bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Acoustic Characteristics for a Novel Liquid-Conveying Pipeline Elbow Structure
Authors: Wu Lan Ying , Wang Yan Lin , Chen Ming Wen
Published: July 2011

Pipeline elbows are extensively applied in the liquid-conveying piping system, which vibration and noise control are always difficult and critical. In this paper, the fluid noise and its distribution of the original elbow and optimized structure will be studied based on the structural optimization and solid-liquid coupling characteristics for the liquid-conveying 90ºpipeline elbow. The results show that the max-fluid noise of original pipeline elbow is 22.44dB, the max-fluid noise appears in the original pipeline elbow inside; When the guide plates are designed according to the gold ratio, the number, the radius and the length are 2, 200mm and 40mm respectively, the max-fluid noise is 18.21dB, it decreases 4.23dB compared with the result of original pipeline elbow, the max-fluid noise appears in the original pipeline elbow inside too, when the fluid impact the guide plate, the local fluid noise will be generated.
Vibration Simulation of Air Slide Table in Ultra Precision Machines
Authors: Vahdati Mehrdad , Rasouli Seyed Alireza
Published: July 2011

The compressed air vibration in air slide table of ultra precision machines is an obstacle for gaining Nano-metric level of accuracies in the products created by these machines. In this article, the vibration behavior of air slide table due to compressed air layer is analyzed. The air slide table fluid and dynamic analytical model has been derived. In order to have air exit velocity from clearance gap, the finite element software FLUENT was applied. Finally, in order to calculate the displacements of table due to vibration and drawing its curves via time at the presence of varieties of air pressure, the second order differential equation was solved by MATLAB. In solving differential equation the Rang-Kutta method was used.
Research on Credit-Based Real-Time B/S Teaching Evaluation System
Authors: Cheng Wei Yuan
Published: July 2011

This paper describes the need for development of real-time online teaching evaluation system with the credit management mode, and promotes a new teaching evaluation theory in accordance with the development of credit management.
Data Reduction Used in CAPP Application of Processing Methods of Reasoning
Authors: Mu Zhen Dong , Xiao Hua Bo , Zheng Jian , Xing Yong Ping
Published: July 2011

In the computer aided process design, the choice of processing methods is one important part. In order to improve quality and short the design process, the intelligence of computer aided process planning system is a research direction. This paper use the theory of data reduction, based on success stories, then the rule base derived. According to the method designed in this paper, tested through the use of Finishing the hole (black metal) test samples, finishing the hole (non-ferrous metals) test samples, the super finishing hole test samples, the hole semi-finished test samples, Achieve the purpose of processing methods Automatic select.
Establishment and Experimental Research of Performance Test Table of High-Speed Ball Screw Feed System
Authors: Li Ya Qin , Han Yang Yang , Yao Jia , Liu Chun Shan , Lu Wei
Published: July 2011

The high-speed processing performance test table has been built, the automatic return circuit test has also been designed to ensure convenience. The high-speed processing performance measurement test system has been established, the corresponding test results have been obtained. Finally, effective measures have been obtained through the rational analysis of the test results to improve the precision CNC(computer numerical control) machining.
Meshing Efficiency Analysis of 2K-H Type Differential Gear Train Closed by CVT
Authors: Huang Yun Feng
Published: July 2011

For the problem that power circulation and low efficiency easily occur in closed Continuously Variable Transmission (CVT), the input-coupled CVT drive system was taken as the object of study, the fundamental structure and working principle of the input-coupled CVT drive system were briefly introduced. In the circumstances of no energy loss, the sufficient condition for the input-coupled CVT drive system to realize power split was deduced in detail. Next, the meshing efficiency expression for the 2K-H type differential gear train was simplified under the sufficient condition. The condition for maximizing the meshing efficiency of the 2K-H type differential gear train was demonstrated. Finally, the conclusion was verified by example. The results show that the condition of maximum meshing efficiency ensures the highest meshing efficiency of the 2K-H type differential gear train from the design point of view.
Study of an Experiment System and Flow Measurement of Group Nozzles in a Heavy-Duty Gas Turbine
Authors: Li Xu , Liu Kai
Published: July 2011

Study of experiment system and experimental investigation results of the group nozzles in a heavy-duty gas turbine are expatiated. In order to measure gas flows of every flow branch in the group nozzles, flow meter of type SH-1 is specifically developed, The measure system, control system, data display system, data acquisition analysis system subtly combine, the SH-1 gas flow test equipment and these measured flows data are precise, stable, good reproducibility, the errors of the measuring are less 0.5%. Using SH-1 flow meter, gas flows of Ⅲ,Ⅳ,Ⅴbranches are precisely measured, the combustion testing of the group nozzles in the flame tube is made, its performance is satisfied with the design requirements, these demonstrate: the testing results by using SH-1 flowmeter are reliable, stable.
FE Modeling of Living Human Brain Using Multifrequency Magnetic Resonance Elastography
Authors: Naeeni Hamed Ajabi , Haghpanahi Mohammad
Published: July 2011

