bluuebunny/crossref_metadata_2025 huggingface dataset:
Penetrating Resistance of the Laminated Composite with Stepwise Graded Foam
Authors: Sha Feng Huan
Published: October 2010

The present study focuses on the penetrating resistance of the laminated composite with stepwise graded foam target struck normally by conical-nosed projectiles. The dynamic cavity expansion theory is applied to formulate analytical model. Experimental results verify that this model on account of rigid-perfectly plastic-locking model is suitable for analyzing penetration depth of the projectile into a cellular target. The difference types of foam configurations, with identical areal density, were arranged according to the density of the respective foam. The penetrating process can be divided into 7 stages. Penetrating depth; the effect of mass density and the change of graded/layered core structures of the difference configurations are analyzed. It is found that composite target have a higher penetrating resistance than the monolithic foam material target of equal mass. The analytical results show great potential to reasonable structures for absorbing the dynamics energy and improving the overall penetrating resistance.
Research on Preparation of Topological Type PMMA by Atom Transfer Radical Polymerization
Authors: He Tian Tian , Yang Yu
Published: October 2010

The atom transfer radical polymerization is successful for synthesizing the topological type PMMA with α-D-glucose/2-bromoisobutyryl bromide as initiating system, CuBr as catalyzer and PMDETA as ligand. PMMA synthesized by such method has a controllable relative molecular mass and structure. The narrow distribution of relative molecular mass really achieves the controllable activity of ATRP.
Tool-Swinging Cutting of Binderless Tungsten Carbide
Authors: Zhang Zhi Yu , Yan Ji Wang , Kuriyagawa Tsunemoto
Published: October 2010

Tool wear reduction is very important in cutting of ultra hard and brittle materials. In this paper, a tool-swinging cutting method was applied to reduce the wear of round-nosed diamond tools in cutting of tungsten carbide (WC). In this method, the geometrical center of the cutting edge was adjusted to be in coincidence with the rotation center of the B-axis table, and thus the cutting point could be changed along the cutting edge by swinging the tool about the B-axis center. Experimental results showed that the width of the flank wear land was greatly reduced compared to that in the conventional cutting. This work can shed light on ultraprecision machining WC parts without or with less need for subsequent polishing process.
Optimization of Thermal Performance of Hybrid Journal Bearings for High Speed Machine Tool Spindle with Small Diameter
Authors: Yang Xue Bing , Xiong Wan Li , Hou Zhi Quan , Yuan Ju Long
Published: October 2010

Multi-array hole-entry hybrid journal bearings have been widely applied to support the high speed precision machine tool spindle with small diameter used in high efficient inner grinding, due to their prominent properties of high rotation accuracy, high dynamic stiffness, high vibration damping and long life. But the imperfection of the hybrid bearing is the significant temperature rising in the oil film on the condition of high speed operation, which brings about the sharp decreasing of load capacity and the larger thermal deformation of the bushing that cause the bearing failure immediately. In this paper, CFD analysis of the temperature fields of the multi-array hole-entry hybrid journal bearing with various bearing construction parameters and operation parameters are presented. According to the simulation results, the temperature rising in the oil film can be controlled efficiently by optimizing the matching of the bearing construction parameters and operation parameters and excellent characteristics of load capacity and static stiffness have been obtained simultaneously.
Automatic Polishing Technology on Free Surface by Grinding Center
Authors: Wu Xiao Jun , Sun Shu Dong , Zheng Chao
Published: October 2010

Die and mold are constructed with various free surfaces. In the machining of die and mold, it takes a long time to finish the curved surface. In this study high accurate polishing technique by GC (grinding center) with elastic ball type wheel is developed. In polishing process it is very important to remove cusp height without decreasing machined form accuracy. It is available to use GC in free surface grinding and finishing of die and mold with elastic ball type wheel. In polishing process only cusp height is removed in order to keep form accuracy that is produced in cutting process with ball end mill. In order to know the polishing characteristics of elastic ball type wheel, basic experiments were conducted. The polishing parameters Sp. were obtained experimentally by changing the values of polishing process. Using polishing parameter, removal amount can be obtained and polished surface is possible to estimate.
Research on Adiabatic Shear during Serrated Chip Formation of High Speed Turning of Hardened Steel
Authors: Duan Chun Zheng , Yu Hai Yang , Wang Min Jie , Yan Bing , Cai Yu Jun
Published: October 2010

The development of chip morphology, critical cutting condition of adiabatic shear during serrated chip formation and cutting forces were observed and measured by high speed turning experiment for 30CrNi3MoV hardened steel. Results show that the cutting speed and rake angle are leading factors to influence chip morphology and cutting forces. With the increase of cutting speed, the continuous band chip transforms into serrated chip at a certain critical value. As the rake angle is changed from positive to negative, the critical cutting speed of adiabatic shear significantly decreases, the cutting forces abruptly reduces when the serrated chip forms. The results from predicting critical cutting speed using the critical cutting condition criterion of adiabatic shear in metal cutting process show that the leading reason of serrated chip formation is that the adiabatic shear fracture repeatedly occurs in the primary shear zone.
Effect of Cutting Conditions on the Stability Lobes for End Milling Process
Authors: Wan Min , Wang Yi Ting , Zhang Wei Hong , Dang Jian Wei
Published: October 2010

