bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Photochromic Materials with Synthesis and Application of 1-(2-methyl-3-benzothienyl)-2-[2-methyl-(5-ethynyl)trimethylsilane-3-thienyl] Perfluorocyclopentene
Authors: Ma Le Le , Xu Hong Yan , Liu Gang
Published: July 2014

A new unsymmetrical photochromic diarylethene compound, 1-(2-methyl-3-benzothienyl)-2-(2-methyl-(5-ethynyl) trimethylsilane-3-thienyl) perfluorocyclopentene (1o) has been synthesized, and its optoelectronic properties, such as photochromism and the fluorescence spectra of diarylethene 1o in hexane solution was investigated. The results showed that this compound exhibited reversible photochromism in solution. The maxima absorption of compound closed-ring isomer 1c are 538 nm. Its fluorescence intensity decreased along with the photochromism from open-ring isomers to closed-ring isomers upon irradiation with 297 nm UV light.
Efficient Synthesis, Photochromism and Fluorescence Properties of a Novel Diarylethene Bearing a Fluorene
Authors: Xia Shui Jun , Dong Xiao Rong , Liu Gang
Published: July 2014

A new symmetrical photochromic diarylethene, 1,2-bis-[2-methyl-5-(9,9-dibutyl-9H-fluorene) -3-thienyl] perfluorocyclopentene (1a), was synthesized and its optoelectronic properties, such as photochromism in solution and fluorescence were investigated. The photochromic reaction kinetics indicated that the cyclization processes of 1a belong to the zeroth order reaction and the cycloreversion process belong to the first order reaction. The new diarylethene also exhibited relatively strong fluorescence by photoirradiation in solution and the fluorescence intensity decreased along with the photochromism upon irradiation 297 nm light and its closed-ring isomer showed almost no fluorescence.
Hydrophobic Modification on Surface of Silicone Rubber by Tetrafluoromethane Radio Frequency Inductively Coupled Plasma
Authors: Gao Song Hua , Gao Li Hua
Published: July 2014

Hydrophobic modification on surface of silicone rubber by CF4 radio frequency inductively coupled plasma is discussed. Static contact angle and X-ray photoelectron spectroscopy were used in characterizing the hydrophobic property and chemical composition of the modified silicone rubber. The results show that the improvement of surface hydrophobic property on modified silicone rubber is put down to the introduction of fluorocarbon functional groups (C-CFn, n=1, 2,3) and fluosilicic structures (Si-F and Si-F2) during the treatment.
Characterization and Photoluminescence of Sr2B2O5:Eu3+, Na+ Red Phosphor
Authors: Ying Li Li , Zheng Song Sheng , Zheng Jiang Hui , Cai Li Han , Chen Chao
Published: July 2014

A kind of red emitting phosphor, Sr2B2O5:Eu3+, Na+ for white light-emitting diodes (W-LED) was synthesized by high-temperature solid-state reaction method. The characterization and luminescence properties of the phosphor were investigated. It is found that this phosphor can be effectively excited by 394 nm near-ultraviolet (n-UV) light, and exhibit bright red emission centered at 613 nm corresponding to the 5D0→7F2 transition of Eu3+ ions. It is shown that the 11 mol% of Eu3+ doping concentration in Sr2B2O5:Eu3+, Na+ phosphor is optimum, and the concentration quenching occurs when the Eu3+ concentration is beyond 11 mol%. The concentration quenching mechanism can be interpreted by the dipole–dipole interaction of Eu3+ ions. The present work suggests that this novel phosphor is a kind of potential red emitting phosphor.
Research on Biological Materials with Effect of Constant Magnetic Field Intervention on Bone Growth and Development in Rabbits
Authors: Lv Lin , Yang Jian Hui
Published: July 2014

To investigate the effect of constant magnetic fields on bone deformation, 16 rabbits were randomly divided into the control group and the experimental group. Biological materials with effect of constant magnetic field were attached to the hind legs of rabbits in the experimental group for a period of 4 months. Rabbit bones were periodically measured and compared. Results showed that compared with the control group, rabbits in the experimental group exhibited significant bone growth, indicating that constant magnetic field may significantly activate bone growth in rabbits.
Mechanical and Rheological Properties of Aluminous Cement under High Temperatures
Authors: Holčapek Ondřej , Reiterman Pavel , Konvalinka Petr
Published: July 2014

The following article deals with the relations between rheological behavior and strength characteristics of high aluminous cement paste. There were investigated the values of flow of fresh mixture (tested with Högermann ́s table), tensile strength in bending and compressive strength at the age of 28 days on specimens 40 x 40 x 160 mm. The influence of high temperature was examined by exposure to 600 °C and 1000 °C. The results of provided experimental program confirm the fact that with increasing water-cement ration decreases compressive and tensile strength before and after temperature loading. Also was shown the effect of high temperature on refractory aluminous cement paste properites.
Cement Composites for High Temperature Applications
Authors: Koňáková Dana , Vejmelková Eva , Spedlova Veronika , Polozhiy Kirill , Černý Robert
Published: July 2014

