bluuebunny/crossref_metadata_2025 huggingface dataset:
FEM Analysis of EDM in Gas Based on Birth and Death of Element
Authors: Hu B.L. , Zhang Qin He , Wang F. , Zhang Jian Hua
Published: August 2009

An axisymmetric two-dimensional thermal model, whose boundary conditions are constantly changing both in magnitude and position, has been developed based on the basic principles of electrical discharge machining (EMD) using the finite element method (FEM). The thermal load of heat flux are applied on the surface of the workpiece using the programming language Python provided by ABAQUS FEM software. The temperature field distribution, diameter, and depth of the crater are simulated by this model. Finally, the model is validated by comparing the theoretical crater diameter with the experimental crater diameter obtained from the experimental setup developed in the laboratory.
Experimental Research on the Electrochemical Abrasive Belt Grinding 0Cr17Ni4Cu4Nb Stainless Steel
Authors: Yi Liang , Huang Yun , Liu G.H. , Huang Z.
Published: August 2009

This article introduces a new way combining electrochemical and traditional abrasive grinding belt called Electrochemical Abrasive Belt Grinding. Through the study of grinding the 0Cr17Ni4Cu4Nb stainless steel, analyzes the influence of all the key factors for surface roughness during the process of electrochemical abrasive belt grinding by means of multivariate orthogonal experimental methods and single factor experimental method.
Research on the Integrated System of Digital Design/Manufacturing/Management in Aeroplane Process Equipments
Authors: Li W. , Guo C.F. , Tang X.Q.
Published: August 2009

Aiming at the existed deficiency of integrated application of digital technologies, the integration scheme of digital design/manufacturing/management in aeroplane process equipments is proposed. Its collective technologies and practical research items are analyzed, together with existed CAX systems and their data transfer relationship with MES/PDM. The united information model and knowledge reuse technologies are studied to ensure the successful product development. Based on the above researches, an integrated application system is set up, which is composed of seven sub-systems, like management of process equipments orders etc. Therefore, “paperless” manufacturing in the Hafei Aviation Company has finally come true.
Application of HSS Roll in Hot Strip Mill
Authors: Xu H.B. , Zhang Jie , Cao J.G. , Huang W.M. , Liao Q.S. , Zhang P.W.
Published: August 2009

Due to the problems of very serious wear, serious scale and poor ability to controlling strip shape of work roll, considering the advantages/disadvantages of HSS roll and the field practices, a 3D elastoplastic FEM model of rolls system with strip, which is used to analyze the ability of strip shape control of rolls system when HSS rolls work at any two stands of F1-F4, is modeled. The calculating results sho: The control ability of mill is relative greater when HSS rolls are used at F4, the advantages of HSS roll are not taken fully if HSS rolls work at F1 and F2. And HSS are available for either F2 or F3, furthermore, F3 is better for shape control. The analysis results are verified by the experiments. A strong theory base of application of HSS rolls in Hot Strip Mill is brought forward in this paper.
Optimization Research on Dynamic Balance of Spatial Engine under Limiting Shaking Moment
Authors: Zhu Yong Yong , Gao S.Y.
Published: August 2009

Dynamic balance of the spatial engine is researched. By considering the special wobble-plate engine as the model of spatial RRSSC linkages, design variables on the engine structure are confirmed based on the configuration characters and kinetic analysis of wobble-plate engine. In order to control the vibration of the engine frame and to decrease noise caused by the spatial engine, objective function is choosed as the dimensionless combinations of the various shaking forces and moments, the restriction condition of which presents limiting the percent of shaking moment. Then the optimization design is investigated by the mathematical model for dynamic balance. By use of the optimization design method to a type of wobble-plate engine, the optimization process as an example is demonstrated, it shows that the optimized design method benefits to control vibration and noise on the engines and improve the performance practically and theoretically.
A Policy Based Access Control Model of PDM System
Authors: Ye Chun Xiao , Fu Yun Qing
Published: August 2009

In PDM system, there exist many users, such as employees, partners, and customers. To protect resource from illegal access, it is very important to enforce access control policy in PDM system. RBAC is widely used as an access control model in PDM system. But, it is difficult for RBAC to support complex access control policy. This paper proposed a simple, flexible way to express and enforce access control policy. To keep the integrity of system security and make the system administer work easier, we propose auto revocation triggered by time and access control policy in our model. At the end of this paper introduces a system architecture and auto revocation algorithm. We also give some examples to show how this model works in PDM system.
Study on Product Service Oriented Enterprise Servitization Methods
Authors: Sun Hui Bin , Mo R. , Chang Zhi Yong
Published: August 2009

In order to servitize manufacturing enterprises and meet the need of product service system, approaches to servitization are studied. Design for service method, manufacturing for service mode, and product-based service are regarded as key problems and discussed in detail respectively. Concept and evaluation standards of product service relationship are also discussed. And some significant topics for future studies are put forward.
Application of DSP/BIOS to the Design of Virtual Terminal of Tractor
Authors: Cao Q.M. , Zhou Zhi Li
Published: August 2009

