bluuebunny/crossref_metadata_2025 huggingface dataset:
Combination of M-Estimation and Gaussian Filtering for Characterizing 3D Engineering Surfaces
Authors: Li H.F. , Jiang X.Q. , Li Z.
Published: March 2009

A reliable reference is the key to characterize surface topography. Gaussian filtering is strongly recommended by experts in the international standardization field. However, it can be affected by abnormal surface features. Based on the principle of M-estimation, a novel robust weighting function is proposed to improve the Gaussian filtering and a 3D robust Gaussian filtering model is developed. Experimental results have proven them effective.
A Polarized Optical Fiber Pressure Sensor with a Sampling Reference Optical Path
Authors: Huang Yuan Qing , Lin Y.X. , Huang Z.L. , Zhu L.M. , Chen Y.M.
Published: March 2009

The design of a polarized optical pressure fiber sensor system is presented. The system mainly consists of a laser, a birefringent crystal, a quarter wave plate, two polarizers, a sensing element and two photodetectors. The design of the sensing element is based on the photo-elastic effect. This type of sensor can be used to detect pressure, force and weight of an object. In addition, the sensor can be used to detect and to monitor the condition of overload of a vehicle real time and on line.
An Automatic Sorting System Based on Pneumatic Measurement
Authors: Wang Y.H. , Hu S.Q. , Hu Ying
Published: March 2009

For reducing the machining difficulty and increasing the conjunction precision, an automatic sorting system is presented. The system combines the backpressure pneumatic measurement with a pneumatic-electric transfer technology. A semiconductor pressure sensor is used for the pneumatic-electric transfer. The air chamber pressure is converted to an electrical signal. The merits of the semiconductor pressure sensor include high conversion precision, high frequency response, and small volume. But it has a relatively big temperature drift if no compensation is provided. The sensor can compensate temperature drift. But the null shift and sensitivity shift still exist. Reducing supply voltage using an electric bridge or reducing supply current using a constant current source can reduce the shift. The null shift and sensitivity shift can be further reduced by auto-compensation using a calibrated gauge. The automatic sorting system can automatically sort injector valves and orifices quickly with a resolution of 0.2µm. The sorting accuracy is 0.5µm and the speed is approximately thirty pieces per minute. The system has the function of auto-control and error auto-compensation and has a high measuring efficiency and high precision.
Measurement of Finishing Errors for Evaluation of Dynamic Characteristics of NC Machine Tools
Authors: Kim S.C. , Lee C.H. , Lee B.H.
Published: March 2009

Efficient development of method for performance evaluation of machine tools has been regarded as the most important issue to enhance accuracy and quality for users and manufacturers. Recently, a method of accuracy evaluation for machine tools has been studied as interests on precision machine tools have rapidly increased. From this point of view, the circular interpolation test of machine tools is recognized as the most useful method to identify the dynamic accuracy of NC machine tools by ISO, ANSI/ASME and others. In this paper, we studied and developed a formal measurement system with a grid encoder to analyze the final accuracy of NC machine tools. We analyzed the servo system error and the geometric error of NC machine tools through measuring the dynamic error signals by using this system. We verified the experimental result and enhanced the reliability by means of comparing the characteristics of the developed system with the kinematical ball-bar system.
Power System Frequency Tracking Using an Adaptive Lattice Notch Filter
Authors: Zhang S. , Li Dan , Sun J.
Published: March 2009

A new approach for power system frequency estimation is proposed. The approach consists of two stage adaptive notch filters. The first stage eliminates harmonics and enhances the fundamental waveform. After the down-sampled processing, the second stage produces an accurate estimate of the fundamental frequency. The notch filter is based on all-pass filter with an efficient lattice structure and is simple to realize. Simulation is presented to demonstrate the effectiveness of the algorithm.
Digital Image Processing for a Liquid Signature Analyzer System with CCD Camera
Authors: Chen H.X. , Qiu Zu Rong , Zhang Guo Xiong
Published: March 2009

CCD camera is used in the liquid signature analyzer system to capture images of the liquid drop of the tested sample. The digital image processing work is presented. CCD camera records the variation of the liquid drop during growth. The outline information of the drop is available through image processing. The instantaneous volume of the liquid drop can be gained through mathematical calculation. With the use of CCD camera, the information of the tested sample we can get during the measurement is enhanced. The function of the liquid signature analyzer is enriched and the discrimination ability of this technology is improved.
An Application of the Fractal Theory in the Design of Heat Sink for Precision Measurement Instrument
Authors: Lee S.R. , Li Z.G. , Wang B.G. , Chiou H.S.
Published: March 2009

Temperature variation on accuracy and stability in measurement instruments is an important issue. High performance and miniaturized instruments have rigorous requirements on temperature. Heat transfer and temperature control are important in instruments design. For laser interferometer, temperature variation will adversely affect the frequency stability of the laser and the measuring precision. In order to effectively stabilize the frequency, a simple and effective heat sink design for laser interferometer is presented. It is based on the fractal theory and the heat transfer characteristics to allow higher dissipation for temperature control to generate higher heat transfer area in a finite space. Experimental results in frequency stabilization clearly show that this method is effective.
A New Ellipse Recognition Algorithm for CCD Camera
Authors: Sun Chang Ku , Zhang X. , Wang Z. , Ye S.
Published: March 2009

