bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction of 3D Strata Model Based on the Multiple Source Data
Authors: Liu Chun Yuan , Gu Shi Meng , Liu Yu
Published: March 2013

According to the raw multi-source data, all strata should be standardized. With the aid of the cubic spline interpolation function, the virtual drilling could be created. With the help of Deluanay triangulation, every stratum is turned to triangular net, namely initial stratum surface. A top triangle of stratum is connected with a corresponding bottom triangle of stratum in the net. It makes a triangular prism unit. Finally, according to certain rules, numerous triangular prism units are assembled orderly to form a geologic body. The GTP model can realize 3D strata simulation and the purpose of true three-dimensional.
Removal of Congo Red from Dyeing Wastewater by Biodegradation with Myriophyllum
Authors: Fan Zheng , Lv Bo Sheng , Zhang Ji Wei , He Jin Zhe , Zhang Guo Liang
Published: March 2013

In this study, Myriophyllum was used to remove Congo Red dye from wastewater. The influence of operation factors include illumination intensity, initial pH, biomass and dye concentration on the degradation rate of Congo Red were investigated. The experimental results demonstrated that Myriophyllum can effectively degradate Congo red dye. The Congo red dye was almost completely discolored in 10 days under the conditions of 5000 lx of illumination density, 7.5 of pH, 15g /L~17.5 g/L of initial biomass and less than 20 mg/L of Congo red concentration. Furthermore, the great reduction of intermediate products and COD indicated that biodegradation of Congo red dye with Myriophyllum not only produced less secondary pollution, but also mineralized azo dye into inorganic matters. Myriophyllum in pollutants degradation presented obvious technical advantages and environmental benefits.
Sensitivity Analysis of Influence Factors at Open-Pit Coal Mine High Slope Based on Uniform Experimental
Authors: Zhang Fei , Cao Jing , Zhao Hui Min
Published: March 2013

The number of test times and test effectiveness are dependent on the test approaches in sensitivity analysis of the slope stability. In the paper, considering the mechanical parameters and groundwater of rock and soil, the sensitivity analysis of the slope is researched by the uniform experimental design. Its results are analyzed through grey correlation analysis. It is shown that the change of groundwater level in the open-pit slope is the most sensitive in the open-pit slope.
A Kind of Car License Plate Location Based on Color Feature and Mathematical Morphology
Authors: Hu Hong Ping , Bai Yan Ping
Published: March 2013

The proposed method of the license plate location is based on mathematical morphology, color feature and edge detection. It consists of two parts on raw location of license plate and refined location of license plate. In the raw location part, resize the image into the same size, consider the relation of R, G, B components in the image to deal with the noise, detect the edge and use the operations of mathematical morphology repeatedly to obtain the license plate candidate, obtain the raw location by the up-down bound and left-right bound of the license plate. In the refined location part, for the obtained raw location of the license plate, use Radon transformation, edge detection, use the operations of mathematical morphology, find the up-down bound and left-right bound so that the refined location of the license plate is obtained. It is shown that the proposed method is suit for the Chinese license plate with white character and blue background.
Hierarchical Regression Model for Truck Collision Severity Analysis
Authors: Wang Hui Li , Shi Zhong Ke
Published: March 2013

Collisions involving trucks have long been a major safety concern for the collision severity. This paper describes the rationale and construction of a hierarchical model that can be used to assess severity of truck collisions in a freeway network. The outcome of models and associated data analysis revealed that presence of ramp and freeway segment length were important factors affecting truck safety performance. Furthermore, weather condition was found to be a significant factor in the severity of truck collisions. Using these models, practitioners can identify freeway sites where truck crashes are more likely to occur and then take measure to mitigate the severity.
Sensitivity Analysis on Influencing Factors of Double-Row Piles for Excavation
Authors: Jiang Kai Yu , Cao Jing , Liu Hai Ming , Zhao Hui Min
Published: March 2013

Sensitivity analysis of double-row piles is often obtained by changing the value of single influencing factor and doesn’t considering the interaction of influencing factors. So, a new sensitivity analysis method is proposed which can consider the interaction of influencing factors. In this method, uniform design (UD) and alternating conditional expectations regression (ACE) are used. The embedded depth of the forward pile, row space, length of the back pile, equivalent thickness of forward pile, equivalent thickness of coupling beam, and equivalent thickness of back pile are six input parameters called influencing factors. The maximum horizontal displacement of the pile head (MDP), maximum bending moment of forward pile (MMF), maximum ground settlement (GS), and coefficient of global stabilization (CGS) are four outputs as target parameters. The sensitivity can be obtained in this geological condition, excavation depth and surrounding environment. It is showed that the stiffness of back pile is the critical influence factor to MDP, the stiffness of forward pile is the critical influence factor to MMF and GS, and the length of back pile is the critical influence factor to CGS.
Prediction Models of Short-Term Traffic Flow Based on Neural Network
Authors: Dong Chao Jun , Cui Ang
Published: March 2013

