bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Configuration Technology in Traffic Light Control System Based on PLC
Authors: Yao Yu Peng , Shi Ying , Fei Ji You
Published: February 2012

Configuration technology is a new technology for monitoring in the current society; it is the result of the development of computer control technology. To traffic light control system, it is to combine the use of configuration technology and procedures related to PLC, and through software simulation and traffic lights light changes, traffic light control system could achieve the monitoring problem, and if the system is in good condition, its application can save a lot of labor powers and materials.
An Appraisal System for Bilateral Vehicle Accident
Authors: Tseng Wen Kung , Lu Chung Sheng
Published: February 2012

There are hundreds of accidents every day recorded by government due to the human factor and environmental factor in Taiwan. The accident usually involved the money dispute; therefore the accident appraisal must indicate the bilateral parties’ blame clearly: all blame; major blame; minor blame and none blame. Although the local police can give a preliminary analysis report at first, the report cannot be official evidence. If the people need a credible appraisal report, they have to apply for the Taiwan Provincial Government Traffic Accident Investigation Committee’s accident appraisal report. However, applying for Committee’s accident appraisal report will take long time. Therefore, this study employed radial basis function neural network to build an expert system for appraisal of bilateral vehicle accident. The database was built from 307 accident cases in Taiwan from the year of 2004 to 2010. According to Committee’s analysis, there are 30 appraisal basses including 6 environmental basses and 24 vehicle basses chosen to be the input of the expert system. The training data includes three types: 70 cases training; 140 cases training; 207 cases training. Validation stage was carried out by using 100 fixed cases and the correctness was recorded. In the first stage, correctness rate is 76% for training with 70 cases. In the second stage, correctness rate is increased to 81% for training with 140 cases. In the third stage, correctness rate is increased to 89% for training with 207 cases. The training and validation processes were completed in one second. Therefore, the expert system proposed in this work is demonstrated to be an efficient system for the accident appraisal.
Deconstructing Forward-Error Correction
Authors: Fang De Jian
Published: February 2012

Hash tables must work. In fact, few experts would disagree with the development of rasterization, which embodies the natural principles of cryptoanalysis. We present new distributed symmetries, which we call NOG.
The Preparation of a Novel Environmentally Friendly Green Antimicrobial Packaging Film
Authors: Duan Jiu Fang , Zhao Heng , Zhang Xiao Jian , Li Zi Yu , Shi Ling Ling , Zhao Guang Jie
Published: February 2012

Antimicrobial packaging is a hot research in food packaging research. A new type of antibacterial packaging film preparation was introduced in this paper. The new composite membrane was successfully prepared by using poly (succinic acid - adipic acid - butanediol) ester (PBSA) film as the base film through surface grafted approach, and nano-silver ions were used as antimicrobial agent in the antimicrobial film. The results showed that the new PBSA film has a good antibacterial antibacterial properties, and the best antibacterial agent formulations have been identified.
Interacting Fatigue Crack Growth Analysis with Boundary Cracklet Method
Authors: Yavuz A. Kadir , Senalp A. Deniz , Türkmen Halit S. , Phoenix S. Leigh
Published: February 2012

In this study, interacting crack growth in an infinite plate is analyzed with new, fast and accurate Boundary Cracklet Method (BCM) developed by Phoenix and Yavuz. An interior crack is under consideration to watch its propagation because of cyclic loading which is very common for aerospace, naval and civil engineering structures. BCM is very useful to determine the overall stress field as well as stress intensity factors for crack tips and singular wedges at crack kinks. BCM uses integral equations expressed in terms of unknown edge dislocation distributions along crack lines. These distributions derive from an accurate representation of the crack opening displacements using power series basis terms obtained through wedge eigenvalue analysis, which leads to both polynomial and non-polynomial power series. The process is to choose terms of the series and their exponents such that the tractions on the crack faces are virtually zero compared to the far field loading. Applying the method leads to a set of linear algebraic equations to solve for the unknown weighting coefficients for the power series basis terms to make no use of numerical integrations unlike in other methods. Thats why, solution takes just a few seconds on a PC. A simple crack growth emanating from a triangular hole in an infinite plate is analyzed. The fatigue crack growth is assumed to follow Paris-Erdogan Law. The results are compared to those of other numerical methods. A parametric study is performed via graphs and tables to demonstrate the ability of BCM in analysis of fatigue crack growth.
Upper Bound Analysis and Finite Element Simulation of Bi-Metallic Tube Backward Extrusion
Authors: Momeni-Khabisi H. , Haghighat H. , Momeni-Khabisi M.J.
Published: February 2012

In this paper, the process of bi-metallic tube backward extrusion through a conical punch, by means of upper bound method and finite element method is investigated. A cylindrical admissible velocity field is developed and by calculating the internal, shear and frictional powers, the extrusion force is estimated. The extrusion process is also simulated by using the finite element code, ABAQUS. Analysis and simulations are done for two types of bi-metallic tubes: aluminum as core, copper as sleeve (Al-Cu) and copper as core, aluminum as sleeve (Cu-Al). The extrusion force from the upper bound method is compared with the Finite Element results. This comparison shows that the upper bound predictions are in good agreement with the Finite Element results. The results also show that, the extrusion force in the case of Al-Cu tube is smaller than Cu-Al tube and in both types of bi-metallic tubes, the aluminum leaves the deformation zone sooner than the copper. Finally the effects of various extrusion parameters, such as the friction factor, reduction in area and semi-punch angle upon the extrusion force are investigated and the optimum semi-punch angle is determined.
Effect of Melt Quality and Quenching Temperature on the Mechanical Properties of SIMA 2024 and 7075
Authors: Tan Engin , Tarakcilar Ali Riza , Dispinar Derya
Published: February 2012