This study explored the application of DSP real-time operating system BIOS to the software design of virtual terminal of tractors. In accordance with the functional requirements for the virtual terminal specified in ISO11783, the hardware system for the virtual terminal controller was developed, and the method of establishing DSP/BIOS configuration files, including the configuration of various parameters used in DSP/BIOS as well as the configuration of other DSP/BIOS modules needed, is studied. This study also explained the software program frame and the program design flow for the virtual terminal. The introduction of real-time operating system enabled the virtual terminal to be operated and controlled more easily and to run more smoothly.
Bi-Level Quantum Evolutionary Algorithm for Scheduling of Dynamic Alliance
Authors: Wang W.L. , Chen S.X. , Zhao Yan Wei , Zhang J.L. , Wang H.Y.
Published: August 2009

The plan scheduling is an important part for forming a dynamic alliance on the ASP platform. In order to solve this problem, in the first place, a scheduling model of multi-objectives and multi-enterprise has been developed. The scheduling objectives of this model considered the enterprise credibility, production tasks, production process and the relationship between them. Secondly, a bi-level quantum evolutionary algorithm is provided for this model. One level is the coding of processes that determines the sequence of process. The other level is the coding of bidding enterprise that chooses each procedure of bidding enterprise. This scheduling approach in an ASP platform realizing dynamic alliance production scheduling system has been applied actually. And the approach can get faster convergence and better characteristics.
Modeling and Simulation of Control System for Power Magnetic Bearings
Authors: Ge Yan Jun , Zhang Wen Yue , Yang Jun Yue
Published: August 2009

In the light of the strongly coupled and nonlinear characteristics of a power magnetic bearing, a new control algorithm, which can integrate the vector control of torque windings and the independent control of levitation windings, is proposed to solve the coupled relationship between torque windings and levitation windings effectively. Additionally, a good speed regulating performance and stable levitation capability can also be obtained by using the algorithm. Finally, a simulated model is built according to the essential method of the algorithm and MATLAB/Simulink is adopted to analyze the control system quantitatively and qualitatively.
Investigation on Unitary Piezoelectric Four-Component Cutting Dynamometer
Authors: Qu G.J. , Qian Min , Zhang J. , Xing Q.
Published: August 2009

The purpose of this paper is to show the investigation on a type of unitary piezoelectric four-component cutting dynamometer. Based on piezoelectric effect of quartz crystal, such as torsion effect, transverse effect, lengthways effect and shearing effect, horizontal moment and three-direction orthogonal forces carried on the dynamometer during cutting process can be measured simultaneously. The dynamometer can be used to measure forces and horizontal moments in drilling, grinding, milling, turning. A secondary purpose is to optimize structure parameters of the dynamometer by ANSYS. The dynamometer has good performance with high sensitivity, good linearity and repeatability and low crosstalk after optimizing.
Design and Analysis of a Cylindrical Traveling Wave Ultrasonic Motor Using Composite Transducer
Authors: Liu Ying Xiang , Liu Jun Kao , Chen Wei Shan , Shi Sheng Jun
Published: August 2009

A cylindrical type traveling wave ultrasonic motor using composite transducer is proposed in this paper. A composite transducer is attached to the cylinder on its outer surface to excite two degenerate flexural vibration modes spatially and temporally orthogonal to each other in the cylinder. In this new design, a single transducer can excite the flexural traveling wave in the cylinder. Thus, an elliptical motion is achieved at the particle on the tooth. And the driving force is the frictional force between rotor and teeth. The working principle of proposed motor is analyzed. The cylinder and transducer are designed with FEM. The sensitive parameters of resonance frequencies of transducer and cylinder are gained with modal analysis. The resonance frequencies of two vibration modals of stator are degenerated, and the motion trajectories of nodes on the teeth are analyzed. The result of transient analysis shows that the trajectory of node on the tooth is nearly an ellipse. The results of this paper could guide the development of this new type of motor.
The Innovative Design of Folding Umbrellalike Mechanism
Authors: Zhou Wan Chun , Zhou Tong , Wang Dong
Published: August 2009

The innovation of mechanism is essential to the creative mechanical design. The innovative design of mechanism not only has important theoretical academic values, but also has greater economic and social benefits. In this paper, we have conducted an innovative design on folding umbrellalike mechnism by using regenerated kinematic chain. This creative design is feasibile in technology, and is meaningful to improve the self-design of our mechanical products, the ability of innovation and internation空al competitiveness.
The Reconfigurable Innovation of Reciprocating Rectilinear Moving Mechanism at High Frequency with Low Load Driven by Two Symmetrical Eccentric Cams
Authors: Wang Ming Di , Zhong Kang Min , Chen Zheng
Published: August 2009