For the city’s road conditions, a nonlinear regression prediction model based on BP Neural Network was built. The simulation shows it has good adaptability and strong nonlinear mapping ability. Using the wavelet basis function as hidden layer nodes transfer function, a BP-Neural- Network-topology-based Wavelet Neural Network model was proposed. The model can overcome the defects of the BP Neural Network model that easy to fall into local minimum and cannot perform global search. The feasibility of the model was proved using measured data from yingbin avenue in jiangmen city.
Study on Safety Evacuation Time for Passengers in Subway Station and Its Application
Authors: Zhou Xiao Jun , Yu Xue Ying
Published: March 2013

This paper discusses the determination of safety evacuation time for passenger and staff in subway station in accordance with passenger flow and traffic capacity of escalator and stairs in subway station, concurrently modifies the formula to calculate the safety evacuation time by means of different determination of passenger flow predicted in advance by dint of origin and destination investigation in subway station. And a proposal to consider the maximum passenger flow within every subway train departure interval is also presented in determining the evacuation time when calculating the traffic capability of escalators and stairs.
Analysis of Electrical Engineering Project Management in Construction
Authors: Wang Ye Bing , Chen Li Juan
Published: March 2013

Project management, an important branch of management science, has got an increasing attention in various countries. Investment efficiency, social benefits, environmental benefits are affected by the quality of the construction investment projects. With the rapid development of industry and intelligent buildings, electrical engineering will become more and more useful and important. This thesis based on the engineering practice gives a systematic analysis of the role and significance of electrical engineering project management in construction.
Research of Building Pavement Maintenance Management System of Downtown Area - Zhongli City, Taoyuan County for Example
Authors: Lin Jyh Dong , Hung Ching Tsung , Peng Jr Hung , Tsao Jung Hsuan , Ho Min Che , Shen Chien Jung
Published: March 2013

Currently urban road works has changed from new constructions to conservations, but unlike municipalities with rich resources, most road maintenance works of most townships are done by a few engineers, manually and complicated, affecting the quality and progress of road maintenance works. To this end, this study uses pavement maintenance management system, replacing parts of the manual tasks, and a standard with objective data to decide the appropriate range and conservation engineering methods, in order of increasing the efficiency.
Research on Service Modes of Steel Processing and Distribution Centers in China
Authors: Liu Gui Rong , Liu Jun
Published: March 2013

Steel processing and distribution centers in China have been constructed by iron and steel enterprises, by warehousing enterprises, by steel circulation enterprises, or by end users. These centers connect steel mills with end users, which’s logistics service level affects the competitive advantages of steel supply-chain. So their common characters, problems and development tendency are analyzed in this paper. Based on this analysis, three service modes with cases are proposed, such as integrated logistics service mode, comprehensive logistics service mode, integrated value chain logistics service mode. Which one mode has been adopted, these centers should take some measures to improve service level and reduce costs. Four measures are put forward for these centers, respectively mastering the dynamic market situation, designing market oriented service mechanism, optimizing the supply chain, re-engineering business process.
The Analysis about Reliability Factors in Management System and Their Application for Reliability Allocation Theory
Authors: Tong Qian , He Jiao , Shen Le Ping
Published: March 2013

System reliability distribution theory is mainly used in electronic system engineering and logistics management. With a view to the vital function and influence that reliability factors have made in business management, the author gives the methods to definite the concept of the reliability of management system in enterprise and to calculate its index. Besides, the author discusses the application of reliability allocation theory in management system and establishes the optimized mathematical model for marketing distribution about enterprise production. Finally, this article gives a calculation example by using the optimized mathematical model.
Practical Application Study of Gaussian Process Model in Construction Project Cost Estimation
Authors: Liu Xin Liang , Yin Tao , Wu Guo Dong
Published: March 2013

Early understanding of construction cost represents a critical factor of a feasibility study in the early design phase of a project. A new project cost estimation model based on Gaussian Process was proposed. Gaussian Process model theory was introduced, and project cost estimation model based on Gaussian Process’ flow chart was analyzed in detail. Through example analysis, project cost estimation model based on Gaussian Process using Nelder-Mead and genetic algorithms algorithm was proven feasible for this problem and represented accuracy than BP neural network.
Optimized Construction Equipment Allocation Method for Highway Construction Projects
Authors: Choi Jaeh Yun , Song Ho Jeong
Published: March 2013

Highway construction projects are divided into new roadway construction and rehabilitation projects. In Korea total contract value of highway construction projects was over $2 Billion in 2011, which took over 24% of the total budget of the Korea Highway Corporation, and the volume is expected to be increase due to many rehabilitation projects for the existing roadways. Highway construction is known as a collection of linear and repetitive operations that are highly equipment intensive. Typically, construction equipment costs made up to 40% of the total construction costs on the highway construction projects. Therefore, construction cost and time for the highway construction projects are highly dependent upon the effective usage of construction equipment. In other words, the utilization of construction equipment has a great impact on the entire construction process and the optimal selection of the equipment becomes the key factor to the project success. However, most construction projects rely on experience or intuition without proper consideration or planning when it comes to select construction equipment. This research involves analyzing current equipment utilization to identify the major factors affecting equipment selection process for the asphalt pavement operation with the help of a computer simulation technique. The methodology developed can replace educated-guessing in the planning process for the equipment selection process.
The Influence Factors Analysis on Heavy Cone Dynamic Penetration Test Method to Geotechnical Exploration in Gravel Soils
Authors: Shan Mei , Yang Bin , Wu Ping , Mo Si Hao
Published: March 2013