Spherical grains can be obtained by several semisolid processes in aluminium alloys. One of these methods is called Strain Induced Melt Activated (SIMA). In this work, commercially available 2024 and 7075 alloys were subjected SIMA process. First, optimised process parameters were investigated for the homogeneous spherical grain structure. This was followed by solution heat treatment of the parts. For the quenching medium, room temperature and 80°C boiling water was selected. The effect of different quenching temperatures over the mechanical properties was tested. Hardness, tensile and fatigue tests were applied. In addition, reduced pressure test was used to assess alloy quality and the results were compared with the mechanical tests.
Statistical Evaluation Tensile Properties of High-Density Polyethylenes
Authors: Koyun Ahmet , Koksal Baris , Ahlatcioglu Esma , Yoruç A. Binnaz Hazar
Published: February 2012

The mechanical properties, among all the properties of plastic materials, are often the most important properties because virtually all service conditions and the majority of end-use applications involve some degree of mechanical loading [1]. In the present work three different commercial polyethylene materials are tensile tested at four or five different tensile rates and two or three temperatures. Tensile test results against tensile rate include stress at 0.5 % elongation, tensile strength, yield strength, modulus of elasticity, elongation at yield and % elongation are determined. It is concluded that the structure, chain lengths and branching rates of polymer matrix significantly effected tensile test curve characteristic.
A Case Study on Quality and Productivity Optimization in Electric Discharge Machining (EDM)
Authors: Dalai H. , Dewangan S. , Datta Saurav , Patel S.K. , Mahapatra S.S.
Published: February 2012

Quality and productivity are two important aspects have become great concerns in todays competitive global market. Every manufacturing/ production unit mainly focuses on these areas in relation to the process as well as product developed. Achieving high quality necessarily requires higher degree of skill, sophisticated machine/ tools, advanced technology, precise control, immense attention-inspection and considerable time. Improvement of quality results reduction in productivity and vice versa. Thus, optimality must be maintained between quality as well as productivity. The case study highlights EDM of stainless steel in which best process environment (optimal) has been determined to satisfy productivity and quality requirements simultaneously. Material Removal Rate (MRR) during the process has been considered as productivity estimate with the aim to maximize it; whereas surface roughness i.e. (Ra value) of the machined surface has been chosen as surface quality estimate with the requirement to minimize it. These two contradicting requirements have been simultaneously satisfied by selecting an optimal process environment (optimal parameter setting). Desirability Function (DF) approach coupled with Taguchi method has been used to solve the problem.
Correlation between Mechanical Properties and Porosity Distribution of A356 in Gravity Die Casting and Low Pressure Die Casting
Authors: Dispinar Derya , Akhtar S. , Nordmark A. , Syvertsen F. , Di Sabatino M. , Arnberg L.
Published: February 2012

Gravity die casting (GDC) and low pressure die casting (LPDC) methods were used to compare the mechanical properties and porosity distribution in a 5-step mould design. Commercially available A356 alloy was used for the experiments. Ar and Ar+H2 mixture were used to achieve two different hydrogen levels, i.e. 0,1 and 0,2 ml/100g Al, respectively. Although the porosity level was lower in LPDC, the tensile properties were lower than GDC due to the fact that LPDC melt had 50 mm bifilm index, whereas GDC melt had 20 mm. This investigation has shown that the metal quality has a larger effect over the mechanical properties than the porosity content.
Finite Element Modelling in Ultrasonic Sheet Metal Forming
Authors: Daud Yusof , Lucas Margaret , Jamaludin Khairur Rijal
Published: February 2012

Finite element (FE) model of die necking process of an aluminium hollow thin cylinder has been developed. The input parameters of material properties and coefficient of friction, µ for the model have been deducted from our previous experimental study. Later the models have been validated against experimental data as reported in the previous studies. For the die necking process, the FE model has successfully to predict how much the original diameter of the aluminium hollow cylinder can be maximised necked with and without applying ultrasonic vibration. FE models showed that the application of ultrasonic vibration during the necking process has reduced buckling of the cylinder body if compared to the necking process without ultrasonic. The benefit of applying ultrasonic vibration in sheet metal forming process has been related to the reduction of interface friction between die and specimen.
Experimental Investigation of the Rubber-Filled Tubes in the Tube Inversion Process
Authors: Niknejad Abbas , Liaghat Golam Hosein , Moeinifard Majid
Published: February 2012