A novel 2D pattern used in camera calibration is presented. An array of circles with one feature circle located at the center is photo echoed on the pattern. According to the category of the pattern, an ellipse recognition algorithm is proposed. It facilitates acquisition of the distinguished points without human operation. The 3D space coordinate system of these points can be established automatically and accurately. A series of experiments show that the algorithm is robust and reliable. The calibration error is less than 0.4 pixels. The new ellipse recognition algorithm can be widely used for computer vision applications.
Determining the Radial Modulus of DNA Measured by VPSFM
Authors: Chen Y.H. , Li X.J. , Zhou X.F. , Sun Jia Lin , Huang W.H. , Hu J.
Published: March 2009

Mechanical properties of DNA, for example the elastic modulus, are of vital importance for its biological function. Previously, the modulus is mainly obtained by bending, stretching and twisting DNA using various techniques and tools. By applying vibrating mode scanning polarization force microscopy (VPSFM), deformations of DNA under ultra-small indentation forces can be measured and so the radial modulus can be computed. In this paper, modeling of the VPSFM measuring system is presented. The system is modeled as a spring-mass-damper oscillator under various force fields, such as van der Waals force, attractive electrical force and repulsive interactions between the tip and sample. The electrical polarization force is described by using uniformly charged line model and the DNA is considered to be a simple elastic rod. By numerically integrating the equation of tip motion, the contact force and the radial modulus of DNA under different deformation can be calculated. We found that in measuring radial modulus of DNA, the existence of substrate cannot be neglected, especially when the relative large deformation is reached.
Determining Representative Stress and Representative Strain in Deriving Indentation Flow Curves Based on Finite Element Analysis
Authors: Jeon Eun Chae , Baik Min Kyung , Kim Sung Hoon , Lee Baik Woo , Kwon Dong Il
Published: March 2009

A new method [1] to evaluate indentation flow curves using an instrumented indentation test has been applied to many materials for several years. Though the method produces relatively good results compared to uniaxial tensile tests, a few parameters had not been verified by theoretical or numerical methods. In this study, proportional constants of representative strain and representative stress were verified using finite element analysis and proven to be unaffected by the elastic property and strain level. The constants were generally dependent on the plastic property; however, one combination of the constants is independent of all properties. The values of this combination are consistent with early research and produced overlapping indentation flow curves with uniaxial curves.
A LTCC Material with Low Temperature Coefficient of Resonance Frequency
Authors: Iwao Masaru , Umayahara Yoshio , Shindo Kazuyoshi
Published: March 2009

For high frequency packaging applications, LTCC materials are required to have a low loss tangent to reduce the total microwave loss. For multi-layered ceramic devices with embedded passive components, besides a loss tangent, a small temperature coefficient of resonance frequency (TCF) is an important factor. To meet these demands, we developed a new LTCC material with a smaller TCF, less than +/-3ppm/oC, and a low loss tangent, 0.0012 at 15GHz. We designed the glass composition to precipitate two low-loss crystal phases during firing at 900 oC. One phase has a plus TCF and the other phase has a minus TCF. We also controlled the amount of the two crystal phases, so these crystal phases and the fixed amount of alumina filler make the sum of TCF for the LTCC material close to zero.
Evaluation of Characteristics of Electromagnetic Wave Absorbers of Composites Fabricated by Mechanical Milling
Authors: Hiraki Kiyohiro , Kusunoki Hiroki , Kondo Takatoshi , Takada Kazushi , Nezaki Masahiro , Yoshikado Shinzo
Published: March 2009

It is found through simulation that electromagnetic wave absorbers made of composites of Ni-Zn ferrite and SiO2 particles, which are isolated in a continuous medium of Ni-Zn ferrite, show absorption in the frequency regions both below and above 1 GHz. The measured complex permeabilities are close to simulation values above 1 GHz. Both absorbing bandwidth and center frequency of the composites are close to the desired values expected from the simulation result.
Reflection Intensity Measurement for Dielectric Material Using a Microwave Single Probe and Its Electromagnetic Field Analysis
Authors: Kakemoto Hirofumi , Wada Satoshi , Tsurumi Takaaki
Published: March 2009

Microwave reflection intensity for microwave absorber, Cu-plate and Al2O3 (0001) single crystal substrate was measured from 8GHz to11GHz as a function of distance between single probe and sample at room temperature. The minimum reflection intensity was observed in the distance of 0.2mm between single probe and sample at 9.4GHz, although the reflection intensity was decreased with increasing distance in other measurement frequencies. The electromagnetic field analysis was hence carried out for simulation model that is defined with coaxial cable, probe and sample using finite differential time domain method. The reflection coefficient and impedance for simulation model were calculated, and compared to the experimental data. From results of electromagnetic analysis, the minimum point of reflection intensity was caused from an impedance matching.
Lithium Intercalation Properties of Octatitanates Composed of Nanosheets with Various Dimensions
Authors: Suzuki Shinya , Miyayama Masaru
Published: March 2009