In many occasions of the practical engineering, the reciprocating rectilinear movement at high frequency is appeared commonly, which is usually completed by the slider-crank mechanism. But there has big friction force between the guide rail and the block, thus the big friction loss can be caused. So when working in a long time, the mechanism will be heated and distorted. And a big torque will be caused in the guide rail, the oscillation will be generated when move at high frequency. In order to overcome these defections, the reciprocating rectilinear moving mechanism at high frequency with low load driven by two symmetrical eccentric cams is innovated. And to realize the different travel in economical way, the rapid reconfigurable devices based on this mechanisum are innovated too. These innovated mechanism is quite symmetrical, so the friction force between the guide rail and the leader can be almost ignored and the oscillation is very small too. Then, the mechanical and movement property are analyzed and compared with the slider-crank mechanism, which proves that these mechanism have simple structure and good property. Through the analysis of the travel, the merit of strong adaptability is found out. Furthermore, the components in these devices can be reused in different occasions, so the reconfigurable thinking provides one economical method for big production rapidly.
Optimization of Preloaded Coefficient Based on the Adapted CBR
Authors: Li H.L. , Lang Li Hui , Jiao W. , Su H.Z.
Published: August 2009

Selecting an appropriate preloaded coefficient has always been a challenge in wire- winding prestressed structure optimum design. Cased-based reasoning (CBR) has become a successful technique for knowledge-based systems in many domains. However, hardly any research has addressed the issue of how to generate the adaptation solution when the case has been retrieved. The present paper investigates the adoption of genetic algorithm(GA) to explore the suitable adjustment model. Two adapted model were presented and assessed in terms of their mean relative prediction error rates.The experiment results shown that applying GA to adjust the preloaded coefficient selection model is a feasible approach to largely improve the accuracy of estimation model. It also demonstrate that the adapted CBR presents better estimate accuracy than the results ontained by other unadapted CBR methods.
Characteristics of Singular Point on Cycloid and its Application in Parallel Indexing Cam Mechanisms
Authors: Cheng J.S. , Tao X.H. , Liu J.
Published: August 2009

A planar cam theoretical profile can be considered as cycloid of the roller center. There is singular point on the cycloid when the roller center is located on the instantaneous axis. Then, the curvature of the cycloid at the singular point is likely to be infinite and interference may be inevitable. Thus, avoiding such singular point is imperative in cam profile design. But, in analyzing the characteristics of the tangent vector and curvature at such singular point, it reveals that the curvature may be finite, even zero, if the cycloid fulfills some condition at the singular point. This leads to a very important property that at the singular point the tangent of the cycloid is parallel to the normal of the instantaneous center curve. The pressure angle is very small even zero. These results would be very efficacious in planar cam mechanism applications. The characteristics of singular point on cycloid are detailed in this paper. As application, a novel kind of parallel indexing cam mechanism is developed. Its configuration and principle are described.
A User-Centered Multi-Agent Framework for Extensible Modular Design
Authors: Wang Y.Q. , Huang Y.Q. , Xie Q.S. , Li J.T.
Published: August 2009

To target both present users and future potential customers, which are often ignored by most researches, very early in the collaborative conceptual design stage, a multi-agent framework is presented to integrate the distributed design activities. By introducing a cost-effective and timely modular design system and modeling its ‘users’, a typical intelligent and autonomous agent is constructed and the principle of cooperation among multiple agents is discussed for maximizing today’s and tomorrow’s customer requirements. The proposed system is successfully demonstrated on the hydraulic press products design.
Elliptic Gear Parametrical Design and Machining Simulation
Authors: Xie Zheng Heng , Wang S.Z.
Published: August 2009

The principle of generating conjugate tooth profile for elliptic gear was studied. On this basis, 3D modeling and parametrical design of elliptic gear were realized by using Solidworks API. The program provides a useful tool for further using finite element analysis to conduct strength analysis, numerical manufacture and computer aided simulation.
Research on Implementation Mechanism of Networked Collaborative Design System Based on Project Management
Authors: Qu Li Gang , Wang Wei , Wu Da Wei
Published: August 2009

The functional and structural models of networked collaborative design system based on project management are brought forward in this paper. Its typical workflow is defined according to the system architecture. In process of studying implementation mechanism of collaborative design system, the algorithm of Fuzzy Analytic Hierarchy Process (F-AHP) is employed in choosing partners as personnel management mechanism, the method of Design Structure Matrix (DSM) is applied in process of decomposing and assigning design tasks, and weight-coefficient recursively statistic algorithm is used in controlling task schedule. The archetypal system of networked collaborative design based on project management is developed and tested, realization supported “multi-user &multi-task” is drown the conclusion.
Frequency Reliability Analysis of Francis Turbine-Generator Units Based on Nonlinear Vibration
Authors: Li Z.J. , Yang X.J. , Cai G.W. , Liu X.S.
Published: August 2009

