bluuebunny/crossref_metadata_2025 huggingface dataset:
Design the Network Attack and Defense Training Simulation System Based on HLA
Authors: Song Yu , Zhou Hai Jun , Ren Guo Lei
Published: September 2013

We propose an integrated design method to Network attack and defense Simulation training system. Firstly, taking the actual network attack and defense subjects as materials, establishes the system-related military scenario and models several use cases from the perspective of system resources and user needs. Then, using these use cases plans every system components (federate members) in terms of the distributed framework of HLA. More importantly, the workflow of a typical use case according to the publish/subscribe relationship among federate members is described. Associated with this use case, the structure (and behavior) model, internal/external class and program points of the system are modeled, defined and designed respectively. Finally, the expansibility of the system is described in detail. This method can accurately grasp the properties, functions, behaviors and other characteristics of system members (objects) and improve the rationality and consistency of the simulation system modeling.
The Characterization of the Stability of Gel Ink by Rheological Method
Authors: Yao Wang Zhao , Wang Wei Chao , Chen Ai Ping , Shen Hui , Hao Hong Fei , Sun Zong Yuan , Cai Li Feng
Published: September 2013

The rheological performance of gel ink was investigated by the experimental methods of steady-state shear rate scanning, dynamic stress scanning and dynamic time scanning. The results show that some rheological parameters (such as n, K, τ0, and ect.) can be used to characterize the stability of gel ink.
Speed-Sensorless AC Drive Based on MRAS Scheme with a Novel Observer
Authors: Cui Ting Rui , Zhang Li Wei
Published: September 2013

This paper proposes a new flux observer, which combines a current model and a modified voltage model based on an adaptive feedback compensation method. And an adaption algorithm based on MRAS for simultaneous speed estimation is presented. The effectiveness of the proposed method is tested through simulation and is experimentally verified.
Attitude Maneuver Duration for an Agile Earth Observation Satellite
Authors: Tang Zhong Xing , Han Chao
Published: September 2013

The attitude maneuver duration is an important constraint for an agile Earth observation satellite between its imaging tasks. A method for calculating the attitude maneuver duration from pointing to the last observation target to the next one is proposed. Based on this method, the relationships between the observation times and the attitude changing duration are discussed. The analysis results show that the difference of the observation time and the observation target causes the difference of the attitude maneuver duration between the last and next observation tasks. An attitude maneuver strategy example for an agile satellite in one-orbit strips-jointed observation mode is given. The results of the relationships analysis validate the effectiveness of the attitude maneuver strategy.
Development and Design of Rain and Shine Dual-Use Bicycle Based on Solid Edge
Authors: Jia Wen Qi , Wu Tao , Liu Xu
Published: September 2013

Responding the green commuting, Solid Edge V18 drawing software for the shape and function improvements of existing bicycle is proposed in this paper. This bicycle achieves the role of rain, shine dual-use and loading. It also satisfies the function requirements that people live in contemporary on bicycles. This article will elaborate the transmission device calculation and bicycle design based on Solid Edge Modeling.
Toward Realization a 7-Links Biped Robot - Trajectory Generation
Authors: Ghanbari Ahmad , S. Noorani S. Mohammad Reza , HajiMohammadi Hamid , Parvaresh Aida
Published: September 2013

Naturalistic walking is one of the most important purposes of researches on biped robots. A feasible way is to translate the understanding of human walking to robot walking. One of the options that affects the quality of motion in a biped robot is concerned with trajectory generation. So, in this paper it's focused on trajectory generation methods for implementing a 7-links planar walker biped robot. Also, this model is simulated by VisualNastran software package and run according to a Clinical Gait Analysis (CGA) reference that has been modified for a planar model. Lastly, the results of simulation are reported.
On the Treatment of Neumann Boundary Conditions in Solving Poisson Equation Using Meshless Galerkin Method
Authors: Zhang Xiang Dong , Wang Lei
Published: September 2013

This paper studies the treatment of Neumann boundary conditions when solving Poisson equation using meshless Galerkin method. We find that Neumann boundary conditions can be implemented more accurately by adopting proper method. Advantages of doing this are also shown.
Research of Synthesis Loop Experiment Simulation System
Authors: Wang He Fei , Wu Jian Wen , Jiang Yuan
Published: September 2013

To save the experiments cost of verifying the synchronous control systems performance, a set of synthesis loop experiment simulation system is designed in this paper. Firstly, on the basis of analysis the working principle of the synthesis loop, the components used for the various parts of the synthesis loop simulation system are designed. Secondly, according to the characteristics of the two experimental loop, Will experiment, High-Closing experiment, circuit diagrams are designed respectively, software is debugged, and finally get the simulation system which meet the requirements.
An Experimental Study on Electrical Discharge Machining of Copper Alloy Grade HR750
Authors: Muttamara Apiwat , Treeranurat Nitipud
Published: September 2013