Lithium intercalation properties of octatitanates composed of nanosheets were examined. Several types of nanosheet-octatitanates were prepared by the reassembly of tetratitanate nanosheets in colloidal suspension, which were separated centrifugally at various revolutions, and then by a heat treatment. The colloidal suspension was obtained by the exfoliation of tetrabutylammonium tetratitanate intercalation compound. The capacities of the octatitanates composed of nanosheets were approximately 160 mAh/g, and they were maintained even after the exfoliation and the reassembly. The octatitanate composed of nanosheets with relatively small dimensions centrifugally separated at 6000 rpm exhibited a large capacity of 140 mAh/g at a relatively high current density of 1 A/g. The nanosheet process was found to be effective in improving the high rate capability.
Preparation and Its Photovoltaic Effect of Ferroelectric Film
Authors: Ichiki Masaaki , Kobayashi Takeshi , Furue Harumi , Morikawa Yasushi , Nonaka Kazuhiro , Endo Chiaki , Maeda Ryutaro
Published: March 2009

This paper reports on the formation of film structures and the highly improved photovoltaic output current of the lead lanthanum zirconate titanate (PLZT) employed. The photovoltaic effect of ferroelectrics has the advantage of its simple mechanisms of non-bias applications which are indispensable for semiconductor p-n junctions. But the output current of PLZT bulk is too low for use as a device current source. The PLZT film structure exhibited μA output current upon light illumination. The photovoltaic current of the PLZT film was more than 102 times than that of bulk PLZT. These differences are due to the characteristics of the design of the film including the configuration of the electrode. The PLZT film also has the advantage of easy output control and suitability for use on Si. Results show that the photovoltaic effect of the ferroelectric film is useful as the current source for micro-electro-mechanical systems (MEMS).
Enhancement of Luminescent Properties of Sol-Gel-Derived BaTiO3: Pr
Authors: Li Juan , Wu Yong Jun , Kuwabara Makoto
Published: March 2009

Praseodymium (Pr3+)-doped BaTiO3 was synthesized by a high concentration sol-gel process and sintered at different temperatures from 800oC to 1200oC. The emission was due to intra-4f transitions of Pr3+ which were mainly from the excited states 3P0 and 1D2 to the ground states of 3H4 of Pr3+, respectively. Enhancement of the luminescent properties of Pr-doped BaTiO3 was also investigated via adding Mg. For BaTiO3: Pr phosphor added with 0.5 mol% Mg, the emission intensity was about 60 times higher than that of samples without Mg addition. The emission enhancement may caused by the improved crystallinity, the charge compensation and the change of the substitution site of Pr3+ with the addition of Mg.
Control of Nanoscale Morphology of Oxide Crystals Using Aqueous Solution Systems
Authors: Imai Hiroaki , Ohgi Hirotoshi , Takezawa Yoko , Yahiro Junko
Published: March 2009

We successfully controlled nanoscale morphology of ZnO, SnO2 and TiO2 grown in aqueous solution systems. Nanograins, nanorods and nanosheets of the metal oxides were obtained with variation of the preparation conditions including the concentration of the precursor reagents, pH and addition of various organic molecules and inorganic ions. The morphological evolution of wurtzite-type ZnO crystals from hexagonal nanorods to nanoplates and nanosheets was induced by the coexistence of phosphate anions and specific carboxylates. An increase in the concentration of SnF2 and pH changed the nanoscale morphology of crystalline SnO2 from grains into rods, flakes and sheets. Nanorods of anatase and rutile were deposited in the solutions of TiF4 and TiOSO4 by controlling pH and addition of urea. Nanosheets of titanate were prepared with ammonia anions in agar gel containing TiF4 and easily transformed into nanosheets of anatase.
Synthesis of (Ba,Ca)(Zr,Ti)O3 Ceramics from Ultra-Fine Precursors
Authors: Amagai Jin , Kato Yuzo , Ueki Akira , Saito Noriko , Ohashi Naoki , Haneda Hajime
Published: March 2009

Fine powder of CaZrO3 (CZ) was synthesized by using ultra-fine and highly dispersed CaCO3 as a precursor. The results showed that the calcination temperature could be reduced to inhibit grain growth of CZ. Mean grain size of the CZ fine powder was 80 nm. Moreover, the CZ powder was used to synthesize a solid solution of (Ba,Ca)(Zr,Ti)O3 (BCZT) to examine the effect of the powder’s grain size on the reactivity of BT and CZ. It was found that the fine CZ powder enhanced the BT and CZ reaction.
Photoconducting Properties in Oxygen-Deficient Bi4Ti3O12
Authors: Tada Masaru , Osada Minoru , Kakihana Masato , Noguchi Yuji , Miyayama Masaru
Published: March 2009

We investigated the influence of photoexcited nonequilibrium electrons in Bi4Ti3O12-d which contains a high density of oxygen vacancies. As increasing oxygen deficiency, the photocurrent undergoes a rapid enhancement, accompanied by a remarkable change of kinetics. In heavily oxygen deficient Bi4Ti3O12-d (d=0.45), we observed dispersive photoconductivity, a behavior resembles with persistent photoconductivity phenomena in some perovskites. We argue that oxygen vacancies acting as trapping centers for electrons are linked to dispersive diffusion in the perovskite blocks, which control carrier recombination.
Study and Application of Salt-Scaling Resistant Admixture in Concrete
Authors: Wang Yuan , Liu Bin
Published: March 2009

