bluuebunny/crossref_metadata_2025 huggingface dataset:
Elastic Modulus Calculation of GRT Fiber-Rubberized Haydite Concrete
Authors: Xia Bing Hua , Liu Yuan Cai , Zhang Qing Wen
Published: February 2012

Experiment with intensity level for the LC30 ceramsite concrete as the research object, changing the content of cement, GRT fiber, rubber powder by the orthogonal test to configure GRT fiber—rubberized haydite concrete samples, maintenance samples 28d in standard conditions and respectively testing their modulus of elasticity、standard compressive strength and apparent density. Through the analysis of the test data, using regression method to establish the GRT fiber—rubberized haydite concrete static compression modulus of elasticity experiential formula and use new test data to compare the value of calculation. By comparing test values and calculated values proved availability of the regression formula.
Material Properties of a New Hybrid-Fiber Engineered Cementitious Composite
Authors: Hermes Phillip , Zhang Yi Xia , Soe Khin , Bell Joel
Published: February 2012

A new hybrid-fiber Engineered Cementitious Composite (ECC) containing 1.25% steel (SE) fibers and 0.75% Polyvinyl Alcohol (PVA) fibers is proposed, and material properties of the new ECC mix are tested in this paper. The compressive strength, modulus of elasticity, modulus of rupture and tensile properties under various strain rates of the new hybrid-ECC mix are investigated experimentally. The tested results are compared with those for a normal concrete mix, as well as those for other mono-fiber and hybrid-fiber ECCs reported in other literatures.
Corrosion Behavior of Enamel Coated Steel Rebar by EIS
Authors: Tang Fu Jian , Chen Gen Da , Volz Jeffery S. , Brow Richard K. , Koenigstein Michael
Published: February 2012

In this study, the corrosion process of enamel-coated deformed rebar completely immersed in 3.5 wt.% NaCl solution was evaluated over a period of 84 days by EIS testing. Three types of enamel coating were investigated: pure enamel, 50/50 enamel coating, and double enamel. Surface condition of the enamel coatings that were intentionally damaged prior to corrosion tests was visually examined at different immersion times. After 84 days of testing, the damaged coating areas were characterized by SEM, and the corrosion products on and adjacent to the damaged areas were collected and analyzed by XRD. Corrosion initiated at the damaged locations with no undercutting of the coating observed. The 50/50 enamel coating had the least corrosion resistance, due to its interconnected pore structure, and prior damage drastically reduced the corrosion resistance of pure and double enamel coated rebar.
Study on Experimental Behavior of Concrete Circular Column Confined by HFRP under Axial Compression
Authors: Xu Shun De , Li Li Juan , Guo Yong Chang
Published: February 2012

A loading comparison experimental study on concrete circular columns confined by hybrid fiber sheets of carbon FRP sheet, basalt FRP sheet, and glass FRP sheet is carried out to analyze their failure feature, bearing capacity, ductility and economy. Test results show that HFRP can increase the ductility of column and deduce the price on the precondition of having enough bearing capacity.
Influence Factors during Preparation of Low-Temperature PCMs
Authors: Li Zi Qiang , Li Hai Ying , Ji Ai Min
Published: February 2012

For well application in north of China, the optimal properties of phase change materials was screened out by comparing with the same adsorbing material – perlite in Lab conditions. Three main influence factors including adsorption time, experiment temperature and particles of expanded perlite were investigated for all sample of phase change materials. The results showed that capric acid is the optimal one of all samples due to its suitable transformation temperature at 30.1 oC and relative high adsorption proportion of 140% on the vacuum condition at 60 oC in 45 min. All experiments could provide useful data for the building energy saving of Tangshan district.
Compressive Strength and Microstructure of Multi-Wall Carbon Nanotubes Reinforced Cement Composites
Authors: Liu Jin Tao , Yan Dong Ming , Xu Shi Lang
Published: February 2012

Advancement in the study of carbon nanotube has enabled its application in civil engineering as constitutive materials or additives. In this study, the availability of applying multi-walled carbon nanotube to improve the characteristics of cement composites was investigated with experiments on more than 30 specimens. The multi-walled carbon nanotubes (MWCNTs) were effectively dispersed in the water with surfactant, which can keep stable for over 3 months. Specimens with MWCNTs of 0.025%, 0.05% and 0.1% of cement (by weight) were tested with a loading machine and then analyzed with a SEM. It was found that the compressive strength of the samples increased with the increasing MWCNTs, it can improve the 7-day compressive strength by 22% . Microscopic analysis (SEM) revealed that carbon nanotubes were surrounded with hydration products. The bridging and debonding of carbon nanotubes in cement pastes was observed as well.
Study on adsorption of Methylene Blue by the Modified Kaolin
Authors: Qiu Mu Qing , Zhang Jia Jia , Ni Jia Wei
Published: February 2012

