bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmentally Conscious Wing Design for the Medium Altitude Long Endurance Unmanned Aerial Vehicle
Authors: Iqbal Liaquat U. , Naik Gautam S. , Pothala Daniel , Surapaneni Phani Kiran , Zhao Fu , Sullivan John P.
Published: September 2010

The use of Unmanned Aerial Vehicles (UAVs) has become widespread and is ever increasing. There are plans for utilizing the UAVs for the military as well as the humanitarian and law enforcement missions such as flood and hurricane relief, firefighting, drug trafficking control, and so on. The number of UAVs is likely to continue to grow exponentially in the near future and there is a great need for the environmentally conscious design and manufacturing efforts in the UAV market. The authors are developing an integrated approach to bring the high fidelity Computer Aided Design and Engineering (CAD/E) tools to the preliminary design phase for designing new aircraft. In this paper, this approach is extended to include the environmentally conscious material selection when designing a UAV wing for the medium altitude long endurance mission. Finite Element Analysis is used to determine the material needed for the wing and the computed weights are supplied to the spreadsheet for calculating environmental impacts of different materials selected for the wing design. This spreadsheet has been developed based on the data in the Lifecycle Assessment software package SimaPro/Ecoinvent. The study demonstrates how to integrate environmental considerations into the preliminary UAV design using high fidelity models.
Sustainability and Manufacturing Philosophy: From Mass Production to Intelligent Energy Field Manufacturing
Authors: Zhang Wenwu
Published: September 2010

In the downturn of economy, it is meaningful to reflect on the evolution of engineering philosophies. This paper gives a historical review of major manufacturing philosophies and methodologies, such as mass production, lean manufacturing, systematic innovation, digital manufacturing, and sustainable development. The general strategy of Intelligent EFM and the from nature to nature philosophy of engineering are established to help achieve both prosperity and sustainability.
An RFID-Based Shopping Service System for Retailers
Authors: Hou Jiang-Liang , Chen Ting-Gin
Published: September 2010

With the rapid development of global economy and great improvement on life quality of consumers, the consumer shopping behaviors have been changed significantly. Modern retailers have put intensive effort on merchandise arrangement in order to satisfy the consumer demands on merchandise shopping. However, most retailers do not provide satisfactory shopping services to customers. For instance, without a customized shopping recommendation for each individual customer, consumers have to spend a lot of time for merchandise selection. Furthermore, most large-spaced retailers merely utilize signs in front the aisles of specific merchandise areas to direct consumers, which cannot provide an accurate guidance for merchandise search. Therefore, regarding the shopping services of a modern retailer, this research develops a customized merchandise recommendation algorithm (CMRA) and a shopping route determination and guidance algorithm (SRDGA). Based on the proposed algorithms, a Shopping Service System (3S-System) is established by integrating the RFID technology. Considering the consumer demands, consumer shopping preferences and market promotion plans, this research proposes an integrated, heuristic methodology to provide a customized shopping list, route recommendation and real-time direction guidance for consumer shopping. Moreover, based on the proposed methodology, a Shopping Service System (3S-System) is established, and a simulated market is created in order to verify the feasibility of the proposed model. The verification results show that the system can offer customers appropriate shopping route recommendation in a short time and could achieve real-time guidance. As a whole, this research provides a methodology and system to provide effective shopping services for consumers and as a result the shopping service quality of modern retailers can be enhanced and the sales volume of merchandises can be increased.
An Environmental Analysis of Nanoparticle-Assisted Diffusion Brazing
Authors: Haapala Karl R. , Tiwari Santosh K. , Paul Brian K.
Published: September 2010

Nano- and microtechnologies offer many benefits to society and promise the prospect of paradigm shifts on many technological fronts, including health care, alternative energy production, and efficient chemical processing. Current manufacturing processes for the production of nano- and microscale products, however, are energy and waste-intensive — requiring energy and creating wastes/emissions at orders of magnitude greater than traditional production. Therefore, research is needed to quantify environmental performance improvements in nano- and microproduction technologies, nickel nanoparticle (NiNP) deposition is compared with more traditional nickel phosphorus (NiP) electroplating for facilitating diffusion brazing of arrayed microfluidics. These two technologies are analyzed on a functional basis from an environmental perspective. Potential areas of improvement and future research opportunities are identified and discussed.
An Overview of Possible Integration of Green Design Principles Into Mechatronic Product Development Through Product Lifecycle Management
Authors: Jovanovic Vukica
Published: September 2010