This paper investigated a new type of admixture which can be used to enhance the
resistance of concrete surface to deicing salt deteriorating. Physical and mechanical properties of concrete incorporating this salt-scaling resistant admixture were measured. Practical application on site has proved that this admixture is effective for concrete to resist salt-scaling action.
Mechanism of Using Mineral Admixtures in Concrete to Suppress Alkali-Silica Reaction
Authors: Feng Xiao Xin , Feng Nai Qian
Published: March 2009

The mechanism of using mineral admixtures in concrete for suppressing alkali-silica
reaction has been studied through analyzing pore solution and observing the surface of aggregates in mortar bars with scanning electron microscope (SEM). The results show that when mineral admixtures are used in the concrete, not only the alkali concentration in the pore solution can be reduced, but also the diffusion of alkali ions from the outside of concrete to the inside can be prevented, and the diffusion of alkali ions from the pore solution to the surface of the aggregates can also be prevented. Thus the attack of alkalis to aggregates is reduced, and the alkali-silica reaction is suppressed.
Study of Frost Resistance on Air-Entrained Concrete in Sulfated Medium
Authors: Yong Ge , Jie Yuan , Yang Wen Cui , Zhang Bao Sheng
Published: March 2009

Frost resistance of plain concrete and air-entrained concrete subjected to freeze-thaw cycles in fresh water and 5 % and 7 % sodium sulfate solution are investigated in this paper. The test results show that the frost resistance of concrete is different in the different medium. The properties of concrete frozen in 5 % and 7 % sodium solution are different from that in fresh water, and entraining air into concrete properly can increase the frost resistance significantly whether in fresh water or in sulfate solution. Higher strength concrete could resist the degradation of freezing and thawing cycles in water, but some of them failed suddenly in midspan of specimens under the sulfate solution.
Inspection and Analysis of Prestressed Concrete Girders Deteriorated by Alkali-Silica Reaction
Authors: Hao Ting Yu
Published: March 2009

In-situ inspection and lab study were combined to analyze the prestressed concrete girders of an existing railway bridge built in 1976 in North China. The reactive components in aggregates and the alkali content of concrete were investigated. Typical reaction product was found in site and was analyzed in lab. Residual expansion of concrete cores drilled from some girders was measured. From test results, it can be deducted that alkali silica reaction had affected the concrete girders and would continue to cause expansion in the future.
Exploitation of Particle Migration Mechanism to Promote Economy and Ecology in Concrete Technology
Authors: Stroeven Piet , Hu J. , Stroeven Martijn
Published: March 2009

The computer simulation study of Portland cement blending confirmed the major
mechanism to be size segregation in the Interfacial Transition Zones around the aggregate particles. Fine particles tend to move through the skeleton of larger particles towards the surface of the aggregate grains, improving local density. But the most interesting feature is a disproportionately larger internal bond capacity (based on van der Waals forces between nearby particles). In this contribution, we have isolated the mechanism of internal diffusion capacity of particles, on which blending efficiency relies, for a simulation study on the migration of fine sand articles into the network of coarse aggregate grains. The influences of technical parameters (including gap in size between fine sand and coarse aggregate, as well as the workability conditions) have been investigated on the migration capacity of fine sand particles. This paper will report briefly the outcomes of this computer simulation study on aggregate mix systems.
A Investigation on the Influence of Vitreous Slag Powders on Rheological Properties of Fresh Concrete
Authors: Shi Yun Xing , Matsui Isamu , Feng Nai Qian
Published: March 2009

This paper investigates the effects of vitreous slag powders on the rheological properties of fresh concrete. It was observed that the fluidity of concrete increased noticeably, and the plastic viscosity decreased when vitreous powders were substituted partially for cement. It was demonstrated in the experiments that the fluidity effect of vitreous powders on fresh concrete can be correlated with the vitreous content of the powders.
Compressive Strength and Density of Fly-Ash Substituted Soil-Cement Concrete
Authors: Kawamura Masashi , Kasai Yoshio
Published: March 2009

Soil-cement concrete can be manufactured by mixing portland cement, water and on-site soil and has been studied by the authors. This study deals with compressive strength and density of soil-cement concrete where the portland cement was partially substituted with fly-ash. Saturated surface-dry condition of on-site soils has never been taken into account in the conventional mix design whereas experiments of determining the saturated surface-dry conditions were carried out with the help
of the concept of effective water content to assure the quality and the designed strength. Effects of fly-ash on the strength and density of soil-cement concrete were studied by altering cement-fly-ash ratio, soil-sand ratio, binder-water ratio and age under a constant unit water content
Study on Preparation Technique for Low-Cost Green Reactive Powder Concrete
Authors: Xing Feng , Huang Li Dong , Cao Zheng Liang , Deng Liang Peng
Published: March 2009

Based on experiments, the effect of various types and content of mineral admixtures and steel fiber on flexural strength and compressive strength of reactive powder concrete (RPC) have been studied. The low-cost green RPC is made with the replacement of quartz sand, quartz powder and partial silica fume by natural fine aggregate and fly ash. The preparation techniques of RPC was also improved.
Construction and Quality Control of Concrete Using Barite as Aggregate
Authors: Wu Wen Gui , Gu Qing Xia , Wang Jun , Wu Tie Ming , Lin Huai Li , Sun Ke Ping , Li Qing
Published: March 2009

