bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuzzy PID Control of ABS Based on Real-Time Road Surface Identification
Authors: Wang Bo , Lu Ping Ping , Guan Hsin , Jing Jie
Published: July 2014

Road surface identification is of great significance in vehicle active safety electronic control systems. This paper proposes a real-time road surface identification algorithm on the basis of the estimated instantaneous road adhesive coefficient. Based on Fuzzy-PID controller and automatic road surface identification, the actual slip ratio can be controlled at the optimal slip ratio precisely, which can promote the ABS and braking performance largely. The braking simulation tests are conducted on pre-set varying road surface conditions. And the results show that the identified results are in good agreement with the pre-set road surface, the proposed algorithm can be conveniently used for various active safety electronic control systems of vehicles.
Design of Electrochemical Biosensor on Naphthalene Content Detection in Water Based on SCM
Authors: Liu Yuan , Yu Ya Ping , Wu Hai Yun , Chang Ruo Kui
Published: July 2014

In order to achieve rapid detection of naphthalene content in water, the electrochemical biosensor has been developed based on microcontroller by the cyclic voltammetry (CV). The system is consisted of a three-electrode electrochemical system, converting circuit, IAP15F2K61S2 microcontroller and display unit. The voltammetric oxidation-reduction response of a bare gold electrode has been gained in a potential window from −0.3 V to +0.6V. After data acquisition and processing, according to the change of peak current of voltammograms, the naphthalene content is detected and displayed.the sensor can finish the detection of naphthalene content in 15 minutes.
Statics and Grasp Stiffness Analysis of an Underactuated Cable-Truss Mechanism
Authors: Wu Nan , Liu Rong Qiang , Guo Hong Wei
Published: July 2014

Although much literature is available on the statics and grasp stiffness analysis of underactuated mechanisms, little research has been done on them of the underactuated cable-truss mechanism. The underactuated cable-truss mechanism grasps the target in the form of envelopment. Considering the grasping characteristics of the mechanism, the research on the relationship between the grasping force and the driving force is extremely important, as well as the study of the grasp stiffness. The statics analysis of an underactuated cable-truss mechanism, constituted by five cable-truss units, was given by means of combining with the vector method and the principle of virtual work in this paper. To prove the correctness of the analysis, the simulation was presented. The stiffness of the cable-truss unit was defined and the curve, showing the influence of the proportion relationship between the essential parameters to the stiffness, was obtained. Then, the stiffness of the mechanism was discussed.
Study on Microstructure and Properties of Laser-MIG Hybrid Welding Joints for Ti-70 Alloy
Authors: Zhang Ming , Yang Dong , Chen Gang
Published: July 2014

A number of laser-MIG hybrid welding experiments were carried out for 4 mm thickness Ti-70 alloy by the single channel single full penetration welding procedure, and obtained the excellent surface formation welding joints with no internal defects. Experimental results show that some bulky columnar crystals form in the Ti-70 welding seam under the hybrid heat source, mainly composed by α′ phase martensite and spiculate α microstructure, and while the Ti-70 alloy welding joints have good comprehensive mechanical properties and can meet the needs of practical engineering.
Manufacture of Model Apollo Capsule Utilizing Pulsed-Plasma Jet for Bow Shock Dispersion
Authors: Matsoukas George , Ahmed Noor A.
Published: July 2014

High speed Schlieren imaging, pressure tapping points and optical emission spectroscopy for temperature and heat flux data are essential measurement techniques for analysis of bow shock dispersion, aerodynamic performance or heat transfer of spacecraft in atmospheric re-entry. However, design and manufacturing of a high voltage pulsed-plasma jet for testing in a supersonic counterflow deserves careful examination. High voltage electrification combined with high temperature sparking between electrodes possesses several design difficulties and manufacturing challenges which need to be addressed that form the basis of the design principals and manufacturing methodology of an Apollo capsule pulsed-plasma jet for successful testing and experimentation of the model.
Based on Particle Size of Cuttings to Study the Erosion of the Plugged Tee in Air Drilling
Authors: Zhu Li Hong , Wang Rui He , Huang Yong , Wang Jing Yin
Published: July 2014

Plugged tee is the easilyworn part of an exhaust pipe during air drilling because of the flow of the compressed air with the entrained cutting particles. The effects of the particle size on the erosion of the plugged tee are studied by computational fluid dynamics (CFD). Mathematical models of the flow of the compressed air with the entrained cutting particles through the plugged tee are built and imported into the CFD through embedding procedures. After boundary conditions and the parameter of the particle size are given, the motion paths of cuttings in the different particle size in the plugged tee and its effects on erosion of the plugged tee are obtained. Erosions in the plugged tee are mainly distributed in the wall of the buffer segment and the joints and mainly caused by the scope of the particle size of cuttings. The motion paths and the residence time of cuttings with different particle size are different, so the erosions of the joints and the buffer segment are different.
Research Prevention of Reeling Cocoon Sinking for Automatic Silk Reeling Machine
Authors: Zhao Cai Zhu , Chen Qing Hua , Jiang Wen Bin
Published: July 2014