The cone dynamic penetration test is a kind of test method, which has the features of simple device, easy operation, great adaptability, high efficiency and it also is a continuous in-situ test method. But in the common geotechnical exploration activities, we found that bearing capacity of foundation is always larger than the measured value, by analysis to the blow count of cone dynamic penetration in the standard table. This article set the gravel soil geotechnical exploration of Guangxi province’s city planning exhibition center of China as the example, to start with the theory of cone dynamic penetration, and analysis the reason why there are the abnormal value in the dynamic penetration, furthermore, provide the relative error correction models for it. Finally, establish the rational relationship between dynamic penetration results and foundation soil mechanical parameters.
Numerical Simulation of Explosion in a Confined Box-Shaped Structure
Authors: Yang Fan , He Li , Liu Xiao , Jia Bin
Published: March 2013

In order to study the propagation law of shock wave and blast load distribution when an interior explosion occur in a box structure, a numerical simulation of an interior explosion within a box-shaped structure is presented in this paper using LS-DYNA. Overpressure-time history curve of the blast load at the measured points is obtained by numerical simulation, and compared with the experimental results. Numerical simulation results and experimental results are in good agreement. The results show that the blast wave reflected and superimposed many times in the box-shaped structure. When TNT is located in the center of the box-shaped structure, the center and the corner of the wall suffered the maximum overpressure.
Experimental Research on Steel Bar Reinforced High-Strength Concrete Columns
Authors: Fang Xiao Dan , Chen Guan Xin , Wei Hong , Yao Zheng Qin
Published: March 2013

4 steel bar reinforced high-strength concrete column specimens were tested under axial compression in order to study how different height width ratios, different stirrup ratios and different steel bar reinforcement ratios influence the failure mode of the members and the bearing capacity. Results show that the steel bar reinforced high-strength concrete columns are applicable to practical engineering.
Elastic Results’ Comparison between Computing and Test of a Scaled Model of a Complex Supertall Building
Authors: Chen Yue
Published: March 2013

The height of a complex supertall building is 250m. The central RC tube and peripheral SRC frame with a strengthened truss and a transfer truss are employed to resist vertical and lateral loads. At first, a shaking table test was performed on a 1/30 scaled model of the building to study its dynamic characteristics and to evaluate its earthquake resistant capacity. Then, a 3D finite element analysis of model structure was carried out. Finally, the analytical results were compared with the experimental ones to gain a better understanding of the structural behavior.
Reinforcement and Replacement Technology on Members and Roof Purlin of a Space Grid Structure after Snowstorm Disaster
Authors: Liu Ming , Li Liang , Fan Xin Hai , Zai Xi Mei , Wang Yuan Qing
Published: March 2013

The snow load of a space truss structure subjecting is unevenly distributed after snowstorm disaster, which caused uneven forcing and local damage of the members and roof purlin of the original space truss. The damaged members and roof purlins were strengthened and replaced in loaded condition in order to guarantee the space grid structural safety. The results during the construction process have shown that the presented strengthening plan is successful, which can provide us a good reference of the similar projection.
Soft Rock Roadway Mesh Shell Lining Experimental Study of the Mechanical Properties
Authors: Li Hong Xia , Wang Yong Wei , Tang Bai Xiao
Published: March 2013

Similar model experiment under confining pressure, research latticed shell lining the mechanical properties and the carrying capacity of new support for the underground engineering - network shell support, according to the model experiments and theoretical. Test results prove that the the latticed shell supporting structure has good mechanical properties and a high level of support is a reliable form of support. Can make up for the deficiencies of the existing soft rock roadway structure, calculated to provide a reliable basis for mesh shell lining theoretical analysis.
The Finite Element Analysis on Shear-Lag Effect of the Steel Box-Girder
Authors: Li Yi Sheng , Wang Jun Ping , Liu Wei , Shen Jian Ming
Published: March 2013

The shear-lag effect of steel box-girder is qualitatively analyzed by using the finite element software ANSYS. Various methods to reduce the shear-lag effect are studied, and the most effective method is changing the web layout and increasing the number of box-room among them. The suggested value of effective width to thickness ratio b1/t1 of the flange without considering the shear-lag effect are obtained in this paper.
Yield Surface Applied to Dynamic Elastoplastic Analysis of Frame Structures with Flexibility Method
Authors: Chen Yong Sheng , Wu Bin , Pan Tian Lin
Published: March 2013

The yield surface of section axial force and bending moment (AFBM) is formulated by section assemblage concept. Based on flexibility method , a novel planar beam- column element is proposed using yield surface of section AFBM. Dynamic elastoplastic analysis is carried out on a planar steel frame. The results show that the accuracy of proposed model is close to fiber model, and hence it can be used for dynamic elastoplastic analysis of frame structures.
Relative Impermeability of the Ordovician Top and Risk Assessment of Water Inrush from Coal Floor in Baode Coalfield
Authors: Zhang Wei Jie , Li Shu Cai , Wei Jiu Chuan , Zhang Qing Song , Liu Ren Tai , Li Zhi Peng , Sun Zi Zheng
Published: March 2013