People that work on the development of mechatronic products do not have enough data related to the end of the product lifecycle when making decisions related to the product design. Sustainable design tools in Product Lifecycle Management (PLM) systems could enable more sustainable designs with ‘greener’ decision-making. PLM tools, which are supporting designs of mechatronic products, are lacking more consideration about the product’s overall lifecycle ecological footprint. Most decisions that are made during the design phase are based on costs of materials and processes that are involved in development and manufacturing, not to the service, reuse, recycling and disposal of such products. This study will investigate the possibility of including the data related to the end of the product lifecycle. Integrating green design tools into the PLM systems would help mechatronic engineers to develop more sustainable designs. This paper will investigate the current state of the art in the area of Product Lifecycle Management systems that support design and realization of mechatronic projects. It discusses some ideas that can be used for determining a framework for data capturing of electro-mechanical product related data. This would connect decisions in earlier phases with the ones in final stages of a product lifecycle. This data can be used for the environmental footprint determination.
Selection of Major Locating Surface for Improving Chucking Accuracy
Authors: Byun Jeongmin , Liu C. R.
Published: September 2010

Two different types of surfaces are available as a major locating surface for the chucking of a cylindrical workpiece in turning operation — a flat surface and a cylindrical surface. No systematic study on the selection of a major locating surface has been reported while an appropriate selection considering the geometry of jaws and workpieces results in the significant improvement in the positioning accuracy and repeatability of a range of chucked workpieces. This research covers the most common clamping situation where a cylindrical workpiece is overhung clamped and machined with more than one set-up for finishing. In general, a workpiece with a lower length to diameter ratio should be clamped using an end face as a major locator while using a cylindrical surface can produce better positioning accuracy and repeatability for workpieces with higher length to diameter ratio. Recent studies have demonstrated the benefits of hard turning over abrasive machining processes in terms of surface integrity. A strong need currently exists for improving chucking accuracy since it work a major bottleneck in the implement finish hard turning for the production of precision, load-carrying mechanical components, such as bearings and shafts. This paper presents part of a systematic study on improving chucking accuracy for the implementation of finish hard turning, focusing on the development of criteria on the selection of a major locating surface. First, an analysis on the factors affecting the positioning accuracy for each locating surface is carried out. Then the criteria and guidelines for the selection of a major locating surface were constructed. Finally, systematic experiments were carried out to test the criteria and guidelines. The results showed that the positioning accuracy of the chucked workpieces improved significantly when following the guidelines developed in this study.
Numerical Simulation of Laser Beam Propagation in High Aspect Ratio Channel
Authors: Wu Benxin , Tao Sha , Lei Shuting
Published: September 2010

Laser beam propagation in high aspect ratio channels has been simulated by solving two-dimensional Maxwell wave equation with the finite element method. It has been found that the optical polarization direction has a very important effect on laser beam propagation in the channel, and under certain polarization direction the laser beam profile may keep changing in a very complicated way as the beam propagates through the channel. The above important effects, revealed by the numerical simulation in this paper, need to be considered to realize an accurate modeling or a good process design for laser machining of high aspect ratio microstructures.
The Effects of Integration Time and Size-of-Source on the Temperature Measurement of Segmented Chip Formation Using Infrared Thermography
Authors: Heigel Jarred C. , Whitenton Eric P.
Published: September 2010

This paper illustrates the errors due to integration time and size-of-source effects when measuring the temperature of segmented chip formation using infrared (IR) thermography. Segmented chip formation involves narrow periodic shear bands that experience rapid heating and move at high velocities and accelerations. As a result, the values of the measured temperatures depend strongly on the temporal and spatial measurement window used. In this study, an ideal infrared camera is simulated to understand the effects of integration time and size-of-source on the measurement. This analysis does not consider the temporal and spatial transfer functions of the camera system, thus simplifying the analysis to be applicable to all IR thermography users. Incorporating appropriate transfer functions would make the analysis specific to a given camera system. Finite element analysis (FEA) simulation results provide a reference cutting process which is manipulated to mimic motion blur and size-of-source effects. For this purpose, the FEA results adequately represent the cutting process with rapid heating and high chip velocities. For the studied cases, size-of-source has relatively little impact on the measurement results when compared to the effects of integration time. Results show integration times from 1 μs to 90 μs significantly affect the measurement results. The maximum temperature measured by the simulated IR camera decreases from an FEA maximum of 735 °C to 668 °C at 90 μs integration time. Integration time significantly affects temperature measurement in the periodic shear band but does not significantly affect the simulated measurement error of the chip temperature near the tool rake face.
Modeling, Forming, Modal Analysis, and Gauge Optimization of Sheet Metal Parts
Authors: Fox Andrew O. , Echempati Raghu
Published: September 2010