Electrical discharge machining process (EDM) is a process for removing material by the thermal of electrical discharge. EDM process melts and evaporates workpiece material. Some of the melted and all of the evaporated material is then quenched and flushed away by dielectric liquid and the remaining melt recast on the finished surface. The recast layer is called as white layer. Beneath the recast layer, a heat affected zone is formed. The quality of an EDM product is usually evaluated in terms of its surface integrity, which is characterized by existence of surface cracks and residual stresses. The machinability of EDM in terms of the material removal rate and electrode wear ratio was evaluated in this paper. The machining tests were carried out on a copper alloy grade HR750 with a copper tungsten electrode. The workpiece surfaces are analyzed by optical microscope and XRD technique. The formation of crack is not found.
Modelling and Simulation of Kinematics for Planar R-2RRP-RRR Mechanism Based on SimMechanics and Adams
Authors: Dang Xiao Zheng , Zhou Liang Sheng , Liang Dong
Published: September 2013

Planner multi-linkage mechanism is widely used in the manufacturing industry. In this paper, a kind of planner R-2RRP-RRR mechanism is researched. The kinematics simulation model is established and implemented for this kind of mechanism based on SimMechanics and Adams respectively. Through simulation, the motion rule for the key part of mechanism is obtained. The simulation results show that this method is effective and efficient when the simulation is implemented for a certain machine system. Meanwhile, it provides a foundation for design and manufacturing of the mechanism in the future.
Effect of Cement Type and Air-Entraining Agent on Microbially Induced Carbonate Precipitation in Cement Paste
Authors: Yuan Xiao Lu , Zhou Shi Hua , Hu Wei Min , Tan Sen Yao , Pan Deng
Published: September 2013

The effect of cement type and the air-entraining agent on microbially induced carbonate precipitation in cement paste has been studied. Results indicate that after biodeposition treatment, Sulphoaluminate cement paste behaved with a higher growth rate of compressive strength than OPC paste. Incorporation of air-entraining agent increased the growth rate of compressive strength of sulphoaluminate cement paste. Calcite was formed through microbially induced carbonate precipitation in cement pastes. Sulphoaluminate cement paste achieved a larger amount of calcite than OPC paste.
Structure Optimization of the Small Arm of Feed Mechanism in the Rubber Mixing Production Line
Authors: Zheng Peng , Jia Zhi Yan , Gong Li
Published: September 2013

In the rubber mixing production line, because of the traditional design method, the stiffness of the small arm of feed mechanism is usually not enough and the reserve of strength and weight is surplus. To solve the above problems, we optimized the arm structure with the optimization design module of the finite element analysis software. Based on the structure theory and optimization design theory, the three-dimensional model and the proper optimization model been established with the three-dimensional software and finite element analysis software. The total weight of the small arm is used as the objective of optimization and the dimensions of each parts is used as the design variables. Under the precondition of requirements of strength and stiffness, the optimal solution of these dimensions is figured out. Analysis shows that the method of structure optimization is feasible. This method provides an important reference for the optimization design of feed mechanism's small arm and similar parts.
An Inspection Approach for Nonrigid Mechanical Parts
Authors: Aidibe Ali , Tahan Souheil Antoine
Published: September 2013

Nowadays, a complicated and expensive conformation jig is needed to inspect the nonrigid parts. In a free-state condition, these parts may have a significant different shape than their nominal model (CAD) due to gravity loads and residual stress. In this paper, we present a new method for automatic fixtureless inspection of nonrigid parts. The inspection in our case is limited to the profile deviation as required by ASME Y14.5 standard and the defects are dent shapes. Our method combines the curvature estimation, one of the intrinsic properties of the geometry, with the Thomson statistical test in order to identify the defects due to the inherent variations of the manufacturing process from the deformations due to the flexibility of the part. The method is tested and validated on a simulated flexible part representing a typical sheet metal from the transport industry.
Study on Calculation of Settlement of Rigid Pile Composite Foundation under Embankment Load (Part I)
Authors: Liu Su Xian , Liu Si Jia
Published: September 2013

Based on analysis deformation characteristics of rigid pile and soil under the embankment load pile composite foundation. This paper does to work as follows. First of all, problems of previous pile-soil displacement model were analyzed, and an improved displacement mode has been proposed. Secondly, the stress of pile and soil was analyzed. Base on the analysis, some further work was done in the part II. An engineering example was analyzed and shows in part II.
Study on Calculation of Settlement of Rigid Pile Composite Foundation under Embankment Load (Part II)
Authors: Liu Su Xian , Liu Si Jia
Published: September 2013

Base on the analysis of problems of previous pile-soil displacement model, rigid pile settlement under embankment load method was established, this method can also consider the factors of soil and the relative slip between pile and earth deformation dyssynchrony. Some theories were described in part I. In this part, some theoretical calculations and an engineering example was analyzed and shows that the rationality and feasibility of the method.
A Dynamic Spectrum Access Method for IBOC Broadcasting Based on the Ear Perception
Authors: Jiao Wei , Yang Gang , Fang Wei Wei
Published: September 2013