Viscoelasticity is an inherent property of the soft biological tissue and is increasingly used as a diagnostic parameter, e.g. in characterizing Brain disease, liver fibrosis and breast tumors or tissue-mimicking phantoms preparation. MR elastography (MRE) enables the noninvasive determination of the viscoelastic behavior of human internal organs. In this study, multifrequency magnetic resonance elastography was used to investigate and validate the numerical simulation of human brain viscoelasticity generated by ABAQUS. The dynamic behavior of storage modulus (G') and loss modulus (G") obtained by MRE at different frequency ranges were used to generate viscoelastic FE model of brain tissue. Then, shear modulus (µ) and shear viscosity (η) were compared to experimental data. MRE validate the finite element as an effective technique for measurement of rheological material properties. Results indicate the capability of FEM to simulation and comparison of experimental results.
Strength Check and Optimization Design of Movable Mine Refuge Chamber
Authors: Lei Yu , Jiang Yan Long , Zhu Chun Ling , Shi Hong , Wang Yu
Published: July 2011

Movable mine refuge chamber is widely used in coal mines for protecting miners from coalmine accident. During a coalmine accident, there will be large heat impact load and stress on the movable mine refuge chamber caused by high temperature and high pressure. Therefore the strength of the movable mine refuge chamber should be carefully designed to meet the safety requirement with the possible lightest weight. Based on analysis of the structure dimensions, material properties, and operating conditions, a finite element model is developed with an emphasis on the effect of the layout and sizes of stiffeners and structural form of the chamber. A comparison of different design schemes is made and the calculation result is given. This work could be helpful for optimization design of China’s movable mine refuge chamber.
Oxidation Effect of Welded AA6061 Al Alloy Using ER5356 Filler Metal
Authors: Nur Azida Che Lah , Jalar Azman , Othman Norinsan Kamil , Daud Abdul Razak
Published: July 2011

Test material of welded AA6061 Al alloy using ER5356 (Al-Mg-Si) filler metal was oxidized inflowing air gas for 40hrs at 600oC at a total pressure of approximately 1 atm. The morphology andmicrostructure of oxide formation on welded Al alloy was characterized using SEM and EDAX.Different oxide morphologies were observed on parent and fusion metal due to the differences of thealloying element. The oxidation mechanism represented a complex reaction where the morphology andphase formation of the oxide shows the protective oxide were developed on parent metal side, whilenon-protective oxide formed on fusion metal of the welded Al alloy.
Applied Research on Client Identification Based on Association Rules
Authors: Tian Jun Feng , Li Li Xian
Published: July 2011

Today, with increasing competition, enterprises are facing unprecedented challenges. How to identify clients has become an important project in the development of competition among enterprises. Client identification based on association rules will be conducive to the innovation of traditional business management thinking. An effective method for client identification should be carried out with exploratory data analysis, improving ability to identify clients for enterprises and finding more interesting, more practical and more specific association rules between the data.
Study on Single Crank Flexible Pumping Unit in Oil Field Artificial Lift
Authors: Li Juan , Yang Hong Zhi , Han Mei , Xu Jin Chao , Li Xiao Dong , Han Xiu Ting , Cheng Yuan Fang
Published: July 2011

International tension between energy supply and demand boost developments of energy-saving industry. Structure drawbacks of four linkage bar of the conventional beam pumping unit in oil field artificial lift led to the study of a single crank flexible pumping unit. Because of beam pumping unit issues, such as many energy transfer links, high energy consumption and investment, and so on, the single crank flexible pumping unit made the flexible delivery instead of rigid, substantially reduce the energy transfer links, to reduce the weight of the load rod as a breakthrough to achieve light and compact oil production ground equipment, while minimizing energy consumption, increased functionality, lower investment and overall cost. Field tests show that significant energy savings are found in the single crank flexible pumping unit, which is worth of promoting.
One-Dimensional Model and Numerical Simulation of Two-Stage Light-Gas Launching Facility
Authors: Lu Xin , Yu Yong Gang , Zhou Yan Huang
Published: July 2011

In this paper, a one-dimensional mathematical model is established and simulated numerically for the interior ballistic cycle of two-stage light-gas launching facility with a piston-compressor type. A 35mm/130mm light-gas launcher is taken for the primary computing model, and lots of data, such as the pressure on light-gas chamber, the piston velocity, the diaphragm failure pressure, etc. are obtained by computing the model using the numerical difference scheme with the second order of numerical accuracy in space and the first order in time. On the basis of the results of analyzing these data systematically, some advices on enhancing the launching performance of light-gas launcher are put forward. The numerical results show that the developed mathematical model gives the correct trend and can provide useful calculated parameters for the structural design of the components of two-stage light-gas launcher.
Mechanical Properties and Microstructure of Reaction Sintering B4C/SiC Ceramics
Authors: Lin Wen Song , Fang Ning Xiang
Published: July 2011