In this paper, the effects of the fillers in the rubber-filled circular tubes are investigated during the inversion process of the tubes under the axial loading, experimentally. For this purpose, a comparison between the experimental results of the empty and rubber filled circular tubes was performed. The inversion tests were carried out on the rubber-filled and empty brazen circular tubes. A pair of die and punch was prepared as the fixtures. All the inversion tests are performed under quasi-static axial loading. The experimental results of the filled tubes show a considerable increase in the energy absorption and the axial force comparing with the empty tubes, during the tube inversion process. The filler material in the circular tubes was supplied from the wastage of the tire producer companies. This is one of the best applications of the tire wastage that has good environmental and economical advantages. The tire wastage filled-tubes are introduced as a good energy absorber that can be used in the energy absorption mechanisms such as automobile bumpers, crashing barriers of roadsides, and aerospace.
Morphological Instability in Early Stages of Solidification of Pure Metals Part I: A Theoretical Model
Authors: Yigit Faruk
Published: February 2012

A simple one dimensional model has been introduced to investigate the morphological instability observed in many solidification processes. It is shown that the solidified shell material with higher thermal conductivity might result in planar shell growth, whereas the mold material with higher thermal conductivity may cause irregular growth of the shell which, generally, causes cracking near the surface, and the thicker mold causes faster growth of the shell, and the higher thermal contact resistance leads to faster growth of the shell.
Optimizing the Sintering Parameter of Metal Injection Molding Compact Using Robust Engineering Technique
Authors: Jamaludin Khairur Rijal , Muhamad Norhamidi , Ahmad Sufizar , Ibrahim Mohd Halim Irwan , Mohd Nor Nor Hafiez , Bin Harun Mohd Ruzi , Md Daud Mohd Yusof
Published: February 2012

Sintering is a key step in the metal injection molding (MIM) process, which affects the mechanical properties of the sintered part. The mechanical properties of the sintered compacts are resulted from tremendous sintered part densification. This work utilizes robust engineering technique in optimizing sintering parameters of metal injection molding compacts. Three quality characteristics; shrinkage, density and flexure strength is optimized using Taguchi method-based grey analysis. The modified algorithm adopted here was successfully used for both detraining the optimum setting of the process parameters and for combining multiple quality characteristics into one integrated numerical value called grey relational grade. The sintering parameters investigated are: sintering temperature, sintering time, and heating rate. The result concluded that sintering time is the most significant for the combination of the quality characteristics.
Modelling of Powder Forming Processes in Transient-Dynamic Analysis of Large Plastic Deformations
Authors: Khoei Amir R. , Biabanaki S.O.R. , Parvaneh S.M.
Published: February 2012

In this paper, a transientdynamic analysis is presented for large deformation of powder forming process. The technique is employed using the contact friction algorithm and plasticity behavior of powder. The contact algorithm is applied by imposing the contact constraints and modifying the contact properties of frictional slip through the node-to-surface contact algorithm. A double-surface cap plasticity model is used for highly nonlinear behavior of powder. In order to predict the non-uniform density and stress distributions during powder die-pressing, the numerical schemes are examined for accuracy and efficiency in modeling of a set of powder components.
Investigation of Weld Line Movement in Tailor Welded Blank Forming
Authors: Korouyeh R. Safdarian , Naeini Hassan Moslemi , Liaghat Golam Hosein , Kasaei M.M.
Published: February 2012

Weld line movement is one of the important parameters in Tailor Welded Blanks (TWB) forming. Weld line movement is important from some aspects: First, weld line position in the final part is so important because TWB part will be assembled with other parts and weld line movement can influence on assembling. Second, weld line movement which often is towardthe stronger (thicker) metal cause necking and fracture in weaker (thinner) metal. A forming criterion for tailor welded blank will be presented based on the analytical model in this research. This criterion suggests Limit Strength Ratio (LSR) and Limit Thickness Ratio (LTR) for forming limit of TWB.When thickness ratio or strength ratio in tailor welded blank is greater than LTR or LSR, weld line movement will be increased and cause forming decrease. Some simulation tests are done for correction investigation of this theoretical model.
Porous Hydroxyapatite–Zirconia Composites Prepared by Powder Deposition and Pressureless Sintering
Authors: Pujiyanto E. , Tontowi A.E. , Wildan Muhammad Waziz , Siswomihardjo Widowati
Published: February 2012

In the present study, hydroxyapatite was synthesized from local gypsum by microwave-hydrothermal method. Different percentage amounts of zirconia (0, 20, 30 and 40 wt.%) and poly-methyl methacrylate (40, 50 and 60 wt.%) mixed with hydroxyapatite (HA) for six hours. These powder mixture were deposited using deposition machine to produce specimens. These specimens were sintered at a temperature of 140°C with holding time for 1 hour into the green parts. These green parts were sintered at temperature of 1450°C with holding time for 2 hours. This process produces porous hydroxyapatite-zirconia composites with porosity between 62.76-73.92 percent. These composites were examined by XRD, XRF, SEM-EDX, BET analysis and compressive strength testing. Compressive strength of porous hidroxyapatite-zirconia composite decreased from 3.706 to 0.039 MPa when percentage amounts of zirconia increased up to 40 wt.%. This caused by several factors i.e. increased porosity, grain zirconia cracked, zirconia reacted with HA to produce CaZrO3, β-TCP and α-TCP, HA matrix cracks because of the phase change of tetragonal-zirconia into monoclinic-zirconia.
Properties of Montmorillonite-Reinforced Thermoplastic Sago Starch Composites
Authors: Zuraida Ahmad , Yusliza Y. , Nurizan O. , Anuar H. , Halim Zahurin , Noorasikin S.
Published: February 2012