In-Band On-Channel (IBOC) as an AM&FM digital broadcasting technology is used in HD Radio standard. In Hybrid of HD Radio, the spectra of analog FM signal and digital signal are combined in a fixed way, without taking full advantage of spectra. To solve this problem, this paper presents a Dynamic Spectrum Access (DSA) method, using the idle spectrum on time dimension. And the improved method brings in a Perceptual Evaluation of Audio Quality (PEAQ) module based on the ear perception as the evaluation criterion to measure audio quality. The simulation results show that on the basis of insuring audio quality, this method can save a lot of spectral bandwidth to improve the available spectrum resources.
Case Study: Performance Assessment of Various Sun Shades for Hot-Dry Climate
Authors: Sairam R. , Raviteja P.L. , Naresh A.
Published: September 2013

There are many reasons to control the amount of sunlight admitted into a building. In warm, sunny climates excess solar gain may result in high cooling energy consumption. In cold and temperate climates winter sun entering south-facing windows can positively contribute to passive solar heating; and in nearly all climates controlling and diffusing natural Illumination will improve day lighting. A Well-designed sun control and shading devices can dramatically reduce building peak heat gain and cooling requirements and improve the Natural lighting quality of building interiors. In this casestudy Shading Devices commonly found in India are evaluated to find Optimized Shading Device for Hot-Dry Climate of South India
The Design and Implementation of Virtualization Technology Application on Power Grid Dispatching Automation System
Authors: Ji Zhi Xiang , Li Li Xin , Yuan Rong Chang , Huang Yan , Di Fang Chun , Chen Ling
Published: September 2013

The power grid dispatching automation system is the nerve center of the strong smart grid, and its safe and stable operation is the strong guarantee of power supply. To make efficiently use of computing resources, improve the availability and flexibility of power grid dispatching automation system, this paper proposes to apply the virtualization technology to the power grid dispatching automation system to make it provide the required resources such as computing, storage and network. Through in-depth analysis of the current situation of power grid dispatching automation system and virtualization technology, this paper indicates that the virtualization technology is suitable for application in power grid dispatching automation system. Using the virtualization technology, the virtual resource pool is built; Base on the pool the grid dispatching automation system architecture is given. Then through the deployment of system hardware design, program implementation and advantage analysis, the power grid dispatching automation system based on virtual technology is built. Results show that the power grid dispatching automation system based on virtualization technology has the advantages of high availability, high resource utilization rate, load balancing and easy to scale.
Spatial Target Dual-Band Infrared Imaging Analysis
Authors: Huang Hao , Tao Hua Min , Chen Shang Feng
Published: September 2013

An imaging model of spatial point target in dual-band infrared was set up on the basis of Plancks law. The formation mechanism of differences of point target imaging characteristics in dual-and infrared was revealed. The impact of the target temperature, surface emission, transmission distance and the rate of detector response were analyzed in detail. This paper provides the basis for space target recognition.
Study and Design on Electronic Cash System Security Architecture
Authors: Ai Jing Feng
Published: September 2013

The rapid development of electronic financial services, attendant come an increasingly serious network security problem, especially electronic cash exchange network security issues facing the urgent need to resolve. In this paper, electronic cash scheme detailed research and analysis, and then design a secure electronic cash system based on an improved theory of electronic cash scheme, it includes detailed electronic payment requirements analysis, system design, e-commerce payment system design, server design and client design. Finance and electronics industry combining electronic financial system, if they can effectively solve the security issues, I believe it can be quickly developed.
Design of Intelligent Supervised System Based on Internet of Things
Authors: Song Xiao Na , Zheng Jun , Li Pei , Hou Xiao Xia , Zhang Jing Rong , Hu Yan Ping , Gao Ning
Published: September 2013

Based on technology of Internet of Things, an intelligent supervised system for housing is formed to monitor various parameters at home. This system adopts special sensors to sample the environmental data, and will send alarm information through the GPRS gateway to the mobile phone of the host once the data beyonds the allowable value. Through information exchange between host and the supervised system, people can check the real time information of home and commit intelligent control. This paper introduced the structure, the hardware and software design idea of the supervised system. Special designs ensure that the system has relatively low power consumption and can be easily used for housing supervision and control.
Application of Economic CNC System Based on PLC and Touch Screen
Authors: Wang Wei Da , Fan Yu Jin , Han Teng , Qin Zhong Quan , Li Ai Ran , Zhou Wei
Published: September 2013

With the information technology industry continuously developing and the level of industrial automation continuously improving, PLC and touch screen become more common. In this paper, the touch screen as a PC and PLC as the next crew, a CNC punch press dedicated economic CNC system was designed.The relevant procedures and HMI design was completed based on a comprehensive analysis of punch press feature. The Economical CNC system not only has the advantages of simple operation,easy maintenance and good stability but also can reduce the cost and enhance the adaptability of the enterprise market of small and medium-sized manufacturing enterprises.
Design and Implementation of Online Monitoring and Remote Diagnostic System for CNC Machine Tools
Authors: Jing Lu Yang , Wang Tai Yong , Chen Dong Xiang , Fang Jing Xiang
Published: September 2013