Milling process will be dominated by multiple delays due to the effect of the cutter runout or the pitch angles of the cutter. In this paper, research efforts are focused on the dynamic behavior of milling processes under different cutting condition parameters such as different radial immersions, feed directions, feeds per tooth and helix angles. To improve the prediction accuracy of stability lobe, the combined influences of feed rate and cutter runout on the stability lobes are also taken into account. The basic principle of the method presented in one existing work is applied to examine the asymptotic stability trends for both down milling and up milling. Some new phenomena for certain combinations of cutting parameters are shown and explained in detail. It is found that as cutter runout occurs, feed per tooth, feed direction and cutter helix angle have great effects on the stability lobes.
A New Type of Servo Direct Drive Turret Punch Press
Authors: He Kai , Li Jiu Hua , Ou Xie Feng , Du Ru Xu
Published: October 2010

A new type of servo direct drive turret punch press is presented. A servomotor to drive the eccentric-toggle mechanism is used in our design, which combines the advantages of mechanical and hydraulic turret punch press. The displacement, velocity, and acceleration of the punch are calculated, through the kinematics analysis. So, the motion of the punch is controllable through the rotation of the servomotor. Then, the inverse kinematics analysis is studied in detail, and the corresponding motion of the servomotor can be gotten, for different punch motion curves, according to the production requirement. For example, when we design a motion of the punch for a particular stamping process, the motion of servomotor can be obtained through the inverse kinematics analysis. Finally, Output force is acquired by static force analysis, which decides the working capability of the mechanism.
351nm Excimer Large-Area Lithography by Scanning and Projection
Authors: Zhou Jin Yun , Ouyang Qin , Lin Qing Hua , Pei Wen Yan
Published: October 2010

For the system of a large-area laser projection image exposure using 351nm XeF excimer, its constitution, optical design parameters, and manufacturing process are introduced. The system is capable of patterning in photoresists for large-format products, with feature sizes ranging from 10 µm to below 1µm and substrate sizes ranging from 100×100mm to 600×900mm. 351nm excimer is used in this system because of its capability for exposure of conventional photoresists. Large-area lithography refers to the patterning on such areas with the desired resolution and seamless scanning. Along with the demands for lithography equipment that can provide high-resolution imaging capability, high-precision alignment performance and lower manufacturing costs, it is important for us to design and manufacture such equipment. Some key problems such as laser illumination optics, projection optics, positioning and controlling machinery, are described here. The existing problem and solutions in the optics and machinery are analyzed and discussed.
Carbon Fiber Paper Modified with Carbon Nanotube for Proton Exchange Membrane Fuel Cell
Authors: Zhang Xue Jun , Pei Hao , Shen Zeng Min
Published: October 2010

Carbon fiber paper was modified by adding carbon nanotubes to make it reach the demand of gas diffusion layer (GDL) by the process of impregnation with phenolic resin solution dispersed with carbon nanotubes, molding, and carbonization. The properties of modified carbon fiber paper, thickness, density, porosity, gas permeability, specific resistance and tensile strength, were characterized. The results indicate that surface treatment is helpful to disperse carbon nanotubes in phenolic resin. Phenolic resin is used to bond the carbon fibers, and carbon nanotube could reduce the specific resistance of the carbon fiber paper. When carbon nanotube content is 5 %, modified carbon fiber paper is prepared with thickness of 0.30 mm, density of 0.43 g/cm3, porosity of 77 %, gas permeability of 2400 mL•mm/(cm2•h•mmAq), specific resistance of 0.020 Ω•cm and tensile strength of 15 MPa, which basically qualifies for the application requirement.
A New Method for Temperature Measurement to Determine the Temperature Variation in Cylindrical Grinding Contact Arc
Authors: Li Bei Zhi , Zhu Da Hu , Pang Jing Zhu , Zhou Zhen Xin , Yang Jian Guo
Published: October 2010

Due to the difficulty in arrangement of thermocouples, temperature measurement in grinding presents a number of challenges, particularly in high speed cylindrical-plunge grinding. Based on existing literature, only single thermocouple is considered for measuring the maximum temperature in the grinding contact arc, without considering the overall temperature variation. In this paper, a new method for temperature measurement, named four K-type thermocouples, is proposed aslant along the direction of the width of workpiece which is developed for measuring the overall contact arc in high speed cylindrical-plunge grinding. It is shown that the temperature increases to the maximum with a sharp gradient, then decreases due to the strengthening of cooling effect and the decrease of depth of cut, which is consistent with previous study. The measured temperature signal reveals the generation rule and dissipation rule of grinding heat.
The Simulation of Cutting Force and Temperature in High-Speed Milling of Ti-6Al-4V
Authors: Yang Zhen Chao , Zhang Ding Hua , Huang Xin Chun , Yao Chang Feng , Ren Jun Xue
Published: October 2010

