components and mesoscale movement, which could help us to design tools, choose materials of tools and determine cutting parameters.
Research on Sticking Failure Characteristics of Cemented Carbide Blade
Authors: Li Zhe , Zheng Min Li , Chen Xian Zhi , Tong Meng
Published: April 2012

Through the analysis on damaged tool in sticking failure experiment by cutting austenitic stainless steel (1Cr18Ni9Ti) with scanning electron microscopy (SME), found that there are micro cracks existent on rake face near the tip of the cutting tool, through the research of the emergence, development and distribution direction of the crack, the direct reason for tool breakage is the crack being out of control. Combining the study of cutting tool element density change in cutting zone and grooving wear on rake face, this paper analyzed the cause of the binding between chip and tool and the influence factors of sticking failure during the cutting process.
An Experimental Study of Orthogonal Cutting of SiCp/Al Composites: Cutting Forces Analysis
Authors: Huang Shu Tao , Zhou Li , Wang Jin Lei
Published: April 2012

Due to the superior mechanical and thermal properties of SiCp/Al composites, their poor machinability has been the main deterrent to their substitution for metal parts. Machining of SiCp/Al composites has been considerably difficult because the extremely abrasive nature of SiC reinforcements causes rapid tool wear. In this paper, an experiment was carried out to investigate the influence of the cutting speed, cutting depth and tool rake angle on cutting force during orthogonal machining of SiCp/Al composites. The results indicate that the cutting depth is one of the main cutting parameters that affect the cutting force, while the cutting speed and tool rake angle have no significant effects on the cutting force.
Wavelet Transform Denoise of PCB Drilling Force Signal
Authors: Qu Yun Peng , Wang Cheng Yong , Zheng Li Juan , Song Yue Xian
Published: April 2012

In the PCB micro drilling, because the force signal is tiny, and when the micro-drill drill to a certain degree of multilayer PCB, alternate force signals will not appear obvious, through to the drilling force signal analysis, we can know the drill bit position and the materials to the influence of the drill failure, so the drilling force signals denoise seems extremely important. In the processing of the non-stationary signal, traditional signal processing method has a certain extent of insufficient, using the wavelet packet decomposition signal, the white noise variance and amplitude decrease with the increase of wavelet scales, but the signal variance and amplitude has nothing to do with the wavelet transform. According to the view of the signal energy, first of all, we make the multiscale decomposition of the signal, then, by using some of the wavelet packet that has efficient energy to reconstruct the original signal. Comparing with the traditional threshold denoising ,using this method in the test signal to deal with the noise can effectively eliminate the white noise interference, and has good denoising effects besides the simple calculation.
Study on Surface Roughness in Ultrasonic Vibration Mill-Grinding Hot-Pressed Silicon Nitride
Authors: Qiao Guo Chao , Zhou Ming , Wang Ming
Published: April 2012

In order to investigate the influences of machining parameters on surface roughness in ultrasonic vibration mill-grinding, the motion of abrasive grain is analyzed. The analysis indicates that grain and workpiece separate periodically which are beneficial for coolant entering into grinding zone to reduce grinding temperature and grinding force and improve surface quality. Experiments are carried out and detected by SEM and roughmeter, the results indicate that influences of spindle rate, feeding speed, cutting depth and amplitude decrease in turn. Through regression analysis, an empirical formula is obtained. The experiments indicate that material removal mode dominates surface roughness.
Research on the Distribution of Grains in the Grinding Process
Authors: Zhang Hong Xia , Chen Wu Yi
Published: April 2012

Grinding of metals is a complex material removal operation involving cutting, ploughing, and rubbing depending on the extent of interaction between the abrasive grains and the workmaterial under the conditions of grinding. In this investigation, various parameters of the process including the number of abrasive grains in actual contact, the number of actual cutting grains per unit area for a given depth of wheel indentation, the minimum diameter of the contacting and cutting grains, the probability of active contacting grains and cutting grains were determined analytically. The analytical work was proved to be practicable by the means of measuring grinding temperature. Research results enable the use of actual number of contacting and cutting grains in the grinding wheel for thermal distribution and wheel wear analyses and contribute to a better understanding on the mechanics of grinding.
Grinding Surface Creation Simulation Using Finite Element Method and Molecular Dynamics
Authors: Chen Xun , Öpöz Tahsin Tecelli , Oluwajobi Akinjide
Published: April 2012

This paper presents some research results of the application of finite element method and molecular dynamics in the simulation of grinding surface creation. The comparison of these two methods shows that both methods could illustrate the material removal phenomena and provide useful information of grinding mechanics, but they have different feasible application arranges depending on the level of size scales. The investigation demonstrated that rubbing hypothesis of grinding material removal mechanism is valid at all size level even down to nanometre level. Further investigation areas are identified in the paper.