bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Anti-Plane Characteristic of Two Dissimilar Piezoelectric Media with an Interfacial Crack
Authors: Song Tian Shu , Li Dong , Merhej Tammam
Published: October 2009

Dynamic anti-plane characteristic is investigated theoretically on two dissimilar piezoelectric media with an interfacial crack subjected to time-harmonic incident anti-plane shearing in this paper. The formulations are based on the method of complex variable and Green’s function. Dynamic stress intensity factors at the crack’s tip are obtained by solving boundary value problems with the methods of conjunction and crack-division technique. The calculating results are plotted to show how the frequencies of incident wave, all kinds physical parameters of two dissimilar piezoelectric materials, applied electric loads and the dimension of the interfacial crack influence upon the dynamic stress intensity factor (DSIF). And some of the calculating results are compared with other published documents.
The Effect of Stress Amplitude on Multi-Axial High-Cycle Fatigue Failure under Constant Amplitude Loading
Authors: Shi Xin Hong , Zhang Jian Yu , Bao Rui , Fei Bin Jun
Published: October 2009

Studies about the effect of stress characteristics on multi-axial high-cycle fatigue of metals are still insufficient. Up to now, little work about the effect of different ratio of stress amplitude has been done on multi-axial fatigue under the same equivalent stress. In this paper, the effect of ratio of stress amplitude, under the same Von-Mises equivalent stress is studied from theory and experiment. The results show that the main factor of multi-axial high-cycle fatigue failure is the maximum principal stress. For proportional loading, fatigue life raises when ratio of stress amplitude increase. The variety of fatigue life is not obvious when is larger than a certain value and its value closes to that of pure torsion. For non-proportional loading, when ratio of stress amplitude increases, fatigue life raise at first, then has an inflection point. The value of at the inflection point changes with phase difference and its value is 0.5 while phase angle is 90º. Fatigue life of uniaxial tension was lower than that of pure torsion.
Seismic Damage Analysis of the Teaching Buildings in Leigu Town in the Wenchuan Earthquake
Authors: Sun Bai Tao , Zhou Qiang , Yan Pei Lei
Published: October 2009

A great earthquake of magnitude 8.0 occurred on May 12, 2008 (Beijing Time) in Wenchuan, Sichuan Province of China. Leigu town, which adjoins Beichuan county, was the most seriously damaged place in this earthquake. The teaching buildings were destroyed severely and the earthquake disaster phenomena is very typical. In this paper, firstly, the characteristics of structures and the earthquake damage of the teaching buildings in Leigu town are introduced in detail. Secondly, their damage states are calculated by means of structure vulnerability analysis, which are used for comparative analysis with actual damage states, and the influencing factors on seismic behavior are analyzed. Finally, some reasonable suggestions on the reconstruction of teaching buildings after disaster have been given.
Strength and Fracture of Unidirectional Green Composites Reinforced by Hemp Fiber
Authors: Takagi Hitoshi , Itotani Koujirou
Published: October 2009

In this paper, unidirectional Manila hemp fiber-reinforced thermoset composites were fabricated and their mechanical properties and fracture behavior were also investigated. Both unsaturated polyester resin and epoxy resin were used as matrix polymer. The tensile strength and Young’s modulus of the epoxy-based composites reached the maximum of 520 MPa and 17 GPa at the fiber volume fraction of 72%, respectively. Such excellent mechanical properties are seemed to be derived both from a good permeability of resin into hemp fiber bundles and from enough stress transfer between fiber and matrix.
Effect of Vitamin-E Addition on Fatigue Crack Growth Property of Ultra High Molecular Weight Polyethylene
Authors: Tanaka Kazuto , Uchiyama Masatoshi
Published: October 2009

In order to understand the influence of gamma-irradiation, accelerated aging and Vitamin-E addition on the fatigue crack growth properties of UHMWPE, fatigue crack growth tests of UHMWPE plates using compact tension specimens were carried out. The specimen conditioned in -irradiation and accelerated aging (the -aging specimen) has faster fatigue crack growth rate than the virgin specimens. For the Vitamin-E added specimen (the VE specimen), however, K threshold of the -aging VE specimen is smaller than that of the VE specimen. This result shows that the addition of Vitamin-E reduced the decrease of K threshold by -irradiation and accelerated aging.
Investigation of the Compression Recovery Properties of Polyamide-6 Cellular Solid over the Temperature Range of -5°C to 90°C
Authors: Izzard V.G. , Bradsell C.H. , Hadavinia H. , Morris V.J. , Foot P.J.S. , Witten N.
Published: October 2009