CAE tools can be used to study the characteristics and reduce the cost of sheet metal parts that are used in products. Using an instrument panel that is used in a car as an example which is made up of sheet metal components the basic process of analyzing the components and assembly to optimize its design is discussed. The paper is mostly educational in the sense that the integrated procedures and analysis presented here can be adapted in a senior level course and at a university that has state-of-the-art CAE tools as discussed in this paper. Several tutorials have been developed that are user-friendly and show how the subsequent analysis can be conducted. To the best of the knowledge of the authors, no such tutorials exist, or are available to students at a university. To start out, solid modeling of the individual sheet metal components using different CAD programs is discussed. Then a discussion on how these solid models can be imported to different CAE programs to be meshed and then subsequently exported to high end solvers like LS-Dyna or MSC Nastran is presented. The integrated analysis that was conducted for this paper was forming analysis of the individual components, followed by modal analysis and gauge optimization of the entire instrument panel assembly. Also, a design of experiments based on Taguchi method is discussed which was done to determine the effects that the input factors have on the results of the forming simulations that were conducted. It is believed that the contents of this paper serve as an educational tool to the students and the instructors involved in understanding and/or teaching sheet metal forming simulation. Sample tutorials will be presented at the conference meeting.
MSEC 2009 State-of-Art Paper: Micro/Nano-Technology Applications for Manufacturing Systems and Processes
Authors: Obikawa Toshiyuki , Postek M. T. , Dornfeld David , Liu Richard , Komanduri Ranga , Guo Yuebin , Shi Jing , Cao Jian , Zhou Jack , Yang Xiaoping , Li Xiaochun
Published: September 2010

Micro/nano-technology has made tremendous impact in all science and engineering fields in last decades. While review papers on meso/micro/nano manufacturing systems and processes have been published recently, there still lacks a review on how micro/nano technology has been applied to advance fundamental understanding and to enhance practice for manufacturing systems and processes. This paper is not concerned about the advances in meso/micro/nano manufacturing processes and systems themselves, but focuses on their impact on manufacturing applications. This paper presents the state-of-art of the advances on various aspects of how micro/nano technology impacts macro manufacturing systems/processes. Due to the time and space limit, this paper particularly reviews the topics as follows, 1. Micro/nano sensor applications in manufacturing (by Toshiyuki Obikawa and Xiaochun Li), 2. Micro/nano metrology for manufacturing applications (by M.T Postek), 3. Design and manufacturing of micro patterned arrays over macro-scale areas (by David Dornfeld), 4. Functionlized nanodiamonds and applications (by Jack Zhou), 5. Computational simulations at nanoscale for machining (By Ranga Komanduri), 6. Machining surface integrity and multiscale simulation (by C. Richard Liu, Jing Shi, Yuebin Guo, and Xiaoping Yang), and 7. Simulation for forming of parts with micro features (by Jian Cao).
Laser Ablation of Titanium: The Experimental Study on Ablation Rate and Plasma Plume Size
Authors: Zhou Yun , Gao Yibo , Wu Benxin , Guo Nana
Published: September 2010

Nanosecond laser ablation of titanium in air has been studied experimentally. The measured ablation depth at different pulse numbers indicates an incubation effect for the first ∼10 pulses. Compared with steel, the experiments show a larger plasma plume size and lower plume ignition threshold for titanium. The experimental measurements provide very useful information for the further study and practical applications of laser titanium micromachining.
Some Investigations Into Magnetorheological Finishing (MRF) of Hard Materials
Authors: Jain V. K. , Singh Pankaj , Kumar Puneet , Sidpara Ajay , Das Manas , Suri V. K. , Balasubramaniam R.
Published: September 2010