This paper presents mix proportion design and the construction of the barite concrete structure, mixing, transportation and construction characteristic of the barite concrete. Technical solutions were proposed to problems in construction.
Logarithmic Decrement and Dynamic Modulus of Coated Cement Concrete
Authors: Mayama Masakazu , Harada Masatoshi
Published: March 2009

This report presents a research on vibration absorption properties of coated cement concrete, by discussing the logarithmic decrement and dynamic modulus obtained from bending vibration test at various temperatures. The effect of temperature and bitumen content on the vibration properties of materials was evaluated. As temperature and/or coating asphalt content increased, coated cement concrete increased logarithmic decrement and resulted in increasing vibration absorption than the conventional cement concrete. The vibration properties of coated cement concrete were similar to those of conventional cement concrete in the low temperature range. The dynamic modulus of coated cement concrete decreased at higher temperatures. The rate of decrease of dynamic modulus at higher temperatures was comparatively small in comparison with the rate of increase of logarithmic decrement.
Static Properties of Plain Reactive Powder Concrete Beams
Authors: Gao Ri , Liu Zhi Min , Zhang Li Qian , Stroeven Piet
Published: March 2009

Reactive powder concrete (RPC) is a new kind of ultra-high strength and upper ductility concrete first developed in 1990’s in France. In this paper, the RPC mixture proportion is optimized and its mechanical properties, such as compressive strength, flexural strength, elastic modulus, and its durability, are tested and discussed. Based on the optimal mixture proportion, four simply supported plain RPC beams (without reinforcement bars) are made and tested. The mechanical
properties of plain RPC beams, including section deformation, load-displacement relationship, failure forms, crack distribution, crack extension, and ultimate flexural capacity, are discussed. It is concluded that RPC is an excellent material with high strength and durability. Steel fiber is important both to control the crack extension and to enhance the ductility of RPC beams.
Study on Strength and Bond Characteristics of GGBS Concrete
Authors: Xia Jun-Wu , Wang Shou Xiang , Chang Hong Fei , Peng Hua-Qun , Jiang Long , Ding Ping
Published: March 2009

The influence of GGBS (ground granulated blastfurnace slag) on concrete compressive strength is experimentally investigated in this paper. By bond strength experiment of GGBS concrete with reinforcing steel bar, the influence of GGBS mixture proportioning on bond strength is studied. The result indicates that, with an increase replacement percentage of GGBS, the bond strength between concrete and steel bar will decrease, and the depressed magnitude relates to the dosage of slag powder and type of steel bar. The studies provide a reference for the exploitation and application of GGBS concrete. As known to all, blastfurnace slag is a kind of industry waste produced by blastfurnace puddling. A great deal of research has been conducted on the characteristics of slag powder. The
improvements of GGBS on the concrete composites are widely accepted. Studies on GGBS concrete bring remarkable social and economical benefits such as: reducing cost of per cube concrete; improving concrete performance and making full use of industry waste residue. The influence of GGBS mixture proportioning on concrete compressive strength and the bond characteristics between concrete and steel bar is experimentally studied in this paper.
Study on Hysteretic Model and Damage Model of Multi-Ribbed Composite Wall
Authors: Yuan Quan , Yao Qian Feng , Jia Ying Jie
Published: March 2009

The use of composite materials in structural engineering is recent, and researchers need to investigate their behavior features. A new unit of multi-ribbed composite wall is introduced. A multi-ribbed composite wall is the main bearing-load member in multi-ribbed slab structures (MRSS). The bearing-load characteristics and seismic properties of the wall are different from those of other ordinary concrete members In order to study seismic behavior and durability of Multi-ribbed composite walls, experiments of 26 pieces of composite walls under cyclic loading were carried out, and then the hysteretic model of shear force–shear deformation is established. The hysteretic curves of typical composite walls are calculated. The calculated curves agree well with the experimental ones. The damage model is quantified. This study introduces a quantitative analysis means for evaluating seismic behavior aspects of damage and durability of multi-ribbed composite walls.
Investigations of Grinding Forces for Nanostructured WC/12Co Coatings
Authors: Deng Zhao Hui , Zhang Bi , Cheng F.
Published: March 2009

This study focuses on experimental and theoretical investigations of grinding forces for nanostructured WC/12Co coatings. In this study, nanostructured WC/12Co coatings are ground on a precision surface-grinding machine with four diamond wheels of two bond types and three grit sizes. A mathematical model is proposed to predict grinding forces per unit area and per grit, and is used to fit the experimental data. The model is also subsectioned into two different parts with one part
fitting grinding forces for the smaller grit depth of cut condition and the other part for the larger grit depth of cut condition. Grinding mechanisms are also discussed in terms of grinding forces and grit depth of cut.
Mechanism of Surface Formation for Natural Granite Grinding
Authors: Shen Jian Yun , Lin Wei Min , Ohmori Hitoshi , Xu Xi Peng
Published: March 2009