Reaction sintering B4C/SiC ceramics with high density were manufactured. The effect of the carbon content in green bodies on the microstructure and mechanical properties of the ceramics has been studied. Results showed that the carbon content and the value of carbon relative density (ρCRD) in the green bodies were the major factors affected the composition, that is, the free silicon and carbon contents and mechanical behaviors of sintered specimens. The optimal value of ρCRD was gotten at 0.85 g/cm3. The fracture toughness, flexural strength, and hardness of the composites increased with increasing carbon content up to 20 wt.%. The maximum values of fracture toughness of 3.8 MPa∙m1/2, flexural strength of 475 MPa, and hardness of 32.0 GPa were obtained under the following process parameters: value of ρCRD in the green bodies was about 0.85 g/cm3; carbon, B4C and SiC contents in green bodies were 20 wt.%, 30 wt.% and 50 wt.%, respectively; compact pressure was 75 MPa and sintering temperature was 1600°C.
Warp Phenomenon Analysis in Hemming Process of Autobody Panel
Authors: Yun Shi Zhi , Liu Yu , Jian Yu Shi , Yang Peng Chao , Bing Wang An
Published: July 2011

In this paper, the hemming process, which widely used in automobile industry, was studied by a method of constructing mechanical models combined with FEM simulation results. The warp producing mechanism in the straight edge- plane hemming process was analyzed in detail using this mechanical model. The reason why the warp produced at the position of near the contact point between the out panel and the position surface of hemming die during the pre-hemming process, and the phenomena of warp reducing firstly and then increasing before the position point T and the warp reducing again after point T during the final hemming process were interpreted. The work finished in this paper provides a theoretical basis to understand hemming process and a tool to analyze the reasons why warp produced in the hemming processes.
Test Research and Parameter Analysis of Grain Drying Model
Authors: Liu Chun Shan , Wu Wen Fu , Yao Jia , Li Ya Qin , Liu Chuang
Published: July 2011

The purpose of this study is to explore the effecting principle in the drying process. The factors such as hot air temperature, hot air flow, drying time on the grain moisture content have been all investigated. Using UD to establish the optimization mathematics model which making the grain dryer moisture content as the goal of the design, making the factors of hot air flow, drying time, air temperature as parameters, with the help of UD to analysis the effecting principle of the drying process parameters on the grain moisture content, some references have been provided to the tower dryer.
Locomotive Engine Cylinder Head and Fuel Injecting Vibration Signal Analysis
Authors: Hu Qing Song , Li G. X. , Cao Shou Qi , Xu Li Hong
Published: July 2011

Cylinder head and fuel injecting vibration consist of rich information about the working state of the locomotive engine, which shows important potential on the engine fault online diagnosis and regular maintenance. Through acquiring the cylinder head and fuel injecting vibration signals, comparing with the standard signals, fault diagnosis strategy is researched. By analyzing the cylinder head vibration curve with the method of vibration comparison value, the working states of all the cylinders are obtained. With the vibration curve of the fuel injecting, the problem of the injectors is found which helps to locate the fault. The strategy is applied to the No.0015 locomotive of the Rizhao Seaport Transportation Company. The matching between the analysis result and practical locomotive state shows the validity of the strategy which can dramatically improve the maintaining efficiency as well as decrease the degree of over maintenance and lack of maintenance.
Scenario Analysis of Carbon Emissions in Jiangxi Transportation Industry Based on LEAP Model
Authors: Liu Yan Yan , Wang Yan Feng , Yang Jun Qing , Zhou Ye
Published: July 2011

Transportation industry is an important field to reduce greenhouse gas emissions and climate change. Scenario analysis of transportation industry can provide theoretical support to the formulation and implementation of carbon emissions reduction policy. In view of this, The transportation industry of Jiangxi province will be given into four departments including civil aviation, railways, highways and waterways, and it was used the LEAP model to set three scenarios in the different application of economic development mode and different traffic development mode, then forecasted the main carbon emissions of Jiangxi transportation industry in 2010-2030, and analyzed the result of forecasting. It shown that the way to ease the nervous energy supply and the pressure of carbon emissions, and achieve the sustainable development of energy and the environment, must be set the four departments of reasonable transportation distribution under the condition of different energy sources, and increase the scope of using the new energy and renewable energy.
A Robot Arm Actuated by Mckibben Muscles
Authors: Zhao Huai Lin , Bian Jian Ling , Jiang Jian , Ji Wei Ming
Published: July 2011

A humanoid robot arm with both shoulder joint and elbow joint is built. It is actuated by pieces of Mckibben muscles. Its skeleton-muscle formation is similar to the anatomical structure of the human arm. A pneumatic experiment system is established for supporting and testing the robot arm. The relationship between the robot arm actions and the Mckibben muscles is studied. Some main actions of the robot arm including the elbow bending, the whole arm arising and the rotating around the arm axis are realized.
Design and Implementation of Virtual NC Real-Time Machining Process Control System
Authors: Li Jie , Guo Rui Feng , Shao Zhi Xiang , Wang Shang Bin
Published: July 2011

After the virtual NC real-time machining process control technology is studied, we design the NC code interpreter using the pipeline control method of overlapped resources in this paper. In order to improve the availability of interpreter, the design adopts the function pointer array and expression evaluation algorithm. By using two methods, the scalability is enhanced. Also the versatility is improved by using keywords information table to some extent. The system achieves a straight line and arc of the trajectory interpolation by the digital sampling algorithm and makes the efficiency improved by using RCS communication mechanism, windows thread and timing mechanism.
Improved Semantic Similarity Algorithm Based on Ontology
Authors: Wei Jun Ying , Zhong Pei Si , Guo Chun Fen
Published: July 2011