Explain the existing device to avoid reeling cocoon sinking in automatic silk reeling machine, research the prevention of cocoon sinking automatically, and provide the integrated solution to keep cocoons in arrangement for reeling. In general, stop motion rod sends a signal when a minor fault occurs in each end, takes the initiative to prevent fault spread to knotty fault which causes a series of bad effects. Then coordinate with interlocked equilibrium, through end feeding cam to control separating plate, ensure the process safe in the most economical way for the industrial market demand. Operators need not handle the system manually while treating the faults, then removing hidden trouble and raising labor efficiency, so higher grade raw silk can be produced. This technique used can improve machine performances, it is the basis on which silk reeling machine should continue to develop.
The Design and Research of Connecting Rod Teaching Machine Based on the Principle of Metamorphic Mechanism
Authors: Zeng Su Ying , Zhou Shuai , Yue Zan , Yu Chao , Xu Bing
Published: July 2014

To meet the demand of the innovative teaching research in machinery or relevant major, a connecting rod teaching machine based on metamorphic mechanisms was put forward, which was suitable for the teaching and experiment simultaneously, improving the teaching effectiveness. The metamorphic mechanism was proposed as the kernel of whole design, integrating multiple evolution of linkage. The virtual prototype technology is applied to create model. The dynamic simulation of topological change in the process was carried out to verify the feasibility of mechanism motion, and two solutions to reduce impact were put forward. The screw transmission telescoping mechanism was designed. Parameter simulative analysis of the model by ADAMS verified the rationality of the design, combining with mechanical analysis.
Numerical Simulation and Analysis of Internal Flow Field for Control Valve Inlet Blocking Fault
Authors: An Yan Tao , Ma Ru Jian , Zhao Dong
Published: July 2014

The internal flow field and the noise of inlet blocking fault and trouble-free for control valve are numerical simulated by CFD. The study shows that it is a greater influence on the internal flow field by inlet blocking, the back-end of stemming appears reverse flow, and it make vortex, the phenomenon of the two fluids mixing is appeared below the valve core. The tremendous noise is appeared in the blocking, and it increases the noise of the surrounding area.
Inlet Passage’s Development and Optimization of New Tidal Unit-Shaft Tubular Turbine
Authors: Yang Chun Xia , Lu Meng Tian , Zheng Yuan , Tian Xiao Qing , Zhang Yu Quan
Published: July 2014

A new type of tidal unit-vertical shaft tubular turbine is designed with high efficiency, large flow rate and low water head ,which has large power under the 2~3 meters water head. According to the data of the being installed tidal units and principles of tubular turbine’s design, the high efficiency vertical shaft tubular turbine was designed under large discharge and low head, which was suitable for the tidal power station. The design also considered the requirements of turbine’s size and the details of flow through the whole flow passage were attained. The turbine’s property was predicted by the 3-d numerical simulation software on the whole flow passage. Moreover, the influences of vertical shaft’s sizes were analyzed. And the terminal of vertical shaft with or without transverse brace and longitudinal brace were analyzed to get the influence. Considering the hydraulic performance of various methods, the best guide vane opening was chosen. The results show that, the turbine unit has the best performance on efficiency, hydraulic loss, etc. with the guide vane opening 62°, meeting the power station’s design requirements. The results show that the optimal designed flow passage’s efficiency reaches up to 88.4%, the flow rate becomes much larger and the power reaches 174.63kW. Without partial vortex, the flow pattern is smooth through the whole passage also with lower hydraulic loss.
Study on Performance of 8YSZ Thick Gradient TBC
Authors: Qin Jin , Chen Gang , Du Zhi Ming , Jin Yu Hui
Published: July 2014

Plasma spray zirconia gradient thermal barrier coating (TBC) and the traditional double-layer structure thermal barrier coating were both studied in this paper. NiCoCrAlY alloy powder was used as bottom bonding materials, 8YSZ (8mol% yttrium stabilized zirconia) was used as top layer materials and the different proportions mixed powder of 8YSZ and NiCoCrAlY was used as gradient layers materials. Bonding strength of thickness gradient coating was measured by tensile experiment. Thermal cycle experiment was carried on to test the thermal shock resistance of TBC. The microstructure after thermal shock experiment was observed to analyze the failure mechanism of TBC. The research result shows that the bonding strength and thermal shock resistance of gradient TBC are much better than the traditional double-layer structure TBC. With the increasing of top layer thickness, thermal shock life of TBC substantially reduces. With the decreasing of ZrO2 composition proportion in gradient layer, thermal shock life of TBC significantly rises. This result has important significance for the future study of thick TBC.
Study on Hydrothermal Process Variables Correlation to WO3 Nanostructure through Design of Experiments (DOE) Approach
Authors: Rashid Amirul Abd , Saad Nor Hayati , Sheng Daniel Bien Chia , Lee Kah Yaw , Lee Wai Yee , Noriah Yusoff
Published: July 2014