In order to provide theory basis for optimizing high-speed milling parameters, the high-speed milling process of titanium alloy Ti-6Al-4V was modeled using the commercial general purpose machining software package ADVANTEDGE. Effects of milling parameters like milling speed, feed per tooth, milling depth and milling width on cutting force and temperature were analyzed. The results show that cutting forces decrease with milling speed increasing, and increase with feed per tooth, milling depth and milling width, and the influences of feed per tooth, milling depth and milling width on cutting forces are significant. The maximum temperature in the cutting zone located on the rake face at a distance of about 0.02~0.03 mm from the tool tip. As milling speed and feed per tooth increase, the maximum temperature in the cutting area increases. The milling speed has significant impact on cutting temperature, but the milling depth has little impact.
Research on Overhanging Rigidity and Auxiliary Support Characteristics of the Large and Exact NC Rotary Table
Authors: Yu Chun Jian , Huang Xiao Diao , Hong Rong Jing
Published: October 2010

According to high-frequency chattering of workpiece overhanging the support area of the NC rotary table while gear milling, overhanging rigidity of the table was analyzed and the auxiliary support program was bring up. Online test of gear milling can be used to establish dynamic model of the overhanging structure. For enhancing increase the axial rigidity and circumferential damping of the rotary table, a kind of auxiliary support apparatus with hydraulic pressure was designed to reduce the influence of high-frequency chattering on gear milling, which doesn’t affect circular division accuracy. As a result, efficiency of gear milling was increased more than 3 times and the machining diameter of workpiece was increased from 2250mm to 3200mm, so the auxiliary support equipment can be used on many kinds of NC rotary table and machine tool.
The Technology Research of CO2 Laser Micropore Drilling on Carbon Steel
Authors: Chen Dai Min , Li Zhan Guo , Li Jing Jing , Li Jia Xing
Published: October 2010

. Five kind of carbon steel were chosen to do the test of CO2 laser micropore drilling in the paper, it were obtained that the influence curves of laser power, pulse width, defocusing amount and repetition rate to the upper aperture and the taper of the hole, and the influence of laser parameters and the carbon content to the drilling quality were system analyzed using double factors without repeating test method, the result show that the value of laser power and pulse width has significant influence to the upper aperture, to taper of hole is less. The influence of the repetition rate of laser and defocus amount to the upper aperture was weak, and the influence to the upper aperture was very significant with the change of the value of carbon content and the repetition rate.
Experimental Study on the Relationship between Surface Roughness and Cutting Parameters when Face Milling High Strength Steel
Authors: Ding Yue , Liu Wei , Wang Xi Bin , Xie Li Jing , Han Jun
Published: October 2010

In this study, surface roughness generated by face milling of 38CrSi high-strength steel is discussed. Experiments based on 24 factorial design and Box-Behnken design method are conducted to investigate the effects of milling parameters (cutting speed, axial depth of cut and radial depth of cut and feed rate) on surface roughness, and a second-order model of surface roughness is established by using surface response methodology (RSM); Significance tests of the model are carried out by the analysis of variance (ANOVA). The results show that the most important cutting parameter is feed rate, followed by radial depth of cut, cutting speed and axial depth of cut. Moreover, it is verified that the predictive model possesses highly significance by the variance examination at a level of confidence of 99%. And the relationship between surface roughness and the important interaction terms is nonlinear.
Micro-Positioning Platform Based on Giant Magentostrictive Material
Authors: Lu Quan Guo , Chen Ding Fang , HU Ji Quan , Zhao Ya Peng
Published: October 2010

Piezoelectric (PZT) material is widely used to drive micro-positioning platform, but the energy density of PZT is low, which restricts the application of PZT micro-positioning platform. In order to overcome its disadvantages, A kind of new micro-positioning platform actuated by giant magnetostrictive material (GMM) was presented in the paper. Based on integrated optimization method, structure designing, magnetic circuit designing and temperature control designing were carried out. The dynamic performance of GMM micro-positioning platform was simulated, and simulation result shows the designing is feasible. The prototype was manufactured, and the measurement system was set up. The experiments on the platform were carried out, and experiment results show that the platform has good output performance with positioning accuracy of ±0.03μm and load capacity of 50kg, and can meets the requirements of large-power system.
Study on Dynamic Design Technique of Machine Tools Structure Based on Energy Balance
Authors: Zhang Nan Nan , Weng Ze Yu , Zheng Yan Qin , Cai Yong
Published: October 2010

The energy balance of system is one of the basis for the dynamic design of machine tools structure. The paper applied finite element technique to machine tools dynamic design based on the energy balance, in view of finite element model of machine tools dynamics structure, mean squared deviation of various energy distribution was used to describe the structural dynamic characteristics quantitatively, and the method was combined with structural dynamic optimal theory to establish the improvemental direction. The author applied the technique to the structural dynamic characteristics analysis of a surface grinder, through the energy distribution analysis and quantitative analysis of structural dynamic characteristics of the grinding machine tools, the weak link of the grinding machine structure was found, which had instruction function for structure optimization of the grinding machine.The result proved this structure dynamics design technique had obvious superiority.
Optimal Design and Process Analysis of the Blade for High-Speed Shearing Stainless Steel Tube
Authors: Sun Jun , Wang Yu Ling , Lu Bo
Published: October 2010