Using Kaolin as the main raw material,l ultrafine particles modified Kaolin were prepared. Then loading transition metals (copper and zinc), the final modified Kaolin composite photocatalyst was finished. This study used a composite photocatalyst in three main factors photocatalytic oxidation degradation of methylene blue simulated waste Textile Industry water effects. The results showed that the best conditions for simulated wastewater of 100 mL was: methylene blue initial concentration of 40 mg/L, hydrogen peroxide of 0.4 mL, composite photocatalyst of 60 mg, pH 10.21. Under this condition, the chromaticity of methylene blue dropped from 1 600 to 10 after aeration reaction of 120 min, and its removal rate was 99.32%.
Strength Model Analysis of the Foam Concrete
Authors: Cheng Long Fei , Fu Ya Nan , Zhou Ting Qiang
Published: February 2012

Foam concrete aggregates and inclusions have greater strength, but the pore almost has no compression resistance; hydrated cements and pores are the weak links in the pressure cross-section of the foam concrete. As for unit volume of foam concrete, cement accounts for a large space and the pore occupies less, so the block intensity will be larger. Considering mechanical properties of the aggregates and hydrous cements are different, the volume ratio of hydrous cements to the sum of cements and pores is used to build the strength model of foam concrete, which can be simple and feasible. It can response the foam concrete strength characteristics more accurately.
Orthogonal Experimental Study on Thermal Insulation Mortar Containing Mixed Ceramic Sand and Vitrified Micro Bead Aggregates
Authors: Xie Zhi Lling , Sun Lin Zhu , Yang Fang
Published: February 2012

Mixed light aggregates can effectively reduce the coefficient of thermal conductivity of composite materials. Through orthogonal experiments of thermal insulation mortar containing mixed ceramic sand and vitrified micro bead aggregates, we analyzed the law of influence of relevant factors on the dry bulk density, coefficient of thermal conductivity and compressive strength of mortar containing mixed ceramic sand and vitrified micro bead aggregates and provided basic data for further improvement of such thermal insulation mortar so as to promote the development and application of high performance thermal insulation materials.
The Comparative Analysis of Lime Burst between Sintered Shale Brick and Light-Weight Sintered Brick
Authors: Huang Bang Biao , Jing Jia Hua , Zhu Ji Zhen , Chen Cai Xia , Luo Shan
Published: February 2012

The sintered shale brick and light-weight sintered shale brick are both of brittle wall materials. The mechanical and other properties will be affected greatly by tensile force producing the lime burst. Through analysis of physical and chemical properties of raw materials, the reason of lime burst, and the comparative experiments of lime burst, studied on similarities and differences between the two wall materials, providing important technical parameters for the follow-up research, production and construction in the feature.
Flame Retardant of Epoxy Resin Composites
Authors: Dong Jin Hu
Published: February 2012

Epoxy resin (EP) be widely used owning to its superior performance and usability, however the flammability of EP bring trouble for its application. So, flame retardant of EP is very important research subject. This article reviewed the flame retardant methods for EP, and introduces research results from the types of phosphorus-containing flame retardant, organic montmorillonite (OMMT) flame retardant, hydrogen peroxide flame retardant and double hydroxyl hydroxides (LDH) flame retardant respectively.
Degradation Kinetics of Xylose and Arabinose in Subcritical Water in Unitary and Binary System
Authors: Chen Xiu Ju , Liu Xiao Qin , Xu Fang Lian , Bai Xin Peng
Published: February 2012

The degradation process of xylose and arabinose in a binary compositions system at temperatures from 210 to 250°C was studied to clarify the reaction mechanism and to examine the effect of the degradation products of a substrate on the disappearance of another substrate. The activation energy and frequency factor for the degradation of each substrate were estimated from the temperature dependence of the rate constant. The molar yield of a pentose to furfural was ca. 0.3 at any temperature, Acidic compounds were also formed from the pentoses in proportion to the amount of consumed substrates. The formation of acidic compounds resulted in a rapid decrease in pH
Quality Control of Fly-Ash Concrete Strength at early Age and Evaluation Application Research
Authors: Niu Hui
Published: February 2012

This manuscript briefly introduces an engineering example.The method of fly-ash concrete presumption at early age is used in mixing proportion design. we can control concrete quality and improve accuracy of the early evaluating presumption concrete among measures and results.
Stress-Strain Model for Confined Concrete in Cross-Shaped Columns
Authors: Sun Lin Zhu , Wang Tie Cheng , Yang Fang
Published: February 2012

To establish complete stress-strain curve equations for confined concrete in cross-shaped columns, we designed 7 test specimens corresponding to the usable eigenvalue range of stirrup of the cross-shaped columns. We obtained the test results of the reinforced concrete cross-shaped columns through axial compression test, got the system parameters of a stress-strain model through statistical analysis of the test data, and then established stress-strain curves for confined concrete in the cross-shaped columns. This model reflects the variation rule of the stress-strain curve of confined concrete in cross-shaped columns. Compared with the stress-strain model for confined concrete in square columns, the confined concrete in cross-shaped columns has smaller peak stress, larger peak strain, and relatively steeper descending part of curve. The research results provide theorotical basis for nonlinear analysis of cross-shaped columns.
A Research on Design Strategies for “Non-Landmark Buildings” in Urban Design
Authors: Xu Jian Sheng , Li Zhao , Liu Yi Wei
Published: February 2012