In order to study the safety mining of the deep buried coal seams being threatened by high pressure karst water, relative impermeability of the Ordovician top is demonstrated through studying lithology，filling degree of the karst fissures as well as wash water quantity, in the Baode mine field. Furthermore, the main influencing factors on impermeability of coal seam floor are analyzed, and divisional risk assessment of floor water-inrush from the Ordovician karst aquifer is performed. Overall，by considering the relative impermeable strata in the Ordovician top, the accuracy of risk assessment on coal floor water-inrush can be improved.
Influence of Suspension Length on the Mechanical Response of Submarine Flexible Pipe under Internal Pressure and Transverse Load
Authors: Gu Fan , Wang Hui Xin , Wang Dan , Sun Jia Quan
Published: March 2013

According to the actual structure of submarine flexible pipe, considering the combined effect of internal pressure and transverse load by wave-current flow that is based on 50 year return period wave statistics data of Cheng Dao sea area, ANSYS finite element model of flexible pipe is established. The influence of internal pressure and suspension length on the axial stress of steel wire reinforcement layer and the Mises stress of rubber layer was analyzed. Comparatively, suspension is the main cause for the failure of steel submarine pipeline, but could hardly lead to the failure of submarine flexible pipe, which shows that flexible pipe is stronger applicable for submarine pipeline.
Numerical Investigation on Bending Failure of Concrete Beam Strengthened by Bonded Steel Plate
Authors: Xu Bing , Wang Da Guo , Wang Zhi Xiu
Published: March 2013

Based on micromechanics, an elastic-plastic-brittle damage model of concrete beam strengthened by bonded steel plate is proposed by considering the aggregate gradation curve algorithms and the heterogeneity. In this model, the concrete beam strengthened by bonded steel plate is taken as a five-phase composite material that consists of the mortar matrix, coarse aggregate, bonds between matrix and aggregate, steel plate, and the adhesive layer between steel plate and concrete beam. Through the numerical investigation on bending failure of concrete beam strengthened by bonded steel plate under external force, the results show that the model can clearly simulate microscopic plastic yield, and the initiation and extension of crack. The strength of the steel plate is relatively lower and it firstly yield and damage, then the bending stress born on the steel plate is transferred to the concrete beam. This results that the inner cracks of concrete beam increase rapidly and coalesce until the failure of the whole specimen. The final failure mode of concrete beam strengthened by bonded steel plate is the ductile bending failure.
Membrane Separation of CO2 from Natural Gas: A State-of-the-Art Review on Material Development
Authors: Latif Ahmad Abdul , Adewole Jimoh K. , Ismail Suzylawati Binti , Peng Leo Choe , Sultan Abdullah S.
Published: March 2013

Natural gas (NG) processing and membrane technology are two very important fields that are of great significance due to increasing demand for energy as well as separation of gas mixtures. While NG is projected to be the number one primary source of energy by 2050, membrane separation is a commercially successful competitor to other separation techniques for energy efficient gas separation processes [1]. Most of the NG produced in the world is coproduced with acid gases such as CO2which need to be removed to increase the caloric value of NG. A comprehensive review of research efforts in CO2separation from natural gas is required to capture details of the current scientific and technological progresses on the development of new membrane materials with better separation performance, and the improvement of properties of the existing ones. This paper presents the progress that has been achieved in eliminating the limitations that dominate the large scale application of membrane materials at the present time. Various polymers that have been developed to resist plasticization and the method employed to fabricate these polymers are highlighted. Also the range of plasticization pressures (together with corresponding selectivities and permeabilities at these pressures) that have so far been achieved by these fabrication methods is presented. It is believed that this review will serve as a good reference source especially for research in design and development of membrane materials with better resistance to CO2-induced plasticization.
Effect of Grain Size on the High Temperature Oxidation Behaviour of Austenitic Stainless Steels
Authors: Fujikawa H. , Iijima Y.
Published: March 2013

The effect of grain size on high temperature oxidation behaviour of 316 steels at 700º, 850º and 1000°C in air was studied. The results show that the mass gain increases with the increase of grain size. Particularly, the gradient of mass gain is severe in at lower oxidation temperatures. In the oxidation at temperatures of more than the solid solution temperature, the grain size before the oxidation changed to coarse grain size. Therefore, in this case, it is not enough to estimate the oxidation behaviour by the grain size before the oxidation. The exfoliation of oxide scale is severe in steel with coarse grains. Over 850°C, the exfoliation was observed in 316 steel with coarse grains. At 1000°C, the oxide scale of 316 steel was exfoliated, but it was extreme in the coarse grains. Cr, Mn and Si in the oxide scale were enriched in the oxide scale of the steel with fine grains. Particularly, Si was remarkably enriched at the metal-oxide interface and grain boundaries.
Pseudopartial Grain Boundary Wetting: Key to the Thin Intergranular Layers
Authors: Straumal Boris B. , Rodin Alexey , Shotanov A.E. , Straumal Alexander B. , Kogtenkova Olga A. , Baretzky Brigitte
Published: March 2013

