bluuebunny/crossref_metadata_2025 huggingface dataset:
Biaxial Ratcheting Response of SS 316 Steel
Authors: Kumar R. Suresh , Lakshmana Rao C. , Chellapandi P.
Published: June 2010

Ratcheting is one of the challenging phenomena that needs to be investigated for the Fast breeder reactor (FBRs), to arrive at the optimum structural dimensions that are safe and yet do not have undue redundancy. Austenitic stainless steel is the principal structural material for Indian FBR. Preliminary assessment indicates that there is a need to demonstrate that the main load carrying vessel made of this material can provide sufficient safety margin against ratcheting under biaxial loading conditions. This exercise calls for carrying out many simulated experiments, particularly with biaxial tension torsion specimens to generate adequate data for developing robust constitutive models to predict ratcheting. Accordingly, many biaxial tension-torsion experiments for austenitic stainless steel pipes were conducted and the best results have been reported here. The mechanical behavior of this material has been reported for a given axial tensile stress superimposed with a given range of cyclic shear stress for many cycles of loading. Rectangular rosette is used for capturing the biaxial response. Important material responses like cyclic hardening and biaxial ratcheting have been experimentally observed. Maximum accumulation of 2700 μ axial strain has been observed for a loading condition of constant axial stress of 102 MPa super imposed with a cyclic variation of shear stress amplitude of 120 MPa over 2450 cycles. The amount of progressive accumulation of axial strain was found to be directly dependent on the number of cycles. The observed rate of axial strain accumulation found decreased with increase in number of cycles. All these results are presented in detail in this paper and important conclusions that are useful in modeling the observed behavior are discussed.
On the Mutual Interactions of Monotonic and Cyclic Loading and their Effect on the Strength of Aluminium Alloys
Authors: Kowalewski Zbigniew L. , Szymczak Tadeusz
Published: June 2010

The paper investigates the interaction of monotonic cyclic loading and their effect on the yield strength of aluminium alloy. Two different loading combinations were considered, i.e. torsion-reverse-torsion superimposed on monotonic tension and monotonic torsion combined with tension-compression cycles. All strain controlled tests were carried out at room temperature using thin-walled tubular specimens. The maximum value of the total cyclic strain amplitude was less than 1%. The influence of amplitude, frequency and shape of cyclic loading signal on the proportional limit and conventional yield point was investigated. The experimental results presented in the paper may be useful to designers of structures that utilize manufacturing processes such as drawing, extrusion, forging of selected semi-finished elements or researchers working on the development of new constitutive equations.
Towards the Derivation of Stress Intensity Factors by Parametric Modelling of Full-Field Thermoelastic Data
Authors: Hebb R.I. , Dulieu-Barton Janice M. , Worden Keith , Tatum P.
Published: June 2010

Thermoelastic Stress Analysis (TSA) is a well-established full-field technique for experimental stress analysis that has proved to be extremely effective for studying stress fields in the vicinity of cracks. Recently, work has focused on the observation that the stress-sum contours (isopachics) obtained from TSA take the form of a cardioid. Genetic Algorithms (GAs) and Differential Evolution (DE) have proved successful for accurate parameter estimation of the cardioids, thus allowing the SIFs to be calculated. Originally, some curve-fits indicated that a pure cardioid form is inappropriate for the base model, especially for mixed-mode cracks. The deviation from the cardioid form has been shown to be due to higher-order terms within the stress function. The objective of the current paper is to use a modified version of the original methodology (that fitted parameters to a single isopachic) to find the higher-order parameters from the entire data field obtained from the TSA.
Acetabular Component Deformation under Rim Loading Using Digital Image Correlation and Finite Element Methods
Authors: Everitt H. , Evans S.L. , Holt C.A. , Bigsby Rob , Khan Imran
Published: June 2010

Total hip replacement is a highly successful operation; restoring function and reducing pain in arthritis patients. In recent years, thinner resurfacing acetabular cups have been introduced in order to preserve bone stock and reduce the risk of dislocation. However concerns have been raised that deformation of these cups could adversely affect the lubrication regime of the bearing; leading to equatorial and edge contact, possibly causing the implants to jam. This study aims to assess the amount of deformation which occurs due to the tight peripheral fit experienced during press-fit by applying rim loading to three different designs of acetabular cup: a clinically successful cobalt chrome resurfacing cup, a prototype composite resurfacing cup and a clinically successful polyethylene monobloc cup.
Digital Image Correlation (DIC) was used to measure the deformation and to validate Finite Element (FE) models. DIC provided a non-contacting method to measure displacement; meaning the load could be increased continuously rather than in steps as in previous studies.
The physical testing showed that the cobalt chrome cups were significantly stiffer than the composite prototype and polyethylene cups. The FE models were in good agreement with the experimental results for all three cups and were able to predict the deformation to within 10%. FE models were also created to investigate the effect of cup outside diameter and wall thickness on stiffness under rim loading. Increasing outside diameter resulted in a linear reduction in stiffness for all three materials. Increasing the wall thickness resulted in an exponential increase in cup stiffness.
Rim loading an acetabular shell does not accurately simulate the in vivo conditions; however it does provide a simple method for comparing cups made of different materials.
Skin Thermal Effect by FE Simulation and Experiment of Laser Ultrasonics
Authors: Li Chun Hui , Li Sin An , Huang Zhi Hong , Xu Wen Bin
Published: June 2010