The measuring of semantic similarity is the key technique in information retrieval. Based on the common semantic similarity algorithm between concepts, this paper makes use of semantic weighted distance and introduces such factors as node density, concept attribute and concept information content, and presents an improved semantic similarity algorithm to make the measuring semantic similarity more accurate. Through experimental calculation and analysis, the semantic similarity obtained from the improved algorithm can describe more accurately the similar relation between ontology concepts, and correspond to a higher degree with human subjective judgment.
Secondary Path Estimation by PCA-Compressed Frequency Response Function in Active Vibration Control
Authors: Li Xin Hui , Yang Tie Jun , Dong Jian Chao , Lu Ze Qi
Published: July 2011

The FXLMS algorithm is widely used in active vibration control system. The estimation of secondary path plays very important roles in such a system. This paper presents an experimental investigation of effective secondary path estimation in active vibration control using measured Frequency Response Function (FRF). Principal component analysis (PCA) is pursued to the measured FRF for noise elimination, and then the PCA-compressed FRF data are used for secondary path estimation. The control results indicate that the proposed method has good control performance.
Room-Temperature Mechanical Properties and Glass Formation of Zr50Cu20Ni15Al(15-X)Tix (x=3, 5, 7) Bulk Metallic Glass Alloys
Authors: Zou Jia Hua , Zhang Zhi Chen , Sun Shu Quan
Published: July 2011

In the present study, the Zr-Cu-Ni-Al based bulk metallic glasses with different Ti addition was successfully prepared by suction casting . It was found that the glass forming ability was improved with increasing of Ti content from 3 at.% to 7 at.%. However, with increasing of Ti content, the room-temperature plasticity decreased from 4.33% to 0.66 %.
The Phase Structure of Fe Doped LiFeXMn2-XO4 Prepared by a Molten-Salt Combustion Synthesis
Authors: Liu Gui Yang , Guo Jun Ming , Wang Bao Sen , He Ying
Published: July 2011

Fe doped LiFexMn2-xO4 materials were prepared by a low-temperature molten-salt combustion synthesis method. The phase structure and compositions of the products were determined by X-ray diffraction (XRD). The investigation on Fe doping content indicated that the main phase of the as-prepared products was LiFexMn2-xO4, and the impurity was Mn2O3. With increasing Fe doping content, the relative content of Mn2O3 and the lattice parameter of the products were decreased, and the crystallinity was increased. The study of the calcination temperature on LiFe0.1Mn1.9O4 suggested that the main phase of the LiFe0.1Mn1.9O4 materials prepared at 300-600°C wasLiFe0.1Mn1.9O4. Mn3O4 and MnO impurities could be investigated in the product prepared at 300°C, and single impurity Mn2O3 could be observed in the products prepared at 400-600°C. The relative content of Mn2O3 decreased, and the lattice parameters and grain size of the products were increased with increasing calcination temperatures.
Workspace Analysis of a Hybrid-Driven Cable Parallel Mechanism
Authors: Bin Zi , Cao Jian Bin
Published: July 2011

This paper presents a new-type hybrid-driven cable parallel mechanism, which combines hybrid-driven mechanism with cable parallel mechanism, and the mechanism can not only operate with high speed, high accuracy, and high payload, but also have high performance output movement. The workspace of hybrid-driven cable parallel mechanism is characterized as the space where the end-effector can reach with tensions in all cables, and it is studied in this paper. Firstly, through the kinematic analysis, it can be derived the location equations of the end-effector. Then, the paper analyzes the main factors influencing the workspace of hybrid-driven cable parallel mechanism such as cable tension, workspace of hybrid-driven mechanism, the length of cables, and the motion range. At the end, with the location equations and constraints, the workspace is determined. Computational example is provided to demonstrate the effectiveness of the proposed analysis method.
Polymerization of Aniline on Mild Steel and its Corrosion Protection
Authors: Kadhum Abdul Amir H. , Musa Ahmed Y. , Mohamad Abu Bakar , Takriff Mohd Sobri , Lynnyen Long
Published: July 2011

The production of polyaniline films on mild steel from sulfuric acid was carried out using cyclic voltammetry. Corrosion protection of the coating was observed in 3.5% NaCl using electrochemical impedance spectroscopy, (EIS) and potentiodynamic polarization measurements. Results showed that the polyaniline layer has the potential to protect mild steel by stabilizing the oxide layer formed on the steel surface and thus prevent the metal dissolution process.
Research on Microstructure and Refining Effect of Al-3Ti-0.5B Master Alloy Produced with Ti Sponge
Authors: Chen Xiao Wei , Gao Ya , Zhao Hong Liang , Weng Kang Rong , Zhang Bao Feng
Published: July 2011

Al-3Ti-0.5B master alloy was prepared by reaction of Ti sponge, KBF4with aluminum melt. The morphology and distribution of the second phases effected by the feeding methods have been discussed. And the grain refining performance and the resistance to fading of the master alloy were investigated. The result shows that the Al-3Ti-0.5B master alloy which was prepared by adding mixture of Ti sponge and KBF4power into molten aluminum contains a large number of granular TiB2phase and blocky TiAl3phase. The average grain size of commercial purity aluminum was refined from 920μm to 120μm by adding 0.5wt.% of the master alloy. And the refining performance of the master alloy shows no obviously fading phenomenon when the holding time up to 30min.
The Tribological Properties of Thermoplastic Polyetherimide Composites Filled with Kevlar Pulp
Authors: Cai Chi Lan , Wang Wen Xia , Li Jian
Published: July 2011