Fiber reinforced composites designed for better thermal resistance, which can be used in constructions with a higher fire hazard, are studied. The matrix of studied composite is based on aluminous cement, because of its proved higher thermal resistance than ordinary Portland cement. Basalt sand is used as alternative aggregate replacing silica sand, and basalt fibers are employed for an improvement of mechanical performance. The presented analysis of basic physical properties, mechanical, hygric and thermal properties shows that basalt is an appropriate material for cement based composites for high temperature applications.
Influence of Casting Direction on the Mechanical Properties of Cementitious Fiber Reinforced Composites
Authors: Tvarog Michal , Fornůsek Jindrich
Published: July 2014

This paper is focused on behavior of fiber reinforced cement composites (FRC) and ultrahigh-performance fiber reinforced cement composites (UHPFRC) in dependence on the direction of casting. Almost fifty prismatic samples of size of 400 x 100 x 100 mm were cast into horizontal and vertical moulds. Forty of them with most corresponding results were used in this paper – twenty for FRC and twenty for UHPFRC. In each mixture three samples of both series were cast in the common horizontal direction and the other three in the vertical way. It was found that specific fracture energy of horizontally cast prisms was approximately four and half times higher for both materials than the vertically cast ones. The peak loads of FRC were very similar for both ways of casting. On the other hand the UHPFRC behaved differently, the peak load of horizontally cast prisms was approximately three times higher than the vertically cast ones. It was demonstrated that these differences are caused by the way of casting and vibration.
A Comparative Study on Thermal Properties of Two Types of Concrete Containing Fine Ceramic Waste and Burnt Clay Shale as a Supplementary Material
Authors: Scheinherrová Lenka , Trník Anton , Vejmelková Eva , Reiterman Pavel , Medveď Igor , Černý Robert
Published: July 2014

In this paper, the effect of elevated temperatures (up to 1000 °C) on thermal properties of two similar types of high-performance concrete containing fine ceramic waste and clay shale, respectively are used as a partial replacement of the cement binder is investigated. Samples were prepared in the same manner and both types of concrete contained from 0 to 60 mass% of either replacement. Both replacements were used in our study as a pozzolana active material which can partially replace cement binder and can improve the final properties of concrete. The aim of this paper is to compare the influence of two different pozzolana active materials on selected thermal properties of high-performance concrete at high temperatures up to 1000 °C. The investigation was performed using the differential scanning calorimetry and these results were supplemented by measurement on horizontal dilatometer.
Research of Dynamic Cutting Force in Hardened Steel Precision Turning Process
Authors: Chen Guang Jun , Kong Ling Guo , Liu Xian Li
Published: July 2014

Dynamic cutting force will induce vibrations in hardened steel precision turning process. The dynamic cutting force in the process of turning was studied, and the dynamic cutting force model of hardened steel precision turning system was set; Based on DEFORM-3D software, a three-dimensional model of hardened steel turning was established by pre-set some fluctuations workpiece geometry; the turning test of hardened steel GCr15 in CAK6150DI lathe by using PCBN cutting tools, simulation and experimental results show that the high-speed precision turning will produce strip and sawtooth chip morphology; the maximum cutting force of hardened steel precision turning is the radial cutting force, which is greater than the main cutting force; cutting forces have a larger amount of fluctuation, which can reach 30% -55%. This research will provide a theoretical basis for related study on the vibration of the hardened steel turning process
The Mathematic Model of End Mill’s Rake Face Based on the Fillet and Two Attitude Angles of Grinding Wheel
Authors: Zhao Xian Feng , Shi Hong Yan , He Lin
Published: July 2014

The mathematic model of rake face was set up for precise description on the rake face of end mill in grinding process, with its basis on the fillet of grinding wheel with six axes linkage movement and two attitude angles. The sectional drawing of rake face and three-dimensional entity were drawn based on the mathematic model in SolidWorks. At the same time, the discrete entity of rake face also set up based on the Boolean calculation. The sectional drawing of mathematic model and the discrete entity tallies with each other perfectly, which indicates the correctness about the mathematic model of rake face.
Finite Element Method Simulation Study of High-Temperature Alloy Serrated Chip
Authors: Wang Yu , Wang Bao Tao , Qiao Shuai
Published: July 2014

High-temperature alloy can easily produce jagged chips in high-speed cutting conditions. The serrated chips will lead to the volatility of cutting force and impact the processing efficiency and quality. The formation mechanism of serrated chip has important significance to improve processing quality and efficiency. As the serrated chips have very short generation time, it is very hard to measure the changes of the stress, strain and temperature during the formation of serrated chips in experimental method. And it is more difficult to carry out quantitative and qualitative analysis. So it has been the research priorities and difficulties in the field of metal cutting. In this paper, both the finite element method simulation and experimental method are used to study the formation mechanism of serrated chip, deformation of material and the degree of variation of jagged. It has an important reference value to select cutting parameters for high-temperature alloy cutting.
Finite Element Simulation and Experiment on Residual Stress in Turing 45# Steel with Complex Groove Tools
Authors: Zheng Yong Chun , Liu Er Liang , Li Jiao , Ju Hong Yan , Zhao Li Guo
Published: July 2014