Laser ultrasonics opened possibilities to measure thermal and mechanical property of skin which occupies an essential position and is beneficial in industrial and medical applications. This paper focuses on the thermal effect in the thermal section of the laser ultrasonic technique. A transient thermal analysis is developed and promoted to simulate the interaction between the laser pulse and human skin, using a multilayered ﬁnite element model (FEM). Chicken leg had been used and irradiated by KrF laser, the thermal reactions were detected and recorded by a thermal camera. By comparison, the thermal result of experiments and simulation matches.
Biomechanics and Numerical Evaluation of Cervical Porcine Models Considering Compressive Loads Using 2-D Classic Computer Tomography CT, 3-D Scanner and 3 -D Computed Tomography
Authors: Beltrán-Fernández Juan Alfonso , Hernández-Gómez Luis Héctor , Urriolagoitia-Calderón G. , González-Rebatú A. , Urriolagoitia-Sosa G.
Published: June 2010

In this paper the biomechanical behavior and numerical evaluation results of three C3-C5 porcine cervical models created with different modeling techniques are shown. The objective of this evaluation is to know the differences between the biomechanical effects on a bone graft, which replaces a damaged C4 vertebral body, a titanium alloy (Ti-6A1-4V) cervical plate, used to isolate the C4 damaged vertebra, and the influence on the compressive loads on the complete and instrumented C3-C5 cervical model. The biomechanical integrity of the healthy C3 and C5 vertebral body after the fixation of the cervical plate using titanium alloy screws is considered. Besides, 2-D Computer Tomography classic technique, 3-D Scanner Z-Corp 700 and a CT scanning Philips Brilliance system was used to create the three FEM models. In addition, 3-D Software as Pro-E Wildfire 4.0, ScanIP 3.1, UGS NX-4 and Geomagics R 10.0 was used to create specific numerical model. Main displacements and von Misses stresses between the upper and lower surfaces of the vertebral bodies and the bone graft and the influence of the titanium alloy (Ti-6A1-4V) screws on the vertebral body of C3 and C5 were evaluated. The contribution of this study is to optimize the actual surgical technique once the numerical results on the FEM model have been analyzed. In other words, the numerical disparity between classic CT techniques versus 3-D modern techniques is established.
Spot Weld Strength Determination Using the Wedge Test: In Situ Observations and Coupled Simulations
Authors: Lacroix Rémi , Monatte Joël , Lens Arnaud , Kermouche Guillaume , Bergheau J.M. , Klocker Helmut
Published: June 2010

This paper describes an innovative way to characterize the strength of spot welds. A wedge test has been developed to generate interfacial failures in weldments and observe in-situ the crack propagation. An energy analysis quantifies the spot weld crack resistance. Finite Element calculations investigate the stresses and strains along the crack front. A comparison of the local loading state with experimentally observed crack fronts provides the necessary data for a failure criterion in spot weld fusion zones. The method is applied to spot welds of Advanced High Strength steels.
Performance Evaluation of Sustainable Supply Chain Based on AHP and Fuzzy Comprehensive Evaluation
Authors: Guan Yong Hua , Cheng Hai Fang , Ye Yong
Published: June 2010

Due to limited materials and energy, more attention has been paid to the adverse impacts of the global economy’s rapid development on the environment and society. The sustainable and long-term development strategy becomes extremely urgent and important for the enterprises. Manufactures and their supply chain should take measures to implement sustainable development strategy in future production. The concept of sustainability is introduced into the field of supply chain and the structure of sustainable chain is constructed in this paper. And a method of sustainable supply chain performance evaluation is proposed. It evaluates the supply chain performance in four dimensions, namely, operational, financial, social and environmental dimensions. Then a performance evaluation model of sustainable supply chain based on AHP and fuzzy comprehensive evaluation method is established. This paper gives a case to evaluate the sustainable supply chain performance with the model and implications are given finally.
Research on Quality Control Processes Management in Manufacturing Network Based on Workflow and Multi-Agent
Authors: Wang Lei , Liang Hai Peng , Guo Wei , Lv Jie
Published: June 2010

In this paper, The author researched the integrated management of quality control processes in manufacturing network using workflow and multi-agent technologies, analyzed the advantages and basic ways of integrated application of these two technologies, established Quality Control Processes Workflow Managed by Agents (QCPWMA) model and discussed the agents’ structure, configuration and execution and so on, then using this model to realize integrated and collaborated management of dispersed quality control processes workflow in manufacturing network. Through this research it can further improve enterprise's ability of quality processes control in complex manufacturing network environment.
Large Network Model of Complex Systems
Authors: Du Cai Feng
Published: June 2010