It is a fundamental response of any polymeric foam material to undergo non-recoverable deformation following the application of a defined compressive strain, exacerbated by temperature and humidity. This process is commonly referred to as compression set. The ability to predict recovery after the application of a compressive strain is crucial to both the manufacturers and end users of foam materials. Specific compression set test procedures have been established to quantify the extent of non-recoverable deformation in specific foam types but to date no general predictive approach exists. In this work, compression set (fixed strain) tests were undertaken on a cellular polyamide-6 material at various temperatures (-5°C to 90°C) and the foam recovery monitored over time periods in excess of those dictated by standard methods (ISO 1856 [1]). An empirical formula has been proposed to allow the prediction of recovery after compressive strain, covering recovery periods from 10 minutes to 24 hours (up to 168 hours at 23°C).
Numerical Simulation on Residual Stress Distribution of the Pipe-Plate Welding
Authors: Li Li , Wang Ren Fu , Xue Gang , Min Xiang Jun
Published: October 2009

The pipe-plate welding is a common type of joint in almost all industries. However the presence of residual stresses can be detrimental to the performance of the welded product. Therefore a good method for accurate estimation of the welding residual stress is needed. In this paper, three-dimensional finite element analysis is carried out to simulate pipe-plate structure. Based on the ANSYS software, the residual stress distribution of the pipe-plate structure during welding and after welding is predicted. The calculation results show that the residual stress of weld bead is higher than other places. The radial stress, hoop stress and axial stress are not significantly sensitive to the angle.
Mechanical Properties of Chemical Etched Biomedical NiTi Alloy Wires
Authors: Li Zhen , Li Zhao Qing , Hou Li Da , Li Li
Published: October 2009

Nickel-titanium alloy wires are widely applied in manufacturing biomedical devices; however, it is difficult to be micro-fabricated. Chemical etching process can successfully micro-fabricate the Ni-Ti alloy. The surface morphology, the etching products and the mechanical properties of the fine NiTi wires after the chemical etching process are investigated in the paper. After etching process, the characteristics of the wire surface are studied by Scanning Electron Microscopy (SEM). The X-Ray Diffraction (XRD) phase identification analysis is used to identify the etching products on the side surface of the etched wire. The Vickers Micro-hardness Test shows that the micro-hardness in peripheral surface is slightly higher than that in bulk. Mechanical properties of NiTi alloy fine wires after etching were studied by means of tensile tests.
Research on Long-Term Expansive Deformation of Steel Fiber Reinforced Expansive Concrete
Authors: He Huan An , Wang You Gang
Published: October 2009

The inherent low tensile strength and shrinkage result in cracking of concrete under work loads. A new way to improve cracking properties is distributing steel fibers into expansive concrete to form a type of composite which is called steel fiber reinforced expansive concrete. This type of high performance concrete could compensate shrinkage as well as improving crack strength. For this concrete, the key point to ensure high performance and safety of concrete structure is to keep a stable expansive deformation during long-term service. A series of tests were carried out to measure long-term restrained expansive deformations of steel fiber reinforced expansive concrete with ages under various restrictions like steel bars and steel fibers. The test investigated some 3-year specimens. For all specimens, test parameters included 2 ratios of steel bar reinforcement, 4 volume fractions of steel fiber and 4 dosages of expansion admixture. The test results showed that the expansion of concrete decreased with increasing of steel bar reinforcing ratio as well as steel fiber volume fraction. In addition, when being in a lower dosage of expansion admixture, the specimens presented remarkable retraction of the expansive deformation. However, when beyond a certain dosage of expansion admixture, the long-term expansive deformation had less change with ages and almost remained the same with 90-day deformation, namely less losses of deformation. Hence, for steel fiber reinforced expansive concrete, using an appropriate dosage of expansion admixture could meet the requirements of designed strengthening and compensating shrinkage.
Research on Modeling and Simulation of Scheduling with Tool Failure in FMS
Authors: Zhao Dan , Zhang Jia Tai , Li Ling Li
Published: October 2009

Failure in FMS includes two aspects: equipment breakdown and tool failure of which should be considered in an excellent FMS scheduling system. Most of past scheduling researches have only discussed the former and the analysis of the latter rarely seen in relevant papers. The scheduling system without tool failure processing seems to be not coincident to the actually production in which tool breakdowns are very common. This paper gives a dynamic scheduling simulation model with concern of the two kind failure using Object-Oriented technology and Colored Petri Net (OOCPN). Rescheduling strategy of tool failure is proposed and the simulation analysis is given which shows that our model and principle are effective and adaptable to actual case.
Research of Equipment Selection and Matching Expert System in Fully Mechanized Caving Face Based on Ontology
Authors: Liu Zhi Hai , Zeng Qing Liang , Wang Cheng Long , Li Yu Shan
Published: October 2009

The technologies of expert system, ontology modeling and reasoning are studied and applied in this paper. A framework of ontology-based expert system for equipment selection and matching in fully mechanized caving face is built up. The OWL(Web Ontology Language) based equipment knowledge base is set up, and the redundant test is made in the protégé environment. The equipment selection and matching rules are built up by using SWRL(Semantic Web Rule Language). By using JAVA language, the output of equipment selection expert system is optimized based on the theory of Analytic Hierarchy Process. At last, the functions of the expert system are achieved under JESS(Java Expert System Shell) environment. Practical application shows that the equipments selected and matched by ontology-based expert system are more realistic.
Research on Extrusion Velocity in Freeform Extrusion Fabrication of Aqueous Alumina Paste
Authors: Liu Hong Jun , Leu Ming C.
Published: October 2009

