bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Fatigue Damage Characters of the Cement Soil under Dynamic Load
Authors: Wang You Kai , Zhang Min Xia , Xu Ping , Jian Wen Bin
Published: November 2010

Through INSTRON1304 electric hydraulic servo fatigue testing machine, the fatigue experiment of soil-cement is done, and the ultrasonic velocity of soil-cement under dynamic loading is obtained. The results show the ultrasonic wave velocity through the cemented soil samples free surface obviously attenuates as the cycles of the dynamic loading increases. Based on the damage variable defined by the ultrasonic wave velocity, the evolution equation of soil-cement accumulated fatigue damage is established. The equation indicates that the fatigue damage of soil-cement l under dynamic loading can obviously be divided into three stages: the initial rapid decay of the initial state, stability decay and rapid damage close to the destruction. The experiment results provide an important reference for non-destructive testing of soil-cement under dynamic loading.
Kinetics of Order-Disorder Transition of Antiphase Domain Boundary Formed between DO22 Phases: Microscopic Phase-Field Study
Authors: Zhang Ming Yi , Yang Kun , Chen Zheng
Published: November 2010

Based on the microscopic phase-field model, the precipitation process of Ni75Al4.3V20.7 alloy at 1190K is simulated, and the kinetics of order-disorder transition at antiphase domain boundary (APDB) formed between DO22 (Ni3V) phases is investigated. After the ordered APDB formed by the impingement of growing DO22 (Ni3V) domains, the order-disorder transition at APDB is happened. Accompanied with the enrichment of Ni and Al at the APDB, the ordered APDB transforms into a thin disordered phase layer. The second phase L12 nucleates at the order-disorder interface between DO22 and disordered phases, and grows along the disorder phase layer quickly. The order-disorder transition at the ordered APDB accelerates the nucleation and growth of L12 phase at the APDB. The disordered phase caused by the order-disordered transition can be considered the transient phase during the precipitation process of L12 phase.
Wear Behaviour and Wear Debris Characterization of UHMWPE on Alumina Ceramic, Stainless Steel, CoCrMo and Ti6Al4V Hip Prostheses in a Hip Joint Simulator
Authors: Wang Shi Bo , Ge Shi Rong , Liu Hong Tao , Huang Xiao Long
Published: November 2010

Ultra-high molecular-weight polyethylene (UHMWPE) has been used in total hip replacement for the last three decades. Despite the advancements in prosthesis design, the wear of UHMWPE remains a serious clinical problem; the release of wear debris may induce osteolysis and implant loosening. Understanding of wear behavior and wear debris morphology of the polyethylene is essential to improve the reliability of hip joint implants. The investigation in this paper carried out wear simulation tests of UHMWPE on Al2O3, 316L stainless steel, CoCrMo alloy and Ti6Al4V alloy, respectively. The lubrication of plasma solution and bovine serum solution was presented in wear tests. The effect of motion and loading on the wear behavior and wear debris morphology, and the influence of femoral head material and assembly style were studied in order to obtain a better understanding of the morphology of ultra-high molecular weight polyethylene wear particles. It is shown that the wear of UHMWPE acetabular cups against metal femoral heads was significantly higher than that against ceramic heads. The presence of protein in lubricant increases the wear of UHMWPE acetabular cups on Al2O3 heads. The wear rates of UHMWPE in multi-directional motion are approximately 2.5 times of those in uni-directional motion. The size distribution range of the UHMWPE debris particles for all head materials varies from submicron particles up to several hundreds micron. The size distribution range of wear debris particles is not directly related to wear resistance of UHMWPE, but significantly influenced by wear mechanisms. The UHMWPE debris particles produced in hip wear simulation tests are classified as round debris, flake-like debris and stick debris, which are closely related to the primary mechanisms of abrasive wear, adhesive wear and fatigue wear.
A Brief Review of Visualization Techniques for Nerve Tissue Engineering Applications
Authors: Zhu Ning , Chen Xiong Biao , Chapman Dean
Published: November 2010

In nerve tissue engineering, scaffolds act as carriers for cells and biochemical factors and as constructs providing appropriate mechanical conditions. During nerve regeneration, new tissue grows into the scaffolds, which degrade gradually. To optimize this process, researchers must study and analyze various morphological and structural features of the scaffolds, the ingrowth of nerve tissue, and scaffold degradation. Therefore, visualization of the scaffolds as well as the generated nerve tissue is essential, yet challenging Visualization techniques currently used in nerve tissue engineering include electron microscopy, confocal laser scanning microscopy (CLSM), and micro-computed tomography (micro-CT or μCT). Synchrotron-based micro-CT (SRμCT) is an emerging and promising technique, drawing considerable recent attention. Here, we review typical applications of these visualization techniques in nerve tissue engineering. The promise, feasibility, and challenges of SRμCT as a visualization technique applied to nerve tissue engineering are also discussed.
Design of a Press for Densification of Waste Biomass in Developing Countries
Authors: Mazzù Angelo
Published: November 2010