The thin layers of a second phase (also called complexions) in grain boundaries (GB) and triple junctions (TJs) are more and more frequently observed in polycrystals. The prewetting (or premelting) phase transitions were the first phenomena proposed to explain their existence. The deficit of the wetting phase in case of complete wetting can also lead to the formation of thin GB and TJ phases. However, only the phenomenon of pseudopartial (or pseudoincomplete, or constrained complete) wetting permitted to explain, how the thin GB film can exist in the equilibrium with GB lenses of a second phase with non-zero contact angle.
Design and Development of Nb-W-Mo Alloy Membrane for Hydrogen Separation and Purification
Authors: Yukawa Hiroshi , Nambu T. , Matsumoto Yoshihisa
Published: March 2013

The concept for alloy design of Nbbased hydrogen permeable membrane is applied to NbWMo ternary system. The alloying effects of tungsten and molybdenum on the solubility of hydrogen, the resistance to hydrogen embrittlement, the hydrogen permeability and diffusivity are investigated in a fundamental manner. It is found that the addition of tungsten and molybdenum into niobium decreases the hydrogen solubility. As a result, the resistance to hydrogen embrittlement improves and higher hydrogen pressures can be applied to the NbWMo alloy membrane. It is shown that the designed Nb5mol%W5mol%Mo alloy membrane with single solid solution phase exhibits excellent hydrogen permeability together with strong resistance to hydrogen embrittlement. In addition, it is found that the alloying of tungsten and molybdenum with niobium enhances the hydrogen diffusivity. In fact, the activation energy for hydrogen diffusion decreases in the order, pure Nb > Nb5mol%W > Nb5mol%W5mol%Mo.
Effective Synthesis and Isomerization of Cyclotetrasiloxanetetraol
Authors: Endo Hisayuki , Unno Masafumi
Published: March 2013

Recently we have reported the syntheses of a variety of silsesquioxanes including laddersiloxanes and cage silsesquioxanes. As a precursor of these compounds, cyclotetrasiloxanetetraols are very useful. Several groups reported the syntheses of alkyl-substituted all-cis-cyclotetrasiloxanesilanolate that can be converted to all-cis cyclotetrasiloxanetetraols. In addition, there was a report of the isomerization of phenyl-substituted all-cis-tetraphenylcyclotetrasiloxanetetraol by hydrochloric acid to give other three stereoisomers. With an aim to elucidate that the reaction is commonly applied or not to other cyclic silanols, we synthesized all-cis isobutyl cyclic silanol. With investigating the reaction condition, we could obtain this cyclic silanol in better yield than previously published methods. Additionally, stereoisomerization reaction with hydrochloric acid was investigated. With a slightly longer reaction time, isomerization reaction was observed to give other stereoisomers. This is the second example of the stereoisomerization of cyclic silanols.
A Constitutive Description of the Yield Strength and Strain Hardening Behaviors of Nano-Twinned Metals
Authors: Gao Chong Yang , Lu W.R.
Published: March 2013

In this paper, a constitutive description of the true stress-strain behaviors of nano-twinned metals has been proposed. The size effects of nano-scale twin boundaries (TBs) and ultra-fine grain boundaries (GBs) are considered in the athermal stress. The evolution of the dislocation density with strain under the influence of strain rate and temperature is introduced in the thermal stress based on our previous meso-scale constitutive model. The new model can effectively describe the strength transition regime in nano-twinned metals. The proposed model’s predictions of true stress-strain relation curves for nano-twinned copper are compared with the experimental results of uniaxial tension tests for validation. The comparisons show that the previous models in literature for the dependence of initial yield strength on twin spacing cannot describe the experimental data correctly when the twin spacing tends to zero; however, the phenomenological model proposed in this paper for the twin spacing depending relation is theoretically rational and can well describe the experimental data in the whole range of twin spacing.
A Phenomenological Energy-Based Model for PBX Simulants Considering the Mullins Effect
Authors: Yeom Kee Sun , Jeong Seh Wan , Huh Hoon , Park Jung Su
Published: March 2013

PBX is known to exhibit highly nonlinear behaviors of deformation such as the Mullins effect of stress softening, hysteresis, residual strain, and frequency dependant responses. This paper proposes a phenomenological energy-based model for PBX considering the Mullins effect for isotropic, incompressible, hyperelastic, particle-filled materials. Uniaxial compressive loading and unloading tests at quasi-static states were undertaken in order to obtain the mechanical properties of the PBX simulants. The phenomenological energy-based model by Ogden-Roxburgh is, then, modified to make it consistent with the test result of PBX simulants in the case that the Mullins effect is dominant. Prediction with the new model shows a good correspondence to the experimental data demonstrating that the model properly describes the Mullins effect and the loading-unloading behavior of deformation.
Dislocation Density Based Plasticity Model Coupled with Precipitate Model
Authors: Lindgren Lars Erik , Fisk Martin
Published: March 2013