This paper mainly researches on the effect from high-speed shearing tool to the quality of stainless steel tube cutting. At first, the relationship between contour line of vertical blade and the direction of shear force and chip flow are studied, and the influence on the quality of shearing caused by the size of blanking clearance is analyzed. Then a new blade contour line that made most of the iron chippings is located outside of the tube and reasonable blanking clearance is obtained. Further, based on the tearing caused by single-blade shear on the top of steel tube, the shape and angle of the vertical blade are studied, and the structure of the vertical blade nose is optimized, which improves the shearing quality of the blade. Finally, the numerical simulation of the process of shearing is done to verify the feasibility of the designed structure by the finite element software DEFORM.
Optical and Electronic Properties of Mn-Doped ZnO Films Synthesized by RF Magnetron Sputtering
Authors: Wu Zhao Feng , Cao Yu Juan , Wu Xue Mei , Zhuge Lan Jian
Published: October 2010

. Zn1-xMnxO films are prepared by radio frequency (RF) magnetron sputtering method. The wurtzite ZnO crystal can be well retained up to a Mn composition of 6.7% and doped Mn ions substituted into Zn sites of ZnO host lattice. All the samples show high transparency over the wavelengths from 450 to 800 nm. Optical transmittance study showed an increase in the bandgap (Eg) with increase in Mn atomic fraction x following Eg=3.26+1.43x eV. Furthermore, the midgap absorption around 420 nm (3 eV) in Mn doped ZnO films suggest that there are impurity levels created by doped Mn ions. The room temperature resistivities of the samples show an increase with the increase of Mn content, which indicates that the doped element is at the status of deep levels.
The Influencing Factors on the Axial Magnetic Field Distribution Characteristics of GMA
Authors: Jiang Xiao Yang , Lu Quan Guo , Chen Ding Fang , Tao Meng Lun , Zhou Min
Published: October 2010

. A direct aspect of influencing giant magnetostrictive actuator's output performance is the driving magnetic field characteristics. Therefore, research on the influencing factors on the axial magnetic field distribution characteristics of giant magnetostrictive actuator is of great significance in the design. This paper analyzes the importance of the axial magnetic field distribution characteristics, analyzes the driving magnetic field using finite element method based on a designed giant magnetostrictive actuator, studies the affections of coil height, coil shape , magnetic block material, shell material , skeleton material, bottom cover material and output shaft material on the axial magnetic field distribution characteristics and reaches some conclusions about the influencing factors on the axial magnetic field distribution characteristics of giant magnetostrictive actuator. According to this paper, it provides the guidance for the optimization design of the driving magnetic field of the giant magnetostrictive actuator.
Machinability Investigation in High Speed Turning of Powder Metallurgy Nickel-Based Superalloy with Sialon Ceramic Inserts
Authors: Qiao Yang , Ai Xing , Liu Zhan Qiang , Zhao Jun
Published: October 2010

An experimental investigation was carried out to understand the behavior of a powder metallurgy nickel-based superalloy when machined with sialon ceramic insert tools. Turning experiments were carried out at different cutting speeds and feed rates while depth of cut was kept constant. Cutting tool performance was evaluated with respect to temperature and cutting forces generated during turning, and tool wear. The sialon ceramic cutting tool showed high performance when increasing cutting speed, the machining experiments showed that sialon ceramic tools performed better at cutting speed up to 80 m/min. Abrasion and adhesion was the dominant wear mechanisms. Chipping on the tool rake and flank faces, as well as catastrophic failure under thermal shock and mechanical loading, was also observed in experiments. As cutting temperature was very high when turning powder metallurgy nickel-based superalloy, good high-temperature strength and thermal shock resistance were indispensable to the cutting tools for machinging this kind of material.
Study on Technology of Drilling Superfine Deep-Hole in 2Cr13
Authors: Wang Tian Qi , Liu Zhan Feng , Zhang Chong
Published: October 2010

The paper studies machining technology, cutting parameter. It does experimentation research for drilling superfine deep-hole drilling of 2Cr13 stainless steel, of which slenderness ratio is greater than 300.The test result indicates that the drilling process is stable and reliable, the optimizing cutting technology and cutting parameters is rational, the production of the type of deep hole drilling technical problems have been solved. It has practical application in common production. The parameter can produce superfine deep holes of 2Cr13 stainless steel with the length to diameter ratio 322. In this paper, the key technologies of drilling 2Cr13 stainless steel deep hole are explained, which include selecting the system of drilling deep hole, designing of structure of deep hole bit, selecting the material of cutter blade of bit , and designing the geometry parameters of blade.
Design Principle’s Research of Traction Gear’s Modification Slotting Cutter of High-Speed Locomotive
Authors: Chen Cong Gui , Hu Liang Bin , Li Bi Wen , Li Sheng
Published: October 2010