The research focused on the finite element simulation of the surface residual stress and took an experiment to get cutting temperature and cutting force by changing different groove and coated tools. Then it analyzed the influence of cutting and tool parameters on cutting force and temperature. Finally, the results reached a conclusion about the way that the tools with different groove and coating influenced the residual stress. The coated tools reduced the residual tensile stress in the machined surface. The axial and tangential residual stress was tensile stress and the tangential residual stress was larger than the axial in machining.
Milling Forces of Compacted Graphite Iron (CGI) and Gray Iron (GI)
Authors: Guo Y. , Wang C.Y. , Yuan H. , Zheng L.J. , Song Y.X.
Published: July 2014

Compacted graphite iron (CGI) has excellent comprehensive performance of strength, hardness, abrasion resistance, shock absorption and thermal conductivity as an ideal material for making engine parts. The material performance of CGI is compared with that of gray iron (GI) and spheroidal graphite Iron (SGI). Some research shows that the strong adhesion between the iron and the graphite forms semi-continuous chips when machining CGI which requires more energy than GI cutting, and there's no MnS layer on the cutting edge during CGI cutting. Thus, the cutting tool life of CGI is greatly reduced than GI. The experiment results indicate that the cutting forces of CGI milling are much higher than that of GI when the feed and the depth of cut increase.
A New Conversion Matrix Model of Strain-Gage Dynamometer
Authors: Wang Sheng Zhang , Zhao Wei , Huang Zhen , He Ning , Li Liang , Yang Yin Fei
Published: July 2014

Dynamometer has a extensive application in high-speed milling. The high frequency dynamometer is a kind of strain-gage dynamometer and produces a relation between the cutting force and voltage. And the relation can be expressed as a conversion matrix model which makes a great impact on the results of measurement. Taking into account cross-sensitivity and point effect at the same time, a new conversion matrix model for the high frequency dynamometer was established in order to improve the accuracy of dynamometer and the dynamometer has been subjected to calibration experiments to obtain conversion matrixes of the model. Finally, a series of high speed milling experiments were conducted. And the results obtained showed that the dynamometer by adopting the model could measure the cutting forces and have a higher accuracy.
FEM Analysis of Residual Stress Distribution and Cutting Forces in Orthogonal Cutting with Different Initial Stresses
Authors: Ma Yuan , Yu Ding Wen , Feng Ping Fa
Published: July 2014

Machining induced residual stress is influenced by many factors. Extensive studies on the influence of cutting parameters, tool parameters, as well as basic properties of materials have been carried out during the past decades, while another important factor, initial stress distribution in workpiece, was often ignored. In this paper a relatively complete FEM simulation on the formation mechanism of machining induced residual stress in high speed machining is carried out, illustrating the three stress zones affected by mechanical and thermal loads, and their influence on ultimate residual stress. And the influence of initial compressive stress on stress formation and cutting forces is analyzed. Initial compressive stress weakens the tensile effect caused by the shear deformation, and the residual stress tend to be more compressive with larger initial compressive stress. Cutting force becomes larger with the increase of initial compressive stress. And the results in this FEM study can be used to explain some unaccounted experimental phenomena in former researches.
Numerical Modeling of Minimum Uncut Chip Thickness for Micromachining with Different Work Materials
Authors: Liu Lu Ning , Shi Zhen Yu , Liu Zhan Qiang
Published: July 2014

The determination of the minimum uncut chip thickness is essential in micro machining in order to achieve desired surface integrity and accuracy. The parameters being considered in determination the minimum uncut chip thickness include the cutting tool geometry, workpiece material, cutting parameters and so on. In this paper, five different materials including OFHC Copper, Al 7050, AISI 4340, Ti-6Al-4V and IN 718 with unequal materials’ properties were investigated to find materials parameters’ effect on the minimum uncut chip thickness. An Arbitrary Lagrangian Eulerian (ALE)-based numerical modeling is proposed to determine the minimum uncut chip thickness for the five different materials by changing depth-of-cut. The Johnson-Cook (J-C) constitutive model is employed to describe the work material behavior. Results show that the flow stress of different materials has significant effect on the minimum uncut chip thickness.
Determination of Capto C5 Shank’s Key Dimensions
Authors: Shi Xiang Yun , Jiang Hong , Zhou Hong Da , Wang Shu Lin
Published: July 2014

Capto shank is widely used in high speed machining, especially in Turning/Milling center. Some of shank’s dimensions exert a tremendous influence on its working performance. In order to find out these key dimensions, finite element method is used to analyze how the change of Capto C5 shank’s nine dimensions affects its radial stiffness. Some key dimensions which have great effects on Capto shank’s properties are found. The research results provide theoretical basis for manufacturing and measurement of Capto shank.
Experimental Research on the Selection of Tool Material in Turning Superalloy GH4169
Authors: Yu Feng Yun , Tu Yuan , Wang He , Wu Lin , Fu Yun Liang
Published: July 2014