A dislocation density based plasticity model is applied to two variants of steels. One is an austenitic (fcc) stainless steel with ordered precipitates and the other is a Ti-Nb microalloyed (bcc) steel. Precipitate distributions are measured and this information is combined with appropriate precipitate hardening models. The flow stress model is also calibrated for an nickel-based superalloy where it is combined with a model for precipitate growth.
Cyclic Behavior of an Industrial Brass Cu Zn32
Authors: Flegeau Grégory , Taleb Lakhdar , Hauet Annie , Vassal Christophe
Published: March 2013

The aim of this study is to investigate the cyclic behavior and the fatigue life of an industrial α/β brass through mechanical tests and microstructural observations. The main obtained results are about the cyclic behavior of the alloy and the characterisation of fatigue life in connection with the evolution of the microstructure. Cyclic tensile test shows a great and rapid evolution of the isotropic hardenig during cycling.
Finite Element Simulation of Bending Fretting Fatigue Considering Ratchetting and Cyclic Hardening
Authors: Ding Jun , Kang Guo Zheng , Zhu Yi Lin , Zhu Min Hao
Published: March 2013

Based on a simplified equivalent 2-D plane strain finite element model, the bending fretting fatigue process of 316L stainless steel is simulated numerically by ABAQUS code. In this simulation, the effect of ratchetting on the fretting fatigue process is discussed by implementing an advanced cyclic elasto-plastic constitutive model for cyclic hardening materials into ABAQUS code as a user material subroutine (UMAT). From the numerical simulation, the effect of bending loads on the bending fretting fatigue of 316L stainless steel is addressed, and then the failure lives are predicted by using Smith-Watson-Topper critical plane criteria. Comparison with the corresponding experiments shows that the predicted results are in good agreement with the experimental ones.
Deformation and Recrystallization Textures of Surface Layers of Aluminum and Copper Sheets Cold-Rolled under Unlubricated Condition
Authors: Lee Dong Nyung , Han Heung Nam , Choi Hyun Sik
Published: March 2013

The texture of rolled sheets is known to vary with depth from the surface to the center due to inhomogeneous deformation, which can be caused by a characteristic deformation zone geometry and friction between materials and rolls during rolling. In order to study the deformation and recrystallization (Rex) textures of the surface layers of Al and Cu sheets cold rolled without lubrication, 5 Al sheets were stacked and rolled by 88% and 4 Cu sheets were stacked and rolled by 93% in 4 passes at room temperature. The surface layers separated from the rolled sheets were annealed for 1 h at 500 °C for Al and at 550 °C for Cu. The deformation textures of the surface layers were characterized by different shear textures, which gave rise to very different Rex textures.
Tensile Strength of Electrospun Poly(ethylene-co-vinyl alcohol) Nanofibre Sheets
Authors: Wang Bin , Chao X. , Li Y. , Reid S.R.
Published: March 2013

Electrospinning technology was used to obtain non-woven sheets made from fine fibres in a controllable diameter range from 50 nm to 3 µm. Poly(ethylene-co-vinyl alcohol), a large molecule polymer was chosen to make the fibres for its biodegradable and biocompatible properties. The thin sheets obtained were tested in uniaxial tension for their mechanical properties in view of the potential use as wound dressings. It is found that the sheets show a mild hardening behavior with extensive elongation and necking before failure in multiple fractures at random locations. Due to the random orientation of the continuous fibres in the sheet, detachment, shear, straightening and twinning. etc., occur amongst fibres to different extends at the same time. The Young’s modulus and the yield stress (at 0.4~0.5% proof strains) are predominately affected by fibre diameters, and are largely insensitive to strain rate over the range tested.
Accurate Prediction Approach of 3D Trimming Line for Auto Panel Part
Authors: Bao Yi Dong , Sang Yang , Wang Hou Min
Published: March 2013

It is difficult to obtain 3D trimming line using traditional prediction methods for auto panel parts. An initial geometrical development method with element layer is proposed based on one step inverse analysis theory for this problem. The flange mesh can be unfold onto the die surface layer by layer according to nodal adjacent element relation, then the above development mesh is smoothed by mesh smoothing method with sliding constraint surface in order to delete overlap and distorted mesh, the 3D initial mesh can be obtained for one step inverse analysis method. The accurate 3D trimming line of auto panel part can be achieved by plasticity iteration of one step inverse analysis. A typical real part of 3D trimming line prediction is selected to prove this method, the comparison results between the simulated and experimental values show that this method has enough precision and can handle complex parts, satisfies the engineering practical demands.
Finite Element Analysis Using Dynamic Material Model to Design Process Variables of Radial Forging
Authors: Lim Jeongsuk , Lee Young Seon , Moon Young Hoon
Published: March 2013

In order to obtain a refined and uniform microstructure in the final billet, the radial forging process needs to be optimized and controlled with various process parameters such as temperature of ingot and die, die size, ram speed, upset ratio, etc. Grain size control is one of the most effective ways for the control of mechanical properties. The change in grain size is significantly related with strain, strain rate and temperature of forged part. To understand material properties and to analyze stability and instability area of forged workpiece, hot compression test of Ti-6Al-4V was carried out within the strain-rate range 10-2 to 10 s-1, and the temperature range 800 to 1100oC. And dynamic material map of Ti-6Al-4V was tabulated. In this study, a three-dimensional rigid-plastic finite element method(FEM) was used to analyze the radial forging process, focusing on the effects of feed rate and rotation angle for appropriate forging pass schedule. And the simulation result was confirmed with dynamic material model of Ti-6Al-4V. The optimal combination of feed rate and rotation angle has been determined by quantifying the radius profile in the longitudinal direction, roundness of the product and uniform strain distribution.
Investigation of Copper Foil Thinning Behavior by Flexible-Pad Laser Shock Forming
Authors: Nagarajan Balasubramanian , Castagne Sylvie , Wang Zhong Ke
Published: March 2013