In many developing countries wood is the main energy source, and its exploitation is accelerating deforestation and desertification. In order to reduce wood consumption, an innovative biomass press was designed, aimed at providing alternative fuel by compacting dry waste biomass. The machine is based only on mechanisms, and can work by animal power, in order that it can be used in places where there is not electric power. The main machine element is a cam, designed according to the criterion of making manual running possible, on the basis of an experimental biomass behaviour law. The whole machine design was conceived with the aim of allowing construction in the developing countries. A prototype for research was realised, equipped with an electric motor and electronic control system. Biomass compaction tests were carried out, from which the machine characteristics were derived, and the validity of the biomass behaviour model was confirmed. Pilot plants, both manual and electric, were realised in Burundi and Chad, obtaining encouraging results as far as the appropriateness of this technology to developing countries is concerned.
Development of Composite Material from Agricultural Wastes
Authors: Osarenmwinda J.O. , Nwachukwu J.C.
Published: November 2010

Study was carried out to develop a composite material from agro waste consisting of sawdust and palm kernel shell and to determine its physical and mechanical properties. The sawdust / palm kernel shell compositions by weight were in the ratios of 100: 0, 90: 10, 80: 20, 70: 30, 60: 40 and 50:50. Urea formaldehyde was used as the test binder at concentrations of 20% of oven dry weight of agro waste. Particle size of agro waste used was 300µm .Yield strength, ultimate tensile strength, modulus of elasticity, modulus of rupture, internal bond strength, density, thickness swelling and water absorption of the formed composite materials were determined and observed to be enhanced at high palm kernel shell composition. The composite composition by weight that gave the best results out of the six compositions tested was the one with sawdust: palm kernel composition of 50%:50% with its properties as: yield strength ( 4.47 N/mm2) ,ultimate tensile strength (7.75 N/mm2), modulus of elasticity (2603 N/mm2), modulus of rupture (16.67 N/mm2 ), internal bond strength ( 0.54 N/mm2 ), thickness swelling (10.30%) ,water absorption (18.90%) and density (996.18kg/m3).
Thermochemical Evaluation of Hydroxyl and Peroxyl Radical Precursors in the Formation of Tropospheric Ozone Reactions
Authors: Umosekhaimhe G.O. , Umukoro S.E.
Published: November 2010

The thermochemical properties of varieties of species needed to assess the most prominent pathways of tropospheric ozone transformation have been established. In the troposphere, ozone which is a secondary pollution produced by photochemical induced transformation, acts as an oxidizing agent to numerous atmospheric reactions leading to the formation of particulate matter. Based on the climate related problems resulting from the precursor of particulate matter, it is adequate to establish the feasible routes of ozone formation. In this study, the electronic structure methods which approximate the Schrödinger equation to compute Gibbs free energies and enthalpies of formation of the various chemical species participating in the reactions were used. These thermodynamic properties were determined using four computational model chemistry methods integrated in the Gaussian 03 (G03) chemistry package. Five known reaction pathways for the formation of NO2 (the O3 precursor specie), as well as the dominant ozone formation route from NO2 were examined and their energies determined. Of all the computational methods, the complete basis set (CBS-4M) method produced energies for all species of the five reaction routes. Out of the five routes, only the reactions involving radical species were favoured to completion over a temperature range of -100 and +100oC. The most relevant reaction route for the formation of NO2 and subsequently O3 is that involving the peroxyl acetyl nitrate (PAN) and hydroxyl radicals. Chemical equilibrium analyses of the reaction routes also indicated that reduction in temperature encourages NO2 formation while increase in temperature favours O3 production.
Statistical Analysis of Polarized Wide-Band MIMO Channels in an Indoor Environment
Authors: Muhehe J.D. , Muia L.M. , Ogola W.O. , Pardo C.G. , Molina-Garcia-Pardo J. , Juan–Llacer L.
Published: November 2010

In this paper, a 2x2 and a 4x4 indoor MIMO measurement campaign at a (2 -5) GHz is presented. A statistical analysis to study the effects of a 2x2 and a 4x4 MIMO on the channel capacity with their respective received fixed signal to noise ratios were analyzed both in the LOS and in NLOS scenarios. Furthermore, investigations were carried out on all the possible wide band antenna polarizations in order to ascertain which mode of propagation yields a highly decorrelated spatial channel. The three received signal to noise ratios namely 10dB, 20dB and 30dB were used to model various received signal powers. It was found that copolar configurations HH and VV yielded the maximum capacity values both in the LOS and in NLOS respectively. Finally, a validity test was conducted and it was realized that the empirical distribution is similar and within the theoretical (i.i.d) distribution.
Frequent Pattern Mining in a Design Supporting System
Authors: Kotulski Leszek , Ślusarczyk Grażyna
Published: November 2010

This paper deals with reasoning about designs using frequent pattern mining methods. It also describes a prototype system supporting design and reasoning, where graph theory is applied to the computational process. Searching a large database of solutions for frequently occurring patterns allows us both to retrieve solutions of similar design tasks and to evaluate newly created innovative solutions.
Computer Modeling and Simulation of Spur Involute Gears by Generating Method
Authors: Fetvaci Cuneyt , Imrak C. Erdem
Published: November 2010