We proposed a random network model to describe complex systems. The model is solved exactly by mean-field method and differential equation. We demonstrated the triangle distribution firstly to calculate the clustering coefficient. When the size of the network tends to infinity, the model has high clustering coefficient.
Research on Knowledge Transfer and Sharing in the Implement of Manufacturing EPR
Authors: Zhang Lin Ling , Li Ya , Chen Yi Bing , Wang Xiao , Li Jun , Shi Yun Feng , Shi Yong
Published: June 2010

In order to improve ERP implement efficiency. This paper uses knowledge sharing theory to analyze three stages of EPR implements. Based on the WSR systems methodology, this paper studies the factors which affects knowledge transfer and sharing in the three stages, and proposes a model to improve the efficiency of the knowledge transfer and sharing in this process. At last the paper uses an iron and steel company a case to verify the model.
A Service Oriented Architecture for Collaborative Product Design
Authors: Rong Zhi Jun , Ying Bao Sheng , Dan Bin Bin
Published: June 2010

The recent advance in information technologies has the potential to greatly enhance product development, and to make distributed designers, engineers, manufacturers and customers work together over networks. This paper reviews related work on service-oriented architecture, distributed infrastructure and highlights the need to integrate service-oriented architecture technologies for meaningful and interactive collaborative design processes. This paper presents a service-oriented architecture implemented by web services for collaborative design. The collaborative workspace is presented to facilitate the design participants’ collaboration. The proposed architecture is applicable to different requirements of design participants and enhances design interaction during the product realization process.
A Study on Manufacturing Efficiency and Quality of Thermoforming
Authors: Ma Guang , Shen Yun De , Li Zhen Zhe , Xuan Dong Ji , Cheng Tai Hong , Jiang Rui
Published: June 2010

Thermoforming is one of the most versatile and economical processes available for shaping polymer products. The heating time and heater power must be optimized for obtaining good products efficiently. In this study, the method for calculating the required heat flux was researched at first. In the following step, the analytic solution was studied for getting optimal heating time and heater power. Finally, the relationship between heater power and heating time was discussed. The developed method in this study will be widely used to shorten the cycle time under the condition of satisfying requirements of thermoforming.
Sensitivity Analysis on Effect of Parent Materials Parameter on Formability of Tailor Welded Blank
Authors: Tao Xin Yang , Lin Jian Ping , Chen Shui Sheng
Published: June 2010

The parent sheet selection in TWB designing is largely dependant on the effect of parent materials parameters on formability of TWBs. Experiments and FE simulations were performed to study the effect of material parameters of TWB’s parent sheets such as t (thickness ratio), k (strength factor of materials), n (strain hardening index), r (anisotropy index) on LDH and weld-line movement of TWB. Orthogonal experiments and range analysis were used to analyze the sensitivity on effect of different parameter on LDH and weld-line movement. The results show that LDH of TWB decreases with increasing ration of stronger sheets parameters to weaker ones, and the rate decreases gradually; in contrary, weld-line movement increases and the increasing rate decreases gradually. Furthermore, different parameters make various contributions to LDH and weld-line movement of TWBs and the effect degree of each parameter changes with different thickness ratios.
Research on Double Parameters Discharge Gap Detection of Gap Voltage and Charging Current in Micro-EDM
Authors: Zeng Wei Liang , Liu Ying
Published: June 2010

In micro-EDM, for discharge energy and gap is very small, discharge state is much complex and changes very fast, traditional detection of average voltage can’t judge discharge state in real time, so double parameters detection mode of gap voltage and charging current is designed. Based on characters of RC pulse discharge, three threshold voltage and current values of high, medium, low are devided according to charge constant. Gap voltage and charging current have fixed corresponding relationship, through this relationship, these two parameters can be combined as five different situations to determine three states of discharge machining, representing open-circuit, normal discharge and short-circuit. The combination of gap voltage and charging current can accurately judge gap state and further improve working efficiency in micro-EDM.
Calculation of Inverse Kinematics Problem of a 5-DOF Rehabilitation Robot for Upper Limb Based on Screw Theory
Authors: Lan Zhi , Li Zhen Liang , Li Ya
Published: June 2010

A novel 5-DOF rehabilitation robot for upper limb, which can implement single joint and multi-joint complex motions and provide activities of daily living (ADL) training for hemiplegic patients, was presented. Based on the method of screw theory, the rehabilitation robot’s kinematics model was set up according to the 5-DOF rehabilitation robot for upper limb. For the kinematics model set up by the method of screw theory, the inverse kinematics calculation was realized by using Paden-Kahan sub-problem method and algebraic elimination method, and the result of explicit solution was given. It offered reliance for the actual intellectual control of the position and speed about the rehabilitation robot.
Characterization and Morphology of Composites Prepared from Polyacrylonitrile and Silver Nitrate
Authors: Chen Yan , Liu Hong Yan , Zhang Zhao Jun
Published: June 2010

Polyacrylonitrile (PAN)/silver (Ag) nanoparticle composites were prepared via heat treatment of composite solutions of silver nitrate (AgNO3) and PAN in N, N-dimethylformamide (DMF). The resultant composites were characterized by infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and Thermo gravimetric analyses (TGA). TGA results showed that the PAN/Ag composite are thermally more stable than the corresponding neat PAN. XRD results showed that pure phase Ag was obtained in the prepared nanocomposites. They also showed that crystallinity of PAN was largely decreased after the composition with nano-sized Ag. TEM results showed that the Ag particles were in sphere shape with 30-60nm diameter in the as-prepared nanocomposites.
Finite Element Analysis for Machine Joint
Authors: Guo Tie Neng , Li Ling , Cai Li Gang , Liu Zhi Feng
Published: June 2010