There are few known parameters which govern tungsten trioxide (WO3) hydrothermal synthesis process which includes material source concentration, synthesis temperature, duration, pH value and additive level. Using design of experiments (DOE) approach, a systematic experimental procedure was conducted to investigate the effect of each parameter to the final morphology of the synthesized nanostructure. Despite the response obtained from this study is in qulitative form, the analysis still can be done to identify the combination of variables that most likely can produce either 1-D, 2-D or 3-D nanostructure. This insight is essential before further optimization of the process can be done in order to predict the behavior of the WO3 hydrothermal synthesis process.
Gear Meshing Noise of the Closed Gearbox
Authors: Chen Fu Zhong , Shi Yong Jun , Yu Lei Yan
Published: July 2014

The dynamic excitation and the noise of meshing gears were analyzed quantitatively using the three-dimensional finite element contact analysis and the boundary element method. The distribution and variation roles of the gear mesh noise were obtained. The simulation result was verified by sound power measurement. The main excitation was determined additionally. It provides the theory basis for the control of the gearbox noise.
Research on DEH System Characteristics Effect on Power System Low-Frequency Oscillations
Authors: Pan Feng Ping , Liu Shu Chang , Zhu Ya Qing , Pang Zhi Qiang , Shi Ling Ling , Li Jun
Published: July 2014

This article analysed the impact of speed regulation and power-frequency control on power system low-frequency oscillations from the perspective of its production theory. From the experimental results, it can be seen that the power-frequency control will make the low-frequency oscillations worse and longer, thus need to be modified in further research.
Research of the Impact of Turbine Parameters on Low-Frequency Oscillation Based on Simulink
Authors: Zhu Ya Qing , Zhong Min , Pan Feng Ping , Luo Jia , Zhang Xi , Huang Wei Jian
Published: July 2014

This paper analyzed the influence of various turbine parameters on the low-frequency oscillation using Simulink, including the oil motive slide valve time constant, the volume time constant, power grid damping factor, power grid power factor, self-balancing rotor coefficient etc. Meanwhile, comparing the influence of the pure speed regulator and power-frequency regulation on low-frequency oscillations, proven that power-frequency regulation will exacerbate the low frequency oscillation.
Numerical Simulation of In-Pipe Turbulent Noise
Authors: Xu Juan , Hao Zong Rui , Zhou Zhong Hai
Published: July 2014

Numerical simulation is used to explore the turbulence noise in pipes generated by high-speed fluid. The characteristics of turbulent noise and its influencing factors are analyzed for different pipe structures and flow rates. The results showed that there is a parabolic relationship between the Overall Sound Pressure Level (OASPL) and the flow rate as the flow rate increases in the pipe. The OASPL of a variable diameter pipe is 20dB higher than that of the straight pipe with a built-in cylinder under the same flow rate. The structure of flow around a cylinder can effectively weaken turbulence noise and reduce high-frequency noise.
Research to the Overall Design of 4-Axis VMC Based on CAD and NC Mfg Verification
Authors: Zhun Wang
Published: July 2014

The author studied the 4-axis Vertical MC (VMC)，designed and created its general layout feature mode in one CAD platform (the author used Solidworks) with the engineer’s natural thought manner: topdown. The 4-axis VMC’s NC machining simulation is also carried out in one NC mfg verification tool (the author selected Vericut), and the conformability and compatibility are confirmed. The following conclusions can be summarized: the modern NC machine tool designer and user can promote their production quality, efficiency, cost reduction goals with the help of the integration between the CAD and NC mfg verification technology.
Manufacture and Material Considerations in Wind Tunnel Experimentation
Authors: Yu H. , Ahmed Noor A. , Flynn T.G.
Published: July 2014

Appropriate selection of methods of manufacture and materials of test models are essential components physical experimentations using wind tunnels. The present paper is written with a view to highlight some of the aspects that need careful considerations in formulating cost-effective test program and gathering of accurate test data for successful outcome of such wind tunnel experiments.
A Study on Contact Angle and Surface Tension on Copper-ABS for FDM Feedstock
Authors: Sa'ude Nasuha , Isa N.M.A. , Ibrahim M. , Ibrahim Mohd Halim Irwan
Published: July 2014

This paper presents the development of a new Copper-ABS feedstock material by the injection molding machine. The material consists of copper powder filled in an acrylonitrile butadiene styrene (ABS) binder and surfactant material. In this study, the effect of metal filled ABS and binder content on the contact angle and surface tension was investigated experimentally. The detailed formulations of compounding ratio with various combinations of a new Copper-ABS feedstock was done by volume percentage (vol. %). Based on the result obtained, an increment by vol. % of copper filler in ABS effected on contact angle and surface tension results. With highly filled copper content in ABS composites increase the surface tension value. It can be observed that, the tendency of the liquid surface that allow to resist an external force in PMC material through an injection molding process.
The Fuzzy Evaluation Based on Entropy Method for Heavy Oil Reservoir Horizontal Well CO2 Huff and Puff Well Selection
Authors: Li Ya Hui , Peng Cai Zhen
Published: July 2014