Magnetorheological finishing (MRF) process is one of the fine abrasive finishing processes used to get better surface finish on a semi finished part. The present work is aimed at investigating the effectiveness and validity of magnetorheological finishing process and finding out the process parameters (such as finishing time, rotational speed of carrier wheel, abrasive concentration, and working gap) and their effectiveness on surface finish characteristics. MRF process is applied on brass and nonmagnetic stainless steel workpieces which were initially finished by the grinding process. The results of experiments were statistically analyzed by response surface methodology (RSM) to form an empirical model for the responses generated during the process. Also, an attempt has been made to model and simulate the finishing operation in MRF process. Apart from this, the micro structure of the mixture of magnetic and abrasive particles in magnetorheological polishing fluid (MR Fluid) has been proposed. Thereafter the normal force on the abrasive particles is calculated from the applied magnetic field and a model for the prediction of surface roughness has also been presented. Finally, theoretical results calculated using the proposed model, have been compared with the experimental results to validate the model developed.
A Reconfiguration Methodology for Multiple Assembly System Reconfigurations
Authors: Smale D. , Ratchev S.
Published: September 2010

Reconfigurable Assembly Systems (RAS) offer the potential to enable rapid exchange of functional modules to facilitate a change in product, system requirements or to provide equipment redundancy. There has however been little investigation into the planning of multiple system reconfigurations. The work proposes a capability-based approach; consisting of a Reconfiguration Methodology, supported by a Capability Model and Taxonomy. The Methodology focuses on multiple system reconfigurations and is based upon operator-oriented definition, thereby utilising existing knowledge and expertise. Furthermore, the Methodology incorporates Production Scenarios, which define the customer’s needs and priorities. The selected scenario is then used to refine the Reconfiguration Methodology with respect to the solution generated. The Capability Model consists of Capability Identification and Comparison processes: by aggregating the results, capability and compatibility sets can be derived. Further, the Model has strong links to the Capability Taxonomy. The work proposed describes the overall approach and key elements and goes on to detail the Capability Taxonomy and Model and the Reconfiguration Methodology. Key conclusions are drawn and future work outlined.
Effect of Minimum Quantity Lubrication on Tool Wear and Surface Roughness in Micro-Milling
Authors: Li Kuan-Ming , Chou Shih-Yen
Published: September 2010

Micro-milling is a suitable technique for manufacturing of microstructures with high aspect ratios and intricate geometries. The application of the micro-milling process in cutting hardened tool steel is particularly challenging. The low strength of the miniaturized end mills implies accurate control of the chip load in order to prevent the tool break and product dimension errors, which requires high positioning accuracy. It is known that the application of cutting fluids can improve the performance of machining operations. However, the supply of cutting fluids in a conventional way is not appropriate for miniature machine tools due to the plentiful electronic components used to construct micro-scale machine tools. Minimum quantity lubrication (MQL) presents itself as a possible alternative for micro-cutting with respect to the minimum impact on the electronic components as well as low tool wear, better heat dissipation, and machined surface quality in metal cutting. This study compares the mechanical performance of MQL to completely dry condition for the micro-milling of SKD 61 steel based on experimental measurements of tool wears and surface finish. The effect of MQL on the burr formation is also observed. Results indicate that the use of MQL leads to reduced tool wears, better surface roughness, and less burr formation.
Integration of Sustainability Into Early Design Through Working Knowledge Model and Visual Tools
Authors: Devanathan Srikanth , Koushik Pranav , Zhao Fu , Ramani Karthik
Published: September 2010

The issue of environmental sustainability, which is unprecedented in both magnitude and complexity, presents one of the biggest challenges faced by modern society. Engineers, including mechanical engineers, can make significant contribution to the development of solutions to this problem by designing products and processes that are more environmentally sustainable. It is critical that engineers take a paradigm shift of product design i.e. from cost and performance centered to balance of economic, environmental, and societal consideration. Although there have been quite a few design for environment (DfE, or ecodesign) tools developed, so far these tools have only achieved limited industrial penetration: they are either too qualitative/subjective to be used by designers with limited experiences, or too quantitative, costly and time consuming and thus cannot be used during the design process specially during the early design stage. This paper develops a novel, semi-quantitative ecodesign tool that targets specially on early design process. The new tool is a combination of environmental life cycle assessment, working knowledge model, and visual tools such as QFD, functional-component matrix, and Pugh chart. Redesign of staplers is selected as a case study to demonstrate the use of the proposed tool. Efforts are on going to confirm that the new design generated using this new tool does have improved environmental performance.
In Situ Chatter Frequency Prediction Using Torque Data From a Wireless Sensor Integrated Tool Holder
Authors: Suprock Christopher A. , Jerard Robert B. , Fussell Barry K.
Published: September 2010