With the development of network technology and fault diagnosis technology, monitoring and diagnosis methods for the CNC machine tools had a great change. In this paper, an online monitoring and remote diagnosis system for CNC machine tools was built. The system was consisted of the multi-channel online acquisition system and remote fault diagnosis system. The online acquisition system achieved a real-time monitoring for CNC machine tools. The remote fault diagnosis system provided the management of devices and assistant for experts to analyze data which was uploaded from acquisition system. The system offered real-time state information of CNC machine tools and reduced downtime of machine effectively.
Online Monitoring Recognition Theory Based on the Time Series of Chatter
Authors: Jiang Yong Xiang , Du Bing , Zhang Pan , Deng San Peng , Qi Yu Ming
Published: September 2013

On-line monitoring recognition for machining chatter is one of the key technologies in manufacturing. Based on the nonlinear chaotic control theory, the vibration signal discrete time series for on-line monitoring indicator is studed. As in chatter the chaotic dynamics process attractor dimension is reduced, the KolmogorovSinai entropy (K-S) index is extracted to reflected the regularity of workpiece chatter, then the k-S entropy is simplified by coarse - grained entropy rate (CER), which can easily evaluated as chatter online monitoring threshold value. The milling test shows that the CER have a sharp decline when chatter occurre, and can quickly and accurately forecast chatter.
Study on the Transmission Spectrum of Fiber Bragg Grating as Temperature Sensor
Authors: Wang Zheng , Zhu Ping Yu , Liang Hong Qiang , Peng Wei
Published: September 2013

The temperature sensing characteristic of Fiber Bragg Grating (FBG) has been studied. The temperature sensing equation of FBG is revised. The accurate analysis results are obtained. The center wavelength drifts of the tested FBG are displayed in the screen of Optical Spectrum Analyzer (OSA).The experimental results show that the center wavelength of FBG is thermally red-shift with the rise of the temperature and blue-shift with the decrease of the temperature. The results are agree with the revised temperature sensing equation. It is noticed that the transmission spectrum width (SPEC-WD) of FBG fluctuates with the change of temperature. Nevertheless, the trend of the fluctuation is demonstrably towards increase, which perhaps is some potential auxiliary sensing function in future.
Dynamic Fuzzy Reliability Analysis of Mechanical Components with Small Samples of Load
Authors: Gao Peng , Yan Shao Ze , Wu Jia Ning , Yang Tian Fu
Published: September 2013

Dynamic fuzzy reliability models of mechanical components are proposed in this paper in the case of small samples of load. The proposed models are established based on the distribution of load obtained from a load history, which reflects the relationship among the occurrence frequency of loads with different magnitude in a given time period, rather than the distribution at each load application. To deal with the uncertainty of the distribution of load from a load history due to the randomness of the magnitude of load at each load application, the statistical parameters involved in the distribution of load are modeled as fuzzy variables. Explosive bolts are chosen as representative examples to illustrate the proposed models. The results show that reliability increases with the increase in the level of cut set. Besides, the dispersion of strength has great influences on the reliability and failure rate of mechanical components.
Design and Implementation of an Interpolation Processor for CNC Machining
Authors: Dong Jing Chuan , Wang Tai Yong , Li Bo , Wang Xian , Liu Zhe
Published: September 2013

As the demand for high speed and high precision machining increases, the fast and accurate real-time interpolation is necessary in modern computerized numerical control (CNC) systems. However, the complexity of the interpolation algorithm is an obstacle for the embedded processor to achieve high performance control. In this paper, a novel interpolation processor is designed to accelerate the real-time interpolation algorithm. The processor features an advanced parallel architecture, including a 3-stage instruction pipeline, very long instruction word (VLIW) support, and asynchronous instruction execution mechanism. The architecture is aimed for accelerating the computing-intensive tasks in CNC systems. A prototype platform was built using a low-cost field programmable gate array (FPGA) chip to implementation the processor. Experimental result has verified the design and showed the good computing performance of the proposed architecture.
Dynamics of Deployment for Mooring Buoy System Based on ADAMS Environment
Authors: Zheng Zhong Qiang , Dai Yuan , Gao Da Xiang , Zhao Xin Lei , Chang Zong Yu
Published: September 2013

Buoy is widely applied in oceanographic research, ocean engineering and so on. The high cable tension and location derivation of its anchor can greatly affected the working condition of buoy. Multi-body software ADAMS is used to analyze the dynamics of deployment for buoy. Firstly, model of mooring buoy is developed. The forces on components of buoy are given such as drag forces, inertia force and impact force between bottom and anchor. The program is developed by macro commands in ADAMS environment. The trajectory and tension force of different nodes on buoy are calculated. This method can simulate the dynamics of deployment process for buoy system. And it is also helpful for guidance for buoy design and deployment process planning.
Research on Product Virtual Prototyping Technology and Design Method for Concurrent Engineering
Authors: Li Xiao Na , Liu Xin
Published: September 2013

Concurrent engineering claims all influence factors within product lifecycle should be took into account during the stage of product design. After analyzing the relationship between concurrent engineering and virtual prototyping, the human-machine system simulation process and method based on virtual prototyping technology were discussed and illustrated with bicycle design, and the product design method based on virtual prototyping was proposed in this paper.
User-Friendly Design of Modern Forest Fire Helmet
Authors: Yang Hong Ze , Li Bo , Wu Ya Nan , Li Bin
Published: September 2013