This study analyzes the forming principle of spur gears with asymmetric teeth profile by rack-type and pinion-type cutters. Mathematical models of generating and generated surfaces manufactured by generating-type cutters are given. Asymmetric gear tooth is also considered. A computer program is developed to display computer graphs of the spur gears with asymmetric involute teeth. The simulated motion path of the generating cutter is illustrated. The developed computer programs are very helpful in the design of involute gears.
Wire Strand and IWRC Modeling and Contact Analysis Using Finite Elements
Authors: Erdönmez Cengiz , Imrak C. Erdem
Published: November 2010

Wire ropes are constructed by using both single and nested helical wires. Three-dimensional solid modeling of nested helical wires can be done by using parametric equations and needs special treatment. Wire strands are basic components of wire ropes and independent wire rope cores (IWRC) are special type of ropes, which are used as a core for complex wire ropes such as Seale IWRC or Warrington IWRC. Large tensile force strength of the wire ropes is very important in application areas where as the small bending and torsional stiffness. In this paper, modeling and analysis of a wire strand and IWRC are investigated in a realistic manner. In addition, contact interactions between wires in a strand are analyzed and finite element results are presented.
Product Based Material Testing for Hyperelastic Suspension Jounce Bumper Design with FEA
Authors: Çalışkan Kemal , Konukseven (1) Erhan Ilhan , Ünlüsoy Y. Samim
Published: November 2010

The basic problem in the finite element analysis of parts made of hyperelastic materials is the identification of mathematical material model coefficients. Furthermore, selection of a suitable mathematical hyperelastic material model may not be straightforward. In this study, a systematic design methodology is presented for hyperelastic suspension jounce bumpers. The presented methodology involves a critical examination of material testing procedures, material model selection, and coefficient identification. The identified material model coefficients are verified through comparison of the finite element analysis results with actual tests.
Design and Optimization of NC Machining Technology for a Kind of Boring Axle
Authors: Ma Xue Feng , Tian Yue Hui
Published: November 2010

Addressing the problems of large size, high precision and the difficulty of machining boring axle, the better machining and detecting methods was presented using the characteristics of centralized processes of NC machining equipment. In order to machine the boring axle in a reasonable, efficient, and high-quality way, the NC machining technology plan was preliminary developed and optimized.
Automotive Crashworthiness Optimization Using Energy Flow Based Variable Screening
Authors: Jiang Li Feng , Xiang Dong , Zeng Duo , Wang Hong Lei , Duan Guang Hong
Published: November 2010

A variable screening method based on energy flow analysis is provided for significant variables selection in crashworthiness optimizing. Two quantities, significance and specific energy absorption, are used to screen design variables. These quantities are calculated from energy relation matrix and energy absorption of parts. Energy relation matrix is built from finite element crash simulation result to describe energy flow path in parts during impact. The method is applied in the case of a car engine room under frontal impact. Optimization for lightweight using response surface method is performed on the reduced variable set at a relatively low computational cost.
Robust Design of Ring Rolling Process for Titanium Alloy Using the Taguchi Method and the Finite Element Method
Authors: Chen Dyi Cheng , You Ci Syong , Guo Ming Wei , Lai Bao Yan
Published: November 2010

To obtain the required plastic strain and desired tolerance values in the ring rolling process, it is necessary to control many factors. Major factors include the mandrel width, the rotation speed of driver roll, the feed ratio of mandrel, and the workpiece temperature. This study uses rigid-plastic finite element (FE) software to investigate the plastic deformation behavior of a titanium alloy (Ti-6Al-4V) workpiece under ring rolling. This study analyzes the damage factor distribution, the effective strain, the effective stress and the die radius load in the workpiece under various ring rolling conditions. We used the Taguchi method to determine the optimum design parameters. Results confirm the suitability of the proposed design process, which allows a ring rolling die to achieve a perfect design during finite element method.
Influences of Nano-Silica on Friction and Noise Properties of Urea Grease
Authors: Yin Ji Hui , Qu Jian Jun , Song Bao Yu , Su Dai Zhong
Published: November 2010

Tribological properties of the urea grease containing nano-silica were investigated with a four-ball tester, and its noise characteristics were evaluated with a BVT-1 bearing vibration tester. The results showed that the nano-silica has good effects on friction and wear resistances, the urea grease with 3% nano-silica has the least value of friction coefficient, and the urea grease with 2% nano-silica showed the best wear resistance. A proper amount of nano-silica can decrease the noise of the urea grease, and when lubricated by the grease with 1% nano-silica, the bearing achieved its lowest noise level as well as the best velocity values of both intermediate and high frequencies.
Seismic Damage Law of Steel Reinforced High Strength and High Performance Concrete Frame Columns
Authors: Zheng Shan Suo , Hou Pi Ji , Wang Bin , Li Lei , Li Zhi Qiang
Published: November 2010