According to the traditional tooth profile, modification process cannot meet the traction gear’s technical requirements of the high-speed locomotive. A new way for the tooth profile modification technology was provided in the paper. The slotting profile modification process was proposed, the formulating methods of the tooth profile modification K diagram was introduced, modification curve fit as the sections of involutes, the modification profile angles of slotting cutter corresponding sections of involutes was deduced using the profile angle error analysis theory and the tooth profile of modification slotting cutter precision was designed. The feasibility and advantages of modification slotting cutter were validated by examples, which indicates the widely use of this technology in high-speed locomotive traction gear.
The Design of DF-Windspout Separator Cleaner
Authors: Dong Peng Min , Wang Tian Qi , Li Guan Zhu , Zhang Jian Li , Yao Zhi Gang
Published: October 2010

The detritus of drilling well carry the important information of stratum, which is the important basis for discovering and evaluating oil and gas layer. So it is important to get detritus from the viscous drilling mud. In this paper, it studies the technology of cleaning detritus. According to the requirements of cleaning process and water - saving on the drilling well spot, DF - Windspout separator cleaner is designed, which is used to clean detritus. The mixture of viscous drilling mud and the detritus are accelerated through the double fluid (DF) system. Then they go into the windspout separation, they are separated to fluid and solid at here. Next the fluid is purified by ultrasonic microfiltration plant. The water can be recycled again. It can ensure the clean debris, the accuracy of collecting debris, accurate, remove the fake block and solves the lack of the dis - continuity of sampling.
The Key Technology of Hob Design for Hobbing Screw Compressor Rotors with Cycloid-Arc Profile
Authors: Ouyang Ba Sheng , Lin Guo Xiang , Zhang Chun Liang
Published: October 2010

The profile of cycloid-arc screw compressor rotors is not a smooth profile, and it has a tip on it. When designing the hob cutter is used for machining this kind of rotors, the profile of hob edge will appear separation. In this paper, the design theory of hob cutter for hobbing the no-symmetric cycloid-arc rotor with tip profile is researched, and the best way for design this kind of hob cutter with a separate edge is attained according to practical design, manufacture and test. Its results are shown that it is good practice to design the hob cutter and hob the cycloid-arc rotor. Thus, the machining method for hobbing screw compressor can enhance high productivity and machining accuracy.
Milling Force Forecast of the Matching of Lengthened Shrink-Fit Holder and Cutter in High Speed Machining
Authors: Zhou Hou Ming , Deng Jian Xin , Xie Wen Wei
Published: October 2010

Present work of this paper focus on developing a milling force model according to the characteristic of the matching of lengthened shrink-fit holder (LSFH) and cutter using back propagation neural network (BPNN). Time parameter is taken as a factor of the input vector besides 6 processing conditions which mainly affect the milling force, and then the forecasting of 3D transient milling forces are achieved. A lot of milling experiments were performed to get training and testing samples and a Matlab program was designed to evaluate and optimize the network. The test experiments show that the forecasting results are well agreed with the experimental results and the errors of 3D force components are less than 0.18. Besides an extended performance, the BPNN model has higher efficiency and higher accuracy than the customary analytical model.
Preliminary Study on Deep-Hole Drilling Gamma Titanium Aluminide
Authors: Zhu Lin , Chen Xin , Viehweger Bernd
Published: October 2010

γ-titanium aluminide are considered as a potential light weight material. γ-titanium aluminide alloy has the advantages of high temperature resistance, high performance of anti-oxidation effect, low-density, high specific strength and rigidity etc. This material is suitable to be applied in aeronautics, astronautics and automobile industry. But high hardness, brittleness and mechanical strength make it hard to process. This problem is more acute in deep hole drilling. In this paper, we have analyzed the cutting performance of γ- titanium aluminide and designed a deep-hole drill with three different tool materials. The experimental result shows: (1) YG8 cemented carbide is the appropriate tool material for drilling γ-titanium aluminide. (2) Small rake angle of external edge (γo=-1°) and big clearance angle of external edge (αo=10~12°) should be chosen. (3) Best wear results are obtained when oil is utilized as cutting fluid.
Influence of Cutting Speed on Cutting Force in High-Speed Milling
Authors: Zhao Zhen Yu , Xiao Yong Shan , Zhu Yong Qi , Liu Bai
Published: October 2010

High Speed Milling (HSM) is well known as an innovative key technology for modern machining. HSM can obtain very high surface qualities, subsequent manually finishing operations can be eliminated in many cases totally or at least partially. Theoretical and experimental researches have proven that the cutting force in a high speed milling process has significant influences both on surface roughness and deflection of the cutting tool. In this paper, mould steel for high speed milling experiments by multi-factor test on the high speed milling machine tools. By studying the relation of overhang length, cutting speed and cutting force of cutting parameters, the cutting force tested is analyzed in high speed milling. When mold steel is cut at high speed, the influence of cutting speed on cutting force is studied, which has a guidance in the actual production.
Performance Comparison of Aerostatic Gas Bearings of Two Different Gas Supply Modes
Authors: Sun Ang , Wang Zu Wen
Published: October 2010