This article researches and discusses the current situation of the modern forest fire helmet. It focuses on the problems and difficulties in the modern forest fire helmet design and analyses them. With the concept of user-friendly design, this article advances the user-friendly design principles in modern forest fire helmet design.
Gearbox Fault Simulation and Analysis Based on Virtual Prototype Technology
Authors: Chen Xue , Cui Ling Li
Published: September 2013

Simulation study of the failure of gearbox system using virtual prototype technology and analysis of its vibration signal is a foreword topic in recent years. This paper established a rigid-flexible coupling model of gearbox system using SolidWorks, ANSYS and ADAMS. Then, make simulation under the following three conditions: normal, gear fault and bearing outer ring fault. Next, make time domain and frequency domain analysis of the simulated fault signal using MATLAB. Simulation results are consistent with gear vibration mechanism and signal modulation theory, which verified correctness and feasibility of virtual prototype technology in gearbox fault simulation. Lay foundation for gearbox fault diagnosis.
Milling Machine Spindle Dynamic Analysis
Authors: Li Yu , Wang Qi Chen , Ge Yin Ming
Published: September 2013

This paper uses the FE (finite element) and experimental hybrid modeling method to establish the dynamic model of the spindle system. Calculate and analyze how static stiffness, span, and cantilever length affects mode frequency and mode shapes. Analyze the effect of the flywheel on dynamic performance based on harmonic respond. Moreover, the effect of the flywheel is well testified by experiment.
Wetting Angle Measurement of Liquid PbBi on RAFM Steel Surface Based on Ellipse Fitting
Authors: Pan Bao Guo , Wang Wei Hua , Chu De Lin , Yang Jin Hong , Mei Luo Qin , Zhang Qiang Hua , Wang Peng , Wang Jun
Published: September 2013

The fusion power is considered an ideal energy for the future due to abundant, green and safety. Wetting properties between the liquid metal and the structural materials in the liquid blanket of the fusion reactor related to the heat exchange efficiency and the irradiated plasma resistance, and directly related to the service life of the reactor structural materials. This article describes the wetting angle measurement experimental procedure of liquid lead-bismuth (PbBi) at reduced activation ferritic/martensitic steel (RAFM steel) surface based on the high-temperature static sessile drop method under the protection of high purity argon, including the images enhancement processing obtained by CCD camera, using ellipse fitting method to calculate the wetting angle, and were measured at 350-600°C. The experimental results show that the wetting angles of liquid PbBi and RAFM steel are greater than 140°, non-wetting.
Residual Stress Analysis of Polycrystalline Diamond after Electrical Discharge Machining
Authors: Rahim M. Zulafif , Pourmoslemi Arash , Ding Song Lin , Mo John
Published: September 2013

The extreme hardness of Polycrystalline Diamond (PCD) makes it an ideal choice for the machining of hard materials as a cutting tool. Due to the high hardness, fabrication of PCD tools relies on conventional abrasive grinding which suffers from low machining efficiency. Electrical discharge machining (EDM) is an advanced machining process and can be utilised to fabricate complicated PCD tools. High temperature of sintering and EDM processes creates residual stress inside PCD and can result in unmatured failure of PCD tools. This paper analyses the distribution of residual stress in PCD after electrical discharge machining process.
Tool Wear and Surface Integrity in End Milling of Ti6Al4V with Polycrystalline Diamond Tools
Authors: Pan Wen Cheng , Kondaiah Bramha , Ding Song Lin , Mo John
Published: September 2013

Titanium is a difficult-to-machine material due to its low heat conductivity and high chemical reactivity. It creates high tool wear and causes low machining efficiency. The strong relationship cutting forces between and tool wear and surface integrity of work piece makes it necessary to study the effect of dynamic cutting force on cutting tools to analyse the wear propagation and tool life. This paper investigates the tool wear on Polycrystalline Diamond (PCD) cutters in milling Ti-6Al-4V and analyses workpiece surface quality. Based on the experimental results of slot milling, cutting parameters that yields best surface finish were found.
Influence of Heat Treatment on the Microstructure and Properties of 7Cr17Mo Martensitic Stainless Steel
Authors: Du Xiao Dong , Song Zi Li , Chen Yi Qing , Wang Jia Qing , Liu Guang Fu , Shen Jian , Zhou Dan
Published: September 2013