A method is demonstrated to estimate chatter frequencies in real time from cutting torque data using formant frequency tracking. Formant frequencies are derived from the torque data using linear predictive coding (LPC) methods, similar to algorithms used in speech recognition. The estimated frequency response is observed to change throughout a cut as a function of both engagement and cut geometry. Torque data is collected at high bandwidth from a wireless sensor integrated end milling tool holder. The technique is found to be effective and repeatable for forecasting regenerative chatter frequencies in real time. Chatter frequencies predicted during non-chatter conditions correctly estimate the actual chatter condition. To demonstrate the technique, a number of experimental cuts are conducted and discussed.
Diamond Coatings for Machining: Coating Thickness Effects
Authors: Qin Feng , Chou Y. Kevin , Nolen Dustin , Thompson Raymond G.
Published: September 2010

Chemical vapor deposition (CVD)-grown diamond films have found applications as a hard coating for cutting tools. Even though the use of conventional diamond coatings seems to be accepted in the cutting tool industry, selections of proper coating thickness for different machining operations have not been often studied. Coating thickness affects the characteristics of diamond coated cutting tools in different perspectives that may mutually impact the tool performance in machining in a complex way. In this study, coating thickness effects on the deposition residual stresses, particularly around a cutting edge, and on coating failure modes were numerically investigated. On the other hand, coating thickness effects on tool surface smoothness and cutting edge radii were experimentally investigated. In addition, machining Al matrix composites using diamond coated tools with varied coating thicknesses was conducted to evaluate the effects on cutting forces, part surface finish and tool wear. The results are summarized as follows. (1) Increasing coating thickness will increase the residual stresses at the coating-substrate interface. (2) On the other hand, increasing coating thickness will generally increase the resistance of coating cracking and delamination. (3) Thicker coatings will result in larger edge radii; however, the extent of the effect on cutting forces also depends upon the machining condition. (4) For the thickness range tested, the life of diamond coated tools increases with the coating thickness because of delay of delaminations.
Requirements Selection for Rapid Prototyping: Polyphenylsulfone as a Mold Material for Spin Casting Polyurethane Resin
Authors: Martens Thomas , Mears Laine , Dotson Mike , Graham Monty , Sanger Phillip
Published: September 2010

For the development of a rotational symmetrical polyurethane part with a steel reinforcement, a requirement/constraint driven approach to process design has been taken. In this approach a scale model of the process was built using fused deposition modeling rapid prototyping technique, then used to validate design, material and process parameters. After selection and testing on the scaled prototype, results were used to define a full-sized spin casting mold built using Polyphenylsulfone.
Experimental and Finite Element Investigations on the Influence of Tool Edge Radius in Machining Nickel-Based Alloy
Authors: O¨zel Tug˘rul
Published: September 2010

This paper presents investigations on machining of a nickel-based alloy. Orthogonal cutting tests using uncoated carbide inserts with 10 and 25 micron edge radius and 0 and 3 degree tool rake angles are performed. Forces, chip geometry and tool edge conditions are measured. An analytical model is introduced to identify average strain, strain rate, shear stress and temperature for segmented chip formation and friction conditions exerted on the tool during cutting process. Johnson-Cook material model related flow stress data are modified using the experimental data. Finite Element simulations are conducted to investigate the influence of tool geometry on predicted stress, strain and temperature distributions on machined surfaces.
A Framework for Establishing Energy Efficiency and Environmental Footprint Metrics for Sustainable Manufacturing of Products
Authors: O¨zel Tug˘rul , Yildiz Serdar
Published: September 2010

Product sustainability assessment and evaluation metrics are mostly concerned with product usage and disposal only towards the end of the product lifecycle. Common examples include the energy efficiency and environmentally friendliness definitions used for consumer products. However, a product has already left a ‘footprint’ during its design, manufacturing, production and distribution stages. The energy efficiency and ecological footprint of products in manufacturing processes, operations and facility usages has been overlooked for many decades. In this study, we aim to establish a preliminary framework for defining metrics that may help capture energy efficiency and ecological footprint of discrete parts and products during manufacturing activities to control and improve the sustainability.
Statistical Analysis of Variations in Model Predicted Cutting Forces for End Milling
Authors: Hassan Raed , Jerard Robert B. , Fussell Barry K. , Eren Firat , Esterling Donald M.
Published: September 2010

