bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of HAZ Fracture Toughness of Duplex Stainless Steel Weldment
Authors: Pathak C. S. , Navale L. G. , Sahasrabudhe A. D. , Rathod M. J.
Published: July 2010

Most of the serious weldment failures lead to catastrophic consequences in terms of damage to other equipment, loss of production, and risks to workers’ health and safety. Hence there is motivation to find margin between safety and disaster. This necessitates guaranteeing the integrity of a welded structure even if a crack is present. Therefore influence of the material inhomogenity and residual stresses on deformation and fracture behavior needs to be described precisely. A comparison of the applied load with a convenient material parameter is necessary for this purpose. Fracture mechanics parameters J integral & CTOD have attracted great interest in recent years. In case of base materials, fracture mechanics works quite well, but some specific problems occur if fracture mechanics principles are applied when examining the toughness properties of welded joints. These problems are mainly caused by the large difference in material properties and residual stresses. Existing fracture toughness testing can predict fracture behavior, but does not sufficiently address the problem associated with weldment testing. Three SENB duplex stainless steel weldment specimens were tested as per ASTM E1820. This standard is not recommended for weldment, but since no standard is available for testing duplex stainless steel weldment, authors preferred to use it as reference. The aim of this work is to explore the possibility of using the test results in the reliable prediction of weldment fracture and its correlation with microstructure and hardness.
Application of Ab Initio Quantum Mechanical Calculations to Investigate Oxidation of C-7 and C-14 Methyl Esters: An Alternative Fuel
Authors: Shafagh I. , Hughes K. J. , Pourkashanian M. , Williams A.
Published: July 2010

Using Gaussian 03 [1] program the electronic structure of the C-14 methyl ester, C14H28O2 (methyl tridecanoate), one of the components of biodiesel and the species involved in the unimolecular and bimolecular decompositions of it were estimated. For the electronic calculations the density functional theory (DFT) at B3LYP/6-311G(d, p) level and complete basis set (CBS-QB3) were applied. Using the KHIMERA program [2], contributions from energies, harmonic vibrational frequencies and moments of inertia were utilized to construct modified Arrhenius rate expressions for bimolecular reactions. C7H14O2 was selected as a surrogate for the C14H28O2 fuel in order to study the bimolecular reactions with flame radicals. In the present work reactions of carbons number 5 and 6 of C7H14O2, where carbon number 1 is the one single bonded to oxygen atom, with flame reactive radicals such as CH3, HO2 and H were studied. The rate expressions for the cited reactions were estimated using transition state theory as implemented in KHIMERA, over the temperature 500–2000 K. Heat of reactions for unimolecular decompositions were also calculated and compared to those from Methyl Butanoate (MB).
Time Resolved Measurements of Pyrolysis Products From Thermoplastic Poly-Methyl-Methacrylate (PMMA)
Authors: Kramer Cory A. , Loloee Reza , Wichman Indrek S. , Ghosh Ruby N.
Published: July 2010

The goal of this research is to obtain quantitative information on chemical speciation over time during high temperature material thermal decomposition. The long term goal of the research will be to impact structural fire safety by developing a data base of characteristic “burn signatures” for combustible structural materials. In order to establish procedure and to generate data for benchmark materials, the first material tested in these preliminary tests is poly-methyl-methacrylate (PMMA). Material samples are heated in an infrared (IR) heating chamber until they undergo pyrolysis. Time resolved quantitative measurements of the exhaust species CO2, O2, HC, and CO were obtained. During heating the PMMA sample undergoes two distinct processes. First, pre-combustion pyrolysis is characterized by the appearance a peak in the THC signal between 600–650 °C. Secondly, at about 900 °C flaming combustion occurs as evidenced by an exothermic reaction reported by the thermocouples. The time sequence of the production of HC, O2 depletion and CO2 production are consistent with combustion in an excess-oxidizer environment.
Modeling of Initially Curved Beam Structures for Design of Multistable MEMS
Authors: Williams Matthew D. , van Keulen Fred , Sheplak Mark
Published: July 2010

This article describes a mathematical model and solution methodology for efficiently predicting the many equilibrium paths of an arbitrarily-shaped, pre-curved, clamped beam subjected to arbitrary dead loading. Such structures are common among multistable microelectromechanical systems (MEMS), and the presented model provides designers with an easy way to study the effects of loading, shape, and imperfections on beam behavior. Results are presented for switch and actuator applications motivated from the literature.
On the Use of Meshless Methods in Acoustic Simulations
Authors: Hahn Philipp , Negrut Dan
Published: July 2010