Kevlar pulps were employed as reinforcement for polyetherimide(PEI)composite. All filled and unfilled polyetherimide composites were tested against CGr15 ball and representative testing was performed. The effects of Kevlar content on tribological properties of the PEI composites were investigated. The worn surface morphologies of pure PEI and its composites were examined by scanning electron microscopy (SEM) and the wear mechanisms were discussed. Results show that all filled polyetherimides have superior tribological characteristics to unfilled ones.
The Improved Genetic Algorithm for Multi-Objective Flexible Job Shop Scheduling Problem
Authors: Yang Jian Jun , Ju Lu Yan , Liu Bao Ye
Published: July 2011

To solve the multi-objective flexible job shop scheduling problem, an improved non-dominated sorting genetic algorithm is proposed. Multi-objective mathematical model is established, four objectives, makespan, maximal workload, total workload and total tardiness are considered together. In this paper a dual coding method is employed, and infeasible solutions were avoided by new crossover and mutation methods. Pareto optimal set was taken to deal with multi-objective optimization problem, in order to reduce computational complexity, the non-dominated sorting method was improved. The niche technology is adopted to increase the diversity of solutions, and a new self adaptive mutation rate computing method is designed. The proposed algorithm is tested on some instances, and the computation results demonstrate the superiority of the algorithm.
Study on Spreading of Liquid Droplet Impacting on a Solid Dry Surface
Authors: Song Yun Chao , Wang Chun Hai , Ning Zhi
Published: July 2011

A numerical computation and theoretical model are presented on spreading of a single droplet impacting on a solid surface at low Weber number. The numerical simulation uses combined Level Set-VOF method and a precise wetting model. The singularity at the moving contact line was analyzed and removed by present wetting model. A theoretical model based on the energy balance was developed to predict the maximum spreading ratio, accounting for wetting effect by a correction factor. The droplets shapes, the dimensionless spreading radius and the dimensionless height of droplet calculated by present numerical method were compared with the experimental data. The theoretical model is used to predict the maximum spreading ratio. The numerical and theoretical results agree well with the experimental data. Present theoretical model indicates that capillary effects may be neglected if 6We(We/3+4)>>Re.
Study on Plasma Treatment and Adhesion of Wood/Polyethylene Composites
Authors: Tao Yan , Di Ming Wei
Published: July 2011

The surface of wood/polyethylene (PE) composites was treated by low-pressure glow discharge of air plasma to improve its adhesion properties. And the changes on the surface properties of the treated composites under different discharge time were studied by contact angle, AFM and FTIR analysis. To determine the effect of plasma treatment on the adhesion of the composites, shear bond strength tests were conducted. The results showed that the contact angle decreased gradually with the increasing of discharge time. The roughness of plasma treated samples increased. The FTIR analysis results showed that the polar groups such as -OH, -C=O and -O-C=O were formed on the surface of the composites treated under plasma. The data of shear bond strength analysis also showed that the adhesion strength of composites increased remarkably after plasma treatment, and the durability of bonding joint under water and heat environments also be improved.
A Parametric Design and Simulation System for Globoidal Indexing Cam Mechanisms
Authors: Gong Hui , Yin Ming Fu
Published: July 2011

The paper researched on the globoidal indexing cam, and established the parameter design system based on VC++ Object-Oriented method and Pro/E secondary development, which can guide user to complete the data input with the friendly interface. It made synthesis of the mechanism and generation of the cam profile automatic. The system is proximate, easy to operate and adjust. Then the assembly model was built under the circumstance of Pro/ENGINEER directly. And meanwhile the movement of the mechanism was simulated and the interference was checked so that we can certify the design. This is a new method for the mechanism's deep research and extensive application.
Effect of Interactive Periods to Corrosion-Fatigue Life on LY12CZ Alloy
Authors: Zhang Hai Wei , He Yu Ting , Liu Chao , Wu Li Ming , Ding Hua
Published: July 2011

To study life differences between pre-corrosion fatigue and corrosion-fatigue test, LY12CZ standard specimens are selected in pre-corrosion fatigue test to get the C(t) curve at first. Then, combining with Miner linear cumulative damage theory, theoretical fatigue life is calculated by simulated corrosion-fatigue interactive process. Compared with actual corrosion-fatigue interactive test, theoretical life is rather conservative. Afterwards, a modified model based on C(t) curve method and actual interactive test at different periods of specific flight strength is established. The result shows that the modified C(t) curve method is in good agreement with corrosion-fatigue interactive test.
Accident Warning and Fast Reaction in Emergency Management of Manufacturing Enterprises
Authors: Zhou Hui Wen
Published: July 2011