The stiffness and damping of mechanical joint are modeled by the zero thickness joint interfaces theory. The method is applied to analyze the dynamic characteristic of the gantry frame in a five axis turning-milling compound CNC machine tool. The model test is carried out in the gantry frame, and the maximum error of the first sixth mode is 5.63%. The experimental and analysis result show the zeros thickness joint element can provide an effective method to model the machine joint and predict the dynamic characteristic of the assembled structure.
Genetic Algorithm Based Analysis System for Gun Pipe Linearity
Authors: Wang Guo Hui , Li Xiang Rong , Hou Xin Zhong
Published: June 2010

Gun pipe linearity check and measure belongs to difficult deep-hole space check and measure. After the deviation data is obtained using designed linearity check and measure instrument for gun pipe, it need carry out analysis and operation to get the error. The essence of using minimum envelope region method to resolve and evaluate gun pipe linearity error is one optimizing problem about envelopment column surface, wherefore, it built error solution model of space linearity based on genetic algorithm, and it developed one solution and analysis software system using VB program. Application shows that the algorithm can be used to resolve linearity error quickly and conveniently, and the precision is good.
Study on the Properties of Microwave Curing Epoxy Resin/Nano-Fe Composite Materials
Authors: Sun Xiao Feng , Ma Shi Ning , He Jia Wu , Zhu Nai Shu
Published: June 2010

Nano-Fe particles were selected as microwave-absorber, and added in the epoxy resin. Epoxy resin/nano-Fe composite materials were cured by microwave irradiation and heating. Vector network analysis, dynamic mechanical analysis(DMA) and scanning electron microscope(SEM) were used to study the curing behaviors of composite materials under the different curing ways. Results show that the dielectric constant(εr) and the dielectric loss factor(tanδ) of the epoxy resin increased obviously when nano-Fe particles were added, and microwave absorption properties of epoxy resin/nano-Fe composite materials improved greatly with increasing contents of nano-Fe particles. DMA results indicate that the storage modulus (E’) and glass transition temperature(Tg) of epoxy resin samples with nano-Fe particles were higher than those without nano-Fe particles. The microstructure and phase composition of the samples were studied by SEM and EDX. Results show that nano-Fe particles were homogeneously dispersed in the epoxy resin matrix under microwave irradiation, which implies improved strength and toughness of epoxy resin/nano-Fe composite materials.
Regulation Thought of Auto Bidding Advertisement for Search Engine Keywords
Authors: Zhang Qing Hua
Published: June 2010

The technical nature of search engine in collecting and extracting mass internet information enables auto bidding advertisement based on search engine enjoys a powerful advantage beyond the rules of the game, compared with the advertisement of ordinary web page nature. However, because Internet and search engine is a newly developed matter with many of their behaviors drifting away outside the traditional government supervision and industry self-discipline, it has caused the frequent occurrence of unhealthy tendencies, provoking great dissatisfaction of society. It has become a must to effectively regulate auto bidding advertisement. The three aspects could be considered the starting points in terms of government supervision, industry self-discipline and social supervision. We shall not only insist on and perfect government supervision, but also strengthen the industry self-discipline for realizing organic entity of administrative supervision of government and management of industry self-discipline as well as organic entity of administrative review and self-discipline examination, offering useful references for perfecting the advertisement regulation mode of government leadership system in China. While guaranteeing a healthy and orderly development of search engine, our purpose is to render back an honest and clean searching environment of internet information to the public.
Kinematics Analysis and Simulation of a Quadruped Robot
Authors: Rong Xue Wen , Li Yi Bin , Ruan Jiu Hong , Song Hong Jun
Published: June 2010

This paper presents the mechanical configuration of a quadruped robot with 4 rotary joints per leg firstly. All joints of the robot are activated by 16 identical hydraulic servo cylinders. Then it gives the forward and inverse kinematic equations of one leg with D-H transformation matrix. Furthermore, it also gives the jacobian matrix of the legs. The jacobian matrix establishes the relationships between the angle velocities of the 4 joints of the supporting leg and the moving velocity of the robot trunk. Lastly, a simple trot gait simulation is given based on MSC.ADAMS under the assumption that there are no slippages between the supporting feet and the ground.
A New Method to Determine the Periodicity of Time Series
Authors: Liu Zhi Min , Zhang Hong , Dong Ke Qiang
Published: June 2010

Rescaled range (R/S) analysis has regained in popularity as a robust tool for the examination of long-term dependence. This paper modified the R/S method to determine the periodicity. We firstly apply the modified method to artificial time series for investigating the validity of the new method. Then the proposed technique is employed to research periodicity of the sunspot time series and the results indicate the robustness of the modified method.
Influences of Inflow Mode on Nutrient Removal Efficiency in a New SBR System
Authors: Li Ang , Zhang Yan Qiu , Li Yan , Diao Zhi Jun
Published: June 2010