This paper quantifies statistical variations in model predicted machining forces while cutting aluminum, carbon steel, stainless steel and titanium. An accurate estimate of the variability is essential for use in process planning to determine appropriate factors of safety when setting cutting conditions that are both safe and efficient. A linear regression is performed to estimate the coefficients of a tangential cutting force model. Density ellipses are used to define the confidence limits of the coefficients under varying spindle speeds and radial immersions. The locus of coefficients at the 95% confidence level is then used in a mechanistic force model to quantify the variability in the cutting force predictions. Forces calculated by the model were within 20% of the nominal predicted values for cases for aluminum, steel and stainless steel. The results were much worse for titanium because of a smaller sample size. Experimentally measured forces were within the error bounds predicted by the simulation.
Milling Cutter Data Structures for Use in Force Models
Authors: Yalcin Cuneyt , Jerard Robert B. , Fussell Barry K.
Published: September 2010

In this study we present a new general representation for describing a milling cutter and an internal data structure that systematically stores the cutting edge segment properties of the milling cutter. The intention of this effort is to enable commercial milling simulation software packages to communicate and store complicated cutter information, and thus enable them to include improved models developed in academic research. Examples with various milling cutters are given, and the versatility of the structures is demonstrated by using two different cutting force models with three different milling cutters. Force calculation time was decreased by a factor of four by using the internal data structure to store pre-calculated trigonometric functions.
Acoustic Emission Condition Monitoring of the Coroning Process
Authors: Yum Juil , Kamouneh Amir , Wang Wencai , Kannatey-Asibu Elijah
Published: September 2010

Acoustic emission (AE) is introduced for tool condition monitoring during the coroning process. The frequency components of the AE signal were used as features for classification. Two different feature selection methods were investigated, namely visual observation and the class mean scatter criterion. The minimum error rate Bayesian rule was used to distinguish between two extreme tool conditions. Although the features from visual observation could result in 100% classification, features based on the class mean scatter criterion showed excellent monitoring capability of tool failure when fewer features were used.
Investigation of Process-Induced Cell Membrane Stability Using Molecular Dynamics Simulation
Authors: Yin Jun , Huang Yong
Published: September 2010

Manufacturing process-induced damage to cells is of significant importance in biomaterial direct writing. For safe and reproducible cell direct writing, the process-induced cell damage must be understood in addition to biological property research. The objective of this study is to investigate the cell membrane stability under the external normal pressure. It is performed by studying the dipalmitoylphosphatidylcholine (DPPC) bilayer behavior under different normal pressures using molecular dynamics (MD). It is found that as the normal pressure increases, the thickness of DPPC bilayer decreases and the area of per DPPC molecule increases; and as the normal pressure increases, the rupture force to break the bilayer structure decreases, which can also be explained by the change of free energy difference before and after rupture under different normal pressures. This study serves as the first step towards understanding of the cell damage mechanism in cell direct writing.
Chip Rebonding in Dry Turning of Nickel Based Alloys
Authors: Oh Jae-Wook , Kuo Hsin-Yu , Meyer Kevin , Lindle Roger , Weaver Howard , Ni Jun
Published: September 2010

At some cutting conditions chips formed during high-speed face turning of nickel based alloys are re-bonded to the machined workpiece surface, even when coolant is applied. Unfortunately, chip-rebonding reduces surface quality, which leads to a shorter fatigue lives for machined parts. Although several researchers have documented this phenomenon and its effects, the root causes of this phenomenon is currently unknown. In order to determine the root causes of chip rebonding, past test samples exhibiting chip rebonding were first analyzed. Metallographic analysis revealed that the chip rebonding material is the same as the workpiece material and that the bonding is mechanically driven. Next, screening design of experiments (DOE) were completed to reliably reproduce chip rebonding in dry cutting cases. Chip rebonding detection and severity were measured using multiple equally spaced surface roughness measurements (Rt parameter). In addition, in-process cutting forces and tool wear measurements were recorded and compared. Finally Taguchi methods were applied to identify the key variables their influence on chip-rebonding. In dry cutting tests it was found that decreasing feed-rate while cutting at a constant cutting speed is the most influential factor in obtaining chip rebonding. High-speed video revealed that at lower feed-rates the chip curls back to the surface of workpiece, while at higher feed-rates the chip flows away from the cutting region with minimal curl. Additional testing performed verifies this theory.
The Microstructural Effects on Magnesium Alloy AZ31B-O While Undergoing an Electrically-Assisted Manufacturing Process
Authors: McNeal Timothy A. , Beers Jeffrey A. , Roth John T.
Published: September 2010