An enterprise should establish an emergency management mechanism that includes accident warning mechanism and fast reaction mechanism. Accident warning mechanism can let the enterprise do predictive analysis and judgment and make reasonable strategies and suggestions. Fast reaction mechanism can help the enterprise make correct decisions in a short time and improve efficiency and effectiveness of emergency management. Rules and regulations are necessary to ensure smooth implementation of accident warning mechanism and fast reaction mechanism.
Vibration Suppression of the Flexible Joint Manipulator Based on Controllable Local Degrees of Freedom
Authors: Gao Zhi Hui , Yu Jing Jing , Bian Yu Shu
Published: July 2011

In order to suppress vibration of the flexible-joint manipulator, a new topological structure of the manipulator with the controllable local degrees of freedom is suggested. By kinematic and dynamic analysis, it is found that arbitrary motions introduced by the controllable local degrees of freedom are independent of the nominal end-effector motion, but can greatly affect dynamic performance of the manipulator. As a result, a vibration control strategy is put forward based on the controllable local degree of freedom. By planning the branch link motion, the vibration of the flexible-joint manipulator can be reduced. The results of numerical simulations verify the effectiveness of the vibration control strategy proposed in this paper.
CRH VIP Seats Human-Machine Scale Analysis
Authors: Ding Lei
Published: July 2011

China railway high-speed still in the infant stage, no matter referring to technology or design, we have relative big gap comparing to German ICE, French Alstom and Japanese Shinkansen. Nowadays, the inner seat (first-class, second class) of our country’s very high-speed train mainly depended on introduction, and we did not match well the seat’s man-machine measure and Chinese man-machine measure as we introducing from abroad the technology. Accordingly, it is easily to cause a lot of problems.
Platelet Adhesion on Silicon Modified Carbon Nanotubes Films
Authors: Li Gang , Zhu Shuang Xia
Published: July 2011

Owing to its high mechanical strength, chemical inertness, low frictional coefficient, high wear and corrosion resistance properties and so on, carbon nanotubes (CNTs) films have emerged as a potential material for biomedical applications. In order to investigate the blood compatibility properties of CNTs films synthesized on the silicon (Si) substrate using thermal chemical vapor deposition, the blood compatibility was evaluated in vitro by the platelet adhesion and the activated partial thromboplastin time (APTT). The experimental results demonstrated that the Si-CNTs films reduced thrombus formation by minimizing the platelet adhesion, activation , aggregation and had a tendency to retard the intrinsic coagulation activities of blood due to a higher APTT compared to Si, lower temperature isotropic pyrolytic carbon (LTIC) and Polydimethylsiloxane (PDMS) materials. Further, we found that hydrophobic surfaces are more prone to direct cellular motility in comparison with hydrophilic surfaces. It is concluded that CNTs films on the Si substrate were effective for improvement of blood compatibility.
Design of an Experimental Platform for Hydraulic Servo System
Authors: Zhu Jin Fang
Published: July 2011

VRLA (valve-regulated lead-acid) and Pump-control are the two kinds of power components for hydraulic servo system. With different command device, feedback measurement device and different corresponding electronic components, the hydraulic servo systems are different. To ensure maximum performance of the whole device, the overall design (including mechanical, electrical design) should be considered for hydraulic servo system. Machinery-electric-hydraulic should be in coordination with each other. The hydraulic system components are used to change the speed of hydraulic cylinder and alter direction of hydraulic cylinder and hydraulic motor. The solenoid valve for motor and hydraulic servo system and the control of pressure relay can implement by the electric section.
Target Location and Accuracy Analysis in near Space Bistatic Radar
Authors: Zhang Jia Qiang , Wang Shen Shen , Wang Fang Nian , Feng Jin Fu , Huang Feng
Published: July 2011

Monostatic surface wave radar is vulnerable by the threat of stealth targets and establishment of near space bistatic radar is the most achievable way to solve this problem. The positioning principle and accuracy in near space bistatic radar is discussed in this paper. The geometrical dilution of precision expression of single measurement subset is calculated. The position precision contours of measurement subsets are obtained and which subset can be chosen for positioning at different area is pointed out. Simulation results show that different subset has different position accuracy and a high accuracy subset distributing picture is presented. Research of this paper provides a theoretical base of detecting and tracking for near space bistatic radar.
Impact Resistance and Energy Absorption of Functionally Graded Cellular Structures
Authors: Wang Xiao Kai , Zheng Zhi Jun , Yu Ji Lin , Wang Chang Feng
Published: July 2011

The dynamic response of functionally graded cellular structures subjected to impact of a finite mass was investigated in this paper. Compared to a cellular structure with a uniform cell size, the one with gradually changing cell sizes may improve many properties. Based on the two-dimensional random Voronoi technique, a two-dimensional topological configuration of cellular structures with a linear density-gradient in one direction was constructed by changing the cell sizes. The finite element method using ABAQUS/Explicit code was employed to investigate the energy absorption and the influence of gradient on stress wave propagation. Results show that functionally graded cellular structures studied are superior in energy absorption to the equivalent uniform cellular structures under low initial kinetic energy impacts, and the performance of such structures can be significantly improved when the density difference is enlarged. The stress levels at the impact and support ends may be reduced by introducing a gradual change of density in cellular structures when the initial impact velocity is low.
The Study of TiC/C Composite Fiber by Chemical Vapor Deposition
Authors: Wang Hai Quan , Wang Lin Tong , Zhang Hong Yan
Published: July 2011