In this paper, the damage performance of 13 SRHSHPC frame columns are tested and analyzed under low cycle loading. The effect of concrete strength, axial compression ratio and shear span ratio on the damage of SRHSHPC frame columns is discussed, and then the experimental result is quantified with damage index. Based on existing seismic damage models, a new seismic damage model is put forward for SRHSHPC frame columns by a nonlinear combination of deformation and accumulative dissipation.
Productivity Improvement with Lean Production in Glove Manufacturing Industry
Authors: Chen James C. , Lee Hunter , Chiu Sean , Tseng Benny
Published: November 2010

The study illustrates the application of lean production in a glove manufacturing company in south China. Glove manufacturing has the following production steps, cutting, sewing, pruning, checking, ironing, and packing. With the strong support from the company’s top management and the cooperation with a lean consulting company, the alignment on lean production at different level of management and operators is reached. Value Stream Mapping is used to develop current state mapping showing as-is model. Future state mapping with to-be model is planned through the re-thinking and re-design from “zero”. Significant improvement in lead time reduction and productivity increase are achieved in pilot lean lines. Expansion of the best-practice at lean lines to the other production lines is in progress.
Applying TRIZ Methodology to Assist Product Improvement – Take Folding Bicycle as an Example
Authors: Hu Shu Jen , Su Ling Huey , Lee King Lien , Chen James C. , Chang Chih Heng
Published: November 2010

In this research, patent maps were first drawn by searching, organizing and classifying those patents related to bicycles’ capabilities and technologies, and the direction of improving and inventing folding bicycles was found out with the patent maps. Next, the methodology of TRIZ was applied to analyze the problems; the basic technological contradictions were confronted, and the resolve program was developed. In the end, an improved folding bicycle was designed, using PRO/E, the drawing software, to complete the product’s blueprint.
Study of an Identification Method of the Mesoscale Tool Position
Authors: Park Hyung Wook
Published: November 2010

The increasing demand for micro/mesoscale components for electronic, biological, and medical applications has brought about continuing developments in mechanical micromachining. Various economic and technical advantages have led to decreases in the overall sizes of the machine tools used in this process, which are known as mesoscale machine tools (MMTs). Rather than shrinking and adapting conventional instruments, this technical trend has motivated the development of new techniques involving clamping devices, inspection, spindles, etc. This study reviewed possible detection techniques for mesoscale tool positioning, including conductivity-based, laser-beam, thin-plate, and acoustic-emission (AE) methods. Preliminary experimental studies of the laser-beam and AE methods were carried out using simple test beds.
Impact of Integral Structures in the Design for Manufacture and Assembly of Airframes
Authors: Tavares Sérgio M.O. , de Castro Paulo Manuel Salgado Tavares
Published: November 2010

From a lean philosophy viewpoint, the huge amount of fasteners used in airframes appears to be the inverse of what the design for manufacturing should seek. New design concepts with integral joints may be produced using welding processes, simplifying and optimizing the design for manufacturing and assembly process; however, crack arrest capability may be compromised. An introductory quality function deployment (QFD) analysis applying the Cross method evaluates the main design goals in the application of new joining processes in lightweight reinforced structures. The analysis shows that new welding process can improve airframe structures provided the structural integrity is ensured.
Experimental Study on Reciprocating Electroplated Diamond Wire Saws Cutting SiC Wafer
Authors: Wang Xiao Ye , Li Yan , Li Shu Juan
Published: November 2010

The experiment that WXD170-type reciprocating rotating diamond wire saw cuts SiC wafer was studied using orthogonal test method in this paper. The influence of cutting speed of diamond wire saw, work-piece feed speed and rotating speed of work-piece on cutting process were analyzed. The optimized cutting parameters which can improve surface quality of slices and reduce tangential force were obtained. The results show that: the surface quality of slices which was cloud-shaped can be improved significantly due to the increase of the work-piece rotation. The work-piece feed speed and the rotation speed have greater impact on the tangential force than the saw wire speed; the work-piece feed speed and the work-piece rotation speed have greater impact on surface roughness than the saw wire speed. An important way to be obtained the smaller tangential force and better surface quality of slices is considering of a reasonable match among cutting speed of diamond wire saw, work-piece feed speed and rotating speed of work-piece comprehensively.
Study of Car Multi-Link Rear Axle Considering Their Kinematic Incompatibilities
Authors: Dobre George , Mateescu Viorel , Tica Mihai , Mirica Radu Florin
Published: November 2010

Multi-link rear axles offer some important advantages relative to vehicle handling. But the structure of the multilink split type generally determines kinematic incompatibilities in its operation. The paper studies some aspects surrounding constructive solutions that could minimize these kinematic incompatibilities. Some rear axle mechanisms from different cars were measured and analyzed as component shape by authors; this process allows the geometrical modeling and animation of systems using specialized software (Autodesk Inventor Professional 8). The effects of these modeled structures (the variations of track width and wheel camber angle) have been studied using the above-mentioned software. The variation of track width caused by the studied mechanisms along the compression and relaxation of the suspension spring defines the trajectory of the tyre contact patch. The results are contextualized in diagrams showing that the modifications of the analyzed parameters are very important, with a negative influence on car stability and the comfort of passengers. The interpretation of these diagrams allows the choice of favorable constructive solutions to increase car performance.
Mathematical Model of Manufacturing a Novel Type of Hourglass Worm with Circular Tooth Profiles
Authors: Zhao Ya Ping , Zhang Zhao
Published: November 2010