Due to its high viscosity, it is very difficult to develop heavy oil cost-effectively. Currently, CO2 huff and puff method is a better choice to develop heavy oil reservoir. The key to this method is to choose the suitable candidate target wells. However, it is now very difficult to judge the suitability of the horizontal target wells’ heavy oil reservoirs’ CO2 huff and puff. In according to such issue, this paper, based on the entropy weight method of fuzzy comprehensive evaluation, and used the established horizontal wells’ index in heavy oil reservoir CO2 huff and puff, evaluates the suitability of candidate wells comprehensively. Moreover, this paper presents a set of indicator system that suits the choice of horizontal wells with regard to its heavy oil reservoir CO2 huff and puff, and proposes a specific method and procedures to evaluate an individual candidate well. This project uses such method to calculate 19 horizontal wells in area G, and the evaluation results are consistent with the actual situations. Therefore, it proves that such proposed evaluation method and evaluation index system are feasible to a certain extent. Keyword:heavy oil reservoir;horizontal well;CO2 huff and puff;Well selection; entropy method;Fuzzy comprehensive evaluation。
Research on Carbon Materials with Synthesis and Characterization of Graphene-Based
Authors: Li Pei Pei , Deng Bao Xiang
Published: July 2014

Carbon materials has been a popular application materials, especially in graphene. Graphene, the mother of all graphitic materials, has emerged to become an exciting two-dimensional material with wondrous properties. Atomic and electronic structures of graphene have been investigated by employing a variety of micro-scopic, spectroscopic, and other techniques. The results show it has better thermal stability, and larger surface area than graphite, graphite oxide. Keywords: graphite; oxidation-reduction method; graphite oxide; graphene
Influence of Original Surface Roughness on Ultrasonic Deep Rolling Effects
Authors: Pei Dong , Deng Fang Gang , Hu Jun Wei , Yang Zhong Jun , Li Li
Published: July 2014

A series of samples which have different surface roughness made by 45 steel were treated by Ultrasonic Deep Rolling (UDR), influence of original surface roughness on UDR effects, such as surface profile, surface roughness and residual stress, were studied. Results shows that surface roughness was reduced substantially through UDR treating and lager the original surface roughness, larger surface roughness and surface residual stress induced by UDR treating.
Harmonic Computation and Analysis of Nonlinear Magnetic Field in the Ferromagnetic Core of the Transformer
Authors: Zhao Xiao Jun , Chen Xiao Li , Cui Can , Zhong Yu Ting
Published: July 2014

The single-phase three-limb transformer is used to carry out experiments under sinusoidal and dc-biased excitations. The exciting currents and magnetic vector potential are computed simultaneously by the harmonic-balanced finite-element method. Harmonic analysis of the nonlinear magnetic field is presented based on the harmonic solution of the magnetic vector potential. The calculated exciting current agrees well with the measured result, which verifies the effectiveness of the proposed method.
Metrology Information System for Management and Field Scene Detection
Authors: Qiao Jin Wei , Liang Qing Guo , Tang Gong Min
Published: July 2014

In order to deal with the field metrology, this paper proposed an information management system which contains daily work management section, human resource section, data management section, auto-reminding section and portable device. It combines the human resource management, equipment management, data processing and filed detection and embodies them in one system located in office and the other one in field. As an information system, it ensures the security and reliability of detection data.
Research on Embedded System with Implementation of a Moving Object Tracking Algorithm Based on Improved Meanshift on DM6437
Authors: Liu Yan Fei , Li Qi , Fang Hao , Xu Hua Chun
Published: July 2014

To improve the real-time performance of the meanshift algorithm in the embedded system, an improved meanshift algorithm for tracking moving target is proposed in this paper. In order to reduce the influence of background pixel in a target model, the target model is build by using the target model of continuous frames; to reduce the times of iteration, a kalman filter is used to predict the position of moving object in the current frame; to improve the accuracy of the target model, it is updated in real-time. At last, the improved algorithm is realized on a DM6437 platform and the experimental results show that the improved algorithm can track moving objects effectively.
Data Processing and Applied Technology in the Algorithm and Cracking of NTLM-Hash - A Highly Proficient Parallel Computing Architecture
Authors: Bi Jing Cun , Zhang Cheng Guang , Liu Yan Fei , Dou Wen Hui
Published: July 2014

Compared with CPU, GPU has a stronger parallel architecture and with specific API, the powerful potential contained in GPU can be released to become GPGPU. High computational capability of GPGPU can be used in scientific computation and data processing. This paper focuses on the research of the high frequency collision crack for normal Windows NTLM-Hash by resorting to CUDA API. The result shows that the computation capability of low-end graphic cards could be almost 100 times that of the normal dual-core CPUs, which could greatly lift the efficiency of encryption cracking.
An Algorithm for Testing the Unreachable Instruction of an Assembly Program in Software Coverage Testing
Authors: Bi Jing Cun , Liu Yan Fei , Dou Wen Hui , Xu Jian Feng
Published: July 2014

Coverage testing is a basic method for dynamic software testing. Based on the basic block theory, an algorithm is proposed for calculating the branch routes of an embedded assembly program in software coverage testing. The correctness of the algorithm is verified on a sample assembly program and it’s time complexity is analyzed also.
The Research of NURBS Curve Interpolation Algorithm Based on Parabolic and the First-Order Taylor Expansion Interpolation Algorithm
Authors: Zhang Zhi Qiang , Wang Wen Jin , Zhang Jing , Zhao Jian , Sun Li Ying , Li Jian Jun , Zhang Ling Li
Published: July 2014