A Chinese proverb says “being willing to be leaves to set off the beauty of flowers”, which encourages individuals learn to giving yourself to create harmony. Similarly, there are various kinds of architecture in a city, what kinds of buildings should be the flowers, what kinds of buildings should be the leaves? In regard to the leaves, what kind of attitude should we hold toward them？And what are specific design strategies for the leaves? Through analyzing and summarizing some typical examples, this paper discusses and demonstrates how to adopt an integrative way to balance the relationship between different kind of buildings like the leaves and the flowers from the view of urban design. Moreover, raising awareness of the importance of “non-landmark buildings” design is the aim of this paper.
Analysis of Time and Cost Overrun in Malaysian Construction
Authors: Ramanathan Chidambaram , Potty Narayanan Sambu , Idrus Arazi B
Published: February 2012

The construction industry in Malaysia is very important for creating employment, both directly and indirectly. It faces two repeated problems during the construction stage: slippage of project-schedules, i.e. time overrun and overrun of project cost; to the dislike of owners, contractors and consultants. This paper studies the time delay and cost overrun factors for Design and Build D&B projects in Malaysia. A Questionnaire was used to collect data from practitioners and analyse the responses and rank the factors and groups on overall view of the contracting parties. Identified risk factors from the theoretical domain were used to prepare 79 time related question and 18 cost related question categorized in 9 groups and 1 group respectively. Total of 136 respondents recorded their ratings to the factors in the questionnaire. Labour-related group has the top 1 rank with RII 0.684. The results can be used as a guideline to successfully handle construction projects in Malaysia; contributing for better project performance and lead to positive risks, opportunities.
Study of the Electromagnetic Shielding Efficiency of Ni-Cu-P Amorphous Alloy Film on the Surface of PVC
Authors: Du Shi Guo , Cui Hai Ping , Yan Jun , Wang Ming Qiu
Published: February 2012

The surface of PVC has been treated by coupling agent before plating Ni-P alloy film .Then Ni-Cu-P film with different components was prepared on the surface of PVC according to copper salt concentration. The effect of these factors such as time and copper salt concentration on the film component and surface resistivity was analyzed. And the electromagnetism shielding efficiency of all the Ni-Cu-P alloy film on the PVC was tested by the network analysis measurement. The result showed that for the plating solution of lower copper salt concentration, when the reaction time increased, the Cu component of Ni-Cu-P alloy films increased too. The surface resistance ratio of the Ni-Cu-P films decreased with the increase of Cu component. Ni-Cu-P amorphous alloy film performs a stable electromagnetic shielding property of 35 to 60dB when the electromagnetic wave frequency ranges from 5K to 1.5GMHz.
Safety Research on the Tritium System for China TBM
Authors: Fu Wan Fa , Luo De Li , Tang Tao
Published: February 2012

Tritium safety research on the tritium system of Test Blanket Module(TBM) was carried out. At first, according to safety analysis task and method of tritium system, the research process framework about the tritium safety analysis was given. Failure Mode and Effect Analysis (FMEA) on tritium system was carried out, analyzing the calculation process of permission value of TBM Tritium release. In order to compare and assess safety grade of the tritium system among all kinds of nuclear facilities, calculation formula was given, finally.
Pharmacokinetics and Tissue Distribution of Norfloxacin in Eel Following Oral Gavage
Authors: Hui Yun Hua , Cai You Qiong , Feng Bing , Ruan Wen , Yu Hui Juan
Published: February 2012

The pharmacokinetics of norfloxacin were investigated in the European eel after a single oral gavage of 10 mg norfloxacin per kg body weight. The concentrations of norfloxacin in the main tissues (kidney, muscle, hepatopancreas and blood) were simultaneously detected by HPLC. All of the concentration-time curves of norfloxacin in the plasma, muscle and liver were consistent with absorption of a two-compartment open kinetic model. Norfloxacin was widely distributed in different tissues in the European eel. Apparent volume of distribution (Vd) was 52.025 L/kg, 34.589 L/kg, 2.795 L/kg, and 0.969 L/kg, in plasma, muscle, liver and kidney, respectively. Norfloxacin in the eel was proved to eliminate slowly, and half-time (tβ1/2) in plasma, muscle, liver and kidney, was 201.222 h, 123.789 h, 120.634 h and 627473.495 h, respectively. Body clearance was 0.689 L / ( kg•h ), 1.793 L/( kg•h ), 0.097 L/( kg•h ) and 0.028 L /( kg•h ), in plasma, muscle, liver and kidney, respectively.
Application of Central Composite Design Based on Numerical Integration for Optimization of Laser Shock Peening
Authors: Zheng Gang , Fan Jin Rong , Huang Shu , Zhou Jian Zhong , Ruan Hong Yan
Published: February 2012

In order to analyze effect of processing parameters on Laser Shock Peening(LSP), a novel numerical model integrated with FEM and statistical optimization algorithm was established, and the numerical simulation of LSP process was carried out. In simulation, laser pulse energy, beam diameter and center distance were considered as control parameters, while the compressive residual stress and the deformation value as output aim parameters,. The results indicates that the laser pulse energy has the strongest impact on the surface residual stress, while the spot diameter affects the section residual stress and the surface deformation. Moreover, the response surface function was applied to predict and optimize laser parameters. Lastly the presented method was veriﬁed by experiments.
Seismic Retrofit of RC Beam-Column Joints Using the MF-EBR Strengthening Technique
Authors: Coelho Mário , Fernandes Pedro , Melo José , Sena-Cruz José , Varum Humberto , Barros Joaquim , Costa Aníbal
Published: February 2012