In the present study, zirconia ceramic, crystal and two typical natural granites were ELID ground on a precision grinding machine under the same condition. The surface appearances during the grinding process with different mesh size metal bonded diamond wheels were examined to describe the formation of finely finished granite surfaces. According to the detailed micro-observation of ground surfaces, it can be concluded that the material removal mechanism of the main mineral components for natural granites are really similar to other brittle materials during ELID grinding process. However, the differences of material performances cause the granite materials to be larger critical grain depth of cut and more ductile during finely grinding.
Study on Grinding Technology of Electrical Discharge Grinding of Curve Edge Polycrystalline Diamond
Authors: Liu Gang , Chen Ming , Hu Z.G. , Zhu X.F. , Xu H. , Li Z.W.
Published: March 2009

PCD tools, especially curve edge PCD compound tools are used widely in machining
nonferrous and non-metal materials with high efficiency and precision because of their excellent cutting properties. But high quality grinding of PCD tools is the uppermost obstacle in application because there are great difficulties to profile and sharpen edge in grinding, especially for milling cutter and drill with curve edge. This paper studied technology of wire EDG curve edge PCD compound tools by wire electrical discharge grinding machine with five-axis CNC system. The grinding quality was evaluated by scanning electron microscope (SEM) and roughometer. Three steps processing technique (roughing, finishing and fine finishing) and optimal process parameters of wire EDG PCD tools were recommended after considering synthetically the surface quality, precision and machining efficiency. The results met the requirement of high surface quality, precision and efficiency. This paper also applied successfully the optimal technology to grind a
PCD milling cutter with outer and inner blade by electrical discharge grinding machine with five-axis CNC system. By the optimal parameters, the process yielded high precision of ±4.3µm and low roughness of 0.30µm. Experiment results have great practical significance to the high precise and efficient wire EDG of PCD tools.
Machinability Evaluation of Engineering Ceramics with Digraph Method
Authors: Zhong L.J. , Yu Ai Bing , Yu S.Y. , Du Hai Yan
Published: March 2009

A new method is proposed for machinability comprehensive evaluation of engineering
ceramic materials based on digraph theory. Machinability attributes of the materials are taken as the nodes and the correlations between attributes are taken as the edges. The digraph model for machinability evaluation of ceramics is set up. According to the diagraph model, the machinability attribute matrix was constituted. Then machinability indexes of ceramic materials were calculated with permanent function and machinabilities of the ceramics were evaluated. In this paper,
mechanical property parameters of ceramic materials, including hardness, fracture toughness and elastic modulus, were selected as machinability attributes. Machinability of four typical engineering ceramics were evaluated and ranked with machinability indexes. The grinding experiments give further proof of evaluation results.
Development of Vitrified Bond CBN Wheel for Internal Precision Grinding of the Air-Conditioner Compressor Piston Hole
Authors: Gao Hang , Zheng Y.G. , Liu W.G. , Li Jian Hui
Published: March 2009

Manufacturing of vitrified bond CBN wheels for internal precision grinding of the
air-conditioner compressor piston hole is still big challenge to all of the domestic manufacturers. Recently, by choosing pre-melting mixed CBN abrasives and a proper sintering process, a cost-effective method was conceived to produce grinding wheels of comparative quality. The grinding performance of wheels was evaluated with a series of internal precision grinding of compressor piston hole. Experimental results show that the vitrified bond CBN grinding wheel produced by this method has better grinding performance, and can be substitute to the same type of grinding wheels imported. But the manufacturing cost is only 60% of the wheel imported according to estimation.
The Investigation of Tool and Mechanism on Non-Abrasive Cryogenic Polishing
Authors: Liu X.Y. , Yu D.W. , Wang L.J.
Published: March 2009

In non-abrasive cryogenic polishing, ice disk is used as polishing tool .The effects of ice disk characteristics by different water quality on surface roughness of machined parts are investigated. Non-abrasive cryogenic polishing is a plastic transfiguration process based on brittle-plastic transition theory. During machining, higher micro peaks become lower and the number of micro peaks increases which results in lower roughness. Experiments are done to attest to the process.
Energy Model in Laser Processing of a Cylindrical Grinding Wheel
Authors: Wang Xu Yue , Wu Yong Bo , Kang Ren Ke , Guo Dong Ming , Xu Wen Ji , Kato M.
Published: March 2009

Laser processing of abrasive grinding wheels is paying a great role in a truing technique to complement mechanical methods. An energy balance model was adopted that took into account the space modes of laser energy absorbed/scattered by the wheel (circular profile). Both geometric and mathematic models were developed to reveal laser processing mechanism and predict various processing parameters, such as incident position, focal offset, and incident power, to perform material removal during laser processing a cylindrical grinding wheel. Moreover, the incident angle for laser processing of small-vitrified CBN grinding wheels was optimized. Further theoretical analysis and experiments determined the focal position of the incident beam with respect to the wheel profile. Experimental studies were carried out using different processing parameters and grinding wheels to test the effects of laser space properties on processing quality. The experimental results were shown to be in reasonable agreement with predicted results.
Experiment Study on the Dynamic Characteristics of the Abrasive Flow in Centrifugal Grinding
Authors: Wang Hao Cheng , Zhang H.T. , Wang Q. , Chen T.W.
Published: March 2009