With influent distribution, high sludge concentration and low substrate state are carried out in ECOSUNIDE technics, bring in high nutrient removal efficiency. The “influent distribution” was introduced into conventional SBR for the treatment of municipal sewage, aiming to improve the nutrient removal efficiency. The whole process included an anaerobic and multiple anoxic/ aerobic units. The distribution ratios and modes are studied in this paper. The results show that the average sludge concentration reaches high to 6000mg/L. The influent mode has significant influences on the nutrient removal in the new SBR system. The mode of instantaneous influent in anaerobic stage and intermittent in frequent aeration stage is optimal, with the distribution ratio of 0.4/0.6, and the removal rates of NH3-N, TN and TP reach 99%, 87%, and 98%, respectively.
Super Fuzzy Defect Classifier Based on Self-Adaptation
Authors: Liu Zhe
Published: June 2010

Aiming at the situation that feature extraction of image defects is slow, the accuracy is not high, this paper proposes a new super-fuzzy defect classifier based on self-adaptation, in which defect classification can be judged and determined intelligently according to different image windows feature. Firstly, a specific model of adaptive super-fuzzy classifier is given. Then, this algorithm is applied to defect recognition of fabric image for algorithm effect checking. Results show that this adaptive super-fuzzy classifier has some characteristics, such as high speed, simple calculation, no membership degree calculation, and the accuracy and threshold of defect classification can be made intelligent estimation according to different cases with this classifier.
The Research of the CSR Appraisal to Bus Listed Companies Based on Factor Analysis
Authors: Zhu Yong Ming , Wu Kang Xin
Published: June 2010

The performance of corporate social responsibility is increasingly becoming the focus of people’s attention. So we have to strengthen the appraisal and supervision of corporate social responsibility to those enterprises who have a significant impact on people's livelihood. In this paper, we chose 10 bus listed companies who have a full disclosure of financial information as samples, selected 260 data, made factor analysis using SPSS software and build a model of corporate social responsibility appraisal, finally made scientific analysis and appraisal to various parts of enterprise’s production and management. This can help enterprises enhance competitiveness and promote innovation according to the comprehensive performance of corporate social responsibility, as well as to help stakeholders make economic decisions.
A Differential Evolution with Scatter Search for Project Scheduling
Authors: Shi Yan Jun , Qu Fu Zheng , Chen Wang , Li Bo
Published: June 2010

The resource-constrained project scheduling is an important problem for enterprise resource planning. We herein propose a differential evolution with scatter search structure (named by DESS hereinafter) to tackle resource-constrained project scheduling problem. DESS follows the scatter search structure but uses differential evolution (DE) to generate new solutions of SS, and applies 3-opt local search algorithm as the improvement method of SS to transform each trial solution into enhanced trial solution. The proposed DESS is compared with the state-of-the-art algorithms on a set of standard problems available in the literature. The experimental results validate the effectiveness of DESS.
Research on Flexible Cables Simulation Based on CATIA/DELMIA
Authors: Shi Jian Ming , Zhou Dong , Geng Jie , Lv Chuan
Published: June 2010

Digital design and assembly of cables is a most important and difficult problem in mechanical industry. The paper solved the problem through the CAD/CAE software. Firstly, 3-D model of electrical bundle was built in the digital mock-up. The model reflected the parameters of the bundle exactly. After the design of cables, the simulation of cable moving was developed. The flexible feature of cable was displayed in the animation. It was an exciting achievement of this article, which can be used in the virtual assembly of cables to detect design problems. Besides the maintenance process containing cable plug and pull was simulated. The ergonomics was then tested in the form of virtual maintenance.
Chaotic Characteristic and Nonlinear Dynamic Performance of Rolling Bearing Friction Torque
Authors: Xia Xin Tao , Lv Tao Mei , Meng Fan Nian
Published: June 2010

Based on the chaotic theory, the methods of the Lyapunov exponent and the box dimension were applied to evaluate the chaotic characteristic and the nonlinear dynamic performance of the rolling bearing friction torque. The time series were obtained via the experimental investigation on the friction torque of the rolling bearings under the condition of different rotational speeds. It is found that the rolling bearing friction torque is of a chaotic system because the maximum of Lyapunov exponents of its time series is greater than zero according to the chaotic theory. And the result shows that the mean of the box dimension of the friction torque increases with the rotational speed of the rolling bearing, revealing the new dynamic performance of the rolling bearing friction torque as a time series.
The Optimal Cost Model of Compound Maintenance for Multi-Component Systems
Authors: Bai Yong Sheng , Jia Xi Sheng , Tian Yan , Cheng Zhong Hua
Published: June 2010

The maintenance tasks in present studies for the maintenance optimization of multi-component systems are mostly simplex, while the compound maintenance that integrates several kinds of maintenance types existing in practice are seldom studied. To optimize the compound maintenance intervals of multi-component systems, the group maintenance strategy was introduced in this paper, the maintenance cost structure and composition were analyzed from system point of view, and the mathematical models were established for expected maintenance cost per unit time. Finally, a numerical example was illustrated to prove the validity of the strategy and models above.
Global Path Planning for Mobile Robot Based on Improved Dijkstra Algorithm and Particle Swarm Optimization
Authors: Chen Nai Chao , He Ping , Rui Xian Ming
Published: June 2010