The NURBS curve interpolation algorithm based on parabolic interpolation error and the first-order Taylor expansion interpolation algorithm is proposed to improve part surface quality and chord error of NURBS curve interpolation algorithm. The part surface quality is improved effectively by the parabolic interpolation algorithm in the conduction that the previous point, the current point and the next point which was computed by the first order Taylor expansion interpolation algorithm were known. The effectiveness of this algorithm is proved by the NURBS curve interpolation simulation.
Investigation into In-Vehicle Information Security
Authors: Huang Yue , Qin Gui He , Liu Tong , Zhao Rui , Wang Xiao Dan
Published: July 2014

Along with the penetration of in-vehicle intelligent devices, the in-vehicle networks are changed from a closed environment to an open environment, and thus the concern of in-vehicle information security becomes increasingly prominent. In this paper, we analyzed the damages of in-vehicle information insecurity, studied the corresponding defense requirements, and summarized the applicable analytical methods. Based on the demands for in-vehicle information security, we analyzed the corresponding defenses, and summarized the defense approaches for in-vehicle networks and in-vehicle field-bus information security.
Synthesis, Photochromism and Fluorescent Switch of 1-(2-methyl-1-benzofuran-3-yl)-2-(2-methyl-5-(4-benzylamine)-3-thienyl)) perfluorocyclopentene
Authors: Tian Zhao Yan , Cui Shi Qiang , Pu Shou Zhi
Published: July 2014

A photochromic diarylethene of 1-(2-methyl-1-benzofuran-3-yl)-2-(2-methyl-5-(4-benzylamine)-3-thienyl)) perfluorocyclopentene was synthesized and characterized. Upon irradiation with UV light with the extended response time, the diarylethene underwent a ring opening reaction to produce opened forms and color change both in solution and in a PMMA amorphous film. Its properties, including photochromic behavior and fluorescent properties have been investigated. The results showed the compound exhibited good photochromism in acetonitrile solution and in PMMA amorphous film.
Study on Corrosion Behavior of Copper-Clad Steel Bars with Unclad Two-End Faces for Grounding Grids in the Coastal Soil
Authors: Shao Yu Pei , Yan Ai Jun , Zhang Xin Hua , Wang Yu Na , Liao Qiang Qiang
Published: July 2014

The corrosion behavior of copper-clad steel for grounding grids in the coastal soil have been investigated using electrochemical impedance spectroscopy (EIS), polarization curve measurement and scanning electron microscopy (SEM). The results show that the corrosion current density of copper-clad steel increase with the increase of soil salinity, and the latter stage is less than the mid-term stage. The resistance increase and then tend to be stable with the increase of immersion time. The corrosion resistance of copper-clad steel in the non-salinized and light salinized soil is fine.
Study on the Properties of Multi-Extruded Recycled PE and PP
Authors: Sun Lu , Zhao Xiong Yan , Sun Zhan Ying
Published: July 2014

This paper mainly describes the changes of properties of low density polyethylene and polypropylene after multiple processing. Melt flow index (MFI) analysis, thermal gravimetric analysis (TGA) ,differential scanning calorimeter (DSC) and mechanical properties measurements were used to characterize the thermal stabilities, processability, mechanical properties of virgin and recycled PE and PP. The results indicated that MFI of PE decreased with increasing the number of processing cycles whereas the opposite trend applies to PP. The thermal degradation temperature of the 6th extrudates decreased slightly in comparison with virgin ones. An amorphous region of recycled PE was observed by DSC. The mechanical properties of extruded materials were also affected due to the thermal mechanical degradation.
Analysis of Thermal Conductivity of Lime Plaster with Pozzolanic Addition by Different Homogenization Techniques
Authors: Fořt Jan , Fiala Lukáš , Pavlíková Milena , Pavlík Zbyšek , Černý Robert
Published: July 2014

Thermal conductivity of lime-pozzolan plaster is analyzed in the paper. At first, determination of basic physical properties of tested material is done for its basic characterization, as well as for the assessment of input parameters in the subsequent analysis of measured data by different homogenization techniques. The measurements of thermal conductivity are performed in dependence on moisture content from the dry state to the fully water saturated state using transient pulse method. Among the homogenization techniques based on effective media theory, Lichtenecker’s and Dobson’s models are used. The measured data presented in this paper can find utilization in practical applications of the studied plaster. The analyzed homogenization techniques are found to be applicable for a rapid evaluation of moisture dependent thermal conductivity.
Thermal Properties of Selected Timbers
Authors: Koňáková Dana , Čáchová Monika , Vejmelková Eva , Keppert Martin , Černý Robert
Published: July 2014