In this paper, we are investigating the potential and limits of a meshless Lagrangian technique, called Smoothed Particle Hydrodynamics (SPH), as a method for acoustic simulations. Currently the most common techniques for acoustic simulations draw on mesh-based methods such as the Boundary Element Method (BEM), Finite Differences Method (FD) and Finite Element Method (FEM). Though many improvements have been made to each class of methods during the last few years, they still have their weaknesses. Difficulties arise as soon as inhomogeneous media, moving boundaries or aeroacoustic effects are involved. These problems are either particularly hard to describe or cannot be simulated with some of these mesh-based methods. The investigation of SPH for modeling sound propagation is carried out in order to assess its potential in relation to the limitations associated with the existing simulation methods listed above. Simple computational experiments will be carried out for the verification of the new approach and applications on the problems listed above will be discussed.
Analysis of Partially Treated Multi-Layer Beam With Magnetorheological Fluid
Authors: Rajamohan Vasudevan , Sedaghati Ramin , Rakheja Subhash
Published: July 2010

The vibration properties of multi-layer beam structure comprising a partial magneto-rheological (MR) fluid layer are investigated to study the influences of size and location of the fluid treatment of the beam. The governing equations for the partially-treated multi-layered MR beam were formulated in the finite element form. The validity of the proposed finite element formulations is demonstrated by comparing the simulation results with those obtained from the Ritz formulation. Two different configurations of a partially treated MR-fluid beam are considered. Simulations are performed to investigate the influences of intensity of an external magnetic field, and the location and length of the MR-fluid layers on the dynamic characteristics of the beam with different boundary conditions. The properties and vibration responses of the partially-treated multi-layer beam are then compared with those of a fully-treated beam. The results suggest that the natural frequencies and transverse displacement response of the partially-treated MR beam are strongly influenced by the location and the length of the fluid pocket, and the boundary conditions, apart from the applied magnetic field.
Experimental Investigations of Sound From Flow Over Rough Surfaces
Authors: Anderson Jason M. , Stewart Devin O. , Blake William K.
Published: July 2010

Turbulent boundary layer flows over rough surfaces are known to produce elevated far-field acoustic sound levels. The nature by which surface irregularities alter the near-field surface pressures and subsequently affect the sound generation to the scattering of high wavenumber convective pressures to low wavenumber acoustic pressures, which is typically interpreted as a dipole-like source. The focus of the current investigation is the experimental interrogation of both near- and far-field pressures due to the flow over roughened surfaces in order to identify the source mechanisms and to validate physical models of roughness sound. For rough surfaces composed of large geometrical elements (defined by large Reynolds numbers based on roughness height and friction velocity), such as hemispheres and cubes, the measured near-field surfaces pressures indicate that the local interstitial flows become important in determining the sound radiation characteristics. In order to describe the aeroacoustic source region, scaling laws are developed for surface pressures at locations around the roughness elements for various roughness configurations and flow speeds. Relationships between surface pressures amongst the rough surface elements and far-field pressures measured at several directional aspects were examined to identify roughness sound source mechanisms. Measurements of a dipole directivity pattern and dipole efficiency factors obtained when normalizing radiated sound by surface pressures offer support to the scattering theories for roughness sound. Using existing pressure scattering models as a basis, an empirical model for roughness sound is generated.
Effects of Process Parameters on Surface Finish in Laser Solid Freeform Fabrication
Authors: Alimardani Masoud , Iravani Tabrizipour Mehrdad , Khajepour Amir
Published: July 2010

Laser Solid Freeform Fabrication (LSFF) is a flexible rapid prototyping technique in which a laser beam is used to melt and deposit the injected powder in a layer-by-layer fashion to form 3D components. In this paper, the effects of the main process parameters such as laser power and traverse speed on the surface finish of the parts fabricated using the LSFF process are investigated. Since these process parameters and their variations determine the microstructure and other resultant physical qualities of the fabricated parts, they should carefully be selected to increase the surface quality without compromising other quality aspects of the outcomes. For this purpose, along with the experimental analyses, an experimentally verified 3D time-dependent numerical model is employed to comprehensively study the temperature distributions, thermal stress fields, and their variations resulted from different process parameters and consequently different surface finishes. The experimental investigations are conducted through the fabrications of several thin walls of AISI 303L stainless steel using a fiber laser with a maximum power of 1100 W. The numerical and experimental results show under a constant power feed rate by increasing the process speed while optimizing the laser power, the surface finish of the fabricated parts can improve without compromising the melt pool conditions.
Mass Loss and Effective Thermal Conductivity of Fire Retardant Nanocomposites
Authors: Tsoi Marvin , Tang Yong , Chen Ruey-Hung , Gou Jihua
Published: July 2010

Carbon nanofiber (CNF) papers, when incorporated onto the surface of glass fiber reinforced polyester composites, were known to enhance the fire-retarding capability by decreasing the peak heat release rate (PHRR) and slowing down the mass loss. In this experimental study, attempts were made to understand the thermal degradation mechanisms of the composites and nanocomposites. The temperature distribution within the composite substrate should be determined because the degradation rate is related to the temperature. The composite was prepared through vacuum-assisted resin transfer molding (VARTM) process. Samples of glass-polyester resin composites were investigated. Thermal conductivity data was calculated from embedded thermocouples on the composite for real-time temperature measurement. Mass loss data was collected using thermal gravimetric analysis on resin and CNF paper samples. These results should help to further understand the depth and degree of the degradation and provide an understanding of thermal properties in composites.
An Improved Drop Impact Model for Lagrangian/Eulerian Coupled Codes
Authors: Brown Alexander L. , Jepsen Richard A.
Published: July 2010