Through machining superalloy GH4169 in center lathe by four kinds material of tool, which are YT763, K313, KC5510 and SM1105, analyzing the changings of cutting force and surface roughness in different material of tool and the forms of tool wear. As the experiment data shows, there is little influence of the different tool in material with the same coating to cutting force and surface roughness. KC5510 is more suitable for constant speed cutting GH4169, which offers the choices of tool material when machining superalloy in common speed.
Circular Milling Cutter Design and Finite Element Simulation for Machining Hardening Steel Mould
Authors: Wang Chang Hong , Chen Tao , Li Kai , Li Lu Bin , Li Xian Chuang
Published: July 2014

This paper aim at frequent alternating load, caused by milling large covering parts with hardened steel give rise to cutting chatter, increase surface size error in mould processing. Based on theory of helix spiral surface, design circular milling cutter with damping groove, and employ simulation of finite element to verify the efficient performance of chip breaker. Effectively reduce milling vibration problem caused by the mutation of cutting force, cutting temperature, provide theoretical model to the subsequent tool structure parameters and manufacture technology research.
Study on Dynamic Properties of Damping Boring Bar with Large Ratio of Length to Diameter
Authors: Xu Cheng Yang , Wang Yu , Wu Shi , Liu Xian Li , Liu Li Jia
Published: July 2014

In the deep hole boring, the vibration of the boring bar is greater. In order to improve the machining processing efficiency and quality of the deep hole boring, this paper designs the deep hole damping boring bar with a single oscillator firstly. It builds a simplified dynamic model of the damping boring bar and calculates its relevant parameters. Moreover, with different external excitation force frequency, the maximum amplitude variation of the boring bar tip position is obtained from the simulation analysis. Finally, the experiments show that: Compared with the hollow boring bar and the solid boring bar, the damping effect of large aspect ratio vibration boring bar increases about 75%.
Application and Technology Research in Deep-Hole Drilling System
Authors: You Hai Yan , Yang Shu Cai , Yue Cai Xu , Wu Xue Feng , Xie Yang
Published: July 2014

With the new type of high strength , high hardness difficult machining parts appear constantly, both for the quality of deep processing, durability of the tools, or reliability of the drilling systems are putting forward higher requirements. This paper mainly describes the characteristics of deep-hole drilling systems and applications, and content selection of cutting parameters, impact of cutting speed and feed rate for chip breaking and so do some explanation, These have certain guiding significance for chip breaking can get better. Finally, introduce the deep-hole drilling in the drilling process causes common problems and solutions, to provide some references for practical manufacture process.
Research of an Open CNC System of Machine Tool for Finding and Repairing Surface Damage on KDP Crystal
Authors: Chen Ming Jun , Jiang Lin Xi , Zuo Ze Xuan , Xiao Yong
Published: July 2014

In order to find and repair surface damage on KDP crystal, an open computer numerical control(CNC) system has been developed. This paper introduces the hardware structure of the control system, explains the development of an open CNC system software, which has friendly human-machine interface (HMI) and can make the finding and repairing process efficiently and conveniently and also expounds the algorithm and related parameters for servo tuning. With the open CNC system, the process of finding surface damage is accomplished in 3 hours and clear images of crystal surface damage is taken by CCD. And also, with the help of the open CNC system, a 600µm-diameter, 25µm-depth Gaussian repair contour with low roughness is obtained. Experimental results prove that the open CNC system for finding and repairing surface damage on KDP crystal meets the requirement of efficient detection and ultra-precision machining.
Experimental Investigation on Surface Roughness in Precision Cutting Ti6Al4V Alloy Using Diamond Tools
Authors: Hu Lin Hua , Zhou Ming , Zhang Yu Liang
Published: July 2014

In this work, cutting experiments were carried out on titanium alloy Ti6Al4V by using polycrystalline diamond (PCD) tools to investigate the effects of the tool geometries and cutting parameters on machined surface roughness. Experimental results show machined surface roughness decreases with increases in the flank angle, tool nose radius and cutting speed within a limited range respectively, and begins to increase as the factors reaches to certain values respectively. And machined surface roughness decreases with increases in feed rate and cutting depth respectively.
Research on Surface Topography and Roughness of Micro Parts by High Speed Turn-Milling
Authors: Jin Cheng Zhe , Fang Rui
Published: July 2014

High speed turn-milling has superiority on the productivity and the quality of work pieces, and is more suitable to machine micro-shaft parts and desirable miniature parts based on the turn-milling technology. In this papers adopting orthogonal experiment method cutting experiments of orthogonal turn-milling Aluminum alloy have been done. The relation between turn-milling regimes (cutter rotate speed, axial feed, feed per tooth etc.) and machined surface roughness has been ascertained. Finally, primary and secondary order of cutting regimes impacting surface roughness has more been confirmed through orthogonal experiments variance analysis, the rotate speed of cutter (cutting speed) influence greatly on surface roughness. Through 2-dimension surface topography diagram and 3-dimension surface topography of processed surface, it can be seen that high speed turn-milling processing technology can process micro miniature component of high surface quality, and features excellent development prospect and application value.
The Tool Path Planning and Simulation Analysis of Surface Flank Milling for Titanium Impeller Blade
Authors: Wu Ming Yang , Zhang Rui , Cheng Yao Nan , Zhang Yue , An Shuo , Li M.Y.
Published: July 2014