Being a high efficient technique for metal surface treatment , centrifugal grinding is
widely applied in the field of polishing and burring for small-sized asymmetric parts. During the process of centrifugal grinding, the dynamic characteristics of the abrasive flow, which is determined by the planetary driver ratio of the instrument, has a profound impact on the quality and producing efficiency of the workpiece. Targeting on the massive abrasive, this paper investigates experimentally theinfluence of the planetary driver ratio of the instrument to the producing quality
and efficiency. On one hand, a high-speed photograph is employed to record the movement of the abrasive flow in the processing of centrifugal grinding. The dynamic characteristics of the abrasive flow have been investigated for different planetary driver ratios. By qualitative analyzing the high-speed photographing results, the perceptual knowledge of the characteristics and the kinematic rules of the abrasive flow have been obtained. On the other hand, the surface roughness data at
different planetary gear ratio and polishing time have been measured. The influence of planetary gear ratio on producing process have been illustrated by plotting the roughness-time curve combined with the high-speed photograph so as to provide a scientific basis for optimizing the parameters of design and technology.
Modeling and Simulation of Lapping Processes Based on Grain Size Sensitivity Model
Authors: Dai Yong , Yuan Ju Long , Zhou Zhao Zhong , Zheng Jia Jin , Zhao Ping
Published: March 2009

It is of high importance to avoid scratches in lapping process. A Grain Size Sensitivity (GSS) model is put forward in this paper. The GSS is a relative parameter which defines the relative change of the depth of cutting, influenced by the change of the size of grain powders, by which it is possible to evaluate quantificationally the capability of lapping machines in avoiding scratches. It is
useful for designing and using lapping machines. The simulating of lapping processes based on GSS model is carried out. The transferring of error is also discussed and a new structure of lapping plate with spring cells developed by the authors is introduced.
The Theory and Experiment Study on the Error Compensation of SK-21 NC Cam Grinder
Authors: Fan J.W. , Guang J.L. , Yue Zh.J. , Dong G.P. , Zhou Shi Sheng
Published: March 2009

Focus on the accuracy problem in machining process of SK21 NC cam grinder, the precision-machining restriction condition equation and the calculation method of precision NC instruction are deduced. The reversible calculation model from NC instruction to the cam’s outline is given and a software package of error compensation is developed. Many error parameters which include the abrasion of the grinding wheel, load distortion of the grinding wheel axis, rotation precision of the cam axis and movement precision of the worktable are measured through experiments. The finally grinding experiments results show that the cam’s machining accuracy can be improved more than 50% by the error compensation method in this paper.
Fabrication of Accurate Diamond - Metal Composite Cutting Blade by Electrotyping Method
Authors: Fang L.L. , Zhang Bing Lin , Yao Ning
Published: March 2009

In this paper, we report that the experimental results of fabricated diamond-metal
composite film. Electrotyping method was used to deposit the thick film. During the deposition, low internal stress electrolytic solution, the electric current density of cathode, PH value, temperature, the distance between cathode and anode, the pretreatment of motherboard cathode were selected simultaneously. It was found that stirring strongly affected the quality of the film. Especially stirring velocity affected the distribution of diamond grains. Scanning electron microscope (SEM),
X-ray photoemission spectroscopy (XPS) and X-ray diffraction (XRD) were used to measure the surface morphology, the crystal microstructure, diamond grains distribution and the chemical environment of the film.
Optimising the Process Conditions in Ultra-Precision Grinding to Achieve Surface Finish of Optical Quality
Authors: Jin T. , Stephenson D.J.
Published: March 2009

Optical surface finish below Ra 10nm can be achieved on a ‘Tetraform C’ grinder of ultra-high stiffness, when grinding a low alloy steel with or without the help of ELID (electrolytic in process dressing). Surface roughness generation modelling has been carried out to predict thepossible surface roughness values. Efforts have been made to transfer the process knowledge to different grinding mode using a rigid 5-axis Edgetek CNC grinder. The effects of material removal rate and grit size and also that of spark out passes on the surface roughness generated have been
investigated.
Edge Grinding of Ceramic Tile by Diamond Cup Wheels
Authors: Yuan Hui , Cheng Y.P. , Wang Cheng Yong , Hu Ying Ning
Published: March 2009

As one of the excellent decorative materials ceramic tiles must be ground and polished to present the glossy surface. In this paper the ceramic tiles were edge ground by diamond cup wheels in the special designed test machine. The surface morphology of the polished ceramic tiles and the wear of diamond cup wheel were examined by Scanning electron microscopy (SEM). The wear resistance of diamond cup wheel and the materials’ removal process of ceramic tiles had been tested. The results showed that the wear of diamond cup wheel was stable when grinding with high grinding ratio. The ground surface showed that only the fracture of ceramic tiles was acted by diamond grits during grinding with water by means of good quality diamond cup wheel.
Cracks in Laminates Subjected to Concentrated Forces and Moments
Authors: Hwu Chyan Bin
Published: March 2009