This paper studies the frequency reliability of the main shaft system of Francis turbine-generator units based on nonlinear vibration. Taking the generator and turbine as an integrated system, the nonlinear coupling dynamic equations of the system are established by the finite element method. According to the dynamic equations, the frequent factors of system are obtained by the method of multiple scales. The criterion is used that the difference between the natural frequencies and driving frequencies including the frequent factors should be less than specific values. The reliability mode and the safety probability of the main shaft system of Francis turbine-generator units are defined as a series mode, and the frequency reliability analysis method for avoiding the resonance is proposed. Finally, an example is presented.
Research on Reliability Allocation of Direct-Drive Hobbing Machine
Authors: Zhang Gen Bao , Liao Xiao Bo
Published: August 2009

In the early design phase of direct-drive hobbing machine, to allocate the reliability index scientifically and reasonably without the related reliability data, fuzzy analytic hierarchy process (fuzzy AHP) is used to allocate the reliability index of the main system units of direct-drive hobbing machine. This method is an effect way for multi-factor decision, which can consider the influence of the factors of every hierarchy on the machine maximatily and calculate the influence weights of the factors of every hierarchy quantitatively. Research on reliability allocation of direct-drive hobbing machine illustrate that this method is suitable for reliability allocation during innovative design phase.
Web Information Based Collaborative Product Growth Design
Authors: Yang Bo , Ze X.B. , Cui W.H.
Published: August 2009

Based on the survey of existing research work on collaborative design and on our experiences and work in product growth design theory, a feasible approach—collaborative product growth design method to integrate the genetic engineering methodology, collaborating tools and web based information into the automatic design activity has been proposed in this paper. Firstly, the product growth design strategy and its characteristics are studied based on automation technology in the product structure design. Then, to guarantee a successful transformation and good use of existing product data and related product series on internet, the information exchange model and web based virtual design gene pool model in the process of product growth design are put forward. Finally, the mechanism of the combination of product growth design and collaborative design process are described, and the framework of collaborative design based product growth design system is introduced. Through theoretical study and hard development work interesting and useful results have been obtained.
Study on Cutter Radius Compensation Methods for 5-Axis CNC Machining
Authors: Liu Yuan , Wang Yong Zhang , Fu Hong Ya , Han Zhen Yu
Published: August 2009

The numerical control (NC) program files need re-generating if there is any tool dimension change or tool wear for multi-axis machining. If the tool is replaced to adapt this change there will be increased cost. To solute this problem, 3D cutter radius compensation method for 5-axis computer numerical control (CNC) machining is deeply researched. Taking five axes linkage machine tools of X, Y, Z, B, C form with rotary tables B and C as an example, coordinate transformation matrix (CTM) and the cutter compensation vector for 3D cutter radius compensation are derived. The discrimination methods for path joint pattern (PJP) are given. A controller with 3D cutter radius compensation function for 5-axis linkage CNC machine tools is developed based on this method. The controller is allocated to a 5-axis milling machine tool and experiments are done. The proposed algorithm is demonstrated using a practical example.
Comparison Research on Inertia Simulation in Brake Dynamometer Test
Authors: Wu B.D. , Ma Ji Jie , Liu X.Y. , Sun Jing Yang
Published: August 2009

Two methods of inertia simulation, energy compensation method and torque control method, using work of electromotor during brake application are discussed in comparison in this paper. Mathematical models are described. Experiment under various brake conditions unfolds the rule of some key factors of energy compensation including working period of electromotor, start point and ending condition of compensation. Comparison experiment shows advantages of the energy compensation method over its counterpart. Limitations as well as corresponding solutions are discussed in the end.
Research on Project Level Collaborative Design Process Oriented to Complex Product
Authors: Wang Ya Ping , Ge Jiang Hua , Shao Jun Peng , Li Zhi Qiang
Published: August 2009

This paper established a decomposition hierarchical network model of project level collaborative design process, based on work breakdown structure WBS, for character complex product collaborative design in dynamic alliance. The workflow of product collaborative design was established using time sequence Petri net, and the key assignment which has influence on design schedule and all design time were solved, after analyzing and comparing existing model method of collaborative design. And then experiments were used to verify. Theses technology support time management of workflow in project collaborative and shorten development cycle of collaborative project.
Quasicontinuum Method Simulation of Nanometric Cutting of Single Crystal Copper
Authors: Liang Ying Chun , Pen Hong Min , Bai Qing Shun
Published: August 2009

A multiscale simulation model was built to study the nanometric cutting process of single crystal copper. This multiscale model distinctly reduces the degree of freedom of the whole system compared with full atomistic simulations. Through analyzing the fluctuations of tangential cutting force and strain energy with cutting distance, we confirm that the deformation mechanism of single crystal copper is plastic deformation caused by generation and evolution dislocation. The highest compressive stress locates in shear zone and highest tensile stress locates in the machined surface and subsurface. Simulation results show that there exists a high value of stress around dislocations, which reveals the local high value of stress is the main reason for the generation and evolution of dislocations in the workpiece material.
Quality Defects and Analysis of the Microfluidic Chip Injection Molding
Authors: Liu Ying , Song M.C. , Wang Min Jie , Zhang C.Z.
Published: August 2009