A novel type of hourglass worm is considered, whose surface is formed by the locus of a circular blade. The worm has circular tooth profiles, which are relatively plain. According to the generation mechanism, the mathematical model for precisely manufacturing this kind of worm is developed, especially including the equation of the worm screw surface. A method to calculate the worm tooth profile is proposed. A numerical example is given to demonstrate the validity of the mathematical model and the proposed method.
A Research of V-Belt Transmission Mechanics with Two Same Pulleys
Authors: Wei Qing Bao , Chen Xin , Zheng Da Yu
Published: November 2010

V-belt is made of a special anisotropic material, its material and pulley groove structure make the V-belt drive mechanics complicated. The elasticity limit, seating and unseating effects, radial compliance makes us consider the macro features of the drive and not to consider the material heterogeneity. We focus on the steady mechanics of V-belt drive in the state of sliding friction between groove and belt. The pulley groove leads to two-dimensional radial and tangential friction forces whose direction depends on the relative speed between belt and the pulley along the contact arc. The belt model is analyzed with comparing method which is performed through acquiring the equivalent coefficient of friction, and replacing the coefficient of friction in the flat belt mechanical equilibrium equations for v-belt analysis. Through the sample calculation it is proved that this method is simple and valid for V-belt mechanical analysis.
Advanced Planning and Scheduling for Color Filter Fabrication Plants
Authors: Chen James C. , Su Ling Huey , Chao Gary C. , Chen Chih Cheng , Peng Tzu Wei , Sun Cheng Ju , Chien Jui Wei , Chien Hui Chien
Published: November 2010

This research proposed Advanced Planning and Scheduling (APS) system to effectively and efficiently balance machine loading for color filter fabrication plants in Thin Film Transistor - Liquid Crystal Display industry. APS uses six modules to estimate future equipment loading and calculate order due dates according to capacity limits by taking into account the due date and size of orders, as well as the capacity, loading, and yield of fabrication plants. These six modules include: Order Priority Module, WIP-Pulling Module, Order Release Module, Material Management Module, Workload Accumulation Module, and Workload Balance Module. A lot’s start processing time at each production step is selected leading to the best workload balance. Simulation and experimental design are used to evaluate the performance of APS. Production manager can use APS to improve color filter fabrication plants’ productivity and competitiveness.
Capacity Planning for Cluster Tools of Wafer Fabrication Plant
Authors: Chen James C. , Chen Chia Wen , Chen Kou Huang , Lin Chien Hsin
Published: November 2010

Wafer fabrication is a capital intensive industry. A 12-inch wafer fabrication plant needs a typical investment of US$ 3 billion, and the equipment cost constitutes about two-thirds to three-quarters of the total production costs. Therefore, capacity planning is crucial to the investment and performance of wafer fabrication plants. Several formulae are presented to calculate the required number of machines with sequential, parallel, and batch processing characteristics, respectively. An AutoSched AP simulation model using data from real foundry fabrication plants is used in a case study to evaluate the performance of the proposed formulae. Simulation results indicate that the proposed formulae can quickly and accurately calculate the required number of cluster tools leading to the required monthly output rate.
Design of Protective Device against Welding Arc and Smoke
Authors: Yang Li Fang , Fan Huai Liang , Zhao Tian Jiao
Published: November 2010

Welding smoke and arc are extremely occupational hazards to the operators. A mobile welding protective device is designed for scattered welding operation. In order to protect operators from welding arc injury and collect welding smoke, a novel welding covering is designed for use of purification device. On the other hand, owing to the large amount of welding smoke, the ordinary filtering material is not suitable for welding smoke purification; the metal-cotton is utilized to pre-filter the welding smoke. In the end, the protective device against welding arc and smoke is designed and tested. The device is effective for mobile welding operation.
Optimal Inspection Allocation for Workstations of Attribute Data with Multi-Characteristics in Multi-Station Systems
Authors: Rau Hsin , Cho Kuo Hua , Wang Yi Hsiang
Published: November 2010

. The study models multi-characteristics inspection for inspection allocation problems with workstations of attribute data in serial production systems. Either 100% or 0% inspection is performed and Type I and Type II errors are considered. In addition, this study considers three possibilities of treatment of detected nonconforming units, namely, repair, rework and scrap. With the above considerations, a profit model is developed for optimally allocating inspections. Moreover, a genetic algorithm is used to solve the problem and it is proved to have much less computation time, compared with an optimization method based on complete enumeration, especially when number of workstations and characteristics becomes more.
The Reengineering of Business and Production Processes for Aerospace Manufacturing Suppliers
Authors: Chang Hsien Ming , Huang Chi Kong , Torng Chau Chen
Published: November 2010