The crack problems are important not only in macromechanics but also in micromechanics. Because of its importance a lot of analytical, numerical and experimental studies have been published in journals and books. Among them, the study of Green’s function attracts many researchers’ attention because analytically it may provide solutions for arbitrary loading through superposition and numerically it can be employed as the fundamental solutions for boundary element method and as the kernel functions of integral equations to consider crack interaction problems. Although a lot of Green’s functions have been presented in the literature, due to mathematical infeasibility most of them are restricted to two-dimensional problems and very few of them consider possible coupled stretching-bending analysis which may occur for general unsymmetric composite laminates subjected inplane and/or out-of-plane forces and moments. In this paper we consider an infinite composite laminate containing a traction-free crack subjected to concentrated forces and moments at an arbitrary point of the laminate. By employing Stroh-like formalism for the coupled stretching-bending analysis, recently the Green’s functions for the infinite laminates (without holes) were obtained in closed-form. Based upon the non-hole Green’s functions, through the use of analytical continuation method the Green’s functions for cracks are now obtained in explicit closed-form and are valid for the full fields. By proper differentiation, the associated stress intensity factors are also solved explicitly.
Prediction of Creep Crack Growth Life Using Backward Radiated Ultrasound
Authors: Lim Byeong Soo , Jeong C.S. , Bae Si Yon , Song Sung Jin , Kim Yong Hwan
Published: March 2009

A nondestructive inspection is required to check for defects inside of the actually used components and structures and to confirm their generation and growth rate. Using the backward radiated ultrasonic inspection system, we performed nondestructive inspection of cracks and micro cavities resulting from creep. From the ultrasound test results, the generation and growth of cracks and micro-cavities were confirmed, and the fracture life of the components and structures could be
predicted. We confirmed degraded region by crack size and cavity based on the amplitude of the backward radiated ultrasound. The size of degraded region at 600oC was about 10mm, while that at 650oC was about 15mm. The size of crack and the cavity area fraction confirmed by ultrasound were very close to the actual size and cavity area fraction, indicating the validity of the predicted creep crack growth rate and creep.
Study on the Mechanical Behavior of Nano Components via MD Simulation
Authors: Fang Nan , Fang Dai Ning
Published: March 2009

In this article, based on the method of molecular dynamics, the mechanics response of nano-component is simulated. Some details of MD technique have been included in this paper, dealing with time step, algorithm and other problems. According to the work of predecessors, systemically a general form of atomic stress under atomic scale, as well as its specific form using EAM method, is derived. Unlike the macro stress, the atomic stress stands for the atom’s potential ability of movement, and should be defined again. The mechanical properties of copper nano-rod are studied, including relaxation state, tensile state and compress state. Because of the high energy atoms on the surface, the surface effect is generated. So when in relaxation state, the nano-rod will be shortened, and the more atoms the rod has, the less is shortened. When the strain is between –0.1 and 0.1, the nano-rod performs elastic situation. The nano-rod has a highly tensile strength. We find that dislocation can reduced the flow stress of the nano-rod. Finally the effect of nano-hole effect is discussed.
Dynamic Characteristics of Smart Hull Structures Featuring Piezoelectric Materials
Authors: Sohn Jung Woo , Kim Heung Soo , Choi Seung Bok
Published: March 2009

In this paper, dynamic characteristics of an end-capped hull structure with surface bonded piezoelectric actuators are studied. Finite element technique is used to ensure application to practical geometry and boundary conditions of smart hull structure. Modal analysis is conducted to investigate the dynamic characteristics of the hull structure. Piezoelectric self-sensing actuators are attached where the maximum control performance can be obtained. Active controller based on Linear
Quadratic Gaussian (LQG) theory is designed to suppress vibration of smart hull structure. It is observed that closed loop damping can be improved with suitable weighting factors in the developed LQG controller.
Effect of Pre-Strain on the Antagonistically Driven Dielectric Polymer Actuator
Authors: Koo Ja Choon , Jung Kwang Mok , Jung Min Young , Choi Hyouk Ryeol , Nam Jae Do , Lee Young Kwan
Published: March 2009

Many publications have demonstrated advantages of smart polymer actuators over the traditional electromagnetic transducers. One of the most significant contributions of the polymers might be their soft actuation mechanism. Hence unlike the traditional actuators, there is morphological freedom for actuator construction that benefits production of either small scale complex mechanisms or human-like applications. Although many different actuation paradigms of polymer actuators presented in previous publications, no significant contributions are made for the actual industrial applications. A noble idea for acquiring controllable actuation is antagonistic drive
mechanism of dielectric elastomer. The mechanism provides fairly accurate controllable motion and relatively large actuation forces. A strong dependency to pre-strain of the polymer is however one of the major constraints of the actuator driving mechanism. A detailed characterization of pre-strain effects should be done for the successful construction of the actuators. Hence an experimental and theoretical consideration about mutual effects of pre-strain and actuator performance is to be presented in the present work.
Influences of the Factors on Fatigue Crack Growth Retardation Behavior due to Multiple Overloads
Authors: Kim Seon Jin , Ahn Seok Hwan , Kong Yu Sik , Kwon Sang Woo
Published: March 2009

Constant K fatigue crack growth tests were performed by applying an intermediate
multiple overloads for S45C steel. The purpose of this study is to investigate effects of specimen thickness at various baseline stress intensity factor range levels (Kb), the application position of the overload (a/W) and the application frequency of the overload (OLHz) on fatigue crack growth retardation behavior. The principal results are summarized as follows. The number of retardation cycles for the constant baseline stress intensity factor level (Kb ) decreases with increasing specimen thickness. The normalized number of retardation cycles ( Nd / Nc ) decreases with increasing specimen thickness. But, at Kb = 45 MPa(m)1/2, the cycle increases with increasing specimen thickness.