Compared with hot embossing, microfluidic chips injection molding is higher efficiency process and more suitable for mass production, but the quality control for injection molding is much more complex. Experiments indicate that the incomplete replication of the micro-channel and the sink mark for microfluidic chips are the chief defects to the molding. Simulation and theoretical analysis show that the stagnant flow of the melt in micro-channel and the shrinkage difference of the chips in different directions are the main reasons for molding defect. A set of new methods that how to control process parameter, design mold, and select polymer material is proposed to reduce or avoid the defects.
Forming Rule Construction for Hourglass-Like Tube Hydroforming with Magnesium Alloy
Authors: Lin Shen Yung , Chang C.M. , Shyu Ruey Fang
Published: August 2009

The objective of this study is to construct the forming rule for hourglass-like tube with magnesium alloy during hydro-forming and offer the analysis results as a guideline for magnesium alloy forming in industry. AZ31 magnesium alloy circular tube is used as the billet material for hydro-forming with hydraulic pressure as the main forming power combined with the mechanical auxiliary force from the punch to fabricate the hourglass-like tubing products. A finite element based code is utilized to investigate the forming characteristics of hourglass-like tube forming, by changing process parameters such as punch velocity, hydraulic pressure gradient and tool-workpiece interface friction etc. to investigate the material flow of tube filling, wall thickness variations, and stress and strain distributions. And the abductive network is in turn applied to synthesize the data sets obtained from the numerical simulations. Consequently, a quantitative prediction model is developed for the relationships among the process variables, corner radius and minimum tube thickness in the process of hourglass-like tube hydro-forming with magnesium alloy. The results show that proper mechanical force can help material flow, prevent large strain deformation from falling into the area of negative strain hardening rate, enhance the magnesium alloy to become easy in forming and make tube fitting may to be formed successfully.
Reach on Impact Line of Hyperboloid Shallow Shell Surface Deflection
Authors: Zhao Li Hong , Zheng Y.F. , Xing Zhong Wen
Published: August 2009

The impact line is a remarkable disadvantage in the auto body panels forming. It is difficult to study because of the complexity shape of automotive panels. The finite element models of hyperboloid shallow shells that can represent automotive panels are established, and suitability of finite element analysis to induce the impact line of automotive panel is carried out. The experiment test method for determining impact line is presented also. The criterion and research technique of auto body panels impact line are introduced. The consistency of results of simulation and experiment shows that the numerical simulation on research of impact line is accurate and feasible. Finally, research works of simulation and experiment on controlling impact line measures are carried out: effects of blank holding force (BHF), sheet thickness and lubricating modes on the impact line are obtained.
Multi-Point Positioning Tooling Technology for Aircraft Manufacturing
Authors: Liu C.G. , Tan F.X. , Li X.J.
Published: August 2009

Multi-point positioning tooling is a flexible fixture used in assembly of contoured panels in aircraft manufacturing. It uses many numerical controlled punch elements to configure a flexible tooling system which shape contour can be adjusted according CAD data. The paper is focused on analysis of the operations to be done on the formed panel when they are clamped and supported on the MPPT. From the results of finite element analysis, it can be concluded that the interval between punches is the key factor which affects accuracy of MPPT. And also sheet thickness, material and geometric shape have influence on performance of MPPT.
Study on Microstructure Character in the Deformable Regions of AISI-1045 Steel Fine Blanking with Negative Clearance
Authors: Li J.H. , Fan Wei Fu , Zhang Zhong Mei
Published: August 2009

This paper obtained work piece of fine blanking with negative clearance by experiment. The microstructure and fractography photograph in regions like rollover zone, shearing band, under sheared surface and fracture band were scanned by instrument of scanning electron microscope (SEM-JSM-6360LV). The fine-blanking with negative clearance makes the metal deformation regions into a state of triaxial stress precise and it causes an intense metallic stream that brings about inter-dislocation and distortion of metallic crystal product under the action of stronger force, so the metallic crystal is reset and the isometric metallic crystal of shearing zone is staved, sloped and pulled and it appears as dense lined and strip crystal. The paper analyzes the full course of producing and development of micro crack in the ejecting stage in the fine-blanking processing of negative clearance. And the course of final rupture is also analyzed. The relationship curve of blanking stroke and micro hardness is measured by Vickers Hardness instrument (MH-6). The deforming principle of fine blanking deformation with negative clearance is analyzed by means of microstructure, metallographic photograph and micro hardness.
Inner Surface Migration during the Internal Crack Healing in 45 Steel
Authors: Meng F.Y. , Nie S.M.
Published: August 2009

Many cracks can occur in heavy forging as a result of inherent defects of heavy ingot and forging process. According to the results of current research, internal crack of metallic material can heal under high temperature. In order to get to the bottom of internal crack healing in heavy forgings, some 45 steel samples containing internal crack were normalized at higher temperature than normal. The phenomena show that new ferrite grains nucleate and grow up on the crack surfaces during the crack healing, and the ferrite grains nucleation is universal but selective on crack surfaces. The relationship of atom diffusion and ferrite grain nucleation and their actions on crack surface migration will be discussed and expounded, and that proves that ferrite grain nucleation and growth will accelerate crack healing.
Multibody System Dynamics Simulation of Loads in Main Bearings of Crankshafts
Authors: Qin Wen Jie , Jia D.W. , Liu Q.Y.
Published: August 2009