Business processes and production processes are complex inside the aerospace manufacturing industry. Quality, cost, delivery and flexibility are the fundamental requirements of aerospace manufacturing suppliers. The aerospace manufacturing suppliers have to coordinate those fundamental requirements and integrate the business and production processes in the competitive market.
This study applies the concepts of reengineering, and allies the functional groups and system resources inside the aerospace manufacturing suppliers. The effective business and production processes are then developed so that the business and production activities can benefit the enterprise. Thereby, the aerospace manufacturing suppliers can strengthen their competitiveness in a dynamic aerospace market.
Crack FEA of the First Stage Blade of Gas Turbines
Authors: Zhao Ping , Li Wei , He Qing Hua
Published: November 2010

To investigate the physical cause of premature blade cracking during the acceleration mission test (AMT) in a test cell environment, an in-depth finite element analysis (FEA) of the blade was conducted using a life prediction system. The results obtained showed that the blades had suffered excessive airfoil creep damage, leading to excessive blade lengthening and airfoil untwisting particularly in the trailing edge region. It is predicted that the uneven rubbing action might have contributed to the fatigue crack nucleation and growth process just below the platform in the shank region of the blade under AMT fatigue cycling conditions, and the excessive creep deformation made a significant effect on the overall crack nucleation process.
Simulation Study on the High-Speed Single-Point Accumulation Forming Process of Involute Spline
Authors: Li Yan , Yang Ming Shun , Yuan Qi Long , Cui Feng Kui
Published: November 2010

The high-speed cold roll-beating technology is adopted to realize the single-point accumulation forming of involute spline. Firstly, the principle of the forming technology is analyzed. Then the FEA model of the cold roll-beating of involute spline is built, the forming process simulation is finished with the ANSYS/LS-DYNA software to obtain the stress, strain and the metal flowing law of the forming process. Finally the experiments are carried out to verify the feasibility of the simulative results. This study can provide guidance for further study of the forming mechanism and practical application of the single-point accumulation forming technology.
An Accurate and Quick Measuring Method for Mix Proportion of Concrete Paste in Construction Site
Authors: Cai Li Peng , Jang Ii Young , Yun Ying Wei , Kim Seong Kyum
Published: November 2010

An effective in-situ monitoring method for MPCP is urgently needed in civil engineering field. In this research, a quick and accurate in-situ measuring method for mix proportion of concrete is put forward. This method can succeed in measuring real mix proportion of any concrete paste precisely within 20 minutes according to four parameters of concrete before initial setting time of concrete. By comparing the designed mix proportion of concrete with the real measured one in construction site by this method, the quality of concrete can be demonstrated. This method can evaluate the reliability of mix proportion for real concrete in construction site quickly and precisely, and ensure the quality of concrete structures to avoid the occurrence of engineering accidents.
A Kinematic Model Used to Customize Design of Manual Wheelchair
Authors: Shyu Jenq Huey , Chang Ta , Shyu Yu Chen
Published: November 2010

That wheelchair user’s shoulder joint injuries are directly related to poor wheelchair design and the location of the wheelchair driving mechanism has been proven clinically. This work presents a novel approach to rapidly customize the design of manual wheelchairs, such that each user can easily obtain a custom manual wheelchair, thereby reducing the potential for shoulder joint injury. In this study, a human-chair system composed of a human body and a wheelchair was simulated as a plain single-loop five-bar linkage. Mobility analysis was conducted to identify the corresponding joint workspace. By analyzing linkage movement and the upper-limb muscle strength of a user, the optimal location of the wheel hub and optimal radius of the handwheel were identified as the bases of a customized design for manual wheelchairs.
Precise Mechanics Behavior Analysis Method of Mega Members and Nodes in Steel Mega-Frame Structures
Authors: Zhang Ling Xin , Guo Feng Yu , Xu Guo Lin , Du Wen Xue
Published: November 2010

In this paper, a 4-node reduced integration shell element, which has high accuracy and computing efficiency, is adopted to simulate the mega members and nodes. A precise nonlinear response analysis method of steel mega members and nodes in steel mega-frame structures based on 3-D shell element model is given. The parallel computation technique in MSC.Marc is explored to the method to reduce the computing time. The reliability of the method and the efficiency of the parallel computation technique in reducing the computing time are checked by examples.
Investigation on Finite Strain Constitutive Model with Logarithmic Strain Based on Torsion Experiments
Authors: Yang Li Hong , Qu Jia , Zou Guang Ping
Published: November 2010

In this paper, a finite strain constitutive model was proposed by the additive decomposition of the logarithmic strain rate and the generalization of small deformation constitutive model and a complete analysis was made for an isotropic hardening J2 flowing finite strain constitutive model based on torsion experiments. Logarithmic strain and Jaumann stress rate were discussed in solid circular shaft torsion deformation. Utilizing the results obtained from solid circular shaft torsion experiments, the plastic rigidity function in constitutive model was determined. The simple shear problem was studied by using the constitutive model given in this paper. The results shows that the plastic rigidity function corresponding to logarithmic strain was different from one to Green strain and finite strain constitutive model should be analyzed by logarithmic strain and torsion experiments.
Work Assignment Optimization Using Genetic Algorithms
Authors: Wang Yu Ren , Chen Yi Jao , Kung Hsiang Lin
Published: November 2010