The impeller is an important typical part of machinery and equipment industry, and is widely used in energy and power, aerospace, petrochemical, metallurgy and other fields. However, due to the complex shape of the impeller blades, forming more difficult. Flank milling have many advantages, such as forming good accuracy, high efficiency. Therefore, in the paper will choose flank milling for impeller milling. Based on the properties of titanium alloy material and the external characteristics of the impeller blades, proposed control method for machining distortion of impeller blades. Using three offset method to calculate the initial tool position of cylindrical cutter flank milling undevelopable ruled surface, then calculate the initial tool position of cone ball cutter to plan tool path of milling. Through the VERICUT software to simulate the whole process of the impeller flank milling, in order to verify the tool path planning and determine the interference between the tool and the workpiece, the tool and the workpiece does not occur. Finally, through experiments to verify the feasibility of planning algorithm. The trajectory planning and simulation of flank milling titanium impeller blades are foundation of improvement the processing efficiency of the impeller blades and better surface quality.
Double Helical Synchronous Belt Transmission Design
Authors: Guo Jian Hua , Jiang Hong Yuan , Wu Yi Zhen , Chu Wen Ya , Meng Qing Xin
Published: July 2014

The meshing impact noise caused by the gradually engagement between double helical synchronous belt and the pulley was reduced due to its spiral angle effect. Therefore, double helical synchronous belt transmission receives much concern with its excellent characteristics of de-noising, low transmission error and high carrying capacity. The profiles of synchronous belt and belt pulley were studied based on conjugate-curvature high degree contact meshing theory under the circumstance that the pitch of belt and belt pulley are identical. The higher contact strength of the belt teeth and a smaller clearance in the contact point adjacent area were ensured with Hertz contact theory as the synchronous belt is in contact with pulley. And then a conjugated arc tooth profile with two-step contact and three-step adjacent gap infinitesimal was proposed based on the simple easy to processing method, which was adopted as main parameters for double synchronous belt and pulley’s normal teeth profile. The three-dimensional transmission model was built and the static nonlinear contact analysis was done with finite element software ANSYS. Finally, the noise experiment was conducted on the high speed test bench to compare the noise reduction effect between double helical synchronous belt and straight tooth timing belt with the identical end face profile. The simulation and experiment result show that the double helical synchronous belt transmission can reduce noise level by 11dB approximately compared with straight tooth timing belt transmission.
The Research of Cutter-Location Optimization for Flank Milling Blades of Undevelopable Ruled Surfaces with Toroidal-End Cutter
Authors: Huang J.C. , Liu Xian Li , Yang Ye , Tang S.Y. , Li Y. , Yang B.
Published: July 2014

To improve the efficiency and precision of five-axis numerical control machining for undevelopable ruled surfaces,a cutter-location optimization algorithm was proposed for flank milling of blades with a toroidal-end cutter. Firstly, it is established initial cutter-location of toroidal-end cutter by optimizing algorithm of three-point offset based on geometry features of toroidal-end cutter, and optimized cutter vector by introducing scaling factors. A new method which was based on dynamic sliding index calculating optimal cutter orientation vector was proposed. The method which applied deviation measurement algorithm computed overcut or undercut values of programming error in different scaling factors state. Finally, through the instance of machining verified the rationality of the method, and effectively reduces programming error.
Multi Objective Optimization of Cutting Process Based on Improved Particle Swarm Optimization Algorithm
Authors: Liu Xue , Yue Cai Xu , Wu Ming Yang , Yang Yong Heng , Ren Guang Xu , Liu Xian Li
Published: July 2014

With the rapid development of machinery industry, the processing parameters which affect on the quality of the products in machining and measuring index also appeared diversified, which makes the study of multi-objective optimization problem is very important. Among the many factors, cutting consumption plays a key role in many indicators, in effect, cutting force and cutting temperature on the quality and performance of products is the most prominent, so this paper takes PCBN tool cutting Cr12MoV steel as the experimental basis, the cutting parameters to optimize the parameters;the cutting force and cutting temperature as the index;with the aid of the BP neural network modeling of cutting force and cutting temperature, at the same time, this paper improved particle swarm optimization algorithm to achieve multiple objectives, provides multi objective optimization parameters more reliable for die steel production process.
Investigation of Tool Path Patterns in Milling Curvature-Mutated Surface
Authors: Li Jiao , Liu Er Liang , Ding Yun Peng , Liu Xian Li , Zheng Yong Chun
Published: July 2014

High-speed machining puts forward higher requirements not only for tools and fixtures, but also for the tool path patterns with the development of manufacturing. The focus is on analyzing different characteristics of tool path patterns, and influencing factors of choice in milling curvature-mutated surface. Then a reasonable choice is presented on the principle of tool path patterns. According to surface features, milling characteristics and programming requirements, the surface with the curvature changing seriously is subdivided into two patches, thus the subdivision surfaces are roughing machining. Finally, Powermill is used to verify further its feasibility.
Cutting Tool CAD / CAE Integrating System Modeling
Authors: Ding Ming Na , Ji Wei , Wang Yi Wen , Zuo Dian Ge , Cheng Yao Nan
Published: July 2014