The Freeform Extrusion Fabrication (FEF) is a Solid Freeform Fabrication process, which fabricates 3D ceramic green parts by extruding an aqueous ceramic paste of high solids loading. The extrusion velocity is a very important parameter and should be better understood. In this paper, experiments were carried out to investigate extrusion velocity in FEF extrusion process of aqueous alumina paste. It is found that the extrusion velocity has a corresponding relationship with extrusion force. The extrusion run can be divided into 4 stages: compaction stage, transient stage, steady stage and stop stage. The step ram velocity input was applied in FEF process and improved the extrusion velocity profiles in transient stage.
Dynamic Analysis of a 6-DOF Inverted Stewart Platform
Authors: Chao Min , Wang Chin Yu , Lee Cheng Kang
Published: October 2009

This paper concerns the design and analysis of a 6-DOF inverted Stewart platform of an amusement park. In consideration of both the thrill-seeking and the safety of tourists, the platform must have 3 proper translational axial accelerations and 3 proper rotary angular accelerations within one motion cycle, and the impact of seismic force shall be taken into account in order to retain the adaptability to change of the system in case of emergent situations. Besides, the safety factors of various parts and components of the system shall be higher than six. In this paper, a 3D model is developed for the platform by means of Solidwork, and kinematics simulation is carried out by means of Cosmos/Motion software to generate 3D geometrical diagrams which are to be transferred into ANSYS Workbench software, and at last, the optimized design of geometry of each part/component of the system and the evaluation of overall safety of the system are conducted in Workbench software based on foresaid 3D geometrical diagrams.
Loci Conversion and Corner Smoothing with PH Curves in CNC System
Authors: Wang Qi Kui , Chen You Dong , Li Wei , Wang Tian Miao , Wei Hong Xing
Published: October 2009

Free-form surface interpolation functions give more advantages in machining than the traditional line and circle functions. A method is developed to convert lines and circles into Pythagorean-hodograph (PH) curves. In order to get smooth machining process the PH curve is used to replace the joints of the circular/linear elements by the connection situation. The slope of line is used to get the tangent vector in the line conversion. When converting a circle to a PH curve, points of the divided circle are introduced to compute the vectors. The methods of computing tangent vectors are proposed according to the slope of the line and the quadrant of the circle. The transformation errors from lines and circles to PH curves are computed. In the corner smoothing process the tangent vectors are computed by the connection between lines and circles. Replacement errors at the joints are computed for the use of PH curve. The results demonstrate the feasibility of the conversion from line and circle to PH curve. The PH curves at the joints of the circular and linear elements show continuous trajectory.
On Numerical Simulations of the Micro-Gears and their Cold Forging Process
Authors: Wang Chin Yu , Wang Hsin Te
Published: October 2009

In this paper, a parametric cubic spline function for generating gear profile is proposed. The spline function includes new gear design parameters such as pressure angle, number of teeth, module, and tooth tip circle modification. The proposed geometry can improve corner filling condition. Finally, the simulation software DEFORM is used to simulate the cold forging process of the micro-gears with different profiles.
The FUZZY-D-P-GA of Navigation Performance and Structure Characteristic of Ships
Authors: Yang Song Lin , Yang Zhao Long , Ma Lian Xiang , Zhang Hong Qin
Published: October 2009

The authors built up a new algorithm called FUZZY-D-P-GA which was based on the fuzzy optimization, the genetic algorithm, delicate variables’ segments thinking & parallel principle. Meanwhile, they also succeed in applying this composite method on the synthetically optimization of navigation performance and structure characteristic of ships. Through a large number of calculation, the results showed that this kind of algorithm had high efficiency and it was also reliable.
A Study of LED C-Like Linear Tube by Micromachining Technique for LCD Backlight Applications
Authors: Chien Chao Heng , Chen Zhi Peng
Published: October 2009

In order to make the liquid crystal display (LCD) panel thinner, brighter and no-Hg containing, the light emitting diodes (LEDs) are generally beginning to replace conventional cold cathode florescent lamp (CCFL) as light sources for LCD backlight unit (BLU). The thermal management and cost are consideration caused by more LEDs used for larger size BLU. For saving the fabrication cost and considering the luminous uniformity of most commercial BLU, a novel C-like linear tube is fabricated by precision and micromachining technique. The LED C-like linear tube is not only decreasing LEDs for BLU but also increasing the optical efficiency for emitting the light into the BLU. The C-like linear tube is proposed to replace CCFL tube for thin film transistor (TFT) LCD applications.
Using Multiaxial Fatigue Method to Predict Gear Bending Fatigue Life
Authors: Wang Guo Jun , Jiang Mei Hua , Zhu Shi Shun , Xu An Tao
Published: October 2009