The strengthening technique based on the application of multi-directional laminates of CFRP (MDL-CFRP) simultaneously glued and anchored to the surface of the elements to be strengthened has been recently proposed. This technique was designated Mechanically Fastened and Externally Bonded Reinforcement (MF-EBR) and combines the fasteners from the MF-FRP technique with the externally glued properties from the EBR. With the aim of assessing the potentialities of this technique for seismic retrofitting, three interior RC beam-column joints were strengthened according to the MF-EBR technique and tested. This work presents the entire test program executed, including test configuration, results and corresponding analysis.
Research on a Method of PID Error Compensation in Turning
Authors: Li Zhuo , Lu Jun , Wang Yu Kun
Published: February 2012

An error compensation model in turning based on PID adjustment was investigated in this paper. A new method is proposed to eliminate the effects of probe radius. Simultaneously, PID error compensation model is used to regulate the comprehensive error to obtain the actual quantity of error compensation. Computer-aided technology is applied to complete the algorithm, and then a new processing path is generated. The experimental results indicate that the precision of workpiece can be improved from 0.01mm to 0.003mm after three steps of error compensation.
On the Manifestations, Causes and Consequences of the Incoordination between Industrial and Consumption Structures
Authors: Liu Xue Feng
Published: February 2012

From the perspective of internal relationships in the process of social reproductions, the level of solution consumption problems is one major norm to measure whether the performance and development of a country’s economy is healthy, especially productive structure, industrial structure, and the relation between consumption and need. The key problem is whether between industrial structure and demand structure is adaptive. Thus, the measure standard of national economic running lies in the solution of consumption issues, that is, the solution of making consumption structure and industrial structure compatible. Basing on the relation between industrial and consumption structures in China, the paper introduces the manifestations, causes and consequences of the incoordination between industrial and consumption structures.
Bond Behavior between Concrete and Multi-Directional CFRP Laminates Using the MF-EBR Strengthening Technique
Authors: Coelho Mário , Fernandes Pedro , Sena-Cruz José , Barros Joaquim
Published: February 2012

The strengthening technique based on the use of multi-directional laminates of CFRP simultaneously glued and fixed with anchors (MF-EBR) has been recently purposed. An experimental program composed of pullout tests was carried out in order to study the bond behavior between concrete and MF-EBR system. The diameter and number of anchors, the pre-stress level applied to the anchors, and the strengthening procedures were the main analyzed parameters. The present work describes the carried-out tests and presents and analyzes the most significant obtained results.
Mixed Multi-Layered Model for Fracture Analysis of Functionally Graded Interfacial Zone under Anti-Plane Loading
Authors: Di Ke , Yang Yue Cheng
Published: February 2012

In this paper, a new mixed multi-layered model is put forward to study the crack problem of the functionally graded interfacial zone between tow homogeneous half-spaces. In the model, the interfacial zone is divided into some sub-layers with the properties of each layer varying in linear and exponential manners alternately. By applying Fourier transform and using the transfer matrix method, the mixed boundary problem of anti-plane fracture can be reduced to a Cauchy singular integral equation, which is solved numerically. Stress intensity factors of some examples are derived. The results show that the present model is effective and accurate and compared with the liner multi-layered model, the present one can save more CPU time in computation.
Optimization Design of the Two-Stage Helical Cylindrical Gear Reducer Based on MATLAB
Authors: Zhang Jie , Zhang Hui Peng
Published: February 2012

Traditionally, in order to get satisfied design data of reducer, you must cut and try again and again. Although this design data can satisfy conditions given, it is not optimal. In this paper, after establishment of target function, choice of parameters and confirmation of constraint conditions of the two-stage helical cylindrical gear reducer are systematically studied, its optimum mathematical model is set up. The reducer is designed by MATLAB Optimization Toolbox; it simplifies the computer programs and enhances the design efficiency and quality.
Slow Light Properties of 2D Photonic Crystal Waveguide for Optical Storage in Optical Computers
Authors: Liu Qi , Liu Qi Chao
Published: February 2012

Slow light properties of the photonic crystal line-defect waveguide are researched with the plane wave expansion method. The structure of the waveguide is adjusted with several methods mentioned above at the same time and the slow light properties get better. For the structure of dielectric rods, central frequency and the group velocity of the guided modes decrease with the increase of the radii of the defected rods as well as the dielectric constant. Effects on the slow light from the change of the defected rods’ position are also studied, through moving the rods up and down; we get the almost linear guide mode which has flat slow light curve and smaller group velocity. In a word, group velocity of the slow light is mainly affected by the radii and dielectric constant of the defected rods, and group velocity dispersion is decided by the change of the defected rods’ location.
Mathematical Modelling on Dramatic Temperature Change of Reduction Retorts in Pidgeon Process
Authors: Huang Yan Yan , You Guo Qiang , Liu Yong
Published: February 2012