A novel method of improved Dijkstra algorithm and particle swarm optimization is proposed to evaluate global path planning for mobile robot. The first step is to make the MAKLINK graph which is used to describe the working space of mobile robot. The limited length value of free linkage line is conducted to substitute the constant weights in the adjacent matrix, which is well correlated with the fact that the number of paths is drastically less than that using the conventional Dijkstra method. Then the particle swarm optimization is adopted to investigate the global path from the several possible paths. Therefore, the proposed method facilitates reducing the computing time which enhances the efficiency of particle swarm optimization when performs the global path planning for mobile robot. Furthermore, simulation result is provided to verify the effectiveness and practicability.
Stiffness of Fiber-Wood Bonding Interface with Wood Adhesives
Authors: Cheng Fang Chao , Hu Ying Cheng
Published: June 2010

Effects of fiber fabric type, glue spread and adhesive kind on stiffness of fiber-wood bonding interface were investigated. Four different kinds of fiber fabric were bonded into poplar sample with three different adhesives and three different glue spread. Shear modulus of samples were measured by compression shear test to represent the stiffness of bonding interface. The results indicated that stiffness of GFF (Glass Fiber Fabric)-wood and GFMa (Glass Fiber Mat)-wood interfaces was better than that of two other interfaces and shear modulus of CFF (Carbon Fiber Fabric)-wood samples were the least of all. And the effects of glue spread and adhesive kind on stiffness of fiber-wood interface were significant.
Time Series Data Mining Implemented on Football Match
Authors: Chai Ben Cheng
Published: June 2010

This study utilizes time series data mining to find the interesting pattern and cooperation custom. Meanwhile, data mining technique and some special football skills such as ball possession are employed to build a novel decision model in football match. The proposed model is expatiated through real football match. In short, on the one hand, the model provides a feasible route to guide the decision makers including football coach to establish effective mechanism in football match. On the other hand, it extends the application scope of time series data mining.
Research on Tool-Path Generating Methods for NC Machining of Centrifugal Pump Vanes
Authors: Wei Xiu Ting , Du Qiang , Liu Jing Cheng
Published: June 2010

The universal NC program was inefficient for machining centrifugal pump vanes and a new tool-path generation method along section lines was proposed in this paper. After analyzing curve characteristics of centrifugal pump vanes, the mathematical model for calculating cutting step-lengths and determining the next tool contact parameter ui+1 through step estimating method was put forward. Furthermore, a new iterative algorithm was implemented, along with its terminal condition simplified. The proposed algorithm provided a new idea for developing special NC program of impellers.
Full-Field Modelling of Crack Tip Shielding via the ‘Plastic Inclusion’ Concept
Authors: James M. Neil , Lu Yan Wei , Christopher Colin J. , Patterson Eann A
Published: June 2010

This paper presents an outline of the development, verification and application of a new model of crack tip stress fields in the presence of a plastic enclave around a growing fatigue crack. The approach taken rests on capturing the effects of this ‘plastic inclusion’, comprising the crack tip and crack wake plastic zones, via elastic stress distributions applied at the elastic-plastic boundary. The model is therefore independent of the mechanisms of plastic deformation and potentially applicable to a variety of materials. A Muskhelishvili complex potential extension to the Williams crack tip stress field is found for four stress parameters representing a K-stress, a T-stress, a crack retardation stress and a compatibility-induced shear stress at the elastic-plastic boundary. This model is validated via full field fitting to photoelastic stress fringe patterns, obtained from epoxy resin and polycarbonate specimens. It has also been extended to the strain fields measured in digital image correlation techniques, which allows its application to metallic alloys.
Design for Lifecycle Cost and Preventive Maintenance Using Time-Dependent Reliability
Authors: Singh Amandeep , Mourelatos Zissimos P. , Li Jing
Published: June 2010

Reliability is an important engineering requirement for consistently delivering acceptable product performance through time. As time progresses, the product may fail due to time phenomena such as time-dependent operating conditions, component degradation, etc. The degradation of reliability with time may increase the lifecycle cost due to potential warranty costs, repairs and loss of market share. In design for lifecycle cost and preventive maintenance, we must account for product quality, and time-dependent reliability. Quality is a measure of our confidence that the product conforms to specifications as it leaves the factory. Reliability depends on 1) the probability that the system will perform its intended function successfully for a specified interval of time, and 2) on the probability that the system response will not exceed an objectionable by the customer or operator, threshold for a certain time period. Quality is time-independent, and reliability is time-dependent. This paper presents a methodology to determine the optimal design and preventive maintenance of time-dependent, multi-response systems, by minimizing the cost during the life of the product. The lifecycle cost includes a production, an inspection, and an expected variable cost. All costs depend on quality and/or reliability. A roller clutch example highlights the design methodology for lifecycle cost.
Studies on Fatigue Properties of Steel with Co-Based Alloy Hardfacing Coating
Authors: Deng Hong Xia , Shi Hui Ji , Tsuruoka Seiji , Yu Hui Chen , Zhong Bin
Published: June 2010