One of the biggest problems to predict the bending fatigue life of gear is lack of S-N data from the standard gear specimen. It is expensive and long time to spend to do the specimen tests. The bending fatigue property data from database is not enough to fulfill the engineering needs. To solve the problem, multiaxial methods are used to predict the bending fatigue life of gears and FEA method is used to analyze the stress of gear teeth root. Result shows that McDiarmid model, Findley model and Maximum shear stress model fulfill the engineering needs and McDiarmid method is the most accurate.
Exploration for Rapidly Dividing a Complex Structure 3D Modeling into its Assembly Cells
Authors: Wang Zhi Jun , Zheng Guo Lei
Published: October 2009

The definition and creation of assembly cells is one of the most important fundamentals of production general process planning. Currently, only a few researches made on this issue are still based on 2D engineering drawings at home and abroad. Moreover, during practical production general process planning, process designers partition assembly cells especially for complex structure on 2D engineering drawings by manual way. These methods cannot evidently meet the demands of 3D digital technology development and applications for modern products. In this paper, the techniques of assembly cell partition for complex structure are investigated based on its 3D modeling. The 3D Process Split Space is defined and constructed respectively, and the methods of the component recognition and assembly cell modeling are established. The proposed techniques are initially developed and verified on the CATIA V5 system.
Design and Fabrication of a Multi-Functional Nanomanipulator
Authors: Chang Ming , Lin Chia Hung , Lin Chung Po , Deka Juti Rani
Published: October 2009

With rapid expansion of nanotechnology, microminiaturization has become imperative in the field of micro/nano fabrication. A nanomanipulation system with high degrees of freedom that can perform nanomachining, nanofabrication and mechanical/electrical characterization of nanoscale objects inside a scanning electron microscope (SEM) is presented. The manipulation system consists of several individual operating units each having three linear stages and one rotational stage. The body of the manipulator is designed using the idea of superposition. Each operating unit can move in the permissible range of SEM’s vacuum chamber and can increase or decrease the number of units according to the requirement. Experiments were executed to investigate the in-situ electrical resistance of nano materials.
Real Eigenvalue Sensitivity for Reduction of Vibration of Two-Stage Parallel Shaft Gearbox
Authors: Zhu Shi Fan , Maharjan Sanjeev , Li Yong Xin , Zhang Lei
Published: October 2009

. Excitation force produced during gear mating of power transmission system induces vibration to the gearbox. Resonance occurs when excitation force frequency coincides to one of the natural frequencies of the gearbox which will bring not only sudden and unexpected vibration but also potential destruction to the gearbox. Natural frequency is determined by mass and stiffness of gearbox. These two determiners rely on sizes of the parts of the gearbox. That means natural frequency can be shifted by varying the sizes to prevent resonance. To demonstrate this, in this paper, the two stage parallel shaft gearbox modeled by shell-solid elements has been considered. The modal analysis and the real eigenvalue sensitivity analysis have been performed, in MSC. NASTRAN. The sensitivity coefficient and frequency spectrum at particular thickness of gearbox part show the effect on shifting the mode frequency.
Modelling and Analysis for an Electric Power Assisted Steering System of Plug-In Hybrid Electric Car
Authors: Zeng Qing Liang , Li Yu Shan , Wang Cheng Long , Liu Zhi Hai
Published: October 2009

Plug-in hybrid electric vehicles (PHEVs) have been seen as promising vehicles which have merits of hybrid electric vehicles and electric vehicles. Because of difficulties of plug-in hybrid electric vehicles’ development, it is necessary to study revamped method on the base of original car. Electric power steering (EPS) is an advanced steering system that uses an electric motor to provide steering assist. Because PHEVs are often on electric-electric operating mode, steering system power should be supplied with electric motor. Also, reconfigration of the power system including batteries results in added weight and the load change on front axle and rear axle. The steering characteristic of the revamped car are different from that of the original car. Based on the analysis and actual size, mass-force, etc. of the overall car and the parts of EPS, the multi-body dynamic model of the car equipped with EPS is established with multi-rigid-body dynamics analysing software (ADAMS). Based on the virtual prototype, simulation of steady state steering characteristic and transient state response characteristic of revamped car compared with original car under angulus step input of steering wheel have been finished. According to the simulation results, steering characteristic of the revamped car meets the design requirements. The research method is feasible.
Design of Multi-Module Experiment-Rig of Ship Electrical Propulsion Prime Mover
Authors: Xie Chun Ling , Li Shu Ying
Published: October 2009

Diesel engine power plant, gas turbine power plant and steam turbine power plant are in common use in ship main propulsion power. These power plants have each advantage and disadvantage at mass, size, most high-power, economic ability, and maneuverability. But any single power is difficult to meet the requirement of improving the ships’ tactical performance, speed and maneuverability. In developing history of ship propulsion system, in order to solve the contradiction between full speed high-power and cruise economic ability, combined power plant form can change the performance of simple plant, which collected the advantage of all kinds of power plants[1]. Here combined power plant form is two or more same or not the same type engine combine used or trade off. The combined power plant can not only supply total power for ships when cruising, but also be more economical. So this plant is used widely. This paper, designs a multi-module experiment-rig and introduces its composition, working principle and disposition scheme, and carried out the dynamic characteristic experiment of the CODAG power plant.
A Determination Method of Product Design Parameters with Interval Constraint
Authors: Li Zhi Gang , Li Ling Ling , Zhou Jun Gang , Liu Jing Zheng
Published: October 2009