Because we want to be able to model fires from high energy impact events as found in transportation accidents, we are interested in accurate representation of secondary impacts and splash, which presumably contribute significantly to the outcome of the event. We are focused on a Lagrangian/Eulerian framework as a simulation method. Historically, drop impact modeling has been driven by spray combustion applications, as reviewed in a paper by Cossali et al. [1]. They note numerous deficiencies, including that regime accuracy for many of the models is narrow. Testing and model development has provided improved sub-models that have allowed us to construct what we believe to be a more accurate and comprehensive model for impacting drops. The details of this model are presented along with a detailed description of the sub-model components. The model is employed to predict a 10 cm diameter, 10 and 20 m/s water drop impact test. This test case serves as an initial verification and validation test of the implemented code.
Coexistense of Creep and Transformation in High Temperature Shape Memory Alloys
Authors: Lagoudas Dimitris C. , Chatzigeorgiou George , Hartl Darren J. , Kumar Parikshith K.
Published: July 2010

The actuator performance of high temperature shape memory alloys (HTSMAs) can be significantly influenced by viscoplastic mechanisms that appear in metals under high temperature conditions. In this work we investigate experimentally and theoretically the coexistence of phase transformation and viscoplastic behavior in HTSMAs. The experimental study shows that decrease in the thermal cycling rate causes decrease in the actuation strain, as additional irrecoverable strain is generated due to creep mechanisms. The interaction between viscoplasticity and transformation is studied further using TEM. In order to simulate the material response, we propose a constitutive model based on an existing shape memory alloy model, which aims to capture the simultaneous phase transformation and viscoplastic behavior of a HTSMA. After calibration, the proposed model is used in order to identify the impact of the loading rate in the material’s response.
Rapid Prototyping and Manufacturing: A Review of Current Technologies
Authors: Medelli´n-Castillo Hugo I. , Pedraza Torres Joel Esau
Published: July 2010

The idea to develop processes capable to produce physical components quickly and without requiring tooling, led to the development of the “free form fabrication” (FFF) or “rapid prototyping” (RP) technologies in the early 1980s. RP systems generally build up a prototype directly from the computer-aided design (CAD) data by using an additive “layer by layer” method. The RP technologies have brought several advantages to the manufacturing industry in such a way that these technologies are evolving toward the production of end-use parts. This paper presents a review of rapid prototyping and manufacturing (RP&M) technologies from their origins. The review includes commercially available RP systems and RP technologies that are still at the development stage or that have been proposed. The operating principles and the features of these technologies are presented. Process parameters such as accuracy, layer thickness, operation speed are given. An extended classification of RP&M technologies is also included in this paper.
Heterogeneous Detection of PCR-Amplified Intimin Gene From E. Coli O157:H7 via PDMS Microfluidic Chip
Authors: Chen Hong , Abolmaaty Assem , Li Peng , Anagnostopoulos Constantine , Du¨bel Stefan , Faghri Mohammad
Published: July 2010

E. coli O157:H7 strains represent the most important group of food-borne pathogens. PCR-amplified intimin gene of pathogenic E. coli O157:H7 was detected heterogeneously via a microfluidic chip that consists of streptavidin-coated nanoliter chambers. Biotinylated primers and digoxigenin labeled deoxyuridine triphosphate (dUTP) were incorporated into the amplified intimin (eaeA) gene by an off-chip PCR thermal cycler. The amplified products were injected into the chip where they were immobilized via streptavidin-biotin interaction. Detection of the products using alkaline phosphatase (AP) conjugated anti-digoxigenin was performed with an epi-fluorescent microscope. This assay was capable of detecting 0.06 ng/μL biotin-digoxigenin-dsDNA conjugate distinctly, which is a hundred fold more sensitive than the traditional detection by agarose gel.
Transfer Method of Carbon Nanotube Film for Embedded Transparent Electrode
Authors: Lee Kangwon , Lee Jung A. , Lee Kwang-Cheol , Lee Seung S.
Published: July 2010

We describe new transfer method of carbon nanotube (CNT) film onto the poly-dimethysiloxane (PDMS) based on the poor adhesion between Si wafer and Au layer. To combine the CNT film with the polymer-MEMS field, it is required to transfer CNT film onto the polymer substrates. CNT film was fabricated by vacuum filtration method and was transferred onto the Au-deposited Si wafer. Using photolithography process, CNT film was patterned and PDMS is pouring and curing on the wafer. After peeling off the PDMS, patterned CNT film was transferred which was embedded into the PDMS. The possibility of embedded CNT film in the micro system was demonstrated in the application of electro-thermal actuator.
Electric Trapping and Lysing of Cells in a Microchannel Constriction
Authors: Church Christopher , Zhu Junjie , Huang Guohui George , Wang Gaoyan , Tzeng Tzuen-Rong Jeremy , Xuan Xiangchun Schwann
Published: July 2010