Targeting the current status of cutting tool design long cycle and inefficient, this research presents an integrating system of cutting tool design (CAD) and simulation (CAE). First, the paper proposes the system architecture and analyzes the process. And then based on the architecture, the system prototype integrating SIEMENS NX and ANSYS is developed on the Visual Studio 2008 platform. The prototype can generate cutting tool 3D model on SIEMENS NX and continue to simulate on ANSYS based on the information from users. Finally, a kind of ball end mill is presented to certificate this system.
Sensitivity Analysis of Temperature Measuring Points for Machine Tool Spindle Based on Grey System Theory
Authors: Wang Qian Feng , Zhang Song , Chen Yan , Zhang Qing , Zhao Bin
Published: July 2014

This paper presents a sensitivity analysis method of temperature measuring point of the machine tool spindle based on grey system theory. The initial finite element analysis (FEA) is conducted on the spindle model to determine the temperature distribution of the spindle model and ascertain the resultant structural deformation, and eight nodes of the spindle model are selected as temperature measuring points. By means of grey system theory, temperature measuring points of machine tool spindle model are analyzed and then the effects of the different temperature measuring point on the spindle axial deformation are conducted. Finally, the validity of this sensitivity analysis method is verified by conducting the theoretical analysis and developing the linear estimate equation. The analysis results show that this sensitivity analysis method can effectively determine the thermal sensitivity of temperature measuring points, ensure the accuracy of the thermal compensation model and eliminate the coupling problems.
Application of the Bridge Type Circuit on the Large-Scale Machine Tool Gravity Compensation System
Authors: Cai You Jie , Wang Xue Feng , Wang Shi Gang
Published: July 2014

Through the analysis of the spindle ram deformation compensation during the process of large-scale machining, design a bridge type circuit which can improve the accuracy of processing after the ram’s moving out and meet the requirements of the compensation. The bridge type circuit has higher sensitivity for force and torque change, which improves the accuracy of machine tool. The mechanism greatly reduces the spindle rotation accuracy error caused by the gravity deviation, effectively improves the machining accuracy of the workpiece and guarantees the product accuracy of machine tool.
Investigation of Power Consumption in Face Milling Operations
Authors: Ren Xiao Ping , Liu Zhan Qiang
Published: July 2014

In oblique cutting, the assumption of point contact between the tool and theworkpiece often results in the consideration of only the forces in the three principaldirections. This paper disregards these assumptions and confirms the existence ofmoments around the three principal directions through measurements of themechanical factors during a face milling operation. The cutting forces and moments atthe three directions achieved by using Kistler 9275B dynamometer in this paper, andthe development of a calculation algorithm that allows the transport of the cuttingmoments from the center of the dynamometer at the tip of the tooth is developed.Based on the mechanical actions’ theory, the power consumed during the cuttingprocess is determined. A comparative study on the power consumed during thecutting process is undertaken.
The AE Signals Bi-Spectrum Features Study in Batch Drilling
Authors: Zhou You Hang , Xie Sai Yuan , Zhou Hou Ming
Published: July 2014

Based on the coupling phenomena between the batch drilling process quality fluctuation and monitoring signal features changes, the acoustic emission signals of batch drilling are taken as research objects to solve the quality consistency control and detection problem of the high-precision batch drilling step. The average bi-spectrum amplitude of each signal is taken as an eigenvalue for the quantitative analysis of the deviation degree from Gaussian distribution under different conditions. The calculation and analysis results show that there are organic connections between the bi-spectrum feature of monitoring signals and drilling step quality, and the consistency quality testing of batch drilling step is realized by bi-spectrum features.
Experimental Study on Orthogonal Cutting of 0° T700/LT03A CFRP Uniform Laminates
Authors: Qin Sheng , Li Zheng Wei , Zhang Hong Zhou , An Qing Long , Chen Ming
Published: July 2014

Carbon fiber reinforced polymers (CFRP) are increasingly used in aerospace and other industries, due to its high specific strength and stiffness. Machining operations are involved between forming fabrication and assembling as a fining process, during which defects like delamination, burrs and splintering are the main cause of substandard products. This is because that CFRP is a typical difficult to machine material with distinct anisotropy and heterogeneity. Thus machinability of CFRP material under different fiber orientations is a main issue. This paper intensively investigated on cutting forces and temperatures when orthogonal cutting of 0° T700/LT03A CFRP uniform laminates, with fiber orientation from 0°to 180°. Material removal mechanisms and carbon fiber fraction modes under various fiber orientations were discussed. The results showed that fiber orientation of 90°is the worst scenario of cutting, under which condition the force and temperature of the highest level, while that of 150°indicates the other. The results of cutting temperature indicated that it is mainly from the friction heat in the zone III generated by the thrust force.
Research on Error Compensation of Corner Milling Process Based on Milling Force Prediction
Authors: Shi Hui Nan , Yan Fu Gang , Ding Yun Peng , Liu Xian Li , Zhang Rui
Published: July 2014