There are some undetermined parameters that can be get values only in a certain range about products and other objects in the product design rules and calculations. The parameters to be determined are usually affected by many factors and constraints, which are often bound with fuzzy. The problem is solved in the past usually by the designer getting values of undetermined parameters in a limited range based on their experiences. That is inevitable to deal with subjectivity. Two algorithms about solving undetermined parameters are proposed based on evidence theory and fuzzy comprehensive decision-making methods in this paper. The algorithm is as a reasoning method applied in a knowledge-based intelligent system.
Topological Optimum Design Considering Stress Constraint Using Approximate Function
Authors: Shih Chien Jong , Chen Kuang You
Published: October 2009

This paper presents an integrated process of structural topology optimization in minimizing both compliance and structural weight. The material volume fraction acts an additional design variable subjected to the empirical approximate stress constraint in terms of material volume fraction. This explicitly approximate function can provide a convenient way to calculate its gradient information for numerical optimization. An engineer does not require advanced topology optimization and superior finite element technique in applying proposed method.
The Influence Parameters Study on Free Span Allowable Length Design
Authors: Sun Li Ping , Ai Shang Mao
Published: October 2009

Improving the knowledge about the influence factors of the allowable free-span length which required in pipeline design, this study provides information about an evaluation of fatigue life due to vortex induced vibration (VIV). Standard finite element techniques are used to the eigen value analyses of a oil-conveying free-span on seafloor. Combined with VIV response model, the fatigue life under three different end boundary conditions (fixed, pinned and elastic seabed) is evaluated. The influence parameter study has shown that the allowable span length is very sensitive for structural natural vibration characteristic, controlled by axial force, end conditions and internal flow. The natural frequencies of free span increase while both the internal flow speed and compression decrease, and internal flow velocity was found less important for VIV response than other functional load factors, because the speed in reality is not high enough.
Finite Element Analysis of Heterogeneous Sandwich Sheets During Rolling
Authors: Chen Dyi Cheng , Cao Jia Hao , Liu Yao Chow
Published: October 2009

Three-dimensional DEFORMTM finite element simulations are performed to analyze the plastic deformation of heterogeneous sandwich sheets during rolling. The finite element code is based on a rigid-plastic model and the simulations assume that the rollers are rigid bodies and that the deformation-induced change in temperature during rolling is sufficiently small to be neglected. The rolled product is assumed to comprise a central sheet of either A3003 or A6063 aluminum alloy sandwiched between upper and lower sheets of A1100 aluminum alloy. The simulations examine the effects of the sheet thickness and reduction ratio on the maximum effective stress, maximum effective strain, Y-direction load, and maximum damage induced within the rolled product. The simulation results for the final thicknesses of the three layers in the rolled sandwich sheet are compared with the experimental measurements. Overall, the results presented in this study provide a useful insight into the deformation mechanisms involved in the rolling of heterogeneous sandwich sheets.
Numerical Modeling and Design of an Inspection Device with Thermoelectric Coolers for the Coke Oven
Authors: Yeh Tung-Hsin , Jang Jiin Yuh , Chen Yu Bin , Wang Der Her
Published: October 2009

In order to inspect on wall condition inside the coke oven, an inspection device has been developed to protect a camera inside and sustains high temperature long enough so that it can be permanently-installed on the pusher ram beam. The temperature of the coking chamber during operation is about 1200 °C while the maximum tolerable temperature of a camera is less than 40 °C. The device has to function as a good thermal insulator with cooling element for the camera at the pusher head and for signal cables along the beam. In this paper, the necessary conditions of the inspective device were found out by building a three-dimensional numerical model of the device to simulate the temperature distribution inside the device with CFD commercial software.
CFD Investigation of Performance for Marine Current Turbine Based on RANS Simulations
Authors: Fan Rui Jun , Chaplin J.R. , Yang Guang Jun
Published: October 2009

This paper presents the 3D CFD computation of an 800mm diameter model of MCT based on structured grids, RANS equations and turbulence model. A time-accurate, upwind, finite volume method for computing compressible flows on structured grids is presented. Numerical predictions for a series of blade pitch angle settings and speeds are compared with the other simulation results of commercial software, verified by the experimental measurement of the model. Such results provide confidence in using the CFD computation tools to develop the forthcoming design of MCT.
Welding Repair Strategies for Aluminium Structures
Authors: Schaefer Frank Helmut
Published: October 2009