This article deals with thermal properties of selected kinds of timber. Wood, generally, is one of often used natural materials in building structures. For our research, woods were selected according to frequency of utilization in civil engineering branch. Four different timbers were chosen, and experimental determinations of their properties were performed. Basic physical properties as well as thermal properties belong among studied characteristics. From achieved results, it is obvious, that the bulk density of studied wood ranges between 373 kg m-3 and 649 kg m-3, the open porosity differ by 13%. Regarding thermal properties, values of the thermal conductivity as well as the specific heat capacity are influenced mainly by the open porosity and moisture content. The thermal conductivity in dry state varies by about 31% while in the case of the specific heat capacity the difference is about 19%. Obtained date will be used in the mathematical analysis of heat transport in building structures.
Residual Strength of Thermally Loaded Mortars with Treated Municipal Solid Waste Incineration Fly Ash Used as Supplementary Cementitious Material
Authors: Keppert Martin , Polozhiy Kirill
Published: July 2014

Fly ashes collected in Air Pollution Control lines of Municipal Solid Waste Incinerators (MSWI) differ highly from fly ashes generated during coal burning what complicates their utilization in building materials production. Nevertheless after a treatment such ashes can have properties relatively comparable with coal fly ashes and thus can be used as Supplementary Cementitious Material (SCM). The water extracted MSWI fly ash was used as partial Portland cement replacement in mortars. The mortars strength evolution in time was monitored; behavior typical for pozzolans – slower increase of strength – was observed. Influence of thermal load on strength of mortars was studied as well. It can be concluded that water extracted MSWI fly ash can be used as 10 % Portland cement substitute without loss of mechanical properties.
Properties of Cement Composites Containing Coir Pith
Authors: Vejmelková Eva , Koňáková Dana , Krojidlová Anna , Hovorková Veronika , Čáchová Monika , Reiterman Pavel , Černý Robert
Published: July 2014

Application of agricultural waste materials as building materials not just provides solutions of environmental problems related to the waste management, but it also decreases the use of limited available natural resources and energy. The research in this work is focused on using coconut waste, in the form of natural and chemically treated coir pith, as admixture partially replacing cement in cement composites. The coir pith is the residue acquired during the extraction coir fiber from the outer protective husk of the coconut. Basic physical properties, mechanical, thermal and hygric parameters of several mixtures were studied. The results of measurements showed the influence of amount of coconut addition primarily on parameters such as the bulk density, open porosity, mechanical strengths, moisture transport parameters and thermal parameters. Restrictions for utilization of this waste material relate primarily with its low adhesion ability to the cement matrix.
Destructive and Non-Destructive Testing of High Temperature Influence on Refractory Fiber Composite
Authors: Holčapek Ondřej , Reiterman Pavel , Jogl Marcel , Konvalinka Petr
Published: July 2014

The main aim of this contribution lies in the description of mechanical properties fiber cement composites after exposure to high temperatures. Destructive and non-destructive methods were used to investigate the influence of heat loading. The effect of refractory binder compared to common Portland cement binder was observed. Widespread non-destructive testing method can describe the changes of mechanical properties due to influence of external load e.g. high temperature at the level of 1000 °C. The tensile strength and compressive strength were investigated on specimens 40 x 40 x 160 mm. Before these destructive tests dynamic modulus of elasticity and tentative compressive strength were provided.
Retention Curves of Different Types of Sandstone
Authors: Záleská Martina , Pavlíková Milena , Pavlík Zbyšek , Černý Robert
Published: July 2014

Retention curve is the basic material property used in models for simulation of moisture storage in porous materials. The measurement of retention curves (also called suction curves, capillary potential curves, capillary-pressure functions and capillary-moisture relationships) is described in this paper. The water storage of different types of sandstone, the materials frequently used on the Czech territory for many centuries mainly for architectonic details and sculptures, is studied in using pressure plate apparatus. The obtained data gives information on materials behaviour in contact with liquid water and on their absorption capacity.
Investigation of Chip Morphology in High-Speed Milling of Nickel-Based Superalloy GH706
Authors: Xiao Sheng Lei , Liu Xian Li , Wang Yu , Li Kai
Published: July 2014

This paper analyzed the serrated chip formation process and mechanism in high-speed milling of nickel-based superalloy GH706. Firstly, analyzed two theories of serrated chip formation: cyclical fracture theory and adiabatic shear theory. Secondly, used the simulation of chip formation in high-speed milling of GH706 process, and concluded that the two major theories have achieved dialectical unity when machining for such difficult machining materials. Finally experiments for serrated chip, when cutting speed exceeded 200/min, serrated chips became more obvious. Research has shown that for nickel-based superalloy, adiabatic shear instability of the unstable thermoplastic in the first deformation zoon become the leader of formation of serrated chip, followed as the speed increases, fracture aggravate the degree of serrated chip.
Determination of Unit Cutting Force of GH4698 Broaching
Authors: Wang Bao Tao , Yan Fu Gang , Zhai Yuan Sheng , Xu Cheng Yang , Guo Jia Xin
Published: July 2014

Fir tree groove broaching is prone to deformation, which affects the machining precision of rear wheel groove. The numerical broaching force is calculated to improve deformation of the processed round tank .This paper uses the planer to make cutting tests that are carried out in shaping machine to simulate the wheel broaching process and measures the cutting force in the experiment. After analyzing the unit numerical cutting force of GH4698 broaching is finally obtained. It provides a simple method to calculate the cutting force of wheel groove machining.
Investigation on Milling Force with Tilt Angles in Milling Cr12MoV
Authors: Liu Fei , Yue Cai Xu , Liu Xian Li , Feng Xin Min , Ma Jing
Published: July 2014