In this paper, as for the calculation of loads in main bearings in a crankshaft system, multibody system dynamics is used to simulate the dynamic characteristics of the system composed of flexible and rigid bodies, coupled with hydrodynamic lubrication analysis further. The multibody system model with flexible crankshaft of one V8 diesel engine is built in ADAMS software, in which the bearings are modeled as rigid constrained bearings and hydrodynamic bearings respectively. The resulted loads in main bearings using different models are compared. The results show that the deformation of crankshafts has great effect on the values of loads in main bearings, and the bearing loads in different directions tend to uniformity due to the hydrodynamic lubrication.
The Effect of Process Parameters on Weld Quality in Resistance Spot Welding Dual-Phase Steels
Authors: Qian Chang Ming , Zhang Yan Song , Zhang Xiao Yun , Chen Guan Long
Published: August 2009

In order to reduce vehicle weight and improve crash performance, dual-phase (DP) steels are increasingly used for lightweight auto-body. the high cooling rates in Resistance spot welding (RSW) process will make the nugget very brittle and result in interfacial fracture modes. In this study, a servo resistance welding system is firstly introduced to control process parameters during the welding process. The influences of different process parameters (weld current, weld time and electrode force) on the weld strength, nugget diameter, facture modes and weld indentation are analyzed. Finally, an on-line weld failure mode inspection method is proposed based on servo gun’s feedback characteristics.
Investigation on Influence Factors of Bulging of Boren Steel at Elevated Temperature
Authors: Min Jun Ying , Lin Jian Ping , Sun Guo Hua , Bao Wen Hua
Published: August 2009

The finite element model of bulging at elevated temperature was established by using of pam-stamp 2007. The bulging tests of boron steel sheets were also performed on the self-designed and manufactured tool system. The simulated results of bulging height, limit strain and the minimum temperature of specimens are consistent with that of tests. It demonstrates the validity and accuracy of the finite element model established in pam-stamp. The influences of the friction coefficient, the temperature and the stamping velocity on the hot bulging are analyzed numerically. The friction condition should be improved and the minimum temperature gradient is recommended in practical hot stamping production.
Numerical Simulation and Experimental Research on the Rolling Process of Large-Scale Aluminum Ring
Authors: Zhao Yumin , Lin W. , Qian D.S.
Published: August 2009

In the current study, a 3D elastic-plastic FE model for rolling of large-scale aluminum ring on high-voltage switch is developed under the ABAQUS software environment. Based on the 3D FE model, lots of simulation calculations have been carried out. Through simulation, the internal energy and kinetic energy histories during the process are obtained and the optimal mass scaling factor is determined reasonably. Additionally, the stress and stain field-variables and metal flow laws have also been analyzed in detail. The ring rolling experiment was carried out and the experimental results are in good agreement with the simulation ones. The research results provide powerful guidelines for the rolling process design of large-scale aluminum ring on high-voltage switch.
Performance Assessment of Surface Finishing Using Completely Inserted Module of Female-Screws
Authors: Pa Pai Shan
Published: August 2009

It is very difficult to execute the finishing process of the concavo-convex surface of female-screws. The current study offers a screw-form design electrode and a new area-finishing process using an ultrasonic generator. The ultrasonic energy generated is transmitted into the electrolyte to assist the process of electrochemical finishing. The surface of female-screws is electrochemically finished by different types of completely inserted electrodes and put through both continuous and pulsed direct current as a finishing operation. For inserted screw-form electrodes, a smaller circumference electrode on the cylinder provides more sufficient discharge space, which is advantageous for finishing. Pulsed direct current can promote the effect of electrochemical finishing, but the machining time is longer and the cost is raised. The average ultrasonic effect is much better than the pulsed current while the machining time needs not be prolonged by the off-time. The higher current density and higher current rating with ultrasonic assistance can avoid the difficulty of dreg discharge, thus reducing the finishing time. It is a great contribution that the ultrasonic-assistance electrochemical finishing after screw machining requires a shorter time than manual or machine polishing to make the surface of female screws smooth and bright.
Research on Cutting Residual Stresses Based on Thermo-Mechanical Coupling
Authors: Xu Ying Qiang , Li S.J. , Zhang T. , Yang X.H.
Published: August 2009

Mathematical models of basic parameters, force and thermal parameters of cutting were obtained by applying the thermo-elastic-plastic theory and the heat-balance theory, according to the principle of residual stress generation in cutting process. Based on the 2D finite element model of chip molding with separation surface, the direct way was applied in thermo-mechanical coupling, and residual stress of cutting GH4169 were simulated and analyzed by finite element. The results showed that the residual stresses are changed from tensile to compressive with the development of depth away from the workpiece surface. Also its values are changed according to a certain rule as varying the cutting speed. These provide a foundation for the control of cutting quality of workpiece.
Optimization Design of a Vibrating System with Two Motors
Authors: Wang D.G. , Guo K. , Zhao Chun Yu , Wen Bang Chun
Published: August 2009