Aluminium is being increasingly used in all fields of industry. Especially if it is about the structures like car bodies or frames for transportation units aluminium replaces steel. The components used are regularly assembled by joining welds. Therefore there is an increasing need for reliable repair work on aluminium welds. Repair work to aluminium structures is conducted extremely successfully. This paper will present considerations associated with the repair of aluminium structures due to practical examples. A focus will be the investigation of finding reasons for appearance of failures. Repair strategies are developed to help to prevent problems associated with repair work and to help ensure consistently successful repairs.
A Regression Neural Model for In-Process Surface Roughness Monitoring in End Milling Operations
Authors: Huang Po Tsang B. , Chen James C. , Jou Yuan Tsan
Published: October 2009

The key element of the in-process surface roughness monitoring system is the decision-making model, which is utilized to analyze the input factors and then to generate a proper output. The success of the in-process monitoring system depends on the accuracy of the decision-making model. To increase the accuracy and reliability of model, it is important to reduce the variation of the inputs. To achieve this objective, an integration of regression and neural network was developed as a decision-making model in this research. In this integrated model, the regression model was applied as a filter to sort the input variables into groups. Furthermore, the grouped data was implemented to train and to generate different neural networks models to reduce the affection of input variation and increase the accuracy of the monitoring system. The input variables was first filtered by the threshold of regression model, and then analyzed by different neural networks model based on the filtered result. Finally, to evaluate the performance of the integrated model, the regression neural network and traditional neural networks were both developed for surface roughness monitoring system in an end milling operation to compare the accuracy of systems.
The Design of a Novel Sensor Fusion Model for Monitoring People’s Density in Public Places Using Infrared Thermography
Authors: Al-Habaibeh Amin , Yaseen S. , Parkin R.M. , Otham Fadel , Albar O.
Published: October 2009

There is an increasing need in modern cities for automated Crowd Condition Monitoring (CCM) in order to provide continuous real-time on-line information regarding the density, number and movement behaviour of crowd within a specific area in order to allow the required level of services and facilities to be specified and directed. This paper describes the novel application of low-cost infrared system for estimating people’s density using infrared thermography. Sensor fusion system is developed to compensate for environmental noise. The results show that the suggested monitoring system could provide an efficient method to estimate crowd’s density.
Experimental Research of Pneumatic Drop-on-Demand High Temperature Droplet Deposition for Rapid Prototyping
Authors: Zeng Xiang Hui , Qi Le Hua , Huang Hua , Jiang Xiao Shan , Xiao Yuan
Published: October 2009

Generating high-melting-point metals droplet is a bottleneck in the area of droplet-based rapid prototyping. In our research, a pneumatic drop-on-demand (DOD) generator was developed which can spray A2024 alloy successfully, and the maximum ejection temperature can reach to 1200°C. Experiments were conducted to examine the influence of the oxygen content on the metal droplet spray. The uniform A2024 droplet was ejected stably under the condition where the oxygen content was less than 25ppm. As the solenoid valve was opened once with different time span, four cases were observed: droplet stream, three droplets, two droplets and one single droplet. A2024 droplets were deposited continuously on top of each other in vertical direction to form vertical columns, which meant the graphite nozzle can be used in experiment. A simple square tube was produced by regulating the droplet generator, which showed the rapid prototyping by high-melting-point droplet deposition is feasible.
Flow Field Analysis of Gas Jets from Nozzles for Gas-Assisted Laser Cutting
Authors: Yuan Run , Yang Bo , Ruan Hong Yan , Wang Xiao
Published: October 2009

The gas jets from the conical and new designed supersonic nozzles on different working pressure are simulated by a computational fluid dynamics code, FLUENT, using standard k-ε model and unstructured grid finite volume method with compressible axis-symmetry N-S equation. Under the same condition of pressure-inlet, the distribution of symmetry velocity and that of static pressure are compared. The result of the analysis indicates that conical nozzle outlet can reach subsonic or sonic flow. It is fit for low speed and low pressure situation. The gas jet from the new design supersonic nozzle working at design work pressure has better properties than those of other nozzles. So it is better for thick-plate and or high-speed laser cutting. It is obvious that the results of CFD numerical analysis are consistent with the shadowgraph. Thereby it is an effective way to optimize the nozzle according to the performance of flow field.
Cracking Mechanism of Laser Cladding Rapid Manufacturing 316L Stainless Steel
Authors: Song Jian Li , Li Yong Tang , Deng Qi Lin , Cheng Zhong Yang , Chin Bryan
Published: October 2009

Laser cladding rapid manufacturing technology is a kind of new developed advanced manufacturing technology integrating the advantages of rapid prototyping manufacturing and laser cladding surface modification. Due to the complex thermo-physical and metallurgical factors in the deposition process, the cladding layer is liable to crack, which seriously impedes the industrial application of this technology. Experiments of laser cladding rapid manufacturing 316L stainless steel were carried out. The cracking behavior and phenomena has been observed, cracking mechanism of 316L stainless steel was investigated by means of microstructure characterization and phase analysis with optical microscopy (OM), X-Ray diffraction (XRD), scan electronic microscopy (SEM) and phase diagram analysis. Factors influencing the cracking susceptibility has also been studied. Results show that the cracks of 316L stainless steel were hot solidification cracks caused by the high residual stress and separating of the liquid films among dendrites. Through the optimization of process parameters, adding protective atmosphere, etc. cracking sensitivity has been effectively reduced and crack free 316L stainless steel components have been obtained.
Dynamic Analysis of Wafer Slicing by Using Multi Wire Saw
Authors: Feng Yan Bo , Sun Tao
Published: October 2009