In this work, biodegradable polymer was prepared from thermoplastic sago starch (TPSS) plasticized with glycerol. In order to improve the properties of the TPSS, Montmorillonite (MMT), a kind of reinforced additive was used in the preparation of montmorillonite-reinforced thermoplastic sago starch (MTRSS) composites via hot pressing method. The fabricated samples were investigated through X-ray diffractometry, Fourier transform infrared (FT-IR) as well as thermal and morphological properties. FT-IR patterns show that in the MTRSS composites, the C-O groups of sago starch molecules shifted to higher wave number, while the reactive hydroxyl groups of MMT shifted to the lower wavenumber. On the other hand, X-ray diffraction revealed that MMT restrained the crystallization of MTRSS and intercalated in TPSS. Thermogravimetric analysis (TGA) revealed that the thermal stability of MTRSS was better than those of TPSS. In addition, the scanning electron micrograph results show that MMT were uniformly dispersed in the TPSS.
Processing, Structural and Electrical Properties of Textured Potassium Strontium Niobate (Ksr2Nb5O15) Piezoceramic Fibers
Authors: Dursun Sinan , Alkoy Sedat
Published: February 2012

Highly [00 textured KSr2Nb5O15 (KSN) ceramic fibers were fabricated by a combination of novel alginate gelation method and templated grain growth using acicular KSr2Nb5O15 template particles. Fibers were drawn from alginate based slurries without or with 25 and 100wt% KSN template particles. A texture fraction of 0.90 was obtained in the case of 25 wt% and a single crystal like texture was obtained in the case of 100wt%. Piezocomposites with 1-3 connectivity were prepared from the KSN fibers and their electrical and electromechanical properties were investigated. Dielectric constant of 140, piezoelectric charge coefficient of 45 pC/N, remnant polarization of 16.6 μC/cm2 and electric field induced strain of up to 0.035% were obtained from piezocomposites with textured fibers.
Modeling and Placement of Thermopiezoelectro-Magnetic Materials
Authors: Sunar M. , Al-Athel K. , Yilbas Bekir Sami , Al-Qahtani H. , Ayar T.
Published: February 2012

There has been a vast interest in the general coupled field analysis of thermopiezoelectro-magnetic materials under which smart piezoelectric, thermopiezoelectric and magnetostrictive materials can be studied. The smart materials are often bonded as thin films on host structures for the purpose of sensing and/or actuation. It is well-known that the placement of sensors and actuators is important in order to obtain the appropriate sensor input and to provide the adequate actuation power. This study aims at modeling the important phenomenon of thermopiezoelectro-magnetism suitable for beam and/or plate type-host structures. The thermopiezoelectro-magnetic materials are modeled using the finite element method and the resulting equations are used for decision making on the best placement of the smart actuators on various host structures.
Investigation of Polyaniline Nanocomposites and Cross-Linked Polyaniline for Hydrogen Storage
Authors: Demirocak Dervis E. , Kuravi Sarada , Ram Manoj K. , Jotshi Chand K. , Srinivasan Sesha , Kumar Ashok , Goswami Yogi , Stefanakos Elias
Published: February 2012

One of the biggest challenges for the commercial application of existing hydrogen storage materials is to meet the desired high volumetric and gravimetric hydrogen storage capacity and the ability to refuel quickly and repetitively as a safe transportation system at moderate temperature and pressure. In this work, we have synthesized polyaniline nanocomposites (PANI-NC) and hypercrosslinked polyaniline (PANI-HYP) materials to provide structure and composition which could meet the specific demands of a practical hydrogen storage system. Hydrogen sorption measurements showed that high surface area porous structure enhanced the storage capacity significantly at 77.3K and 1atm (i.e., 0.8wt% for PANI-HYP). However at 298K, storage capacity of all samples is less than 0.5wt% at 70 bar. Hydrogen sorption results along with the surface area measurements confirmed that hydrogen storage mechanism predominantly based on physisorption for polyaniline.
Oxidation Kinetics of Chromium Carbide Coating Produced on AISI 1040 Steel by Thermo-Reactive Deposition Method during High Temperature in Air
Authors: Şen Şaduman , Ozdemir Ozkan , Demirkıran A. Sukran , Şen Uğur
Published: February 2012

Oxidation of chromium carbide coating formed on AISI 1040 steel deposited by thermo-reactive deposition method (TRD) has been realized by two stepped reactions. In the initial part of the reactions in the oxidation process, carbon atoms combined with chromium on the outer part of the coating layer react with the oxygen in air, effectively up to 120 min. After that, the chromium atoms react with oxygen in the air and produce Cr2O3 phase on the coating layer. The higher the temperature and the longer the treatment time, the more the Cr2O3 phases became. The kinetic study was realized for the reactions of carbon and chromium with oxygen, individually. The kinetic study of oxidation was calculated by weight changing of the coated samples at the temperatures of 973 K, 1073 K and 1273 K up to 720 min. We established that the chromium carbide coated steel are characterized by an insignificant increase in the mass in the oxidation period up to 3.5 h, after which the degree of oxidation increases somewhat. The nature of oxidation kinetics for chromium carbide coated steel varies from some mass degrease in the initial period ( 2 h) in connection with the formation of CO and CO2 to later mass increase with in connection with the formation of Cr2O3 layer. The oxidation resistance of chromium carbide coated steel decrease with an increase in oxidation temperature. The growth rate constant of oxidation of chromium carbide coated steel ranged from 5.13x10-13 to-9.617x10-11 g4.cm-2s-1 in the initial period of oxidation (up to 120 min), while it ranged from 3,163x10-13 to 2.188 x10-10 g4.cm-2s-1 in the second period of oxidation test (over 120 min). The activation energies of oxidation of the chromium carbide coated steel are 185 kJ/mol for the initial period and 215 kJ/mol for the second period.
Wear Mechanism of ADI
Authors: Khazaei Bijan Abbasi
Published: February 2012