The main task of this paper was to evaluate the influence of hardfacing technique and service temperature on the fatigue properties of heat-resistant steel X45CrSi9-3 coated with Co-based alloy Stellite 12. The results of rotating bending fatigue tests showed that at room temperature (RT), the fatigue strength of specimens welded by the acetylene gas welding (AGW) was lower than that of specimens welded by the plasma transferred arc welding (PTAW). For PTAW specimens, the fatigue strength at 500oC was much higher than that at RT. Two failure modes were presented, one was termed as the coating failure mode at RT and the other was termed as coating-interface failure mode at 500oC. The fatigue life prediction was conducted by using a modified Murakami’s model.
Fatigue S-N Relations of the Cast Steel for Chinese Railway Rolling Wagon Bogie Frames
Authors: Chen Lei , Zhao Yong Xiang , Bing Yang
Published: June 2010

Fatigue S-N relations are investigated experimentally on the grade B cast steel for Chinese railway freight car bogie frames. Group test method was employed. Results reveal that the fatigue cracks were initiated from the material cast shrinking cavities with hot ties. Distinct fatigue striations, river-like flowers, and second cracks appeared on the fracture surface in perpendicular to the fatigue crack path. Lots of dimples in the transient fracture district indicate that present material is ductile. Considering both the scattered S-N relations and no fatigue limits under variable loads, the S-N relations are measured probabilistically in terms of continuous declined probabilistic S-N curves including super-long life regime (SLLR) of >107 cycles. Affordable novel approach, i.e. concurrent probability extrapolation method, was applied. The test S-N data in mid-long life regime (MLLR) and conventional fatigue limits are used. The curves are established by extrapolating the conventional S-N curves crossing the fatigue limits, in a concurrent probability manner, into the SLLR. Appropriate measurements have been given for the test data of the present material.
Investigation of the Hydrogen Embrittlement on the 65Mn Steel from the Nuclear Power Plant with Small Punch Method
Authors: Wang Zhao Xi , Shi Hui Ji , Zhang Guo Dong , Qu Bao Ping , Lu Jian , Zhao Xian Bo
Published: June 2010

Damage of metals due to the influence of hydrogen is quite frequent and leads to dangerous failures. The characteristics of the hydrogen embrittlemnt of the 65Mn steel were evaluated with small punch test. With the increment of the amount of the hydrogen absorbed into the alloy at room temperature, the strength and the toughness of the material reduce. From the small punch experimental results, it is found the total impact energy, the fracture strain and the fracture stress decrease with the increment of the cathodic hydrogen charging time. The fracture surfaces change from the typical ductile fracture with big voids to the typical intergranular brittle fracture mode after hydrogen absorbed in the specimens with higher charging current density.
Infrared Thermography and Acoustic Emission in 2D Plain Woven C/Sic Composites under Tensile-Tensile Fatigue Loading
Authors: Li Bin , Tong Xiao Yan , Feng Zi Yang , Yao Lei Jiang
Published: June 2010

Plain plate specimens of 2D plain woven C/SiC composites were performed on Instron8801. Infrared (IR) thermography was recorded using an infrared camera. Acoustic emission (AE) signal was detected by two AE wide band sensors attached on specimen. They were measured synchronously and real-timely. Thermal dissipation Q was deduced based on the first law of thermodynamics. When the applied stress was lower than fatigue endurance limit, Q rose in the early cyclic loading stage and then the rate of Q accumulation gradually approached a steady value as the proceeding cycles, conversely, Q rose quickly until led to failure of the composites. AE accumulated energy was discussed based on the AE data. Higher applied stress would cause more damage within the composites, and more AE signals were detected. Compared with damage calculated from modulus, Q and AE accumulated energy had fairly well agreement with the damage. It can be concluded that it is possible to employ these non-destructive evaluation methods as in-situ damage evolution indicators for 2D C/SiC composites.
Bifurcation of Non-Semi-Simple Zero Eigenvalues at the Critical Point of the Statical Bifurcation of Nonlinear Rotor System
Authors: Chen Yu Dong , Pei Chun Yan
Published: June 2010

The objective of the study is to discuss the instability of the center subspace of a nonlinear rotor system with gyroscopic, inertial and potential forces, and nonlinear forces of the shaft, whose linear approximation has a m-multiple non-semi-simple zero eigenvalues. That is to discuss how the parameter changes affect the variations of non-semi-simple zero eigenvalues of the center subspace. The Puiseux expansion is used to develop the expressions of variations of non-semi-simple eigenvalues. The method for computing the generalized modes of the center subspace are given, and expression of variations of 2-multiple non-semi-simple zero eigenvalues is transformed into a more convenient form.
The Application of MARS on Crashworthiness Improvement
Authors: Gao Yun Kai , Sun Fang
Published: June 2010