In order to analyze the feature of high-load and high-stiffness gas bearing with tapered recess, the complete gas field consisting of supply hole and clearance is built up, and a laminar flow model and a sectional turbulent-laminar flow model are respectively applied to calculate the pressure distribution of centrally-fed gas bearing with tapered recess in different clearances. The theoretical results agree in general with the experimental. The experimental result demonstrates its high load, however its big gas cavity. On the above basis a circular ring gas supply bearing with tapered recess is presented, the calculation result shows that for this new type of ring inlet bearing the pressure drop in entrance area will be reduced effectively even with smaller tapered recess height, and compared with centrally-fed gas bearing with tapered recess, its gas recess volume decreased and stability increased, while the load capacity is basically the same.
Mechanical Analysis of Unidirectional Fiber-Reinforced Polymers under Transverse Compression and Tension
Authors: Qu Hong Chang , Xia Xiao Zhou , Li Hong Yuan , Xiong Zhi Qiang
Published: October 2010

The mechanical behavior of polymer–matrix composites uniaxially reinforced with carbon or glass fibers subjected to compression/tension perpendicular to the fibers was studied using computational micromechanics. This is carried out using the finite element simulation of a representative volume element of the microstructure idealized as a random dispersion of parallel fibers embedded in the polymeric matrix. Two different interface strength values were chosen to explore the limiting cases of composites with strong or weak interfaces, and the actual failure mechanisms (plastic deformation of the matrix and interface decohesion) are included in the simulations through the corresponding constitutive models. Composites with either perfect or weak fiber/matrix interfaces (the latter introduced through cohesive elements) were studied to assess the influence of interface strength on the composite behavior. It was found that the composite properties under transverse compression/tension were mainly controlled by interface strength and the matrix yield strength in uniaxial compression/tension.
Evolution of Surface Roughness of Ti Plate in Abrasive and Abrasive-Less Polishing
Authors: Han Quan Li , Zhang Bin
Published: October 2010

Polishing the titanium plate is commonly necessary step before being used in many fields. Experiments of the titanium plate polished in the condition of including abrasive and existing abrasive are carried out to study the roughness of polished surface in given state. Surface roughness and morphology were investigated in experiments and experimental results were analyzed. In both experiments, the polished surface roughness value reduces with increase in processing time, and the detects on titanium plate before polishing decreases, which attributes to the mechanical and chemical tooth rising from lap between workpiece and polishing machine with the help of energy required. Material removal block in abrasive polishing is higher than that in case of existing abrasive. This helps to deepen the understanding of change in roughness of surface polished and indicates the promising operation technology for processing titanium in factory and workroom.
Building of Ultrasonic Vibration Precision Cutting System and Experimental Study of Cutting for Plastic Material
Authors: Yang Liang , Gao Ke
Published: October 2010

Precision ultrasonic vibration cutting (UVC) is a promising technology in field of precision and ultra-precision machining. It is a kind of the pulsing cutting process with a constant vibration frequency and sine-wave amplitude of vibration. Its practicability has been a research focus since it came into being. In this article, an precision UVC system is built by designing this system, including the selection of precision machine and ultrasonic generator, the design of ultrasonic transducer, and then many cutting experiment are been done. Different of chips under the conditions of ultrasonic and no ultrasonic are made, and deformation coefficient of chip obtained by vibration cutting is smaller. The effect of cutting parameters on roughness is discussed in precision vibration cutting, the surface roughness decreased with the increase of the amplitude and the decrease of the cutting depth or feed rate, at the same time, there is an optimum cutting speed to receive the best surface.
Design and Research of Amplitude Transformer in Ultrasonic Vibration Drilling System
Authors: Liu Zhan Feng , Feng Ya Zhou
Published: October 2010

The ultrasonic vibration drilling presents superior technology effect than common methods in small-diameter deep hole machining areas, and can improve the machining quality and efficiency remarkably. The amplitude transformer usually is designed by users according to the requirement of production. Thus the design and manufacturing of amplitude transformer and the realization of the resonance of device are key problems in ultrasonic vibration drilling system. In this paper, we firstly analyzed the structure of amplitude transformer in the axial ultrasonic vibration drilling, and then designed and manufactured the composite amplitude transformer for small-diameter deep holes in the ultrasonic vibration drilling. After we carried out the test in the sound vibration system, the result indicated that the resonance of the sound system could be satisfied and the demand of small-diameter deep hole drilling could be met.
Optimization of Ultrasonic Honing Acoustic Subsystem
Authors: Zhang Yun Dian , Zhou Lei , Xi Chang Qing
Published: October 2010

This article is a research about the transmission theory of ultrasonic honing device for "Bending Vibration Disc - Flexible Rod - Whetstone Base" subsystem ultrasonic vibration, and gives out an optimization program of the subsystem. It launches a modal analysis of the ultrasonic vibration honing subsystem by using kinetic analysis and element analysis, and gets the resonant frequency, mode vibration shape and node displacement for both optimized and traditional vibration sub-system. The modal vibration shape of the optimized subsystem is well consistent with the requirements of ultrasonic honing, which will greatly improve the processing capability and reliability of the ultrasonic honing device. The modal analysis results agree well with the theoretical analysis and the optimization program, which provided new ideas and methods for the further development of ultrasonic honing technology.
Investigation of Cooling-Air Grinding Performance by Finite Element Analysis and Experiments
Authors: Cai Yu Lin , Zhang Hua , Liu Ye Feng , Zhao Huan Huan , Yao Jun , Huang Hai Tao
Published: October 2010