In this research wear mechanism of ADI under different intensity of loading with different hardness have been investigated. To study of wear behavior, a series of austempered specimens with optimum mechanical properties were used for wear tests. Dry sliding wear tests were carried out in pin-on-ring wear tester machine at speed of 0.5 ms-1 and loaded with normal loads of 100,200,300 and 400 N. Scanning electron microscopy for microstructure and wear surface analysis was used. To determine the austenite volume fraction and the percentage of carbon content in austenite, X-ray diffraction analysis was used. Results show that the role of retained austenite at wear properties of ADI is dependent on loading intensity and austenite carbon content.
Study of Surface Melting of Pre-Plasma Sprayed WC-14%Co Low Carbon Steel
Authors: Heydarzadeh Sohi M. , Shahbazi S. , Halvaee Ayyub
Published: February 2012

In this study tungsten inert gas (TIG) surface melting of pre- plasma sprayed WC-14%Co low carbon steel has been studied. Surface melting was performed under different heat inputs by using various TIG parameters including intensity and kind of current. Microstructure and microhardness of surface alloyed specimens were then studied. Eutectic structures containing tungsten-rich carbides were shaped in a matrix including martensite lath, when high heat input was used. Decreasing at heat input affected the microstructure of the alloyed layers, and high amount of faceted tungsten-rich carbides (Fe3W3C) were formed in fairly low heat input. Microhardness of melted layers highly improved in comparison with that of the substrate.
Dissimilar Friction Stir Welds in AA 5086-AA 2024: The Effect of Process Parameters on Microstructures and Mechanical Properties
Authors: Akbari Mousavi Seyed Ali Asghar , Sham Abadi S.H.
Published: February 2012

The effect of tool traverse and rotation speeds on the microstructures and mechanical properties are quantified for welds between non-age-hardening Al5083 and age hardening Al2024 and compared to single alloy joints made from each of the two constituents. In this paper, we report the results of microstructural, mechanical property investigations of Al5186Al2024 friction stir welds produced using various rotations and traveling speeds of the tool to investigate the effects of the welding parameters on the joint strength. Metallographic studies by optical microscopy, electron probe microscopy, and the utilization of the X-ray diffraction technique have been conducted. It was found that the weld properties were dominated by the thermal input rather than the mechanical deformation by the tool. In particular the larger stresses under the weld tool on the AA5186 side compared to the AA2024 side are related to a transient reduction in yield stress due to dissolution of the hardening precipitates during welding prior to natural aging after welding.
Mechanical Characterization and Modeling of Cyclic Behavior of Ultra High Molecular Weight Polyethylene (UHMWPE)
Authors: Colak Ozgen U. , Asmaz Kerem , Hassan Tasnim
Published: February 2012

The objective of this work is to study the stress-strain responses of ultra high molecular weight polyethylene (UHMWPE) under uniaxial and biaxial cyclic loading through systematically conducting experiments and model simulations. Experiments involved prescribing axial, strain and stress controlled, cycles to the specimens of UHMWPE. Since the ratcheting strain and its accumulation rate are sensitive to the mean (or steady) and amplitude stresses of the prescribed loading cycles, these parameters were varied in the experiments conducted. The viscoplasticity theory based on overstress (VBO) [ was implemented to simulate the cyclic and ratcheting responses of UHMWPE. Kinematic stress is the main state variable in constitutive models which affect cyclic behavior and the ratcheting. Therefore, different kinematic hardening laws such as Prager, Frederick-Armstrong, Burlet-Cailletaud, Ohno-Wang and Chaboche, are used to investigate ratcheting behavior of UHMWPE. The experimental and VBO simulated responses are compared to demonstrate the current state of the simulations and future model development needs.
Surface Roughness Prediction Model in Machining of 34CrMo4 Steel with Several Tools Using Response Surface Methodology
Authors: Barghikar Hamed , Poursafar Amin , Amrollahi Abbas
Published: February 2012

The surface roughness model in the turning of 34CrMo4 steel was developed in terms of cutting speed, feed rate and depth of cut and tool nose radius using response surface methodology. Machining tests were carried out using several tools with several tool radius under different cutting conditions. The roughness equations of cutting tools when machining the steels were achieved by using the experimental data. The results are presented in terms of mean values and confidence levels.The established equation and graphs show that the feed rate and cutting speed were found to be main influencing factor on the surface roughness. It increased with increasing the feed rate and depth of cut, but decreased with increasing the cutting speed, respectively. The variance analysis for the second-order model shows that the interaction terms and the square terms were statistically insignificant. However, it could be seen that the first-order affect of feed rate was significant while cutting speed and depth of cut was insignificant.The predicted surface roughness model of the samples was found to lie close to that of the experimentally observed ones with 95% confident intervals.
A Multi-TAD Framework for Recognizing Machining Features Using Hint Based Recognition Algorithm
Authors: Parvaz Hadi , Nategh Mohammad Javad
Published: February 2012