In cavity die corner-machining, tool flexible deformation caused by the milling force resulting in the surface error, a method of off-line error compensation is put forward. Instantaneous chip thickness model and the corner milling force model is established based on differential and the characteristics of the corner. Combining the theory of cantilever beam and the finite element analysis, cutting tool elastic deformation model is established.
A Study on Energy Consumption of a CNC Milling Machine Based on Cutting Force Model
Authors: Meng Yue , Wang Li Hui , Wu Xue Feng , Liu Xian Li , Ren Guang Xu
Published: July 2014

Machining operations are performed by machine tools with a large amount of energy consumed for material removal. Understanding and characterizing the energy consumption is essential to explore the potential of energy-saving in energy-efficient machining. For this purpose, this paper proposes a method for modeling energy consumption of end milling operation which is based on cutting theory. The cutting power model is verified with experiments on a CNC milling machine. According to the calculated and experimental results, it is clear that the theoretical prediction can predict the mean cutting power successfully as validated by actual measurements.
Experimental Investigation of Tool Wear and Chip Morphology in Turning Titanium Alloy Ti6Al4V
Authors: Li Zhen , Liu Er Liang , Wang Teng Da , Li Jiao , Zheng Yong Chun
Published: July 2014

The various feed rate and cutting speed have an important influence on cutting force, tool wear and chip morphology in machining titanium alloy. Cutting experiments are carried out analyzing the titanium alloy Ti6Al4V under different cutting speed and feed rate, the cutting force values are obtained. The analysis results show that the dominant wear pattern is adhesion wear and chipping. And the tool wear also has an influence on chip morphology.
Laser-Assisted Machining of Advanced Materials
Authors: Kong Xian Jun , Zhang Hong Zhi , Wu Xue Feng , Wang Yang
Published: July 2014

Laser-assisted machining (LAM) is a hybrid cutting process in which a laser beam is used to heat and soften the workpiece locally in front of the cutting tool edge. The rapid temperature rise at the shear zone reduces the yield strength and work hardening of the workpiece, which makes the plastic deformation of difficult-to-machine materials easier during machining. LAM provides a reduction in the cutting forces/specific cutting energy, longer tool life, better surface integrity, and high productivity over traditional cutting. This paper presents the technical characteristics, material removal mechanism and the application of machining hard-to-machine material in LAM. The latest development of LAM and future scope are summarized in this paper.
Glucocorticoid-induced osteoporosis: 2013 update
Authors: Mazzantini M. , Di Munno O.
Published: July 2014

Glucocorticoids are the most common cause of secondary osteoporosis leading to the so-called glucocorticoidinduced osteoporosis (GIO). A treatment with 10 mg/d of prednisone or equivalent for more than 3 months leads to a 7-fold increase in hip fractures and a 17-fold increase in vertebral fractures. The difference between bone quantity and quality in GIO makes bone mineral density measurements inadequate to detect patients at risk of fracture. The adverse effects of glucocorticoids on the skeleton derive from a direct impact on bone cells with a severe impairment of mechanical competence. Crucial to prevention of GIO is early timing of intervention. The World Health Organization has adopted a fracture prevention algorithm (FRAX) intended to estimate fracture risk in GIO. The American College of Rhematology modified its prevention and treatment guidelines taking into account the individual risk of fracture calculated in GIO on the basis of the FRAX algorithm. Recently, also a joint Guideline Working Group of the International Osteoporosis Foundation (IOF) and the European Calcified Tissue Society (ECTS) published a framework for the development of national guidelines for the management of GIO. Bisphosphonates are the first-line drugs to treat GIO; teriparatide counteracts several fundamental pathophysiologic aspects of GIO; denosumab is useful in patients with renal failure and in potentially pregnant young women. Vertebroplasty and kyphoplasty may be less beneficial in GIO than in primary involutional osteoporosis.
Immediate esthetic crown with a facet of the extracted element
Authors: Di Giacomo Giovanni de Almeida Prado , Magalhães Amanda , Ajzen Sergio
Published: July 2014

The present report describes a case of implant loading with an immediate temporary crown. The buccal crown surface was removed from the extracted tooth to obtain an aesthetically satisfactory result. After periodontal treatment, tooth 21 appeared proclined and showed Grade 3 mobility, indicating the need for its extraction. The remaining bone was imaged using computed tomography, and virtual surgical planning was performed using these results. The implant was immediately loaded postextraction into the fresh alveolus without a graft and flap procedure. The temporary tooth, which was manufactured using the extracted buccal surface, was a simple, fast, and low cost procedure that produced an excellent esthetic outcome.
Characterization of model errors in the calculation of tangent heights for atmospheric infrared limb measurements
Authors: Ridolfi M. , Sgheri L.
Published: July 2014

Abstract. We review the main factors driving the calculation of the tangent height of spaceborne limb measurements: the ray-tracing method, the refractive index model and the assumed atmosphere. We find that commonly used ray-tracing and refraction models are very accurate, at least in the middle-infrared. The factor with largest effect in the tangent height calculation is the assumed atmosphere. Using a climatological model in place of the real atmosphere may cause tangent height errors up to ±200 m. Depending on the adopted retrieval scheme, these errors may have a significant impact on the derived profiles.
Analysis of land cover change and its driving forces in a desert oasis landscape of southern Xinjiang, China
Authors: Amuti T. , Luo G.
Published: July 2014