This paper reports on a novel microforming technique, Flexible-Pad Laser Shock Forming (FPLSF) which uses laser-induced shock waves and a flexible pad to induce plastic deformation on metallic foils. Thickness distribution at the cross-section of the craters formed by FPLSF is analyzed experimentally with respect to laser fluence, which is a significant process variable that controls the deformation pressure. Furthermore, hardness of the deformed samples at the cross-section is measured by nanoindentation testing. It is found that the thinning of copper foil by FPLSF ranges from 7% to 25% for laser fluence ranging between 7.3 J/cm2 and 20.9 J/cm2. Thinning is maximum at the crater center, which can be attributed to the maximum compressive stresses in the thickness direction, and minimum at the edge portions. With increase in laser fluence, thinning of the foil increases whereas minimum change in hardness is observed. The variation in thinning across different crater locations ranges between 6% and 8% only, which indicates that FDLSF can be developed as a competitive technique to produce components with uniform thickness distribution.
Tribological Peculiarity of Galling Position in Square Cup Drawing
Authors: Soejima Tomoki , Yang Ming Xu , Wang Zhi Gang , Yoshikawa Yasuharu
Published: March 2013

The high tensile steel sheet attracts attention in recent years. Galling occurs easily in the press forming processes of the high tensile steel sheet because of the high contact pressure. However, the galling behavior can’t be predicted in the forming process yet. The object of this study is to clarify the galling mechanism and develop a prediction method of galling behavior in press forming. Experiments were carried out to investigate the galling behavior in the square cup drawing of a high tensile strength steel sheet. On the die surface, galling occurs at the bottom of the boundary between the straight and corner. On the drawn cup galling starts at the top of the same boundary. The variations of contact pressure, sliding distance and temperature were investigated by using FEM. It was found that galling occurs on the sheet surface position having the history of maximum temperature and at the moment just before sliding out from the die.
Non-Linear Large Deformation Kinetics of Polymeric Gel
Authors: Toh William , Ng Teng Yong , Liu Zi Shun
Published: March 2013

The transient swelling process of polymeric gels is studied and a finite element model is introduced to simulate the phenomena based on existing hyperelastic theory for inhomogeneous swelling of gels and analogies made to transient heat conduction analysis. Examples of free swelling of a cube and a fixed cylinder were investigated, showing the highly non-linear deformation present during transition from the initial state to equilibrium.
Bi-Directional Evolutionary Structural Optimization for Design of Compliant Mechanisms
Authors: Li Yan , Huang Xiao Dong , Xie Yi Min , Zhou Shi Wei
Published: March 2013

This research presents a topology optimization approach based on Bi-directional Evolutionary Structural Optimization (BESO) for optimal design of compliant mechanisms. Due to the complexity of the design for various compliant mechanisms, a new multi-objective optimization model is established by considering the mechanism flexibility and structural stiffness simultaneously. The sensitivity analysis is performed by applying the adjoint sensitivity approach to both the kinematical function and the structural function. The sensitivity numbers are derived according to the variation of the objective function with respect to the design variables. Some numerical examples are given to demonstrate the effectiveness of the proposed method for the design of various compliant mechanisms.
Energy Absorption Characteristics of CFRP Double Hat-Shaped Section Member with Various Stacking Condition under Axial Loading
Authors: Hwang Woo Chae , Yang In Young , Yang Yong Jun
Published: March 2013

Transport is the safety and comfortableness during the transportation of passenger to desired location. Therefore, goals in transport design can be summarized as environment-friendliness and safety. Demand for weight reduction of transport has been growing in order to solve the environmental problems. In many countries, environment conservation forces the enhanced regulation on gas mileage and emission gas due to exhaustion of energy resource, adding an extra weight of environment pollution. CFRP(Carbon Fiber Reinforced Plastic) which the advanced composite materials has a widely used in lightweight structural materials of aircraft, ship and vehicle because of high strength and stiffness. In this study, collapse mode and energy absorption capability double CFRP hat-shaped section members were analyzed. The stacking condition were selected to investigate the effect of the fiber orientation angle (±15°, ±45°, 90°, 90°/0°and 0°/90° where 0°direction coincides with axis of the member)on the energy absorption of the CFRP double hat-shaped section members. The collapse mode and energy absorption capability of CFRP double hat-shaped section members was analyzed according to the change of the fiber stacking condition of CFRP.
Impact Crushing and Rebound of Thin-Walled Hollow Spheres
Authors: Bao Rong Hao , Yu T.X.
Published: March 2013