The dynamic model of vibrating system with two motors is established. Through dynamic analysis, the equations of frequency capture of the vibrating system and the conditions of implementing stable self-synchronous operation are obtained. Then the vibrating system is optimization designed based on the conditions of implementing stable self-synchronous operation. The simulation program with proper parameters of vibrating system is run, and the results show that the system is in a good synchronous state. Computer simulations demonstrate that the vibrating system realizes speed synchronization and phase synchronization. The results verify the effectiveness of the optimization design.
Effects of Processing Parameters on Energy Efficiency of Squash Presetting Laser Cladding
Authors: Wang Hong Yu , Zuo Dun Wen , Chen Yong Jun , Ma H.
Published: August 2009

The green presetting of powders was performed on the substrate by introducing a novel technique namely squash presetting method, and cladding coatings were prepared by crosscurrent CO2 laser in this work. Based on the concept of laser energy efficiency which being accepted generally by insider, the energy efficiency of squash presetting laser cladding was determined. Meanwhile, effects of processing parameters including specific energy, laser power, scanning speed and spot diameter on energy efficiency were investigated through an orthogonal test. The results show that the energy efficiency increases at first and then decreases with the increase of specific energy, and the energy efficiency is relatively higher when laser specific energy ranged from 90 J/mm2 to100 J/mm2. Among three single-factors, the effects of spot diameter on energy efficiency are most significant, laser power takes second place, and scanning speed comes next. It is considered through analysis that the relationship between energy efficiency and processing parameters is closely related to powders melting and heat-conduction course of squash presetting laser cladding.
Experimental Study on Laser Shock Peening of AZ31B Magnesium Alloy Sheet
Authors: Huang Shu , Zhou Jian Zhong , Jiang Su Qing , Yang X.D. , Wang Cheng Dong , Dai Y.C.
Published: August 2009

Typical specimens of AZ31B Magnesium alloy were processed by single point and continuous laser shock peening (LSP). The selected laser energy was 25 J, spot diameter was 8 mm, peening spacing was 8 mm and peening times were 2. The obtained value of residual compressive stresses were -144.3 MPa and -230 MPa for single and continuous LSP respectively, and the magnitude of residual stress was in direct proportion to the depth of deformation in definite micro-deformation range. The average surface micro-hardness in the laser spot zone was 92.42 HV, which increased by 26% as compared to 73.2 HV of substrate, the depth of hardened layer was about 0.3 mm, and the maximum micro-hardness was about 109.86 HV beneath surface of 0.05~0.075 mm. Large amount of crystal chunks appeared at the crystal grain boundaries and inside the grains, and the average grain size decreased from the untreated 7 μm to the peened 4 μm. The results show that the nucleation of fatigue crack can be retarded and the mechanical properties of AZ31B magnesium alloy sheet can be improved greatly with LSP process.
Wear Behavior of Laser-Hardened GCr15 Steel under Lubricated Sliding Conditions
Authors: Lei Sheng , Liu Quan Kun , Liu Yu Ping , Li Heng
Published: August 2009

Microstructure, microhardness and tribological properties of laser hardened GCr15 steel were investigated in this paper. The wear resistance under lubricated sliding conditions was compared between specimens treated with laser and those of conventionally hardened. The tribological properties of laser surface-quenched GCr15 steel specimens were slightly better due to the effects of the microstructure hardening, high hardness and toughness, with the wear rate (in the order of 10-6mg/Nm) lower than that of the conventionally treated specimens. At the steady state, the frictional coefficient of laser-treated samples had no obvious difference from that of the conventionally treated samples. The wear mechanism for both cases was similar, generally involved surface fatigue wear and slight abrasion wear. LeiQ.K. Liu S. Lei Introduction H. Li
In recent years, among the various surface modification methods, laser-induced surface modification has gained much attention for achieving the desired properties for applications[1]. This method is mainly used for ferrous alloys which undergo martensitic transformation and thus form a very hard surface layer with negligible surface roughness and distortion[2].
Some ideas demonstrated that the wear rate at a particular contact pressure can be strongly influenced by the microstructure of the steel, but there is also contrary idea that under the conditions of mild wear, the microstructural constituents of steels have no significant influence on the wear rate, although they affect the rate of severe wear. Previous studies of the authors demonstrated that under the dry sliding wear conditions, laser surface-hardened specimens of ferrous alloys exhibited enhanced wear resistance than conventionally hardened specimens.
The aim of the study is to investigate the lubricated sliding wear behaviors of laser surface hardened GCr15 steel specimens and to compare the effect of the different microstructure compositions for laser transformation hardening with those of conventionally hardened and quenched. Moreover, the wear properties of the GCr15 steel and its corresponding wear mechanism under the lubricated wear conditions will also be studied.
A Product Design Method Based on Integrated Geometric and Rule-Based Reasoning
Authors: Pan Zhi Yi , Cao X.Y. , Wu Y. , Gao Shun De
Published: August 2009