Magnesium reduction retorts, as vital industrial equipment in Pidgeon Process, have a short service life. The dramatic temperature drop and rise in the retort is predicted to shorten service life. A mathematical model has been developed to simulate the phenomenon of heat transfer of retorts with different wall thickness and temperature of reactant compounds. The computed results are as follows: (1) the rising rate of temperature in the retort overweighs that in reactant compounds, and it takes less time to form a uniform temperature distribution; (2) the rise of retort’s wall thickness will aggravate the sharp temperature change; (3) when the temperature of reactant compounds being placed into increases, the situation will be improved.
Free Convection Heat Transfer from a Row of Horizontal Cylinders
Authors: Cianfrini C. , Corcione M. , Habib E.
Published: February 2012

Steady laminar free convection in air from parallel circular cylinders set side-by-side is studied numerically. The SIMPLE-C algorithm is used for the solution of the mass, momentum, and energy transfer governing equations. Simulations are performed for tube-arrays consisting of 10 equally-spaced cylinders, for different center-to-center separation distances in the range between 1.4 and 6 cylinder-diameters, and for Rayleigh numbers spanning between 101 and 105.
Study on the Performance Evaluation Method of Wheat No-Tillage Planter Based on Gray Theory
Authors: Zhao Li Qin , Guo Yu Min , Zhang Pei Zheng
Published: February 2012

No-tillage planting is one of the most important assignments of the conservation tillage technology. The 2BMF-9 wheat no-tillage planter was taken as object，the planting experiment on field were carried out on eight kinds of surface treatments, then various performance indices, emergence of seeding rate and tiller number were obtained on each surface treatment. The grey correlation analyzing concluded that the seeding uniformity, covering soil ability and passing ability had greatly influenced the emergence of seeding rate and tiller number. Eight kinds of surface treatments were categorized with the principle of gray clustering evaluation.
Theoretical and Experimental Investigation of Compressible Flow through Convergent–Divergent Nozzles
Authors: Mzad Hocine , Elguerri Mohamed
Published: February 2012

The present paper is concerned with the study of compressible flow in a converging-diverging nozzle. From a theoretical and experimental investigation of the flow in an illustrative channel with convergent-divergent area variation, the behavior of the flow along the channel was found to be generally similar in trend to the flow in a stationary convergent-divergent nozzle. In compressible flows, the density and temperature variations are often significant. Therefore, the following study provides additional information on shock location, Mach number behavior and pressure distribution by varying nozzle length. The obtained curves show pressure distribution and Mach number along the two dimensioned nozzles which enable us to compare the experimental data with the theoretical calculations. Furthermore, interesting graphs are plotted which show the relationship between some nozzle parameters and flow characteristics.
Study on the Model Reduction Methods in CNC Machine
Authors: Zhang Ya Wei , Zhang Wei Min
Published: February 2012

In order to research dynamic characters of CNC machine tools, the finite element method is always adopted to model the system, and its dynamic characters are analyzed based on the modeling. The large dimension of the model for CNC machine and its key system become a problem to be solved. In this paper, the model reduce methods are compared and analyzed in order to clarify this problem. The transmission system of CNC machine tool is modeled by FEM firstly, then, the model reduction methods of reduce method, subspace method and Block Lanzcos method are applied for its modal analysis. The reduced method have to search a set of master DoF, the subspace is used for calculating partial mode in a relative large scale system with simple geometries;. Block-Lanczos method is adopted when the system with large scale dimension, but it needs good computer storage capacity and performance
Analysis of “CPOE62” Workover Platform's Bottom Stability
Authors: Bao Ze Fu , Hong Cai , Jiang Ya Zhou , Wang Jiang Ping
Published: February 2012

“CPOE62”platform is a self-elevating workover platform. Under the construction and service process，because of the particularity of work environment，Not only does it bear its own weight and variable load, but also bears the role of environmental load all the time. Sometimes this environment load will have an enormous destruction. Based on the analysis of environmental load, the author checks the bottom stability and verifies it through ANSYS. These will provide some useful information for the deep sea platform research in Bohai Sea deep-water oil and gas development, which achieves higher security and economic efficiency.
Optimization of a Shock Absorber Design Using Model-Based Approach
Authors: Wszołek Grzegorz , Czop Piotr , Jakubowski Dawid , Slawik Damian
Published: February 2012

The aim of this paper is to demonstrate a possibility to optimize a shock absorber design to minimize level of vibrations with the use of model-based approach. The paper introduces a proposal of an optimization method that allows to choose the optimal values of the design parameters using a shock absorber model to minimize the level of vibrations. A model-based approach is considered to obtain the optimal pressure-flow characteristic by simulations conducted with the use of coupled models, including the damper and the servo-hydraulic tester model. The presence of the tester model is required due to high non-linear coupling of the tested object (damper) and the tester itself to be used for noise evaluation. This kind of evaluation is used in the automotive industry to investigate dampers, as an alternative to vehicle-level tests. The paper provides numerical experimental case studies to show application scope of the proposed method
Machine Condition Monitoring by a Novel Fractal Analysis
Authors: Yang Wen Xian , Jiang Jie Sheng
Published: February 2012