Cell lysis is a necessary step in the analysis of intracellular contents. It has been recently demonstrated in microfluidic devices using four methods: chemical lysis, mechanical lysis, thermal lysis, and electrical lysis [1]. The locally high electric fields needed for electrical lysis have been achieved using micro-electrodes and micro-constrictions for pulsed and continuous DC electric fields, respectively. However, since the two determining factors of electrical lysis are field strength and exposure time, opposing pressure-driven flow must often be used in pure DC lysis to reduce the velocity of the cells and to ensure the cells spend sufficient time in the high electric field region [1,2]. Using DC-biased AC fields can easily fulfill these requirements as only the DC component contributes to cell electrokinetic transport. Prior to lysis, cell concentration can be increased by trapping using dielectrophoresis (DEP), which may occur with either DC or DC-biased AC electric fields [3,4]. This operation is useful in cases where the cell supply is limited or when the cell concentration is too low in general. In this work, red blood cells are used to demonstrate the smooth switching between electrical lysing and trapping in a microchannel constriction. The transition between lysis and trapping is realized by tuning the DC component in a DC-biased AC electric field.
Multi-Environment Probability Density Function Method for Modeling Turbulent Combustion in Industrial Equipment
Authors: Denison M. , Borodai S. , Fox R. , Bockelie M.
Published: July 2010

In this paper is described a computational fluid dynamic (CFD) modeling tool based on the Multi-Environment Probability Density Function (MEPDF) method developed specifically to account for finite rate chemistry effects in modeling practical combustion systems. MEPDF originated from multi-environment micro-mixing models used in the chemical engineering community to simulate chemical processes with little or no heat release. Previous uses of MEPDF for combustion applications typically used simple chemistry models. Our work has focused on extending the MEPDF method for combustion applications using detailed chemistry models. Provided below is an overview of the MEPDF formulation and example calculations. The model has been shown to use substantially less computational time compared to more traditional PDF methods using a Monte-Carlo approach.
Effect of the Grinding Oil Type on CBN Grinding Wheels Performance
Authors: Tawakoli Taghi , Rasifard Abdolreza , Vesali Alireza
Published: July 2010

The efficiency of the grinding process highly depends on the coolant lubricant used. In grinding with CBN grinding wheels grinding oils are used increasingly. In the last decade new grinding oils based on different oil types are brought into the market, whose effect on the CBN grinding wheels performance until now not sufficiently been investigated. The Institute of Grinding and Precision Technology (KSF) investigated the influence of four different grinding oils on the performance of vitrified CBN grinding while grinding of 100Cr6 (M.-No. 1.3505), which is a heat-treatable steel with a very good grindability, and Nimonic A80, which is a difficult to grind heat-resistance superalloy. The obtained results show that the performance of the vitrified CBN grinding wheels—while using grinding oil as coolant lubricant—regarding the quality of the work piece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the viscosity of the grinding oil. Moreover, the results show that the surface quality and the grinding forces while using different grinding oils depend significantly on the work piece material.
Investigation of Corner Cavity Formation During Backward Cup Extrusion Process Using Finite Element Method
Authors: Khajeh Arash , Ebrahimi Ramin , Moshksar Mohammad Mohsen
Published: July 2010

This study focuses on the finite element analysis of the formation of corner cavity defect during the Backward Cup Extrusion (BCE) process. In the final stage of this process, when the bottom thickness reaches to a critical value this defect will be appear as a circumferential defect in the corner of the cup. In addition, this research examines the temporal prediction of onset of corner cavity formation in the various amounts of the reduction of areas. The finite element simulation results were compared with those of the experimental, indicating that the amount of the reduction of area and that of the friction coefficient have considerable impact on the onset of corner cavity formation during the BCE process.
Combustion and Emission Characteristics of Gasoline Blended With Alcohols
Authors: Liu Shenghua , Li Yi , Li Guangle , Chi Lei
Published: July 2010

Methanol and ethanol are known as potential alcohol alternative fuels for spark ignition Engines, which can be blended with gasoline to increase oxygen content and to decrease emissions. Six kinds of fuels were prepared, which were commercial 93#gasoline, M10, M20, M30, E10 and E20. With a constant volume bomb, flame propagation speeds were studied under different temperatures, exhaust dilution and air fuel ratios. The flame radiuses were used to calculate the flame speed. The results indicate that methanol can increase flame speed no matter with or without exhaust dilution. At the ambient temperature of 5°C and 15°C, engine cold starting tests prove that methanol can improve engine combustion and lower HC and CO emissions during the first 200 seconds, while ethanol has little effects at the same conditions.
Characterization of Thermomechanical Properties of Polypyrrole Nanowires
Authors: Sul Onejae , Jang Seongjin , Yang Eui-Hyeok
Published: July 2010