Though rule-based reasoning system is easy to create and convenient to extend, it is not flexible because of the demand for precise matching. Geometric reasoning system can obtain engineering semantic from CAD model and connect geometric topology with design knowledge, but it can not drive product design directly. Utilizing the complementary of rule-based reasoning and geometric reasoning, a product design method based on integrated geometric and rule-based reasoning is presented. The method can standardize the expression of design scheme which is from geometric reasoning, and dock seamlessly design scheme and input condition in rule-based reasoning system. Furthermore, the result of rule-based reasoning can drive product design directly. The operation of human-computer interaction and designer’s experience needed are decreased greatly. Digital target in locater is significant to harmonize aircraft tie-in. there are different types in it, and the amount of it is huge, so its design process is complicated and fussy. On the basis of the method, a rapid design software package for locator digital target design is developed and has been applied in aircraft assembly tooling design. The application has proved the method can improve design efficiency, standardization and intelligence.
The Performance Research and Dynamic Analysis for New Steel Coil Upender Clamping Device
Authors: Wang F.H. , Jiao An Yuan , Liu L. , Ma B.Y. , Gao X.Q.
Published: August 2009

A kind of new steel coil upender clamping device was introduced. The model was set up with SolidWorks software and the dynamics analysis was further performed in ADAMS. The results showed that the efficiency of turnover process of the device was high and the system could save driving force. These also provided some theory bases for the design of the device.
Determining Elastic Constants of Material Using Optimization Method and Vibration Test
Authors: Lin Yu Hua , Chang Chia Lung
Published: August 2009

This paper proposes an inverse method to obtain the elastic properties of material. The sum of the squared differences between the experimental resonance frequencies and calculated resonance frequencies from the finite element method is chosen as the objective function. The proposed method presents an optimization method, Hybrid Genetic /Simulated Annealing algorithm, to determine the elastic properties. When the objective function reaches its minimum value, its corresponding design variables are the elastic constants of the material. The inverse method is applied to determine the elastic constants of aluminum plate, Glass/PP laminate, and double coated steel plate .The results indicate that for few elastic constants as an aluminum plate, Hybrid Genetic /Simulated Annealing algorithm has no apparent improvement, but more calculation time in comparison method. While simulated annealing while for Glass/PP laminate and double coated steel plate with more elastic constants, Hybrid Genetic /Simulated Annealing algorithm is superior to the traditional simulated annealing method.
Chemically Induced Mouse Models of Colitis
Authors: Waldner Maximilian J. , Neurath Markus F.
Published: September 2009

Crohn's disease (CD) and ulcerative colitis (UC), both of which are referred to as inflammatory bowel disease (IBD), are chronic inflammatory disorders of the gastrointestinal tract that have characteristic clinical, pathological, endoscopic, and radiologic features. Knowledge about the pathogenesis of IBD has dramatically increased in recent years based in part on the use of experimental models of IBD. Although none of these models exactly mimics the human disorder, they have proven to be useful for studying many important aspects of these conditions. Detailed in this unit is a description of the most commonly used chemically induced mouse models of IBD. These include trinitrobenzene sulfonic acid (TNBS), oxazolone, and acute or chronic dextran sodium sulfate (DSS) colitis models. Curr. Protoc. Pharmacol. 46:5.55.1‐5.55.15. © 2009 by John Wiley & Sons, Inc.
Combined First‐Principle Calculations and Experimental Study on Multi‐Component Olivine Cathode for Lithium Rechargeable Batteries
Authors: Gwon Hyeokjo , Seo Dong‐Hwa , Kim Sung‐Wook , Kim Jongsoon , Kang Kisuk
Published: September 2009

The electrochemical properties and phase stability of the multi‐component olivine compound LiMn1/3Fe1/3Co1/3PO4 are studied experimentally and with first‐principles calculation. The formation of a solid solution between LiMnPO4, LiFePO4, and LiCoPO4 at this composition is confirmed by XRD patterns and the calculated energy. The experimental and first‐principle results indicate that there are three distinct regions in the electrochemical profile at quasi‐open‐circuit potentials of ∼3.5 V, ∼4.1 V, and ∼4.7 V, which are attributed to Fe3+/Fe2+, Mn3+/Mn2+, and Co3+/Co2+ redox couples, respectively. However, exceptionally large polarization is observed only for the region near 4.1 V of Mn3+/Mn2+ redox couples, implying an intrinsic charge transfer problem. An ex situ XRD study reveals that the reversible one‐phase reaction of Li extraction/insertion mechanism prevails, unexpectedly, for all lithium compositions of LixMn1/3Fe1/3Co1/3PO4 (0 ≤ x ≤ 1) at room temperature. This is the first demonstration that the well‐ordered, non‐nanocrystalline (less than 1% Li–M disorder and a few hundred nanometer size particle) olivine electrode can be operated solely in a one‐phase mode.