TiC/C composite fibers were prepared by vapor phase titanizing of the regular carbon fibers via chemical vapor deposition (CVD). The carbon fibers were titanized from the surface of the fiber to the core. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were applied to characterize the morphology and structure of the TiC/C composite fibers. The influences of CVD reaction conditions such as temperature and reaction time on the TiC particle size and the thickness of the deposited layer were investigated. Higher temperature and longer time resulted in the growth of bigger size of the TiC crystal particles, and the particle uniformity was also decreased.
Tool Life in High Speed Turning with Negative Rake Angle
Authors: Adesta Erry Yulian Triblas , Al Hazza Muataz H.F.
Published: July 2011

The present work studies some aspects of turning process applied on mild steel using cermets tools at high speed cutting (1000mm/min) by using negative rake angle (0 to-12). The influence of increasing the cutting speed and negative rake angle on flank tool wear, cutting forces, feeding forces and tool temperature were analyzed. The research studies and concentrates on the tool life estimation and the effect of the negative rake angle and higher cutting speed on tool life. It was found that the maximum tool life is obtained in (-6) rake angle for the cutting parameters.
Application of FEM in Investigating Machining Performance
Authors: Yanda Hendri , Ghani Jaharah A. , Che Haron Che Hassan
Published: July 2011

The two biggest problems that often experienced in machining cast iron are poor machinability and high hardness. Up to now, many researchers have investigated machining performance and how to find optimum condition in machining ductile cast iron. This study aims to investigate the machining performance of ductile cast iron and carbide cutting tool using FEM. Performances were evaluated by changing the cutting tool geometries on the machining responses of cutting force, stress, strain, and generated temperature on the workpiece. Deform-3D commercial finite element software was used in this study. Ductile cast iron FCD 500 grade was used as the work piece material and carbide insert DNMA432 type with WC (Tungsten) was used for the cutting tool. The effects of rake and clearance angles were investigated by designing various tool geometries. Various combination of carbide insert geometries were designed using Solid Work to produce +15, +20 and +30 deg for rake angle and 5, 7, 8 and 9 deg for clearance angle. Machining condition for the simulations were remained constant at cutting speed of 200 m/min, feed rate of 0.35 mm/rev, and depth of cut of 0.3 mm. The results of effective-stress, strain and generated temperature on both chip and material surface were analysed. The results show that by increasing the rake angle (α), it will improves the machining performance by reducing the cutting force, stress, strain and generated temperature on surface of workpiece. But, by increasing the clearance angle (γ), it will not affect much to the cutting force, stress, strain and generated temperature on chip.
Numerical, Analytical and Experimental Study of Structural Properties of Cutting Tool in Endmilling Process
Authors: Abootorabi Zarchi M. Mahdi , Zoghi Hamed , Razfar M. Reza
Published: July 2011

Obtaining the resonance frequency of cutting tools is necessary for dynamic modelling and instability study in milling process. In this paper, two geometrically different endmills are modelled by analytical and Finite Element (FE) approaches and their natural frequencies are calculated. For evaluation of the results, modal testing is carried out. The discrepancies of the analytical results compared to the modal experiments are approximately 25% for both tools. FE results differ 18% and 22% from experimental values for respectively tool 1 and 2. FE values are closer to those of experiment in comparison with analytical results.
Evaluation of PVD-Inserts Performance and Surface Integrity when Turning Ti-6Al-4V ELI under Dry Machining
Authors: Ibrahim Gusri Akhyar , Che Haron Che Hassan , Ghani Jaharah Abd.
Published: July 2011

The great advancement in the development of carbide cutting tool with super-hard coating layers taken place in recent few decades, can improve the performance of cutting tool and machinability of titanium alloy. The turning parameters evaluated are cutting speed (55, 75, 95 m/min), feed rate (0.15, 0.25, 0.35 mm/rev), depth of cut (0.10, 0.15, 0.20 mm) and tool grade of PVD carbide tool. The results that tool life shows patterns of rapidly increase at the initial stage and gradually increased at the second stage and extremely increased at the final stage. The trend lines of surface roughness have are the surface roughness value is high at first machining after that regularly decreases. Work hardening of the deformed layer beneath machined surface caused higher hardness than the average hardness of the base material. However, the softening effect also occurred below the machined surface. Segmentation or serration at the chip edge was caused by high strain and pressure during machining.
Study of Micro-EDM of Tungsten Carbide with Workpiece Vibration
Authors: Jahan Muhammad Pervej , Saleh T. , Rahman Mustafizur , Wong Yoke San
Published: July 2011

Present study introduces low-frequency workpiece vibration during micro-EDM drilling of difficult-to-cut tungsten carbide with an objective to overcome the difficulty in flushing of debris and machining instability in deep-hole machining. The effects of vibration frequency, amplitude and electrical parameters on the machining performance, as well as surface quality and accuracy of the micro-holes have been investigated. It is found that the overall machining performance improves significantly with significant reduction of machining time, increase in material removal rate (MRR), and decrease in electrode wear ratio (EWR). The surface quality improves and the overcut and taper angle of the micro-holes reduces after applying the workpiece vibration in micro-EDM. The frequency and amplitude of 750 Hz and 1.5 μm were found to provide optimum performance.
Cutting Force Analysis of on-Machine Fabricated PCD Tool during Glass Micro-Grinding
Authors: Perveen Asma , Jahan Muhammad Pervej , Wong Yoke San , Rahman Mustafizur
Published: July 2011