Random third party quality audits are mandatory by the regulations for public construction projects in Taiwan. This project and auditor selection process is a difficult work assignment problem because there are normally hundreds of projects and dozens of auditors to choose from. The purpose of this research is to establish a genetic algorithm based model to assist with the project selection and auditor assignment process. The model is set up to find the optimal match between the project characteristics and auditor expertise from approximately 5.09E+29 possible combinations. Information provided by the Kaohsiung County Government is used to test the model. The results show that the model is not only valid but also able to produce a “much better match” between projects and auditors when comparing to manual assignment.
A Data-Driven Neural Network Approach for Remaining Useful Life Prediction
Authors: Yan Ji Hong , Guo Chao Zhong , Wang Xing , Zhao De Bin
Published: November 2010

This paper proposed a neural network (NN) based remaining useful life (RUL) prediction approach. A new performance degradation index is designed using multi-feature fusion techniques to represent deterioration severities of facilities. Based on this indicator, back propagation neural networks are trained for RUL prediction, and average of the networks’ outputs is considered as the final RUL in order to overcome prediction errors caused by random initiations of NNs. Finally, an experiment is set up based on a Bently-RK4 rotor unbalance test bed to validate the neural network based life prediction models, experimental results illustrate the effectiveness of the methodology.
Sliding Mode Control with Fuzzy Tuning to Pneumatic Driving 6-DOF Parallel Robot
Authors: Wu Bo , Xu Li , Yu Xiao Dong , Wang Zhi Wei , Xu He
Published: November 2010

This paper presents a new mathematical model for the pneumatic driving 6-DOF parallel robot controlled by pulse-width-modulation. The models not only overcome discontinuity of switching solenoid valve, but also change discontinuous and non-affine form into a canonical affine form. Then a sliding mode controller with fuzzy tuning is designed based on sliding mode theory and fuzzy theory and implemented on the pneumatic driving 6-DOF parallel robot position servo controlling system. The effectiveness of the controlling approach proposed here is validated by simulation data, which shows its capability of restraining the serious load coupling disturbance among channels and improving the trajectory tracking precision.
Dynamic Sub-Population Genetic Algorithm Combined with Dynamic Penalty Function to Solve Constrained Optimization Problems
Authors: Cheng Dong Mei , Huang Jian , Li Hong Jiang , Sun Jing
Published: November 2010

This paper presents a new method of dynamic sub-population genetic algorithm combined with modified dynamic penalty function to solve constrained optimization problems. The new method ensures the final optimal solution yields all constraints through re-organizing all individuals of each generation into two sub-populations according to the feasibility of individuals. And the modified dynamic penalty function gradually increases the punishment to bad individuals with the development of the evolution. With the help of the penalty function and other improvements, the new algorithm prevents local convergence and iteration wandering fluctuations. Typical instances are used to evaluate the optimizing performance of this new method; and the result shows that it can deal with constrained optimization problems well.
Kinematics Simulation of the Disc-Rod Blade Variable Vector Propeller
Authors: Zhao Wen De , Kong Fan Kai , Xu Kai Jie
Published: November 2010

With the structure more compact and more lightweight, the variable vector propeller can produce propulsive force from all directions, which has important application value as a special purpose to meet underwater propulsion device. As the structure is complex in common and also with some special requirements in design and manufacture, the disc-rod blade adjustment mechanism is a concept meets the requirements. Taking the disc-rod blade adjustment mechanism as the basic design scheme, its structural analysis and basic kinematic analysis were carried out, and then the kinematics simulation was conducted on ADAMS platform. The simulation analysis results can provide necessary support for the control of the follow-up propeller devices.
Research on the Optimization of Engineering Drawings’ Adjusting Technology Based on Parametric Variant Design
Authors: Wang Zong Yan , Huang Qi Liang , Wu Shu Fang , Qin Hui Bin
Published: November 2010

In allusion to the existing shortage of engineering drawings’ adjusting technology, such as time-consuming, imperfect method, complex process, etc., an optimization for them was carried out. The benefits and shortcomings of commonly used view scale adjusting method were discussed and its adjusting process was optimized. Through researching the stretch law of model edges, putting forward the notion of dimension angle and protracting the assembly layout sketch based on it, the view position adjustment was simplified. By studying the distribution law of dimensions, a convenient way to adjust the position of dimensions is proposed. In addition, by proposing the notion of annotation binding element, discussing the effect it had on the position of annotations, and using the marking method on the basis of it, the annotations adjustment was optimized.
High Reliability Pb-Free Printed Circuit Board Assembly
Authors: Weller S.D.T. , Jones I.P. , Fox Ian M. , Hirst Terry
Published: November 2010

The solderability and reliability of SnAgCu and SnAgCuSbBiNi lead-free solders were assessed against SnPbAg solder on a range of PCB finishes. A novel solderability test has been developed to assess the solder system’s ability to realign when a deliberately inaccurate solder stencil printing process was applied. This has shown to be an excellent way to compare PCB finishes and solders, as well as define process parameters. Electroless Nickel Immersion Gold (ENIG) finish proved to give the best solderability and the optimum process parameters were also found. SnPbAg solder has shown superior thermal cycling performance compared to SnAgCu.
Dye-Sensitized Solar Cells Based on Nitrogen-Doped Titania Electrodes
Authors: Guo Wei , Miao Qing Qing , Xin Gang , Wu Li Qiong , Ma Ting Li
Published: November 2010