In today’s industry, the need for lightweight alloys with high strength properties is growing. More specifically, magnesium alloys are in high demand. Unfortunately, magnesium’s limited formability hinders its broad range applicability. Previous research has discovered that the tensile formability of this alloy can be increased using electrical pulsing during the deformation process, referred to as Electrically-Assisted Manufacturing (EAM). Although this method increases a material’s formability (i.e. lowers flow stress, increases elongation, and reduces springback), a detailed analysis is required to further evaluate the effects of electricity on the material’s microstructure. The research herein will examine the microstructure of Magnesium AZ31B-O specimens that were deformed under uniaxial tension while electrically pulsed with various pulsing parameters (i.e. different current density/pulse duration combinations). This microstructural analysis will focus on how EAM affected grain size, grain orientation, and twinning. The microstructure of the following different specimen types will be compared: deformed EAM specimens, deformed non-pulsed baseline specimens, and undeformed non-pulsed “as received” specimens.
Nanodiamond Reinforced PLLA Composites for Bone Tissue Engineering
Authors: Zhang Qingwei , Lelkes Peter , Zhou Jack
Published: September 2010

Nanotechnology shows us many innovations and it is generally accepted view that many could be further developed and applied in tissue engineering. A novel composite material has been produced for bone scaffolds utilizing the biodegradable polymer poly(L-lactic acid) (PLLA) and octadecylamine functionalized nanodiamond (ND-ODA). The composites were characterized by hardness testing (Rockwell) and differential scanning calorimetry (DSC). DSC analysis of the composites showed no significant thermal behavior changes when adding ND into the polymer matrix. Rockwell result shows ND-ODA improves mechanical strength of composites 4 folds. To test the usefulness of ND-ODA/PLLA as a matrix for supporting cell growth, 7F2 Osteoblasts were cultured on scaffolds for 3 days. The results showed that the addition of ND-ODA has almost no influence on cell growth, which indicates the composites are biocompatible. All these results combined suggest that ND-ODA/PLLA might provide a novel composite suitable for bone tissue engineering application.
Experimental Study on the Mechanical Property and Forming Limit of Magnesium Sheet at Elevated Temperatures
Authors: Huang Y. , Huang J. , Cao J.
Published: September 2010

Magnesium alloy sheet has received increasing attention in automotive and aerospace industries. It is widely recognized that magnesium sheet has a poor formability at room temperature. While at elevated temperature, its formability can be dramatically improved. Most of work in the field has been working with the magnesium sheet after annealed around 350°C. In this paper, the as-received commercial magnesium sheet (AZ31B-H24) with thickness of 2mm has been experimentally studied without any special heat treatment. Uniaxial tensile tests at room temperature and elevated temperature were first conducted to have a better understanding of the material properties of magnesium sheet (AZ31B-H24). Then, limit dome height (LDH) tests were conducted to capture forming limits of magnesium sheet (AZ31B-H24) at elevated temperatures. An optical method has been introduced to obtain the stress-strain curve at elevated temperatures. Experimental results of the LDH tests were presented.
The Design of the PE4710 Specification for CC N-755 Revision 1
Authors: Adams William I.
Published: September 2010