Based on actual working condition, this paper takes the mold materials Cr12MoVwhich is widely used in car cover as research object, and uses the finite element software Deform 3D to establish three-dimensional finite element simulation model of milling hardened steel Cr12MoV process. Reliable material model, chip separation criterion and appropriate boundary conditions are applied. The finite element simulation of milling hardened steel is built with different tilt angles. Milling force of simulation results are verified through experiments.Changes in the milling force with tilt angle are discussed, which can provide certain reference for cutting parameters optimization of milling process and 3D finite element modelling in milling.
Changing Boundaries of Serrated Chip in Hard Cutting GCr15 Steel
Authors: Chen Guang Jun , Liu Xian Li , Wang Yu Shuo
Published: July 2014

Hard cutting process is easy to produce serrated chip. Hardened steel GCr15 as the object for the study, chip morphology was studied on hard cutting test and chip cross-sectional microscopic analysis methods. The boundaries of ribbon cuttings to serrated chips cutting was determined, under certain conditions of PCBN cutting tool cutting precision hardened steel GCr15, and form a quantitative description of the chip. With the increase in the amount of cutting, serrated chips have the degree of improved trend, in which the most significant impact of cutting speed, while the hardness increases, the degree of sawtooth also increases. Hard cutting research will enrich the theory provides a theoretical basis for the choice of cutting parameters.
Finite Element Analysis of Dynamic Characteristics of the Machine on Multi-Position Conditions
Authors: Jiang Y.C. , Liu Xian Li , Li Rong Yi , Pang P.F. , Xu J.
Published: July 2014

High speed cutting technology has become one of the most important technology in manufacturing of automobile panel dies. The range of each motion axis of numerical control equipment is large and the entire process system exist certain differences of the dynamic characteristic cause of the large type surface size of automobile panel dies. And affect the stability of the processing conditions directly. In this paper, different locations dynamics of large CNC machining equipment was analysed, then getting the influence of processing on the dynamics of the processing position. Simulation results show the machine dynamic characteristic mainly affected by the working position of the spindle box, and the location of the workbench has smaller impact. In the low speed mode, the stiffness characteristics of the spindle box in the operating position on both sides is better and in the high-speed mode the stiffness characteristics is better in the right side of the spindle box. When the table near the right end position in X, Y have weak stiffness near 90Hz.It has weak stiffness in the left side of table near 80Hz and in middle position it has weak stiffness near 80Hz or 140Hz . In the cutting process to provide guidance for the selection of appropriate processing location and process parameters.
FEM-Based Prediction and Control of Milling Deformation for a Thin-Wall Web of Ti-6Al-4V Alloy
Authors: Chen Ting Ting , Rong Bin , Yang Yin Fei , Zhao Wei , Li Liang , He Ning
Published: July 2014

This paper presents the prediction method of cutting force and dimensional error of Ti6Al4V alloy thin-wall components in end-milling operations. Based on the FEM simulation software and force-model, machining deformation was predicted by two kinds of FEM models, and then compared with the measured data. Results obtained from the proposed models and the tests show that the coupling model of thermal-mechanical having better agreement with the experimental results. Besides, the test results also prove the new tool-path pattern proposed in this paper is useful to reduce the machining error.
The Milling Cutter Design and Simulation for Complex Cavity Machining
Authors: Zhang An Shan , Liu Xian Li , Yang Shu Cai , Zhang Qi
Published: July 2014

Complex cavity generally is machined in 3 axis or 3+2 axis machine tools, it has large amount of metal to be removed. For complex cavity machining, the cutting speed of ball end mill`s head point is zero, which makes its end milling ability poor; Torus cutter `s flat bottom width is wide, which causes curvature interference and concave-uncut. So this article designs a new kind of cutter for complex cavity roughing and semi-finishing, which can improve ball end mill`s poor end milling ability and decrease flat-end width. The simulation results show that the new cutter`s feasibility of machining complex cavity is better, and it can obviously reduce the amount of owe cutting compared with the torus cutter; At the same time, the new cutter can improve machining efficiency by 32.4% compared with the ball end mill, and good surface can also be generated.
Experiment Study of Serrated Chip and Surface Roughness of High Speed Cutting of Ti6Al4V
Authors: Li Guo He , Cai Yu Jun , Qi Hou Jun
Published: July 2014

Under the condition of cutting speed 10-300m/min, rake angle -10°、0°、10°and cutting depths 0.05mm、0.1mm and 0.2mm, the experiment study of adiabatic shear serrated chip and surface roughness are carried out. The influence of cutting condition on serrated chip is analyzed through the metallographic observation of obtained chip. By the measurement of finished surface, the influenc of cutting condition and adiabatic shear on surface roughness is also investigated. The rusults show that the reason lead to serrated chip in high speed cutting of Ti6Al4V is adiabatic shear, not the periodic fracture.The adiabatic shear serrated chip is easier appear and the degree of segment is more large under the condition of higher cutting speed, larger cutting depth and smaller rake angle. The surface roughness is smaller when the cutting speed is higher, cutting depth is larger, and rake angle is smaller.
Influence Characteristics of Tool Vibration and Wear on Machined Surface Topography in High-Speed Milling
Authors: Jiang Bin , Cao Guang Lei , Zhang Ming Hui , Sun Shou Zheng , Liu Xuan Chi
Published: July 2014