Surrogate model produced by using multivariate adaptive regression spline (MARS) approach takes the form of an expansion in a set of basis functions which are selected from data. This approach is especially useful in the case of having no advance understanding of the parametric model. As for MARS procedure, the adaptive adjustment is used frequently to best fit the data optimally. In this paper, the adaptive adjustment is realized by using Matlab programming language and provides support for MARS procedure. Taking crashworthiness improvement for example, the program is applied to produce surrogate model for peak acceleration, and then the optimization is carried out based on this model. The results indicate that the surrogate model constructed by MARS approach can predict peak acceleration precisely and therefore can provide instruct for crashworthiness improvement.
Planning of Step-Stress Accelerated Degradation Test with Stress Optimization
Authors: Ge Zheng Zheng , Li Xiao Yang , Zhang Jing Rui , Jiang Tong Min
Published: June 2010

For highly-reliable products, Accelerated Degradation Testing (ADT) data can provide useful reliability information. Moreover, Step-Stress Accelerated Degradation Testing (SSADT) usually requires a less sample size, shorter time and less cost than Constant-Stress Accelerated Degradation Testing (CSADT). However, in designing an efficient SSADT, the issue about how to choose accelerated stress level was seldom discussed. In this study, first we use drift Brownian motion to model a typical SSADT performance degradation process. Then, under the situation that total experiment cost is not given while the sample size, total test time and the interval of performance inspection are specified, our objective is to minimize the asymptotic variance of the estimation of the reliability of the pth quantile of product’s lifetime under use condition. Form the derivation of our objective, we find a way to improve the speed of optimal algorithm for SSADT. The optimal plan can give the stress levels and test time at each stress level. Finally a simulation example is used to illustrate the proposed method.
General Particle Swarm Optimization Algorithm for Integration of Process Planning and Scheduling
Authors: Xu Shao Tan , Li Xin Yu , Gao Liang , Sun Yi
Published: June 2010

To realize the integration of process planning and scheduling (IPPS) in the manufacturing system, a particle swarm optimization (PSO) algorithm is utilized. Based on the general PSO (GPSO) model, one GPSO algorithm is projected to solve IPPS. In GPSO, crossover and mutation operations of genetic algorithm are respectively used for particles to exchange information and search randomly, and tabu search (TS) is used for particles’ local search. And time varying crossover probability and time varying maximum step size of tabu search are introduced. Experimental results show that IPPS can be solved by GPSO effectively. The feasibility of the proposed GPSO model and the significance of the research on IPPS are also demonstrated.
Reliability Analysis for Crane Boom Base on Probabilistic Finite Element Method
Authors: He Xue Hong , Ding Liang Dong , Lin Gui Yu
Published: June 2010

Working condition and structure for crane boom is quite complex. In order to ensure the safety of crane, there is a high requirement for reliability. In this paper, probabilistic finite element method is used to analyze the reliability of crane boom. Parametric finite element model of crane boom is built and uncertain parameters are obtained by analyzing characteristics of dimensions, materials, loads and constraint conditions for crane boom. Uncertain parameters like structural dimensions, material parameters and loading parameters, etc are processed discretely and reliability of crane boom is obtained by using Probabilistic Design System (PDS) of ANSYS. Meanwhile, we can get the main parameters which affect reliability of crane boom and how much their influences will be by sensitivity analysis.
Research Progress on Fracture Mechanism of Mechanical Products
Authors: Shao Jiang , Zeng Cheng Hui
Published: June 2010

Based on reliability physics theory, investigation on failure mechanism is a kernel job in reliability design and analysis of mechanical products. The basic conception and classification of failure mechanism are introduced. Researches on five kinds of fracture mechanisms (ductile fracture, cleavage fracture, quasi-cleavage fracture, fatigue fracture and intergranular fracture) are discussed in detail. At last, problems are summarized and suggestions for future investigations are also made.
Estimation of Failure Probability and its Applications in Reliability Data Analysis
Authors: Ming Han
Published: June 2010

Evaluation method of reliability parameter estimation needs to be improved effectively with the advance of science and technology. This paper develops a new method of parameter estimation, which is named E-Bayesian estimation method. In the case one hyper-parameter, the definition of E-Bayesian estimation of the failure probability is provided, moreover, the formulas of E-Bayesian estimation and hierarchical Bayesian estimation, and the property of E-Bayesian estimation of the failure probability are also provided. Finally, calculation on practical problems shows that the provided method is feasible and easy to perform.
Shear Strength and Performance of Glass-to-Metal Brazed Joints
Authors: Shen Xi Hai , Sun Chun Xiang , Wang Li Chun
Published: June 2010

Vacuum brazing of glass to Kovar alloy was carried out at 670~700°C using Cu-Ni-Sn-P brazing alloy. The holding time ranges from 5min to 30min. The shear stress was tested to evaluate the mechanical property of the vacuum brazed joints. The results showed the maximum shear stress was 11.6MPa when the brazing temperature was 680°C and holding time was 10min. In accordance with the welded structures, the finite element (FE) model of glass-to-metal brazed joints was established. As result, the shear tests on the lap joints in conjunction with FM analysis were used to optimize the glass-to-metal brazing technology. The above results provide the basis of design against damage and reliable estimation of glass-to-metal seals.