Feature recognition is a powerful tool for integrating CAD and CAM. Hint based algorithm is one of the most useful tools for recognizing features that is usually used with other algorithms forming hybrid systems. In the present study, hint based algorithm has been chosen as the main tool for recognizing machining features by defined recognition rules. Beside the need for low computation, the specific characteristic of the proposed recognition system is its multi-tool access direction (multi-TAD) property where the designed algorithm recognizes and lists each machining feature with its special access direction. It detects all the features available in each TAD and sorts the TADs in descending order of their number of features. The developed recognition system is capable of recognizing different types of isolated and nested intersecting feature types. The developed software accepts neutral file formats (i.e. STEP and IGES) beside the B-Rep CAD model as its input CAD file. The developed system has been tested with different CAD parts.
Wear Monitoring of Connecting Rod Bearing via Air-Borne Method Analyzed by Using I-KazTM Multi Level Value
Authors: Karim Zailan , Nuawi Mohd Zaki , Ghani Jaharah A. , Abdullah Shahrum , Ghazali Mariyam Jameelah
Published: February 2012

Different techniques have been developed in the area of bearing wear monitoring. This paper proposes a different experimental study on bearing wear monitoring by using an airborne technique. The data captured in the airborne technique will be analyzed by using I-kazTM Multi Level (7Z) coefficient and then will be correlated with the conventional specific wear rates, K. The wear tests were carried out by using a pin-on-disc configuration at a sliding speed of 7.85 m/s. A set of sliding distance ranging from 20 160 km at a fixed load of 200 N was utilized and the K value was measured at every interval of 20 km for the speed. SAE40 type lubricant was used in the test to simulate the actual operation of the connecting rod bearing. The audio range frequency below 20 kHz in the airborne technique was obtained through a microphone 40SC type which was placed 10 mm from the pin-disc contact. The analysis result showed that the wear rate, K increased from 1.82 to 6.70x10-8 mm3/Nm as the sliding distance increased, indicating that a mild-abrasion wear regime had occurred. The curve fitting of K as a function of I-kazTM Multi Level coefficient showed a similarity to an established of Taylor Tool Life curve. Thus, it was possible to correlate the Taylor curve and worn bearing, mainly in monitoring and identifying the bearing condition with respect to the sliding distance. The trend of I-kazTM Multi Level coefficient was found to be consistent with the increase of sliding distance which indicates that the I-kazTM Multi Level value can positively be used as wear response indicator for bearing.
Low Velocity Impact Resistance of CPVC Pipes Exposed to Natural Outdoor Weathering Conditions
Authors: Khan Z. , Merah Necar , Bazoune A. , Furquan S.
Published: February 2012

Low velocity drop weight impact testing of CPVC pipes was conducted on 160 mm long pipe sections obtained from 4-inch (100 mm) diameter schedule 80 pipes. Impact test were carried out for the base (as received) pipes and after their exposure to out door natural weathering conditions in Dhahran, Saudi Arabia. The results of the impact testing on the natural (outdoor exposure) broadly suggest that the natural outdoor exposures produce no change in the impact resistance of CPVC pipe material for the impact events carrying low incident energies of 10 and 20J. At the impact energies of 35 and 50J the natural outdoor exposures appear to cause appreciable degradation in the impact resistance of the CPVC pipe material. This degradation is noted only for the longer exposure periods of 12 and 18 months.
Influence of Tool Material on the Electrical Discharge Machining of AISI H13 Tool Steel
Authors: Seyedzavvar Mirsadegh , Shabgard Mohammad Reza
Published: February 2012

This paper presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of tool material on the characteristics of Electrical Discharge Machining process of AISI H13 tool steel. The studied process characteristics included the tool wear ration and thickness of the white layer on the workpiece after the EDM process. The experiments carried out under the designed full factorial procedure and the considered EDM input parameters included pulse on-time and pulse current. The results of this study could be utilized to choice a set of pulse on-time and pulse current according to the outcomes that suit the requirements of tool-workpiece combination processed by the EDM.
The Influence of Technical Factor and Ingredient Design on Crystallization Behavior of MgO-SiO2-Al2O3-B2O3-KF Glass-Ceramics
Authors: Zhang Xiao Li , Fan Ji Wei , Fan Ping
Published: February 2012

In this paper, the the micro crystallization behavior of MgO-SiO2-Al2O3-B2O3-KF glass-ceramics which was prepared by sintering and water quenching method was discussed. The study indicated that the compacts shrinkage of MgO-SiO2-Al2O3-B2O3-KF glass-ceramics were related to its vitrification and its component crystallization degree; about the density of sintered compacts, the higher the crystallization degree, the higher the dense it owns. The conclusion reached above is significant in dimension control to the produce process. In the samples when the proportion of ingredient was closer to the atomic ratio of mica crystal, the higher the micro crystallization degree of the glass-ceramics will be. When sintering temperatuer is 1000oC,the MgO-SiO2-Al2O3-B2O3-KF glass-ceramics begain to present the crystallization; when it achieves to 1050°C, the crystallization degree is highest; continue to increase the sintering temperature, the micro crystallization will be melted again.
Research on Gradient Law of Beam Height in Long-Span Continuous Rigid Frame Bridge
Authors: Zheng Guo Dong , Zhang Huan
Published: February 2012