Existing research on machined surface topography, only consider its response to vibration or wear certain factors, both vibration and wear impact on machined surface topography exist ambiguity and uncertainty, it cannot solve the design conflicts of machined surface topography. For this, this paper analyzes blade installation error, tool wear, vibration and deformation to reveal effects of tip space trajectory, build a three-dimensional model of machined surface topography in simulation, extract its characteristic parameters, by simulation of different amplitudes and wear, found that axis amplitude is a key factor affecting surface residual height, flank wear affects contour distribution distance significantly, by specimen milling experiments, use vibration measuring instrument and ultra-depth microscopy to obtain vibration, wear characteristics and machined surface topography parameters under different cutting parameters, then use the gray system theory to get correlation analysis of the test data, results showed that the influence of tool wear on machined surface topography is prominent than tool vibration.
Experiment on Magnetization of High-Speed Steel Cutting Tool
Authors: Chen Shuang , Lai Wu Jun
Published: July 2014

The W6Mo5Cr4V2 high-speed steel tool was magnetized by an AC magnetization device which made by ourselves, and the cutting experiments were carried out in a general purpose machine with the magnetized high-speed steel tool and non-magnetized high-speed steel tool. The experimental results indicated that the cutting surface roughness of the workpiece could be improved by the magnetized W6Mo5Cr4V2 high-speed steel tool. Meanwhile the magnetization time and magnetization frequency should be regarded as the key of magnetization adjusting parameters. The magnetized W6Mo5Cr4V2 high-speed steel tool presented the different cutting performance under the different magnetization time and frequency, in which there were the better effects in low frequency. In addition, the experimental results also showed that the cutting force could be reduced during the cutting process by using of the magnetized W6Mo5Cr4V2 high-speed steel tool and the formation of the built-up edge in the tool could be inhibited, thereby the tool life was prolonged and the processing quality was improved.
Study on the Correlation between Drawing Education and Special Cognitive Ability Evaluation Based on the MCT
Authors: Li Ping
Published: July 2014

Use the international universal theory of evaluation of special cognitive ability with Mental Cutting Test (MCT) to test the students of Science and Technology University. Compare the MCT average scores of fore-and-aft drawing education, it shows that the effect of descriptive geometry teaching is positive correlative with the scores of MCT, the students improved their special cognitive ability from planar drawing to three-dimensional drawing significantly. The students who got lower MCT scores before taking drawing courses improved their MCT scores obviously. The effect of mechanical drawing teaching is feeble correlative with the scores of MCT; it shows feeble improvement in students’ special cognitive ability.
High Temperature Alloy of Turning Processing Characteristic and Process Analysis
Authors: Wang Xue Feng , Wang Shi Gang , Wu Zi Jing
Published: July 2014

High temperature alloy is the key hot end parts' material, which is often used in the modern aircraft, spacecraft and the rocket engines, as well as naval vessels and industry gas turbine. And it's also used in the nuclear reactor, chemical equipment, coal conversion technologies etc. as the very important high temperature structural materials. High temperature alloy of turning processing is the technical difficulties in mechanical cutting work, this paper introduces the high temperature alloy turning processing features, turning processing tool, cutting parameters, the choice of the cutting fluid and machining notice proceedings, etc.
Residual Stresses Measurement Base on Three Reference Points Theory Using Contour Method
Authors: Yu Kai Qin , Yang Yin Fei , Li Liang , He Ning , Chen Bo , Zhang Xue Feng
Published: July 2014

The objective of this work is to measure the residual stress normal to the cut plane which has a large size using contour method. Translations and rotations are applied to the second point cloud to assure the continuity of the contour. There is still the same work on the opposing cut plane, align and combine the two contour datasets, perform the interpolation and then integrate with a finite element modelling package to apply many thousands of different boundary conditions. The finite element result shows a good continuity indicating the success of transformation means applied on the point cloud. The result gets the stress distribution normal to the cut plane. Beam forming is simulated to study the residual stress distribution of the stretch-wrap bend forming, the residual stress from contour method and forming simulation present the same trend.
Study on Die Casting Simulation for Magnesium Alloy Cylinder Cover Based on JSCAST
Authors: Hu Qing Ming , Wang Shi Gang , Li Dong Sheng , Guo Jian Hua , Xu Cheng
Published: July 2014

Magnesium alloy has widely been used in automotive sector due to its light weight, low density, high stiffness, and excellent casting performance and easy to recover and utilize. The magnesium alloy automotive engine cylinder cover was chosen as researching object to simulate its die casting filling process based on die casting filling process theory and numerical simulation analysis software JSCAST. The simulation results show that the utilization of die-casting simulation software for improving product quality and production efficiency has certain significance during the production of magnesium alloy die casting process.