Dye-sensitized solar cell(DSC) is a new type of photovoltaic device. This paper mainly describes the research results of the development of a novel nitrogen-doped photoanode for DSC in our group. Highly efficient dye-sensitized solar cells (DSCs) of 7.6-10.1% were fabricated using nitrogen-doped titania electrodes. The photoelectrochemical properties of the nitrogen-doped titania powder, film, and solar cell were systemically investigated. We confirmed the substitution of oxygen sites and oxygen deficiency with nitrogen atoms in the titania structure by X-ray photoemission spectroscopy (XPS). The UV-Vis spectra of the nitrogen-doped powder and film showed visible light absorption in the wavelength range between 400 nm and 535 nm. The results of the stability test indicated that the DSCs fabricated by the nitrogen-doped titania exhibited great stability.
Investigation and Analysis on Seismic Damage of Masonry Buildings Subjected to Wenchuan Ms=8.0 Earthquake
Authors: Chen Hong Fu , Sun Bai Tao
Published: November 2010

During Wenchuan Ms 8.0 earthquake, masonry buildings have suffered severely damaged and collapsed, causing heavy casualties and huge economic losses. In this paper, based on seismic site survey data, some new phenomena and characteristics of earthquake damage in comparison with the 1976 Tangshan earthquake, such as seismic damage of large space buildings, inclined or “X” shaped crack in wall between windows or spandrel wall, stair damage, falling of precast reinforced concrete slab and horizontal crack at the bottom of structure, are discussed in detail. Then, the impact factors of seismic capacity of masonry building in Wenchuan earthquake, including construction age, seismic fortification, bay size, floor (roof) form, layer number, thickness of bearing wall are analyzed, respectively; Finally, some recommendations on seismic design and reconstruction of masonry structure by the seismic design code are proposed.
Optimum Design and Numerical Simulation of Automotive Front Side-Door Impact Beam
Authors: Li Qing Fen , Liu Yan Jie , Wang Hai Dou , Yan Sheng Yuan
Published: November 2010

In the present work, the structure optimum design and simulation analysis of automobile side-door impact beam was carried out by using Finite Element (FE) method. The model of the side-door impact beam impacting with the rigid pole was set up according to the requirement of the Federal Motor Vehicle Safety Standards intensity test of side door (FMVSS214). The numerical simulations were carried out using the software LS-DYNA. Attention was focused upon finding an optimum cross- section shape of the beam in order to improve the energy absorption character. Several types of impact beams were studied and compared. Results show that the energy absorption characters of the beam improved obviously when square cross section with the wall slope 10° and a 9 mm long curled edge was adopted.
Lap Strength of Headed Steel Reinforcements with Confinement
Authors: Kim Seung Hun , Lee Yong Taeg , Kim T.S. , Seo Soo Yeon , Baek S.K. , Cho Young Sang
Published: November 2010

In this research, the experimental works were conducted to study the lap strength of the headed reinforcements with confinement provided by stirrups or tie-down bars. Five lap splice specimens were tested. Wide beam specimens were fabricated with a lap splice at mid-span. They were loaded in flexure, placing the lap splice in tension. The variables in this study were: confinement details (stirrups, tie-down bars with stirrups) and lap length (10, 14 times the diameter of reinforcement). Specimens were instrumented to measure the load on the specimen, strain along the reinforcements with in the lap zone, and mid-span deflection. The cracking behavior was also observed and recorded. The following conclusions were drawn from the test results in this study; 1) The initial crack of the specimens lapped developed at the heads of reinforcements. The specimens failed by the crack with the struts acting between the opposing heads of lapped reinforcements. 2) Bond stress and confinement details contributed to increase strength and deformation. 3) CCD method evaluated the maximum strength as 4.95∼6.87 times the test maximum strength. The ratios of the test maximum strength and the maximum strength assumed by ACI 318-08 for headed deformed bars were 1.38∼2.01.
Evaluation on Debonding along the Interface of Reinforced Concrete at Elevated Temperature
Authors: Wang Zhen Qing , Liu Bing , Zhu Da Lei , Qiao Mu
Published: November 2010

Steel and concrete are poured together with a certain way which can be regarded as a fiber reinforced composite material. For this composite material, the issues of bond and pull-out are very important. The bond property of reinforced concrete at normal temperature is different from the property at elevated temperature. The exposure of reinforced concrete structural elements to high temperatures during an aggressive fire leads to significant losses in its structural capacity due to the reduction in the strength of the concrete, possible plastic deformation of embedded steel and most importantly loss of bond between reinforcing steel and concrete. This paper aims to investigate the influence of high temperature to the bond slip of reinforced concrete. The bond behavior between reinforced concrete and reinforcing steel bars was evaluated under elevated temperatures. Based on the energy principle, the debonding criterion of the steel bars and concrete at a high temperature is derived. It was concluded that the bond slip should be included in order to reflect the unloading of the concrete surrounding the reinforcing steel exposed to fire temperature.