Brittle and hard materials are problematic to mechanically micro machine due to damage resulting from material removal by brittle fracture, cutting force-induced tool deflection or breakage and tool wear. As a result, the forces arising from the cutting process are important parameter for material removal. This study was undertaken to investigate the effect of cutting conditions on cutting forces and the machined surface during the glass micro grinding using on-machine fabricated (Poly Crystalline Diamond) PCD tool. Experimental results showed that an increase in depth of cut and feed rate can result in increase of cutting forces and surface roughness as well. Among the forces in 3 axes, force along feed direction is found to be larger, which played a major role in material removal. Finally, it is observed that PCD tool exhibits promising behaviour to machine brittle material like BK-7 glass for producing micro molds and micro fluidic devices, since it has better wear resistance, experiences less cutting forces and generates smooth surfaces with Ra value of as low as 12.79 nm.
Vibration in Traverse Cut Cylindrical Grinding - Experiments and Analysis
Authors: Rudrapati Ramesh , Pal Pradip Kumar , Bandyopadhyay Asish
Published: July 2011

Good surface finish is one of the important demands from the outputs of a cylindrical grinding machine. Also it is expected that dimensional accuracy, including accuracy in roundness, is fine in traverse cut cylindrical grinding. Now, like any other machine tool, cylindrical grinding machines also do vibrate, and vibration will affect accuracy and surface finish of the parts produced in grinding. The analysis of vibration in cylindrical grinding is then very much important. In the present study some aspects of vibration – behavior of cylindrical grinding machine have been experimented and analyzed. The process parameters have been varied and vibration signals have been measured in different directions by positioning an accelerometer at tail stock of the machine. The data have been analyzed through various statistical techniques to identify and predict vibration at given combinations of process parameters. The results and analysis of data give useful idea about dynamic performance of cylindrical grinding machine in traverse cut cylindrical grinding operation.
Experimental Investigation during Finishing of Al/SiC-MMC's by Abrasive Flow Machining (AFM) Process
Authors: Mali Harlal Singh , Manna Alakesh
Published: July 2011

Al/SiCp-MMC’s find their use in engineering and structural components but their machining particularly finishing is a challenge for manufacturing engineers due to their heterogonous nature having abrasive particles randomly distributed and oriented in the matrix material. An abrasive flow machining (AFM) set up has been designed and fabricated with an indigenously developed alternative media to finish the internal cylindrical surfaces of Al/SiCp- MMC components. Work-pieces were prepared by lathe operations after stir casting Al/SiC-MMC, 25 mm diameter bar of 0%, 5%, 10% and 15% SiC by weight. The influence of AFM process parameters e.g. abrasive mesh size, number of cycles, extrusion pressure, abrasive concentration and AFM media viscosity grade on average surface finish improvement, Ra and material removal, MR, mg have been analyzed. The Scanning Electron Microscopy (SEM) study also reveals the improvement in surface finish of these MMC’s.
Statistical Approach for the Development of Tangential Cutting Force Model in End Milling of Ti6Al4V
Authors: Patwari Anayet Ullah , Nurul Amin A.K.M. , Faris Waleed Fekry
Published: July 2011

Dynamic change in cutting force is one of the major causes of chatter formation in metal cutting which affect machining accuracy. Thus, accurate modeling of cutting force is necessary for the prediction of machining performance and determination of the mechanisms and machining parameters that affect the stability of machining operations. The present paper discusses the development of a mathematical model for predicting the tangential cutting force produced in endmilling operation of Ti6Al4V. The mathematical model for cutting force prediction has been developed in terms of the input cutting parameters cutting speed, feed rate, and axial depth of cut using response surface methodology (RSM). Effects of all the individual cutting parameters on cutting force as well as their interactions are investigated in this study. Central composite design was employed in developing the cutting force model in relation to the primary cutting parameters. The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated.
Surface Roughness Prediction in High Speed Flat End Milling of Ti-6Al- 4V and Optimization by Desirability Function of RSM
Authors: Alam S. , Nurul Amin A.K.M. , Konneh Mohamed , Patwari Anayet Ullah
Published: July 2011

High Speed Machining is applicable for producing parts that require little or no grinding / polishing operations within the required machining tolerances. For achieving required level of quality, selection of cutting tools and parameters in high speed machining is very important. In this study, small diameter flat end milling tool was used to achieve high rpm to facilitate the application of low values of feed and depth of cut to achieve better surface roughness. Machining was performed on a Vertical Machining Centre (VMC) with a high speed milling attachment (HES 510), using cutting speed, depth of cut, and feed as machining variables. Statistical prediction model of average surface roughness was developed using three-level full factorial design of experiments. It was observed that depth of cut is the most dominating factor followed by cutting speed and feed. The developed model was used for optimization by desirability function approach to obtain minimum Ra. Maximum desirability of 95.63% was obtained.