The polypyrrole (Ppy) is widely known as a conducting polymer, and many types of microactuators have been demonstrated based on volume change induced by oxidation-reduction reaction of polymer in liquid or dry environments. However, the thermomechanical property of Ppy is not well known. Here we report the measurement of Young’s modulus of polypyrrole nanowires and coefficient of thermal expansion (CTE) by Lateral Force Microscopy. Young’s modulus was measured via tip-deflection of a cantilevered Ppy nanowire. By measuring the applied force and deflection, the Young’s modulus was determined to be 2.3 ± 0.7 GPa. A thin metallic (Cu) film was deposited on only one side of the Ppy nanowire to form bimorph nanoactuators. The CTE was determined to be 12 × 10−6/K.
Effect of Degree of Unsaturation on NOx Formation in Partially Premixed Flames of Biofuels
Authors: Love N. D. , Parthasarathy R. N. , Gollahalli S. R.
Published: July 2010

The effect of iodine number on NOx formation in laminar flames of three oxygenated biofuels was studied at an equivalence ratio of 2. Neat soy methyl ester, neat canola methyl ester, and methyl stearate, which had similar energy content and carbon chain length, were tested. The iodine numbers for these fuels varied from 0.5 to 142. Inflame NOx concentration and temperature were measured. The peak NOx concentration occurred in the near-burner region for all biofuels: 404 ppm for soy, 388 ppm for canola, and 123 ppm for the methyl stearate fuel, and did not correlate with the location of the peak temperature. Therefore, the peak concentration in this region was traced to the Fenimore mechanism. Also, the peak NOx concentration was significantly increased with iodine numbers (degree of unsaturation of the fuel molecule). Thus, a strong correlation exists between the chemical structure of the fuel and the NOx emission of the premixed flame.
Acoustical Scattering by Multilayer Spherical Objects Containing Electrorheological Fluid
Authors: Cai Liang-Wu , Dacol Dacio K. , Orris Gregory J. , Calvo David C. , Nicholas Michael
Published: July 2010

Scattering is the most fundamental problem in the research on phononic crystals and acoustic metamaterials; and scattering in a three-dimensional space poses challenging issues; and yet, the most challenging of all, is the scattering by elastic objects since an acoustic wave splits into different types of waves, propagating at different speeds, when it enters an elastic object. In this paper, a unified formalism is developed to analyze the scattering of an acoustic wave by a multilayer spherical object that is made of a mixture of an arbitrary number of concentric layers of elastic and acoustic media. Using this formalism, acoustical scattering by a multilayer spherical scatterer encasing an electrorheological (ER) fluid layer in an underwater environment is studied. Numerical examples show that ER fluids can alter the scattering characteristics above the first resonant frequency, which itself can be tuned by the applied electric field.
Multifunctional Nanocomposites With High Damping Performance for Aerospace Structures
Authors: Liang F. , Tang Y. , Gou J. , Gu H. C. , Song G.
Published: July 2010

Polymer matrix composites with reinforcement of carbon nanofibers and carbon nanotubes in the form of paper sheet have shown significant vibration damping improvement compared to pure matrix materials. The large specific area (1000 m2/g) and aspect ratio (>1000) of carbon nanotubes and nanofibers promote significant interfacial friction between carbon nanotubes/nanofibers and a polymer matrix, which causes much higher energy dissipation in the polymer matrix. In this study, a unique concept of manufacturing nanocomposites with carbon nanotube/nanofiber based nanopaper sheets for vibration damping applications has been explored. The new approach includes making carbon nanopaper sheet by the filtration of well-dispersed carbon nanotubes and carbon nanofibers under controlled processing conditions. Subsequently, carbon nanopaper sheets are integrated into composite laminates as surface layer using the vacuum assistant resin transfer molding (VARTM) process. To compare the damping property of laminates constituted by different fibers, three kinds of fibers, including glass fiber, basalt fiber, and carbon fiber are used. For the comparative study, the vibration damping ratios of samples with and without carbon nanopaper sheets are determined. To identify the damping characteristics of each specimen, the Frequency Response Function (FRF) was estimated by a pair of piezoceramic patches: one as an actuator to excite the specimen and the other as a sensor to detect the induced vibrations. From the FRF, the damping ratio of the specimen at each modal frequency of interest was calculated. The experimental results clearly show a significant improvement of vibration damping properties of the nanocomposites plates. This research demonstrates vibration damping enhancement of a polymer matrix via incorporation of carbon nanopaper sheets and provided basic understanding of the damping characteristics for the optimal design and fabrication of high performance damping composites, which have the potential to be used as structural components for different applications.
Virtual Prototype of the Tunnel Boring Machine and Movement Simulation in DIVISION Mockup2000i2
Authors: Li Lun , Zhou Zhili , Li Jishun , Xue Yujun
Published: July 2010