This paper describes the influence of heat treatment process on the microstructure and properties of a new martensitic stainless steel, which contains 0.7% carbon, 17% chromium and 1% molybdenum and can be used as kitchen knives and scissors. The microstructure and properties of the tested alloys after quenching at 980 - 1100 °C and low tempering were investigated by means of optical microscope (OM), scanning electron microscope (SEM), Rockwell hardness tester and impact tester. The results show that the microstructure consists of acicular martensite, carbides and a litter retained austenite after quenching and tempering. The carbides are mainly (Fe,Cr)23C6. The content of retained austenite increases with the increase of the quenching temperature. The solubility of carbon in martensite changes similarly. The martensite gets coarser as the quenching temperature increasing. The maximum value of hardness is 59 HRC, when the quenching temperature is 1060 °C. The impact toughness increases when the quenching temperature increases from 980 °C to 1080 °C and then decreases. The suitable heat treatment process for this alloy is quenching at 1060 °C~1080 °C for 30 min and then tempering at 200°C.
Principle and Experiment of Electric Hot Milling Superalloy
Authors: Zhang Tian Yu , Wang Xi , Wu Lin Tao , Zhou Jing
Published: September 2013

This paper introduces a kind of electric hot milling method for superalloy and analyses its feasibility. Fe-based superalloy GH2132 is selected as experimental object. An experiment platform is established. In the machining process, vibration signals are collected by a set of signal acquisition system. Afterward, these signals are processed by using wavelet transform, compared and analyzed in different machining parameters and working conditions. The results of the study indicate that compared with dry milling, electric hot milling can reduce vibration in machining process and machining superalloy more effectively. It also improves the cutting tool durablity.
Effect of Technological Parameters on the Microstructure and Electrical Properties of ZnO Varistors
Authors: Li Li , Liu Qi Bin
Published: September 2013

To improve voltage-gradient and to reduce the sintering temperature of ZnO varistors, high voltage-gradient ZnO varistors were synthesized with a conventional solid state reaction route. By means of SEM and DC parameter instrument for varistor, the influence of different technological parameters on microstructure, voltage-gradient and leakage current of ZnO varistors was investigated. The experimental results show that by using the process that presintering the additives at 850°C, the density is improved, the voltage-gradient is increased, and the leakage current is decreased. The optimum voltage-gradient and leakage current are 371V/mm and 3μA, respectively.
Research of Aluminum Silicon Composite Layer on Heat Resistant Steel Grate by Cast-Infiltration Method
Authors: Wang Zhen , Yu Hua Shun , Wang Xin Ying , Wang Lei , Song Zhao Ding
Published: September 2013

In order to improve the high temperature oxidation resistance, 75 Si-Fe and the silver paint were selected as cast-penetrated agent using the cast-infiltration method to form an aluminum silicon composite layer on the heat resistant steel grate surface. The microstructure and hardness properties of cast-infiltration layer were studied by optical microscope (OM), scanning electron microscope (SEM) with electron dispersive spectrum (EDS), and micro hardness test. The results show that the cast-infiltration layer is composed of ferrite and irregular shape of carbide particles. Most of the carbides are (Fe,Cr)3C and a small amount (Fe,Cr)7C3 also observed in composite layer. The highest micro hardness of fine carbide particles reaches 1253 HV. The optimized silicon content is 50wt%, and the thickness of infiltration layer reaches 0.6mm.
Research on Ultrasonic Testing of Coarse-Grain Materials with Hilbert-Huang Transform
Authors: Li Qiu Feng , Wang Yu , Xi Lu Ying
Published: September 2013

In ultrasonic testing of coarse-grain materials, signal to noise ratio (SNR) is so poor because of the serious structure noise, and reflected wave from defects is difficult to be identified. In order to improve SNR and increase the reliability of ultrasonic testing for coarse grain materials, Hilbert-Huang Transform (HHT) is introduced to analyze and process the testing signal here. Firstly, detected signals from the coarse grain material can be collected by using ultrasonic test system; And then many Intrinsic Mode Function (IMF) can be obtained according to Empirical Mode Decomposition (EMD), and marginal spectrum of different mode can be gotten by Hilbert transform; And finally, the noise should be removed after analyzing the time-frequency information, and SNR is able to be enhanced and the reflection wave from defect is being more obvious. It was shown from the experimental result that the ineffective structure noise could be removed after HHT, and SNR could be improved and the defect reflection is more outstanding.
Probabilistic Failure Analysis of Steel Structures Exposed to Fatigue
Authors: Krejsa Martin
Published: September 2013

The paper is focuses on one of probabilistic methods which can be used for failure analysis and reliability assessment of steel structures which are subject to cyclic loads and exposed to fatigue. A particular attention is paid to creation and propagation of fatigue cracks from edges and surface. On the basis of the reliability assessment, a system of inspections is proposed for structural details which tend to be sensitive to fatigue damage. A new probabilistic method which is still under development - Direct Optimized Probabilistic Calculation (DOProC) was used for this probabilistic task. This method is the basis of the FCProbCalc code.
Green's Function Solution of Multiple Shallow-Buried Cavities and Inclusions in Elastic Semi-Space
Authors: Li Hong Liang , Liu Lei
Published: September 2013