The nonlinearities, induced by structural looseness or wear/fatigue of components, are good indicators of the health condition of a machine or structure. However, most existing condition monitoring techniques were initially designed for dealing with linear systems, thus unable to account for these scenarios properly. A few available nonlinear techniques are tried in condition monitoring. However, they are more or less limited owing to either intensive computation or unsatisfactory sensitivity to incipient abnormalities. In view of this, a new fractal analysis-based condition monitoring technique is researched in this paper. Firstly, a few number of fractal analysis methods with efficient computing algorithms are investigated in order to find an ideal one for condition monitoring application. Subsequently, a detailed investigation was conducted to verify the favored method and understand its instantaneous properties, robust performance against noise, and sensitivity to the abnormalities. Finally, following discussing the window width used in practical calculation, the condition monitoring technique developed based on the favored fractal analysis method is validated experimentally. Experiments show that the proposed technique does provide an efficient and successful nonlinear tool for machine operation condition and structural health condition assessment.
Heat Transfer Prediction for Helical Baffle Heat Exchangers with Experimental Data by Radial Basis Function Neural Networks
Authors: Jiang Bin , Yang Xiao Ling , Zhang Lu Hong
Published: February 2012

In this paper an artificial neural network (ANN) is used to correlate experimentally determined heat transfer rate of non-continuous helical baffle heat exchangers. First the heat exchangers with three helical angles were experimentally investigated under different inlet volumetric flow rate and temperature. The commonly implemented radial-basis function (RBF) neural network is applied to develop a prediction model based on the limited experimental data. Compared with correlations, the RBF network exhibits superiority in accuracy. The satisfactory results suggest the RBF network might be used to predict the thermal performance of shell-and-tube heat exchangers with helical baffles.
Numerical Simulation and Analysis of Low Hysteresis Brush Seals
Authors: Chi Jia Dong , Wang Zhi Li , Li Li Ke
Published: February 2012

To better understand the bristle behavior and leakage performance in brush seals, a Computational Fluid Dynamics (CFD) model has been developed, in which the brush is treated as an anisotropic porous region with nonlinear resistance coefficients. With the calculated pressure distribution and the cantilever beam theory, aerodynamic and contact forces on bristles are calculated utilizing the Finite Element Method; and bristle deflections in the axial direction and in the orthogonal plane are obtained. Subsequently their influences on friction force and torque are evaluated. Computed different kinds of low hysteresis brush seals, discuss the effect of size parameters of front plate and back plate on low hysteresis brush seals.
Design and Electromagnetic Analysis of Anti-Rotary Propulsion PMSM
Authors: Xu Hai Zhu , Xie Shun Yi , Ji Wan Feng , Xu Fang
Published: February 2012

Due to electromagnetic coupling and structure restriction of the two rotors, the design of anti-rotary PMSM is very complex. Inner motor and outer motor are designed respectively and then integrated in aspect of electromagnetic coupling and size restriction in this paper. Main size and electromagnetic relationship are designed according to objectives, and key design equation and project procedure are presented as well. Parameters effect on motor performance such as efficiency and torque density are analyzed. The performance of the prototype, well matches the theory analysis, whose validity is verified by FEA results
Kinematics Research for a High-Precise Multi-Gratings Mosaic Mechanism
Authors: Lu Li Hua , Liang Ying Chun , Yu Fu Li , Su Bao Ku
Published: February 2012

A novel design of high load capacity multiaxis positioning stages with accuracy in the range of nanometers is presented. For strokes of 2mm with no play and high stiffness a general design principle supporting five Cartesian degrees of freedom has been developed using a new parallel kinematic topology based on Parallelogram arrangements. The five uniform feed drives are improved dual mode mechanism with servomotor and ballscrew as macro-actuator and piezoelectric transducer (PZT) with resolution of 1.2nm as micro-actuator. The performance of the setup and its kinematic properties are described as well as resolution of the five motions and their crosstalk. The setup has been implemented with outstanding characteristics and excellent reliability for alignment of a multigrating mosaic compressor in a PW-class CPA-laser.
Simple Program to Investigate Hysteresis Damping Effect of Cross-Ties on Cables Vibration of Cable-Stayed Bridges
Authors: Papadopoulos Panagis G. , Diamantopoulos Andreas , Xenidis Hariton , Lazaridis Panos , Papadopoulou Anastasia K.
Published: February 2012

A short computer program has been developed, for the step-by-step dynamic analysis of cables of cable-stayed bridges, connected to each other and possibly with the deck of the bridge, by very thin pretensioned cross-ties and subjected to variation of their axial forces due to traffic or to a variable wind force. A simplified SDOF model, approximating the fundamental vibration mode, is adopted for every individual cable. The geometric nonlinearity of the cables is taken into account by their geometric stiffness. Whereas, the material nonlinearities of the cross-ties include compressive loosening, tensile yielding and hysteresis stress-strain loops. Seven numerical experiments are performed. Based on them, it is observed that if two interconnected parallel cables have different dynamic characteristics e.g. different lengths, thus different masses, weights and geometric stiffnesses, too, or if one of them has a small additional mass, then a single pretensioned very thin wire, connecting them to each other and possibly with the deck of the bridge, proves effective in suppressing, by its hysteresis damping, the vibrations of the cables.
Detection Accuracy on X-Ray Real Time Imaging for Cast Aluminum Parts
Authors: Wang Ai Guo , Yang Dong Lin , Zhao Peng
Published: February 2012