The virtual reality is a multi-functional, interactive and immersible technology. As an advanced engineering design technology, the virtual reality technology (VRT) has been widely used in large mining machinery design and manufacturing. The system is based on DIVISION Mockup2000i2 software. Virtual prototype of the Tunnel Boring Machine (TBM) is studied in this paper. In addition, the movement simulation of TBM is completed in DIVISION Mockup2000i2. Firstly, CATIA software is adopted to build the parts of TBM. The TBM is assembled in CATIA too. Secondly, the THEOREM software is applied to convert the assembled model of TBM to another format which can be identified in DIVISION MOCKUP2000i2 software. In order to make the TBM image living, life-like and easy to browse, the light of surface, virtual materials and landmark scenes are set up in DIVISION MOCKUP2000i2 software environment. All motion parameters of the parts are defined before the simulation. Then, the virtual movement simulation of TBM components is analyzed with the behaviors property of MOCKUP. The virtual movement of cutting wheel, screw conveyor machinery and the door of mud out are studied. The virtual movement of segments and segment erector machine are completed by setting up virtual parts and virtual event. Five segments are fixed accurately in a cycle. The relations and interference of the parts movement are examined simultaneity. The hotkey is defined before the simulation, which can trigger the continuous implementation of virtual motion. In addition, a virtual voice is used to enhance the performance of movement simulation. The virtual prototype of TBM being set up and simulated will have positive significance for design inspection, structural analysis and product introduction without TBM physical prototype being manufactured.
Simulation of Combustion and Thermal-Flow Inside a Petroleum Coke Rotary Calcining Kiln: Part 1—Process Review and Modeling
Authors: Zhang Zexuan , Wang Ting
Published: July 2010

Calcined coke is an important material for making carbon anodes for smelting of alumina to aluminum. Calcining is an energy intensive industry and a significant amount of heat is wasted in the calcining process. Efficiently managing this energy resource is tied to the profit margin and survivability of a calcining plant. To help improve the energy efficiency of the calcining process, a 3-D computational model is developed to gain insight of the thermal-flow and combustion behavior in the calciner. Comprehensive models are employed to simulate the moving petcoke bed with moisture evaporation, devolatilization, and coke fines combustion with a conjugate radiation-convection-conduction calculation.
Stiffness Analysis of Gear Shaping Machine in Radial Direction With Gear Wheel-Cutter
Authors: Pop Petru A. , Bejinaru-Mihoc Gheorghe , Olaru Ioan
Published: July 2010

The machining of cylindrical gears by gear shaping with gear wheel-cutter has accompanied of known cutting errors met at rolling gears cutting: pitch error, total pitch error, profile tooth error, circular runout, etc. The technical papers consider that two aspects can analyze gears shaping precision with gear wheel-cutter: first by the analysis of profile gear cutting errors, and second by profile gear cutting errors in “closing zone of teeth gear”, with a main factor according of stiffness machine tools. The analysis of stiffness machine has done with the values displacements and relative rotations of machine subassemblies to a fixed datum system and two mobile datum systems, in dependence of load applied during idle running or gear shaping process, could be defined three stiffness’s: static, quasi-static and dynamic stiffness. During the cutting process, the variation predictable distance between cutter axe and wheel-workpiece axe is important. This study is carrying out by stiffness machine analysis in radial direction of OY axe. The paper has proposed a method of quasi-static stiffness machine determination of gear shaping process with wheel-cutter. During cutting process occurs altering positions between subassemblies of ram-toolholder and rotated table, even is used finishing working conditions. The research has done by an integration system “force-displacement”, formed by a dynamometer adaptable of gear machine-MD 250, which allowing the acquisition of cutting forces on three axes and displacements of ram-toolholder-workpiece during machining process. The measurement has done in “closing zone of gear”, respectively the outside of that, due to determination of stiffness machine tools. In addition, this research presented the assessing of working accuracy of gear shaping machine with gear wheel-cutter.
Stress Analysis of Non-Conventional Composite Pipes: An Experimental and Numerical Approach
Authors: Wahab Muhammad A. , Ramachandran Prashanth , Pang Su-Seng , Jones Randy A.
Published: July 2010

This paper discusses an experimental and numerical study to investigate the failure behavior of non-conventional cross-sectioned fiber reinforced composite pipes filled with glass beads subjected to internal pressure and bending loads. An adaptive filament winder for non-conventional pipes was exclusively designed to fabricate the samples used in the experiments. Experiments were conducted on triangular and rectangular cross-sectioned samples as per ASTM standards to find the internal burst pressure, bending strength, and failure modes of the pipes. Numerical analysis for the pipe loading process has been developed based on the finite element method for a linear orthotropic problem for composite pipes. The finite element software ANSYS was used to build the model and predict the stresses imposed on the pipes. The relationships between the applied internal pressure and peak hoop stress, bending load, and bending strength with reference to the fillet radius were determined; and generally a good correlation was found between the experimental and numerical results.
Evaluation of Spray Characteristics in Pharmaceutical Tablet Coating Processes: The Influences of Drum Rotational Speed and Drying Air Flow Rate
Authors: Muliadi Ariel R. , Sojka Paul E.
Published: July 2010