In engineering composite materials, earthquake engineering and modern municipal construction, it can be found that there are shallow-buried cavity or inclusion structure near surface. When structure is impacted by dynamic load, scattering field will be produced because of the cavity or the inclusion, and it could cause dynamic stress concentration at the edge of the cavity or inclusion. In this paper, Green's Function is studied, which is the solution of displacement field for elastic semi-space with multiple shallow-buried cavities and inclusions while bearing anti-plane harmonic line source force at any point. In the complex plane, considering the symmetry of SH-wave scattering, the displacement field aroused by the anti-plane harmonic line source force and the scattering displacement field impacted by multiple cylindrical cavities and inclusions are constructed. Through applying the method of multi-polar coordinate system, the equations with unknown coefficients can be obtained by using the stress or displacement condition of the cylindrical cavities and inclusions in the radial direction. According to orthogonality condition for trigonometric function, these equations can be reduced to a series of algebraic equations. By solving these algebraic equations the value of the unknown coefficients can be obtained. So the total wave displacement field could be got. By using the expressions, an example is provided to show the effect of the change of relative location of the cylindrical cavities, inclusions and the location of the line source force.
Blunt Cracks and Two Parameter Fracture Criteria
Authors: Williams J. Gordon , Patel Y.
Published: September 2013

There is a concern in the fracture testing community about the influence of crack sharpness on measured toughness values. The notion of sufficiently sharp is intrinsic in the standards but does not define how sharp is sharp enough. This requires a definition of a crack tip radius below which the toughness will be Gc. A proposal is made here to modify the stress at a distance criteria in line with cohesive zones such that G GC and a critical stress σC is achieved. This provides a critical radius, ρC, below which, G = Gc. A comparison with FEA cohesive zone results supports the idea and comparison with data on uPVC conforms well to the suggested scheme to determine ρC. Some comments on self-blunting are also included.
Multiscale Modeling of Nanocomposite Structures with Defects
Authors: Brcic Marino , Canadija Marko , Brnic Josip
Published: September 2013

A method for the numerical modeling of mechanical behavior of nanocomposite materials reinforced with the carbon nanotubes, based on the computational homogenization as a multiscale method, is presented. The matrix reinforcement interactions, based on the weak van der Waals forces are incorporated into the multiscale model and are represented by the nonlinear rod elements. The reinforcements, i.e. carbon nanotubes, are modeled as a space frame structure, using beam finite elements. Computational homogenization and representative volume element (RVE) are the basis of the presented numerical model of the nanocomposites. Nanoscale model is based on beam and non-linear rod finite elements. An algorithm is developed for the analysis of the presented nanostructure, and for the purpose of the software verification, examples, i.e. models of the nanocomposite material are presented. Also, the nanocomposite model with various vacancy defects in the reinforcement, i.e. nanotube, has been prepared and the obtained results are compared and discussed.Keywords Nanocomposite materials · Carbon nanotubes · Multiscale modelling · Computational homogenization
Numerical Prediction of the Long Term Creep Crack Growth Behaviour in Type 316H Stainless Steel
Authors: Mehmanparast Ali , Nikbin Kamran M.
Published: September 2013

Life assessment of Type 316H stainless steel (SS) is of great concern to industry due to the widespread use of this material in power plant components that often operate at a temperature of around 550 °C. An important issue to be understood and considered in the life assessment of 316H components is the creep deformation and crack growth behaviour of this material in short term and long term operation times. Due to the limited long term test data available in the literature (i.e. [1, ), a new technique have been recently developed to estimate uniaxial creep ductility trends and subsequently creep crack growth (CCG) behaviour of the material at low load levels [. In this new method the creep ductility trends have been estimated as a function of the applied stress normalised by the temperature dependent 0.2% proof stress of the material, σ/σ0.2, to include the plasticity effects on the creep deformation behaviour of the material. These trends have been implemented in finite (FE) simulations to predict the CCG behaviour of 316H in intermediate and long term tests at 550 °C and provisional results are presented in [.
FE Modeling of FRP-Concrete Interface for very High Cycle Fatigue Behavior
Authors: Mahal M. , Blanksvärd T. , Täljsten B.
Published: September 2013

The fatigue damage of FRP-concrete interface is a major problem in strengthened structures subjected to fatigue loading. The available FRP-concrete interface models published in the literature usually deal with fracture mechanism approach, which is unsuitable for high cycle fatigue damage. In this study, a constitutive micro model is developed for FRP-concrete interface for high cycle fatigue and incorporated into a three dimensional finite-element program. Numerical analysis of a double lap joint is carried out, and the results show that the proposed model is reasonably accurate.
Numerical Modelling of the Change in Stiffness Properties of Cross-Ply Laminates Subjected to Large Bending Curvatures
Authors: Schmitz A. , Horst Peter
Published: September 2013

This paper presents a 3D unit-cell approach which enables the estimation of bending, inplaneand coupling stiffness properties in the sense of the classical laminated plate theory for arbitrarilyheterogeneous plates. Periodic boundary conditions which simultaneously allow for in-plane as wellas for bending and twist deformation modes are introduced. Additionally, bending experiments of glassfibre/epoxy cross-ply laminates with cracked outer layer at the tension side are conducted and the stiffnessdegradation due to these transverse cracks is compared to numerical results.
Hypersingularities in Three-Dimensional Crack Configurations in Composite Laminates
Authors: Hell Sascha , Becker Wilfried
Published: September 2013