Combining the refrigeration and machining technology, the dry cold air at -35°C was gained. With the injecting feeding manner of the cold air for cutting, all application of the green technology is realized in turning manufacturing trials. In order to clarify the cooling and lubrication mechanism of cryogenic cold air, the cutting temperature, cutting forces, wear of cutting tool and cutting chip have been systematically researched with the help of numerical calculation and experiments. The cooling and lubrication effects, as well as the performance of machining quality improvement, enhanced by the low temperature air injecting, have also been analyzed in detail. The results arc as follows. Temperature measurements at several locations on the cutting tool insert agree with the simulation results. The performance of cooling-air spray jet with 25(Nm3/h ) on reducing the cutting tool temperature achieved a maximum effect
Adaptive Integral-Type Sliding Mode Control for Magnetic Levitation Linear Guide Suspension Altitude
Authors: Mao Jing Feng , Wu Guo Qing , Wu Ai Hua , Cao Yang
Published: October 2010

This paper investigates the constant position suspension altitude control problem for a novel magnetic levitation linear guide. The magnetic levitation linear guide is comprised of a magnetic suspension processing platform and a linear motor direct-drive system. The magnetic suspension system has several characteristics of complicated nonlinearity, parameter perturbation and strong disturbance. In view of these characteristics, an adaptive integral-type sliding mode control (AISMC) technique is used to design magnetic suspension system constant position suspension altitude controller. The AISMC can alleviate chattering and reduce steady error by estimating the boundary of uncertain perturbation. The adaptive tuning algorithm is derived in the sense of the Lyapunov stability theorem, thus the stability of the system can be guaranteed. Simulation results indicate that the proposed AISMC has a better stability, transient and robustness compared with PID control.
The Morphological Characteristics and Composition of Body Surface of Ant and its Relation to Reducing Soil Adherence
Authors: Zhang Dian Wu , Wang Yu Xing , Tang Yan Qin , Zeng Wen
Published: October 2010

The surface of ants was observed, analyzed and tested by using of scanning electron microscopy and X-ray energy spectrometer technology. On different surface of the ants, the waveform characteristics which were formed by different sizes of grooves were found. These cross sections of waveform surface were waveform curves which had continuous periods and amplitudes. Their sizes varied with different part of the ant. In addition, there was distribution of setae of various sizes on surface of the body. Under higher multiple of electron microscope, the bigger setae had the waveform surface of smaller periods and amplitudes. The results of composition analyzing indicated that the surface of ants contained multi-elements. Among these elements, the most abundant was O which content was over 57%. The following abundant element was C which content was more than 23%. The other elements such as Na, Mg, Zn, Si, P, S, Cl, K, Ca remained less than 3% respectively. The distribution of morphological characteristics and surface composition may contribute to the property of reducing soil adherence.
Fluctuation of Biped Walking Mechanism Based on a New Two-Level Type Half-Rotating Mechanism
Authors: Ou Shu Bin , Qiu Zhi Zhen , Wang Xiao Yi , Hou Li Ya
Published: October 2010

. A new bionic biped walking mechanism (BWM) was put forward in this paper. Simple in construction, easy in control and droved by usual motor are all advantages of this mechanism. But disadvantage should not be ignored. Especially up and down bumpy of the centroid will influence the smoothness of the motion during walk. Through theoretical analysis of kinematics, motion characteristics and the movement of the spindle were obtained in a circle. To aim to bring down the uneven of the BWM, the relationship of all parameters was found and the scope of the fluctuation was established. In the end, all of the results were verified by simulation program of Matlab. The result provided theoretical guidance for optimal design of the mechanism in the further research.
Influence of Contractive and Dilative Motion of Blood Vessel to Robot
Authors: Jiang Fan , Yu Juan , Wang Yi Jun
Published: October 2010

. In order to study the influence of contractive and dilative motion of blood vessel to robot, the moving surface is to simulate contractive and dilative motion of blood vessel, the model is used for the turbulent of blood flow. The results show that the blood flow field is impacted by the inlet velocity waveform and motion of blood vessel, the variation amplitude of flow parameter is greater than that of rigid blood vessel, the flow physical quantities change with inlet velocity waveform, and different positon has different variation tendency.
Surface Structure Research and Design of Drum's Coating Layer Based on Bionic Tribology
Authors: Xiao Lin Jing , Wang Xi Jing , Sui Xiu Hua , Zhuang Li Fu
Published: October 2010

. The slippage often occurs between conveyor belt and driving drum, reduces the transmission efficiency and even causes accidents due to lack of enough friction. By the analysis of friction drive principle in belt conveyor, three ways were presented to increase the frictional traction. Learning from the bionic tribology theory, we proposed a new structure design of the drum coating layer surface. The micro contact area of fly's seta that can adhere to any surface was taken as a prototype, and its microscopic structure was analyzed, then the surface structure of coating layer with recess long blocks was designed, finally, the solid modeling was created with CAD software. The new surface has sub atmospheric pressure absorption. The purpose is to increase the friction between conveyor belt and driving drum, and to avoid the slippage.
Simulation for Needle Deflection and Soft Tissue Deformation in Needle Insertion
Authors: Gao De Dong , Zheng Hao Jun
Published: October 2010