The dynamic behavior of a thin-walled hollow sphere colliding onto a rigid wall has been studied by experiments, numerical simulation and analytical modeling, as reported in our previous papers. In the present paper, the impact crushing of metallic thin-walled hollow spheres onto rigid plates and the subsequent rebound are analyzed using finite element method. The effects of hollow sphere’s thickness-to-radius ratio, the material properties and the impact velocity on the dynamic responses are systematically investigated. The transition from axisymmetric dimpling to non-axisymmetric lobing is found to depend on the relative thickness of spheres and impact velocity; while the coefficient of restitution almost merely depends on impact velocity.
A Study on Injection Molding Analysis and Structural Analysis with Truck Brake Pedal
Authors: Park Chul Woo , Seo Seong Ho
Published: March 2013

Injection molding process one of the most important methods to produce plastic parts with high efficiency and low cost. Today, Injection molded parts have been increased dramatically the demand for high strength and quality applications. In this study, truck brake pedal is made of Cast iron and plastic materials to replace the frame for the optimization process that minimizes the runner and the gate dimension will determine the size and shape. Runner and gate dimensions of change based on availability of the product. I will discuss the injection molding. This report investigates that the optimum injection molding condition for minimum of runner and gate position. The FEM Simulation CAE tool, MOLDFLOW, is used for the analysis of injection molding process.
Numerical Analysis of Hypervelocity Impact Problems with Large Deformations, High Strain Rates and Spall Fractures
Authors: Liu Kai Xin , Wu Shi Yu , Chen Qian Yi
Published: March 2013

In the study, a software program named “SUPER CE/SE” is developed for the simulation of hypervelocity impact problems with large deformations, high strain rates and spall fractures. In the software program, an Eulerian method consisting of an improved CE/SE (Space-time Conservation Element and Solution Element Method) scheme is used. A void growth model which takes the Bauschinger Effect (BE) into account and a newly proposed front tracking method are adopted in the simulation. The formation and propagation of a crack is described by a newly developed automatic crack growth algorithm. Numerical simulation of spall fracture in a plate when impacted by a spherical projectile at a velocity of 6.0 km/s is carried out. The numerical results are in qualitative agreement with the corresponding experimental data. It turns out that the BE has obvious influence on the length of the crack and better agreement with the experiment is obtained when the BE is considered. It is also validated that the newly proposed front tracking method is feasible and reliable for representing the cracks in the problems with large deformation and high strain rates. According to those research results, it is proved that the software program SUPER CE/SE is robust and effective in the simulation of hypervelocity impact problems.
Compressive Behavior of Luffa Sponge Material at High Strain Rate
Authors: Shen Jian Hu , Xie Mike , Huang Xiao Dong , Zhou Shi Wei , Ruan Dong
Published: March 2013

The strain rate effect of luffa sponge material is an indispensable property for it to be used for acoustic, vibration, and impact energy absorption. Compressive tests at different strain rates on cylindrical column specimens of luffa sponge material were conducted over a wide density ranging from 24 to 64 kg/m3. A photographic technique was applied to measure the section area of the specimen with irregular shape. The mechanical properties of luffa sponge material at various strain rates were obtained based on this measurement. The dynamic data were compared to those of quasi-static experiments. It was found that compressive strength, plateau stress and specific energy absorption of luffa sponge material were sensitive to the rate of loading. Empirical formulae were developed for strength, densification strain and specific energy absorption at various strain rates in the macroscopic level by considering the luffa fiber as base material.
Effect of Tensile Speed on the Failure Load of Laser Welding under Combined Loading Conditions
Authors: Ha Jiwoong , Huh Hoon , Pack Keunhwan , Jang Soonkeun
Published: March 2013

This paper is concerned with the failure characteristics and the failure loads of laser welds in a SPRC340 1.2t steel sheet under combined normal and shear loading conditions. The quasi-static and dynamic failure tests were carried out under nine different combined normal and shear loads including a pure-normal load and a pure-shear load. Especially for the pure-shear condition, a testing fixture was newly designed in order to evaluate the strength of a laser-welded region fabricated by the same welding condition as a two-layered lap joint. The failure load and the failure behavior of laser welds were investigated in each loading condition. Dynamic effects on the failure load of laser welds, which are critical for structural crashworthiness, were also examined based on the experimental data. In order to evaluate the effect of the strain rate on the failure contour of laser welds under the combined normal and shear loads, the failure loads measured from the experiment were decomposed into two components along the normal and shear directions.
A Composite Film of V2O5 and Multiwall Carbon Nanotubes as Cathode Materials for Lithium-Ion Batteries
Authors: Zhou Xiao Wei , Wu Guang Ming , Gao Guo Hua , Yang Hui Yu , Wang Ji Chao
Published: March 2013

In this paper, V2O5-Multiwall Carbon Nanotubes (MWCNTs) composite film is prepared through sol-gel technique and dip-coating method. MWCNTs pretreated by mixed acid, H2O2 and cheap V2O5 powder are used as raw materials. The morphology, structure and components of the composite film are characterized by corresponding testing instruments. The final electrochemical measurements indicate that: the V2O5-MWCNTs composite film as cathode materials for lithium batteries exhibits better electrochemical performance than ordinary V2O5 film.