Combined the design of a long-span continuous rigid frame bridge of a highway in Pearl River Delta of China and based on the longitudinal and lateral force characteristics of the large span, wide margin and wide box structure, the appropriate principles and methods to determine the index of the parabolic line is raised through analyzing and comparing the impact of the gradient law of the parabolic beam height of different index on structural forces.
Settlements of Existing and Widened Embankments over Soft Soils
Authors: Cao Wei Ping , Shi Qi Chao
Published: February 2012

Increased traffic volume has made it urgent to improve highway capacities by widening the existing embankments in south-eastern coastal areas of China. Adding a new embankment adjacent to the existing embankment will result in additional settlement within the existing embankment. And also, differential settlement will occur between the existing and widened embankment over soft soils. Excessive settlement and/or excessive differential settlement may cause longitudinal cracks, drop-off on the road surface, even local or global instability. A numerical analysis was conducted to investigate the influence of the thickness of soft soils on the development of settlements of the existing and widened embankment. The effect of widening time on the settlements was also discussed. The results indicate that the thicker the soft soils, the more time needed for the existing embankment to reach its final settlements. It is also found that there exists a most appropriate widening time for minimizing the additional settlements of the existing embankment on soft soils with a given thickness.
An Experimental Study on the Thermal Properties of Concrete under the Load Ratio Condition in a Fire
Authors: Kim Heung Youl , Kim Hyung Jun , Lee Jea Sung , Kwon Ki Hyuk
Published: February 2012

When a fire occurs, the strength of the concrete structure deteriorates due to temperature rise under the condition of constant load. The deterioration in strength causes the change in axial load ratio, so the structure is deformed. In this study, loaded heating test of concrete lining was conducted to realize the condition of an actual fire outbreak in a tunnel where heating and loading affect the structure simultaneously. The shape of the specimens was planned in compliance with the standard for small scale test prescribed in the EFNARC and 24 MPa, 40 MPa and 50MPa were used to analyze the thermal properties associated with different concrete strengths. Constant loading condition was provided based on the load ratios equivalent to 20 % and 40 % of the sectional stress in the concrete and the MHC fire scenario was selected to realize the thermal impact on the concrete by rapid temperature rise. Under each load ratio, more cracks were observed in higher strength and spalling occurred in 50MPa. In terms of fire damage range, 50mm points from heated surface of the 200mm lining did not satisfy the ITA standard for concrete lining upon a fire.
Study on Optimizing Design of Structural Rigidity of Super-Large Span Continuous Rigid Frame Bridge Using ANSYS
Authors: Xue Xing Wei , Yuan Hong , Li Shan Qing
Published: February 2012

In this paper, the situation of the midspan deflection of the span continuous rigid frame bridge is described, and the cause of the deflection is explained. It may be caused by the problem of the rigidity. Then the ANSYS is used to conduct analysis. The deflection of the biggest cantilever of the rigid frame bridge is the controlled target, and the optimizing design of the Sutong bridge is conducted. A meaningful result is obtained, and it provides a basis of the choice of the height of beams.
Study on Pretensioning Force of Wrapping Wires for Suspension Bridge Cables
Authors: Zhang Shuang , Sun Quan Sheng
Published: February 2012

The question of the pretensioning force of the wrapping wires for a suspension bridge is one of the important subjects. It could prevent the main cable from eroding by air or chemicals. And it must have some loss under the influence of dead loading, each mobile load and environment[1]. Now, the research of wrapping wire of the main cable is not much at home and abroad. And wrapping wire tension is mainly obtained depending on engineering experience. This paper has an experiment about the wrapping wire of Yangmingtan Bridge in Harbin to draw conclusions that wrapping wires tension which is 2m far from the cable clips is reduced extensively, more than 80%. But the residual tension, 8m from the cable clips, is about 35% of the initial tension. In addition, the wrapping wires tension which is about 93cm far from pre-wrapped wire-loops remains stable. Finally, starting from calculation theory, the paper puts forward that the wrapping wire tension should be 2.0kN.
Parameters Analysis with Regard to the Hollow Floor Based on the ABAQUS Secondary Development
Authors: Huang Chuan Teng , Wang Zhi Jun , Qu Yang Yi
Published: February 2012

Nowadays, the hollow floor is widely used due to its excellent mechanical property and economic benefit. However, its related specification is absence of evaluation in geometric parameters; furthermore, the research on the geometric parameters is seldom involved. This thesis has achieved automatic modeling, analysis and data processing concerning the hollow floor by python script. Based on ABAQUS secondary development and the statistical analysis software SPSS, single parameter analysis and the partial correlation between the parameters and the construction cost are carried out in this thesis. According to a number of case studies, the impact of every single parameter on the construction cost and the correlation of geometric parameters with construction cost were achieved. The above mentioned conclusions will be conducive to engineering design and further research in this field.
Finite Element Analysis of the Vertical Bearing Capacity of Single Piles in Tianjin Soft Soil Areas
Authors: Feng Shi Lun , Zhou Yu Ming , Li Jun , Li Pu Lin
Published: February 2012