In this study, drop size, velocity, and volume flux for sprays produced by a pharmaceutical nozzle (Spraying Systems 1/4-JAU-SUE15A-PA67288–45°-SS) were characterized using a Fiber-PDA system (Dantec). Spraying was performed in a 120 cm (24 in) diameter tablet pan-coater (Accela-Cota Model 10, Thomas Engineering, UK). The separate influences of drum rotational speed and drying air flow rate were studied by making measurements at four different pan-coater operating conditions: stationary drum with drying air turned on/off, and 8 rpm rotating drum with drying air turned on/off. For each case, four different spraying conditions (liquid supply rate and atomizing air pressure) were used. PDA scans were performed along the spray semi-major and semi-minor axes at two different axial distances (7.5 and 10 cm) from the atomizer tip. Results were as follows. When both the drying air and drum rotation were absent, increasing liquid supply rate while operating the atomizer at the lower of two atomizing air pressures decreased drop size. The opposite occurred when operating at the higher of the two atomizing air pressures. This suggests that the nozzle operated as a simplex pressure-swirl atomizer at lower levels of atomizing air pressure, but as an air-assist atomizer at higher levels of atomizing air pressure. Regardless, liquid supply rate had no significant effect on drop velocity. In contrast, a decrease in atomizing air pressure or an increase in axial distance always led to an increase in drop size and a decrease in drop velocity. Supplying drying air to the pan-coater resulted in up to a 6 m/s increase in drop velocity, but had mixed effects on drop size. When the spray gun was operated as an air assist atomizer, supplying drying air to the drum led to an increase in D32. The reverse was observed when the gun operated as a simplex pressure-swirl atomizer. These two observations are most evident when operating at the lower liquid supply rate (70 g/min), suggesting that they may have arisen from drop evaporation. Increasing the drying air supply rate also reduced spray extent and volume flux magnitude. Adding drum rotation to the process generally led to (i) increased drop size and (ii) increased drop velocity. (i) likely arose from the transport of small drops away from the spray zone, while (ii) likely resulted from changes in droplet trajectories. Both are the result of the gas-phase swirling motion that is due to the drum rotation. (i) was most noticeable when the nozzle was operated as an air-assist atomizer. In addition, drum rotation decreased spray volume flux magnitude at the spray center, but increased it at other locations, essentially making the spray more dumbbell-shaped. Finally, the influence of drum rotation on drop velocity diminished when drying air flow was included. This was because the drying air momentum helped the drops oppose the effects of the swirling flow induced by the drum rotations.
Set-Based FEM for Product Design With Uncertainties
Authors: Ishikawa Haruo , Inoue Masato
Published: July 2010

Analysis tool such as FEM which can analyze structure with design uncertainty is needed for considering the structural property of the products from the early phase of design dealing with various uncertainties. This paper describes the application of the concept of Set-Based Concurrent Engineering (SBCE) to FEM. The methodology of the set-based FEM analysis of 2D truss structure is presented. A prototype program is developed to obtain the interval solutions satisfying the requirements of deformation and rigidity.
A Micromachined Earth Sensor Based on Measuring the Gravity Gradient Torque
Authors: Ghose K. , Shea H. R.
Published: July 2010

We present the fabrication and testing of a novel MEMS inertial sensor that directly measures the gravity gradient in low Earth orbit in order to sense the relative orientation of a satellite with respect to the Earth. Instead of the current Earth sensing methods that determine the Earth vector by sensing the Earth’s IR emission, we present a much lighter and more compact MEMS-based approach that determine the Earth vector by measuring the Gravity Gradient Torque on an elongated silicon proof mass. Current Earth sensors require optical access on multiple faces of the satellite. This MEMS-based approach does not require optical access.
Design, Analysis and Optimization of Magnetic Microactuators
Authors: Zhou Qingkun , Ben-Tzvi Pinhas , Iqbal Azhar , Fan Dapeng
Published: July 2010

Magnetic micro-electro-mechanical-systems (MEMS) present new class of micro-scale devices that incorporate magnetic materials as sensing or active elements. It exploits the properties of magnetic materials by incorporating them in conventional microfabricated systems. Although their application for microactuation purposes has been limited, the prospects of remote control and large displacements renders them useful, and even unavoidable in certain circumstances. Recognizing the fact that poor electromagnetic flux in micro domain happens to be the most stringent limitation, measures to improve the magnetic field generated by an electromagnetic coil are studied using a microactuator that incorporates a coil and a hard magnetic film deposited on a flexure membrane. This paper describes the design of the microactuator, analysis and optimization that maximizes the deflection. This study also presents an overview of magnetic microactuators covering the scaling effects, materials and processes used in their fabrication and critical review of their limitations.
Investigation of Fuel Lean Reburning
Authors: Kim Hak Young , Baek Seung Wook
Published: July 2010