Multi wire saw is the important basis of integrate circuit, optoelectronic, photovoltaic industry, and it becomes a promising technology for semiconductor wafer production because of its advantage of slicing large ingot into thin wafers with high efficiency and good quality. In the process of moving, the inevitable wiresaw vibration is directly related to the whole process with both benefit and harm. This paper analyses the wire vibration behavior in cutting area, the dynamic model is built by modeling the interaction between the dynamics of wire and hydrodynamic characteristics of slurry flow, available modal analysis provides closed form expressions for the steady state response, obtain the vibration of wire subject to different process parameters on wire saw manufacturing process.
Numerical Simulations of Friction Stir Welding Process and Subsequent Post Weld Cold Rolling Process
Authors: Sun Yu Jie , Zang Yong , Shi Qing Yu
Published: October 2009

A sequential coupled three-dimensional thermo-mechanical analysis was conducted first to simulate friction stir welding (FSW) of aluminum alloy. In thermal analysis, the model included adaptive heat source, contact heat transfer both between work piece and clamps and between work piece and backing board etc; in the mechanical analysis, the model involved contact interaction both between work piece and clamps and between work piece and backing board, mechanical load of tool etc. The simulation results indicate that the longitudinal residual stress is unsymmetrical about weld centerline; the magnitude of longitudinal residual stress for FSW process is lower than that for fusion welding process. Based on simulated results of FSW process, a three-dimensional elastic-plastic analysis was then carried out to simulate rolling process, the simulation result show that rolling process not only causes a marked reduction in the longitudinal tensile residual but also reverse the sign of the longitudinal residual stress.
Constraint-Based Synchronous Fitting of Surfaces
Authors: Ye Tie Li , An Lu Ling , Gao Li , Zeng Qing Liang
Published: October 2009

Constraint-based model reconstruction is one of the key research problems in recent reverse engineering. Surfaces of structural parts are mostly quadratic and have mutual constraints. Aiming at this feature, the paper proposes a method for conducting constraint-based synchronous fitting on multiple surfaces. Synchronous fitting is carried out through constraint optimization method, the constraints among surfaces can be maintained and the original design intents incarnated.
Rapid Manufacturing of Metal-Ceramic Composites
Authors: Liu Fwu Hsing , Ni Tsui Yen , Liao Yunn Shiuan , Shen Yung Kang , Ting Ku En
Published: October 2009

This paper presents a layer manufacturing technology called selective laser gelling (SLG) to fabricate metal-ceramic composites green parts which are difficult to construct using traditional methods for fabricating composites. When a layer of metal-ceramic slurry is scanned via Nd: YAG laser radiation, the metal particles are gelled together by the silica sol to form a composites part. In comparison with other composites processes, the features of this process include lower laser forming energy, faster fabrication speed, less dimensional variations. The material composition is mixing by the stainless steel powder and a silica sol in a proportion of 75 to 25 wt. %. A series of experiments was conducted to obtain the smallest pave-able layer thickness of 50 μm on an experimental rapid prototyping (RP) machine. The feasibility of this process was demonstrated by manufacturing a gear shaped prototype with a surface finish of 18μm under a laser energy density of 3.5 J/mm2.
Comprehensive Hygro-Thermo-Vapor Pressure Model for CMOS Image Sensor
Authors: Hsu Hsiang Chen , Chu Li Ming , Chen Lih Shan , Fu Shen Li
Published: October 2009

A combined effect of moisture diffusion, heat transfer, and hygro-thermo-vapor pressure modeling for pre-mold QFN CMOS Image Sensor (CIS) package has been developed in this study. Hygroscopic swelling properties such as saturation, coefficient of moisture expansion (CME) and activation energy can be extracted through TMA (Thermal Mechanical Analysis) and TGA (Thermal Gravitational Analysis) instruments. Fick’s second law of transient diffusion is solved by using finite element analysis (FEA) to evaluate the overall moisture distributions. With obtained experimental data, a three-dimensional FEA CIS model using the “thermal-wetness” technique is developed to predict the moisture absorption, moisture desorption, temperature distributions, hygro-thermo-vapor pressure mechanical coupled effect and the residual stress distributions at JEDEC pre-conditioning standard JESD22-A120.
Effects of Surface Roughness on Tribological Characteristics in Micro Double Cup Extrusion of Aluminum
Authors: Chang Chao Cheng , Huang Chien Kuo
Published: October 2009