Composite laminates meanwhile are of common use, especially in aerospace engineering. Inter-fiber cracks within a laminate ply are often accepted in practice to be still within failure tolerance, although the structural mechanics of this situation is not fully understood. The situation gets even more complex when the interaction of inter-fiber cracks in neighboring plies is considered. In this work, such three-dimensional crack configurations in composite laminates involving inter-fiber cracks and the influence of the laminate free-edge effect are studied by means of the Scaled Boundary Finite Element Method (SBFEM). The SBFEM is an efficient semi-analytical method that permits the analysis of linear elasticity problems including stress singularities or infinite domains. It is shown that in crack configurations in composite laminates so-called hypersingularities (or supersingularities) can occur, i.e. stress singularities which are of higher order than the classical crack singularity. This indicates that the laminate failure risk induced by certain considered crack configurations is not to be underestimated.
Influence of Crack Front Shape on 3D Numerical Modelling of Plasticity-Induced Closure of Short and Long Fatigue Cracks
Authors: Fiordalisi S. , Gardin C. , Sarrazin-Baudoux C. , Arzaghi M. , Petit Jean
Published: September 2013

The simultaneous effect of crack length and crack front shape on plasticity-induced crack closure (PICC) for a 304L austenitic stainless steel is simulated through 3D numerical modelling using finite element software Abaqus for through-thickness cracks with different curved crack fronts in CT specimens in comparison with bidimensional through crack with a straight front. The influence of possible loading history effect is avoided by applying constant K amplitude. The local stress intensity factor range for crack opening Kop is evaluated from the simulation of the loss of the last local contact between the crack lips near the crack tip. The pertinence of the different crack front shapes is discussed in term of the effective stress intensity factor range Keff and in comparison with the experimental crack front observations.
Modeling of Cure-Induced Residual Stresses in 3D Woven Composites of Different Reinforcement Architectures
Authors: Tsukrov Igor , Drach Borys , Bayraktar Harun , Goering Jon
Published: September 2013

This paper presents finite element modeling effort to predict possible microcracking of the matrix in 3D woven composites during curing. Three different reinforcement architectures are considered: a ply-to-ply weave, a one-by-one and a two-by-two orthogonal through-thickness reinforcement. To realistically reproduce the as-woven geometry of the fabric, the data from the Digital Fabric Mechanics Analyzer software is used as input for finite element modeling. The curing processed is modeled in a simplified way as a uniform drop in temperature from the resin curing to room temperature. The simulations show that the amount of residual stress is strongly influenced by the presence of through-thickness reinforcement.
Mass-Optimized Design of Guyed Wind Turbine Tower Using Struts
Authors: Rudolf Robert T. , Roscheck Florian , Aono Yuuta , Faber Torsten
Published: September 2013

Continuing upscaling trends in turbine height, rotor diameter, and rated power have resulted in massive, expensive tower structures. A modified guyed tower concept with struts (GTS) is proposed for saving material, and the basic design is made for a 2.5MW turbine. The tower and cable dimensions are optimized for lowest system cost given yield constraints. DACE (design and analysis of computer experiments) methods of sampling and surrogate model optimization are used for efficient parameter study and optimization of the ABAQUS finite element model using DAKOTA software. The resulting design is highly effective in transferring turbine loads from the tower to the cables. A mass savings of 41% is calculated vs. conventional structures, and further investigation of the GTS is recommended for both onshore and offshore applications. Additionally, the concept of retowering older turbines is introduced and proposed as an economic alternative to the common practice of repowering old wind farms with larger, new machines. The GTS is specifically suited to this application. Lastly, the design methodology developed for this study is shown to be effective and efficient; it can be applied for the massoptimization of similar cablesupported truss structures.
Experimental Investigation about Surface Damage in Straight and Crowned Misaligned Splined Couplings
Authors: Cuffaro Vincenzo , Curà Francesca , Mura Andrea
Published: September 2013

In this paper an experimental investigation has been carried on, in order to determinate the different damage patterns and the corresponding entity on the surface of splined couplings with straight and crowned teeth, subjected to variable working loadings. In particular, experimental tests have performed by means of a dedicated test rig, allowing to realize different working conditions, as the angle between the axis of shaft and hub and also the presence of lubrication. Teeth surfaces after tests have been analyzed by considering as damage parameters both surface roughness and gap between teeth. Results show that the wear pattern on crowned teeth is completely different with respect to the straight ones; in both cases, the value of the misalignment angle and the presence of lubrication may substantially influence the entity of the surface damage.
Gun Bullet Deformation Analysis for Protection Board Development
Authors: Sakamoto Hidetoshi , Ohbuchi Yoshifumi , Kuramae Hiroyuki
Published: September 2013

In this paper, the effects of collision velocity on bullet deformation were discussed and performance of protection board made of PC (polycarbonate) plate was estimated. The deformation of the bullet and the PC board after collision were measured by 3-dimensional digitizing machine.Furthermore, the bullet collision analysis was performed by FEM analysis code "LS-DYNA", and the impact load carrying capacity of PC plate was discussed by comparing the experimental results with the analytical ones