The ABAQUS finite element software is used to calculate the vertical bearing capacity of single piles in Tianjin, and the finite element results are compared with the data gained through the in-situ static load pile foundation tests. It is found that the Young’s modulus of the soil at the bottom of the pile could have a important role in improving the vertical bearing capacity of single piles.
Reserch for Anchor Mechanical Character of Fully Grouted Bolt
Authors: Bao Xian Kai , Li Yi
Published: February 2012

Fully grouted bolt has been in wide use as a kind of support in geotechnical engineering. But the design method and application for fully grouted bolt is limited due to the shortage of its anchorage mechanism and mechanical behavior at present. So in this thesis an in-depth exploration of anchorage mechanism and mechanical behavior of fully grouted bolt will be done starting from the study of mechanics mechanism of fully grouted bolt, the result will provide reference for the design and application of fully grouted bolt and this have value of theory and engineering.
Shaking Table Tests on Chinese Ancient Tenon-Mortise Structure Strengthened by Iron Hook
Authors: Zhou Qian , Yan Wei Ming
Published: February 2012

Iron hook is widely used to strengthen Chinese tenon-mortise joint to enhance its strength in southern China districts.To find strengthening effects of this material, by shaking table tests dynamic characters as well as seismic responses of a 1:8 scale wooden frame model were studied under conditions that each of its tenon-mortise joint was/was not strengthened by iron hook.By white noise excitation,values of basic frequency of both unstrengthened and iron hook strengthened models were obtained;by inputing El-centro earthquake waves of different peak acceleration values, displacement and acceleration responses of the models were obtained,dynamic magnification factors for tenon-mortise joints as well as models were discussed.Results show that after each tenon-mortise joint of the model is strengthened by iron hook,its basic frequency increases,its displacement and acceleration responses under earthquakes decrease.However as iron hook can only restrict tenon from pulling out of mortise but not rotation of the joint, the dynamic magnification factors for strengthened model still tend to increase under strong earthquake.Thus strengthening effects of this method are limited.
Settlement Calculation and Analysis of Ground Improved by Dynamic Compaction at RSGT Project
Authors: Qin Zhi Guang , Luo Yan , He Ying Xi
Published: February 2012

Red Sea coral reefs in Saudi Arabia were dredged and reclaimed firstly, and then were treated by dynamic compaction as non-cohesive soil ground. Consolidated condition of improved ground within different depth is in different. Calculating settlements for different state ground should consider actual condition. Several semi-theoretical and semi-empirical settlement calculation methods mainly including Terzaghi’s method(1996), Teng’s method(1969), Meyerhof’s method（1956）are applied and analyzed to investigate the actual condition of improved ground according to the RSGT project test results, and the differences are proposed among these three methods.
Fatigue Life Analysis of Reinforced Retaining Wall under Cyclic Loading
Authors: Li Yun
Published: February 2012

Large-scale reinforced earth retaining wall model test has been Designed and completed. The model size is 3.0mχ0.85m χ2.0m(lengthwidthhigh) Slope angle is 70º, Fill with the use of red sandsχtone construction site preparation materials By entering a different amplitude and frequency of the sinusoidal load, to discuss the law of Dynamic characteristics of the model wall and fatigue life under the repetition load. The results showed that, the fatigue life has a linear relationship with the stress amplitude of three reinforced structures ,the logarithm of fatigue life changes with the stress amplitude sensitivity of Gabion reinforced earth retaining wall is low than Geogrid reinforced retaining wall does. The results help to reveal the instability mechanism under cyclic loading, and provide a useful reference for designing the reinforced retaining wall engineering.
Research on Coarse-Grained Soil Collapsibility in Gobi Region
Authors: Nie Zhi Hong , Li Kun , Xia Jian
Published: February 2012

This paper has carried out soaking load test, routine soil test, X diffraction, scanning electron microscopy on coarse-grained soil in Gobi region, analyzed the coarse-grained soil collapsibility and explored the mechanism of collapsibility generation. The results showed that: the coarse-grained soil in Gobi region had a high degree of collapsibility; mineral composition, microstructure and salinity constituted the main internal reasons resulting in such phenomenon. In soaking conditions, the cementation strengthen between grains reduces, the structure is damaged under external force and the grain movement leads to greater settlement.
Undrained Behavior of Unsaturated Bentonite-Sand Mixture
Authors: Sun Wen Jing , Sun De An , Zhang Jin Yi
Published: February 2012

The strength, deformation and hydro-mechanical behaviours of a compacted unsaturated Gaomiaozi bentonite-sand mixture under undrained condition are studied by conducting a series of isotropic compression tests and triaxial shear tests under constant water content. During undrained isotropic compression testing, void ratio and suction decrease while degree of saturation increases. The stress-strain relations are obtained from undrained triaxial shear tests. The volume contraction and lateral expansion can be observed. The suction decreases with increasing shearing. The net confining pressure and initial dry density affect the initial rigidity, undrained shear strength, volumetric deformation and hydro-mechanical behaviour.