This study used the micro double cup extrusion of aluminum to investigate the effects of the surface roughness of workpiece and die on the tribological conditions involving mixed lubrication and plastic deformation. The aluminum billets with the diameter of 3 mm and the height of 4.5 mm in different surface roughnesses were prepared by grinding processes and used in the experiments under conditions of dry and molybdenum disulfide lubrication. To estimate the friction factors, the heights of the extruded cups were measured and compared with those predicted by finite element simulations using the law of constant shear stress. The results show that smaller workpiece surface roughness resulted in low and nearly constant friction in the early stage of the micro extrusion under the dry and lubricated conditions, which were reflected in the estimated friction factors. In the later stage of the extrusion processes, the workpiece surface finish became close to the one of the die for all tested conditions. The friction was clearly reduced in the dry condition but it became greater in the cases with the lubricated condition. The surface condition in the later stage of the micro extrusion process was believed to allow the lubricant to escape from the contact interface.
Manufacturing Technology and Material Characterization of Ti44Ni47Nb9 Alloy Fastener Ring by Tungsten Inert Gas Welding
Authors: Song Yi Guo , Chen Feng , Li Li , Zheng Yu Feng
Published: October 2009

The advanced manufacturing technology of TiNiNb wide hysteresis shape memory alloy fastener ring was performed by using the tungsten inert gas (TIG) welding technique. It was found that transformation temperatures of the joint were about 20 °C higher than these of the base alloy, which should be ascribed to the heat treatment in the joint caused by welding. The strain recovery behavior of the ring after the diameter expanding process was studied. For the ring with the diameter expansion of 16% and without the heat treatment after welding, the strain recovery began at 55°C and ended at 75°C. It is concluded that, by appropriate expanding diameter process, TIG welding technique is suitable for the production of TiNiNb wide hysteresis shape memory fastener ring.
Thermal Cycle Characteristics of AM 50 Magnesium Alloy Welded by FSW
Authors: Lu Sheng , Chen Jing , Jia Xiao Dan , Wang Ze Xin , Gong Jing Jing
Published: October 2009

By means of Friction stir welding (FSW), as-cast AM50 magnesium alloys were welded with travel speed of 50 mm/min and rotating rate of 1200 r/min. The thermal cycle was investigated by thermocouples and a paperless recorder. The results show that phenomenon of dual peaks and hysteresis exist in temperature curves of featured points at the starting part while only hysteresis in the middle part. The finishing part has the highest peak temperature while the starting part corresponds to the lowest one. Featured points for different depths in the same place share the same shape of temperature curves but with different peak temperature. The retaining time over recrystallization temperature at middle part is double that at finishing part.
A Knowledge-Based System for Product Design with Modules
Authors: Tsai Ming Piao
Published: October 2009

In the paper, the knowledge-based architecture for product design with modules is suggested, which discovers and shares the product knowledge and design rules to increase the effectiveness/efficiency of the product design with modules. This solution approach involves modeling modular products knowledge, modular components selection, and feasible sequence of assembly. In modular products knowledge model, an object-oriented approach is introduced to capture the knowledge of modular product. In modules selection and feasible sequence of assembly, a reasoning mechanism is fabricated based on Protegee and JESS expert tool. Last, a particular case of bicycle design is studied through the use of this knowledge-based prototype system to prove the effectiveness/efficiency of product design with modules. However, a knowledge-based system of product design with modules is also implemented to provide adaptive design rules and share design knowledge in distributed environment. It will greatly enhance the competitive capability of companies trying to reduce the engineering design change.
Friction and Wear Behavior of Titanium Complex Grease with Admixture Base Oil
Authors: Yin Ji Hui , Qu Jian Jun , Song Bao Yu , Su Dai Zhong
Published: October 2009

Most of the lubricants are made of mineral oil which has bad biodegradability, and, hence, seriously contaminate the environment. To minimise the lubricants’ impact on the environment, this research developed a new type of lubricant, titanium complex grease. Its base oil is the admixture of vegetable oil and mineral oil. Its production method and experimental results are presented in this paper. The friction, wear and physical-chemical properties of the grease were investigated. The morphology of wear scar of steel ball was observed using the sweep electron microscope. The results obtained contribute to the further development of environmentally friendly lubricants.
Passivity-Based Rotor Time Constant Estimation and Adaptive Position Control of Induction Machines
Authors: Chen Jenn Yih , Lee Bean Yin
Published: October 2009

This paper presents an adaptive controller based on the passivity theorem to control the position of an induction machine. Firstly, an open-loop flux observer estimates the rotor flux linkages, and then adaptive laws are designed to estimate the inverse rotor time constant, mechanical parameters, and load torque. The passive properties of the feedback connection of the rotor flux observer to the inverse rotor time constant estimator, and the adaptive controller are analyzed by the passivity theorem. The overall control system is formally verified to be globally stable by the theorem instead of Lyapunov-like functions. Experimental results show that the parameter estimation errors converge to zero when the position command is a sinusoidal signal with two distinct frequencies. Furthermore, good position tracking responses can be obtained, and the approach is robust with regard to the variation of the parameters and load torque disturbances.