Needle deflection and soft tissue deformation are the most important factors that affect accuracy in needle insertion. Based on the quasi-static thinking and needle forces, an improved virtual spring model and a finite element method are presented to analyze needle deflection and soft tissue deformation when a needle is inserted into soft tissue. According to the spring model, the trajectory of the needle tip is calculated with MATLAB using different parameters. With the superposed element method, the two and three dimensional quasi-static finite element models are created to simulate the dynamic process of soft tissue deformation using ANSYS software. The two methods will be available for steering the flexible needle to hit the target and avoid the obstacles precisely in the robot-assisted needle insertion.
Meshless TL and UL Approaches for Large Deformation Analysis
Authors: Gu Yuan Tong
Published: October 2010

To accurately and effectively simulate large deformation is one of the major challenges in numerical modeling of metal forming. In this paper, an adaptive local meshless formulation based on the meshless shape functions and the local weak-form is developed for the large deformation analysis. Total Lagrangian (TL) and the Updated Lagrangian (UL) approaches are used and thoroughly compared each other in computational efficiency and accuracy. It has been found that the developed meshless technique provides a superior performance to the conventional FEM in dealing with large deformation problems for metal forming. In addition, the TL has better computational efficiency than the UL. However, the adaptive analysis is much more efficient using in the UL approach than using in the TL approach.
Simulation Research of the Condenser in a 600MW Supercritical Thermal Power Plant
Authors: Zhao Yun Yun , Zhang Yan Ping , Deng Wei , Huang Shu Hong
Published: October 2010

A simulation model of the condenser in a 600MW supercritical thermal power plant was developed by using Matlab/Simulink. The important parameters such as condenser pressure, hot well water temperature and cooling water temperature were calculated by using this model. The simulation results under different operating conditions were compared with design parameters, and the relative errors were within -0.2% and +0.2%. This shows that the simulation model developed in this paper is reasonable. The dynamic performance and off-design performance of the condenser were studied by using the simulation model, which would be useful for the optimal operation of the condenser. The model of the condenser, which was developed based on the modular modeling method, would be an important basis for the simulation of the whole power plant.
Influence of Multi-Walled Carbon Nanotubes on the Mechanical Properties of Nanocomposites
Authors: Her Shiuh Chuan , Yeh Shun Wen
Published: October 2010

The effects of matrix stiffness and the content of multi-walled carbon nanotubes on the mechanical properties of the nanocomposites have been examined in this investigation. The matrix stiffness was controlled by changing the mixture ratio between the epoxy and hardener. Two different contents (1 wt.%. and 2 wt.%) of the multi-walled carbon nanotubes (MWCNT) were added to the epoxy matrix. Three-Point-Bending and Shore’s hardness tests were conducted to determine the Young’s modulus and hardness of the nanocomposites, respectively. Experimental results showed that the Young’s modulus of the nanocomposites was significantly increased with the increase of the addition of MWCNTs. However, the improvement of the hardness of the epoxy was insignificant with the addition of the MWCNTs. The reinforcement role of the multi-walled carbon nanotubes decreased while increasing the stiffness matrix.
Effect of Core-Shell Particles on the Properties of Polystyrene/TiO2 Nanocomposites
Authors: Sang Xiao Ming , Wu Peng , Chen Xing Gang , Hou Gui Xiang
Published: October 2010

The well-dispersed core-shell nanospheres (TiO2-g-PS) were synthesized via nano-TiO2 grafting polymerization and were used to prepare PS/TiO2 nanocomposites by melt blending. The tensile and thermal properties of the nanocomposites were measured by means of tensile test and thermogravimetric analysis (TGA). The fracture surface of the tensile test specimens was also explored through scanning electron microscopy (SEM). The reasults show that the tensile performance and thermal stability of the PS/TiO2 nanocomposites depend on the loading and state of the TiO2 in the PS matrix. The optimal properties of nanocomposites are achieved at 1.0wt% of TiO2-g-PS nanoparticles and the tensile strength is increased up to 43.6% comparing to the pure PS. The onset temperature at which 10% mass is lost is increased 10oC. The dispersion of the particles and interfacial adhesion lead to enhance these properties.
Fast Deformation of Skeletal Muscle Using Constraint Functions
Authors: Liang Xiu Xia
Published: October 2010

In this paper, we propose a fast approach to simulate the dynamic behavior of skeletal muscles based on bio-mechanical and anatomical properties. In contrast to physically accurate deformation, this simulation achieves faster and better simulation of skeletal muscles, with the cost of unnoticeable visual accuracy. Internal constrains are generated to conserve linear and angular momentum which is essential for cloth self-collision. Deformation constraints are defined by using the muscle force-length relationship serve as Control Axial Curve, which constrainedly generates the active and passive force of the muscles to drive skeletal motion during the deformation process. This approach generates realistic visual effect, and manages the deformation of muscles on the basis of the bio-mechanical properties with fast speed. We have demonstrated the simulation by creating a musculoskeletal model of the upper limb.