x-ray real time imaging detection technology is a kind of important way for industrial nondestructive test. On the basis of basic theory on X-ray detection, The influence factors on x-ray real time imaging detection precision is analyzed in this article. Through analysis for the focus of X-ray source and the unintelligibility of geometric image, the relation between the optimal amplification multiple and the imaging quality is presented and the electric collimator to solve the influence on imaging quality from the scattered ray. The experimental result shows that the detection resolution ratio is up to 50PL/cm and the sensitivity is up to 1.4 % to solve the on-line real time detection for pore, inclusion and looseness and verify the application feasibility in the detection of cast aluminum parts for x-ray real time imaging detection technology.
Optimization of Bridge Windbreak on High-Speed Railway through Strong Wind Area
Authors: Zhou Ling Ling , Liang Xi Feng , Yang Ming Zhi , Huang Sha
Published: February 2012

Based on 3-d, uncompressible onflow model with steady N-S equation and the k-epsilon double equation, aerodymic characteristics of EMU and windbreaks on bridge under cross wind were studied numerically, the results show: (1) compared to no windbreak, EMU overturning moment was decreased 50% by setting general windbreak , 75% by setting ventilated windbreak; ventilated windbreak’s protective effect on train and pantograph-catenary system is better especially when H≥2.5m ; (2) aerodynamic load on ventilated windbreak is far lower than general windbreak; (3)the higher cross-wind velocity is, the more aerodynamic load decreased when setting ventilated windbreak. Besides, ventilated windbreak’s leak form could significantly reduce bridge’s self gravity and wind load, improve wind break ability and EMU operation safety.
Thermo-Mechanical Coupled Analysis of Heavy Shell Ring Hot Rolling Mill with Two Drive Rolls
Authors: Sun Jian Liang , Liu Hong Min , Peng Yan , Liu Gang , Liu Yan
Published: February 2012

The heavy shell ring rolling mill which produces the large shell ring used in nuclear power, large-scale hydrogenation reactor and coal liquefaction reactor was taken as subject investigated. Because the size of shell ring is very large and the material of shell ring is special, the double drive rolls was taken in the shell ring rolling mill. Based on the elastic-plastic FEM and MARC software platform, the three dimensional thermal-mechanical coupled model of shell ring rolling process was built in this paper. First, the heat simulation text of the shell ring material has been carried out on the Gleeble-3500 thermal simulation test machine and the material properties were obtained. Then, considering the characteristics of heavy shell ring hot rolling mill with two drive rolls, the key problems such as geometry, material and thermo-boundary conditions were solved, the thermo-mechanical coupled finite element model of heavy shell ring hot rolling has been establised. At last, based on explicit dynamic FEM, the thermo-mechanical simulation of heavy shell ring rolling process was made. The stress field, strain field and temperature field were studied, the metal plastic deformation and its influence factors were investigated. The conclusions are agreement with the real rolling process. The conclusions are significant for designing equipments of shell ring rolling mill and developing new rolling schedule.
A New Formula for the Rayleigh Wave Velocity
Authors: Liu Xue Feng , Fan You Hua
Published: February 2012

The formula for the Rayleigh wave velocity in isotropic elastic half-space is studied by many researchers. In their deductions, Cardan’s formula of cubic equations is often used. Based on another formula instead of Cardan’s formula, a new formula for the Rayleigh wave velocity that does not contain complex number is presented here. Our new formula is more reasonable as both the parameters and Rayleigh wave velocity are real. And the computer time can be reduced since there is no complex computation. With this new formula, the variation of Rayleigh wave velocity with the parameters is computed. It shows that Rayleigh wave velocity decreases with the increase of Poission’s ratio when S-wave velocity is fixed.
FEM Analysis of Scrolls with Single Profile and Hybrid Profile
Authors: Wu Zai Xin , Liu Tao , Sun Hui Wei , Hu Chi Bing
Published: February 2012

A new method to design hybrid scroll profile is introduced. The finite element analysis models for hybrid profile and single profile scrolls are established respectively. The stress and deformation of these two kinds of scrolls are analyzed by finite element method under the combined action of temperature load and gas load in the process of one revolution of crank shaft. The analysis data show that the stress and deformation of hybrid-profile scroll are similar to that of involute-profile scroll. Furthermore, the length of baseline of hybrid profile reduces approximately 27.32% with respect to that of involute profile. The results of this study are helpful in the design of scroll compressor with hybrid scroll profile.
Combustion Synthesis of V(CN) Powders
Authors: Mu Yun Сhao , Liang Bao Yan
Published: February 2012

Titanium carbonitride, V(C, N) has been prepared by combustion synthesis from V powders and a carbon-nitrogen precursor. The phase composition of the sample was investigated by X-ray diffraction. The scanning electron microscopy image indicates that the average size of the obtained V(C, N) grains was 1µm.
Establishment of Mathematical Model of Buried Pipeline on Nonlinear Soil Dynamic Model
Authors: Hao Ting Yue
Published: February 2012