Abstract. The combined effects of drought, warming and the changes in land cover have caused severe land degradation for several decades in the extremely arid desert oases of Southern Xinjiang, Northwest China. This study examined land cover changes during 1990–2008 to characterize and quantify the transformations in the typical oasis of Hotan. Land cover classifications of these images were performed based on the supervised classification scheme integrated with conventional vegetation and soil indexes. Change-detection techniques in remote sensing (RS) and a geographic information system (GIS) were applied to quantify temporal and spatial dynamics of land cover changes. The overall accuracies, Kappa coefficients, and average annual increase rate or decrease rate of land cover classes were calculated to assess classification results and changing rate of land cover. The analysis revealed that major trends of the land cover changes were the notable growth of the oasis and the reduction of the desert–oasis ecotone, which led to accelerated soil salinization and plant deterioration within the oasis. These changes were mainly attributed to the intensified human activities. The results indicated that the newly created agricultural land along the margins of the Hotan oasis could result in more potential areas of land degradation. If no effective measures are taken against the deterioration of the oasis environment, soil erosion caused by land cover change may proceed. The trend of desert moving further inward and the shrinking of the ecotone may lead to potential risks to the eco-environment of the Hotan oasis over the next decades.
Cloud and precipitation properties from ground-based remote sensing instruments in East Antarctica
Authors: Gorodetskaya I. V. , Kneifel S. , Maahn M. , Van Tricht K. , Schween J. H. , Crewell S. , Van Lipzig N. P. M.
Published: July 2014

Abstract. A new comprehensive cloud-precipitation-meteorological observatory has been established at Princess Elisabeth base, located in the escarpment zone of Dronning Maud Land, East Antarctica. The observatory consists of a set of ground-based remote sensing instruments (ceilometer, infrared pyrometer and vertically profiling precipitation radar) combined with automatic weather station measurements of near-surface meteorology, radiative fluxes, and snow accumulation. In this paper, the observatory is presented and the potential for studying the evolution of clouds and precipitating systems is illustrated by case studies. It is shown that the synergetic use of the set of instruments allows for distinguishing ice, mixed-phase and precipitating clouds, including some information on their vertical extent. In addition, wind-driven blowing snow events can be distinguished from deeper precipitating systems. Cloud properties largely affect the surface radiative fluxes, with liquid-containing clouds dominating the radiative impact. A statistical analysis of all measurements (in total 14 months mainly occurring in summer/autumn) indicates that these liquid-containing clouds occur during as much as 20% of the cloudy periods. The cloud occurrence shows a strong bimodal distribution with clear sky conditions 51% of the time and complete overcast conditions 35% of the time. Snowfall occurred 17% of the cloudy periods with a predominance of light precipitation and only rare events with snowfall > 1 mm h−1 water equivalent (w.e.). Three of such intensive snowfall events occurred during 2011 contributing to anomalously large annual snow accumulation. This is the first deployment of a precipitation radar in Antarctica allowing to assess the contribution of the snowfall to the local surface mass balance. It is shown that on the one hand large accumulation events (>10 mm w.e. day−1) during the measurement period of 26 months were always associated with snowfall, but that on the other hand snowfall did not always lead to accumulation. In general, this promising set of robust instrumentation allows for improved insight in cloud and precipitation processes in Antarctica and can be easily deployed at other Antarctic stations.
A note on commuting times and city size: Testing variances as well as means
Authors: An Qian , Gordon Peter , Moore James E.
Published: July 2014

Relatively little attention has been paid to the relationship between commute time variances and city size. In this paper, we utilize 2009 Nationwide Highway Travel Survey data and test the relationship between area commute-time means as well as variances in metropolitan-area size. We include tests for metropolitan areas as a whole and for residents from urban, suburban, second city, and town-and-county areas. The regression analysis shows that all estimated slopes are statistically significant but not much greater than zero. Commute time means and variances are highly correlated. These relationships are also invariant with respect to the place of residence. An extensive collection of literature provides evidence for the co-location of workers and jobs hypothesis: average commute times do not rise appreciably as metropolitan population increases. We conclude that these results are additional, although indirect, evidence for the co-location hypothesis.
A mode choice analysis of school trips in New Jersey
Authors: Noland Robert B , Park Hyunsoo , Von Hagen Leigh Ann , Chatman Daniel G.
Published: July 2014

This paper examines the mode choice behavior of children’s travel to school based on surveys conducted at a sample of schools in New Jersey. The main focus is on a variety of network design, land use, and infrastructure variables that have typically been associated with walking activity. Using a mixed logit model, it is found that good connectivity, more intense residential land use, and better sidewalk infrastructure are associated with increased walking to school. The use of a mixed logit model allows the examination of individual heterogeneity. Results indicate substantial heterogeneity in behavior associated with built environment variables.