The present work is focused on a fuel-lean reburn system to experimentally control NOx emission from combustion process. Fuel-lean reburn system is found here to be able to replace a conventional reburning technique due to reburn fuel saving. In the conventional reburning process the NOx emission is reduced up to 45% using 20∼25% reburn fuel of total heat input, while CO emission is restricted within acceptable limits by adopting additional air supplying system. However, in the fuel-lean reburn system, by contrast, the amount of injected reburn fuel into the reburning zone is low enough to maintain overall fuel-lean condition in the furnace, so that no additional air system is required, and CO emission can be maintained at almost zero level. In this study, an experimental study has been done to examine the formation characteristics of NOx in a lab scale combustor (15kW) with various oxygen enhanced combustion conditions. LPG (liquefied Petroleum Gas) was used as main fuel and reburn fuel. Finally, the current fuel-lean reburn system, even with only an amount of reburn fuel of 13% of total heat input, was observed to achieve a maximum of 48% in NOx reduction.
On the Realization of Filament Wound Composite Impeller for Water Refrigerant
Authors: Li Qubo , Wang Jifeng , Mu¨ller Norbert
Published: July 2010

In the present work, the concept of composite impeller through automatic filament winding manufacturing approach was realized. The advantage of using filament winding method to manufacture high performance and light-weight composite impellers is that the production can be rapid, inexpensive and utilize commercially available winding machines. This work focuses both on how to achieve the automation of the production process, as well as evaluate the composite impeller’s mechanical properties. For the automatic production process, a new filament winding facility for manufacturing fiber-reinforced composite impellers was developed. A kevlar/epoxy matrix was selected to manufacture the high strength-to-weight ratio composite material. In order to maintain the epoxy’s freshness, a two component syringe dispensing device was designed to control the dispensation of resin. The composite material’s properties were measured in order to ensure the impeller was able to withstand the large stresses incurred during the high speed rotation required to achieve large volume flows and a high compression ratio. With these properties, a 3D structural analysis using ANSYS was performed, which resulted in a maximum tip speed of 830m/s before the composite impeller’s failure. In terms of momentum change, this is a high tip speed needed to compress water vapor.
Application of Business Rules in Design Processes to Tackle Uncertainty in Product Development
Authors: Spieß Daniel , Anderl Reiner
Published: July 2010

The development of innovative industrial products and systems, like e.g. aeronautical parts, is characterized by its complex processes under tight constraints. The involvement of multiple disciplines, departments and subcontractors to plan and create the optimal solution to fulfill given requirements under the constraints of time, money and quality leads to an urgent need in professional project management and monitoring. Although project management allows the comprehensive planning of the processes, detailed workflows and their implementation cannot directly be enforced, controlled and documented. Especially the lack in documentation and traceability leads to uncertainty in project execution and monitoring, as well as unconformity within the development of vital and safety critical products and systems. Best practices are substituted by ad hoc steps to meet deadlines like milestones and sync-points. Workflow management systems, which could offer some support to reduce addressed uncertainty, do not cover all involved parties and are not directly linked to the project management, leading to characteristic problems in such development projects. This paper presents a new approach to enforce the implementation of planned project plans in development projects with multiple development parties, based on business rules to increase traceability and documentation as well as to promote the adoption of best practices in project execution. The emphasis is placed on two aspects, namely a methodology of modularization of project plans and the formulation in business rules which are to be executed in business rules management systems as well as the implementation of a best practice repository based on the project plan modules. The modularization of project plans in combination with a linked business rules management system allows on the one hand promoting best practice application in project execution and on the other hand to save gathered project planning knowledge based on the actual implementation of the plan and to reuse it in forthcoming similar projects. A further important advantage is the ability to plan and enforce documentation of the actual execution of work packages and deviation from the plan, with a major impact on traceability. The work presented here has a valuable implication on the traceability in complex development processes and facilitate the application of best practices through project management by providing project plan modules with attached rules for their implementation in workflows.
The Design of a Single Degree of Freedom Open-Loop Spatial Mechanism That Incorporates Geared Connections
Authors: Bari Joseph M. , Crane Carl D. , Dooner David B. , Mckinley Javier Roldan
Published: July 2010

A means has been discovered to apply gear pairing to create a one degree of freedom open-loop spatial mechanism. A specially chosen geometry consisting of three pairs of parallel joint axes is constricted by five sets of gears, three of which are parallel planar, allows for a reconfigurable mechanism that is suited for repetitive tasks. Previous work has examined three-dimensional rigid body guidance in closed-loop geared mechanisms, but has not come to a solution for the open-loop case. Gear pairs are designed based upon a desired position and orientation path for the end effector. Numerical optimization is performed to obtain physically realizable gear profiles. Non-circular gear centrodes must be continuous and smooth as well as mono-directional, that is, gear ratios of a given pair may not switch signs. These constraints eliminate non-realizable or non-optimal gears in favor of simple, more easily produced profiles. Variable parameters include link lengths, joint offsets and twist angles. Numerical examples are presented.