The pipe model is simplified as elastic foundation beam model of Euler-Bernoulli in the paper, the supported form of pin rocker bearing in the analysis of transverse vibration. Kelvin viscoelastic foundation model is adopted and the dynamic model of soil spring is regarded as nonlinearity. Applying the principle of Hamilton, the differential equation of vibration is deduced. By utilization of the first three-order modal and the orthogoality of main vibration mode, the equations are discreted and transformed into state formulas. The critical flow velocity is obtained using the Matlab software in a typical numerical example.
Open-Loop Frequency Domain Analysis Based on System Identification
Authors: Jiang Jian Hu , Wu Chao , Bu Ting
Published: February 2012

In this paper, an open-loop frequency domain analysis based on system identification is introduced. Using model identification tools in Matlab, the open-loop frequency domain characteristic could be derived accurately with the open-loop step response. Then, the closed-loop regulator could be designed with the open-loop frequency domain characteristic to fulfill the steady and dynamic requirements. This method is suitable for most of the systems. An example of Buck converter is proposed to represent the analysis process. Simulation model is built in Matlab software, and some factors which affect the precision of model identification and frequency domain analysis are taken into consideration. Finally, both open- and closed-loop experimental results verify the feasibility of the proposed scheme.
Study on the Relationship between BPR Strategy for Enterprises and ERP Performance-Evidence from China
Authors: Qiao Qing Chen , Li Ming Xing , Zhang Tong Jian
Published: February 2012

In order to reveal the incentive functions of BPR and ERP strategies for enterprise performance, the structure equation modeling (SEM) is used in this paper. By theoretical analysis, research hypothesis, model deduction, and model verification, the SEM can effectively reveal the correlation between BPR strategy and ERP performance in Chinese coal enterprises. For illustration, the collected copies are 313 enterprises, in which 278 copies are valid. Ratio of sample size and the number of outcome measures is about 7:1, which meets the basic requirements of SEM. The minimum value of 5 latent variables Cronbach Alpha is 0.778 and the results have higher reliability. The empirical results show that research model fitting effect is well so that it’s no need to continue model updating. The empirical research has revealed ERP-related microcosmic mechanism in the process of BPR implementation in Chinese coal enterprises, which can provide the effective theoretical references and support for enterprises to further promote ERP performance and raise management efficiency of Chinese coal enterprises.
Properties of Surface Layers Processed by a New, High-Temperature Vacuum Carburizing Technology with Prenitriding - PreNitLPC®
Authors: Kula Piotr , Pietrasik Robert , Dybowski Konrad , Paweta Sylwester , Wołowiec Emilia
Published: February 2012

The variety of vacuum carburizing with prenitriding (PreNitLPC® technology) consists in metering ammonia in the stage of charge heating for carburizing to reduce grain growth in the surface layer of carburized steel. This paper presents the effect of nitrogen interaction on the reduction of austenite grain growth during vacuum carburizing and on the mechanical properties (fatigue strength, impact resistance) of the layer treated in this way in relation to conventional carburizing methods.
Thickness Evaluation of Thin Laser Cladding Fe314 Alloy Coating with Surface Ultrasonic Wave Based on Wavelet Analysis
Authors: Liu Bin , Dong Shi Yun , Xu Bin Shi , He Peng
Published: February 2012

The thickness of thin laser cladding coating is evaluated with surface ultrasonic wave based on denoising with wavelet analysis method. Two surface ultrasonic wave transducers with 5MHz frequency, which are employed as a transmitter and a receiver, are employed to detect surface ultrasonic wave signals, and cross correlation function is used to determine the difference in time between signals. Results show that the velocity of surface ultrasonic wave propagating in laser cladding Fe314 alloy coating decreases as the thickness of coating increasing, the microstructure of coating is the main reason for noise, the signal-to-noise ratio increases after denoising with db4 wavelet, the result of coating thickness and the difference in time is fitted with polynomial, and the fitting formulas are obtained responding to initial signal and denoising signal, respectively. Based on metallographic analysis result, this method is considered to be evaluated the thickness of thin laser cladding Fe314 alloy coating and the accuracy can be improved based on denoising with db4 wavelet.
Panoramic Display System of Enterprise’s Financial Prosperity Monitoring
Authors: Huang Yang
Published: February 2012

This paper introduces macro-economic monitoring methods into the financial analysis of micro-economy, and takes innovation in the compiling method of financial prosperity index and the display method of financial prosperity to build a complete panoramic display system of enterprise financial prosperity monitoring. All these researches provide a new approach for managers to grasp financial situation, control financial risk, and forecast financial trends timely.
A Cost Model for Optimal Design of Hierarchic Product Platform under Coupled Architecture
Authors: Cai Yan Ling , Cui Zhen Hua
Published: February 2012

Product platform design is essentially a difficult decision to make, thus a hierarchic platform has been proposed to solve the inherent tradeoff for optimization. However, architecture coupling adds on complexity of the platform design. This paper proposes an improved cost model for the optimal design of platform design in the hierarchic manner with the consideration of the architecture coupling. This cost model uniquely treats the architecture couplings and their decoupling interfaces as latent cost drivers to enable the flexible design of product platform and its family. As a support, the underlying tradeoff mechanism of platform-based product family design is also analyzed in this paper.