Under Section III, the ASME Special Working Group on Plastic Pipe is developing revisions to Code Case N-755 Use of Polyethylene (PE) Plastic Pipe, Sections III, Division I and IX to better specify high performance PE4710 polyethylene source materials and polyethylene materials (pipe and flanges) for use in Section III, Division I, Class 3 buried piping systems. The specification is being developed as a Mandatory Appendix IV for inclusion as part of a revision to Code Case N-755. The intent is for Mandatory Appendix IV to serve as procurement and material specifications for PE4710 polyethylene piping for Class 3 nuclear power plant essential safety systems. The proposed Mandatory Appendix IV specification is performance-based and identifies performance properties and minimum performance values for PE4710 polyethylene compounds (polyethylene source materials) and PE4710 polyethylene materials (polyethylene pipe and flange adapters) manufactured from them. The Mandatory Appendix IV specification addresses pre-processing material forms, processing requirements, and post-processing material verification. This paper reveals the design of the specification and how its various components and aspects correlate to assure product performance including crack growth resistance, and ambient and elevated temperature performance.
Combination of Advanced Supervision System FURNACE With Continues Visual Monitoring ORFEUS for Proper On-Line Performance Analysis of the Furnace Firing Coal in Large Utility Boilers
Authors: Chudnovsky B. , Talanker A. , Kogan B. , Daniliuc M. , Lev S. , Frega L.
Published: September 2010

The high restrictions in environmental requirements have led to modifications of the both coal type and firing mode. In order to prevent a different faults in boiler operation and as a result a reliability reduction, special monitoring and diagnostic techniques is required for engineering analysis and utility production management. In this sense an on-line supervision system FURNACE have developed and implemented for 575, 550, 360 Mw coal fired units. The developed system provides on-line information regards furnace performance, including fireball location, furnace exit temperature increase that indicates the necessity of activate furnace sootblowers to control steam temperatures and prevent excessive accumulations of slag and heat surfaces tube overheating. However, the FURNACE system can not provide flue gas temperature distribution near the burner zone and it leads to limitation of the possibility of furnace fine tuning for the aim of NOx reduction. Due to this reason new diagnostic system ORFEUS was installed in power plant. The ORFEUS is a system for continuous visual monitoring of high temperature processes with a sensor lance. A high quality picture with wide angle of view and a small sensor diameter is achieved using a boroskope as lens. With this technology the CCD camera can be mounted in the cold part of the lance. This way sensitive equipment is mounted outside the combustion chamber, allowing continuous use with high process temperatures. The pictures coming from the sensor can be viewed and analyzed directly in the control room. In order to evaluate capability of both system combined application series of tests with different operation were conducted on the boiler. The testing was primarily focused on quantifying the impact of overfire air (OFA), excess air, primary air flow and unit loads on boiler, furnace, pulverizers performance, NOx and unburned carbon loss etc. The evaluation was performed for 575 MW units equipped with tangentially fired boilers designed by Combustion Engineering. The on-line information obtained from both FURNACE and ORFEUS systems is allowed us to perform fine tuning of the firing system in order to optimize combustion process. Based on performed work may be concluded that combination of both system is able us to receive detail information of furnace performance in real time including flame position in the initial burner zone. As result it was achieved additional NOx reduction by 10–15% at unit full load and by 20–35% at partial load without any impact on boiler performance, efficiency and reliability.
Inspecting U-Tube Bundles Using Acoustic Pulse Reflectometry
Authors: Amir Noam , Barzelay Oded , Yefet Amir , Pechter Tal
Published: September 2010

Acoustic Pulse Reflectometry (APR) has recently been gaining acceptance for a variety of tube inspection applications, as a viable alternative to more entrenched technologies such as eddy current. In this paper we present a case study demonstrating how APR can be used successfully for inspecting U-tube bundles. This type of heat exchanger poses a great challenge to technologies which require traversal with a probe, due to the presence of tight bends in the tubes. These are usually not traversable by probes. APR, on the other hand, uses an acoustic pulse as a “virtual probe”, with the ability to navigate bends, elbows, fittings etc. with no difficulty. In this paper we show how the various typical faults are revealed in the acoustic measurements and demonstrate how the analysis software recognizes these faults and generates the report. In one case presented here we inspected 62 heat exchangers used to heat natural gas, containing 39 U-tubes each, totaling 2379 tubes. Each tube had an internal diameter of 11mm, wall thickness of 2.5mm, and a length of approximately 6 meters, though there was some variability in length due to different lengths of the U bends. An added difficulty in inspecting these tubes was that the tube sheet was about 80 centimeters in distance from the inspection port-hole. The average inspection time in the field was 25 seconds per tube. All measurements were logged to computer files, and automated fault detection software generated a full report showing the condition of the tubes, indicating degradations in wall thickness, full and partial blockages, and holes. In the second case study we examine the variability in u-tubes in a single bundle and discuss the effect this has on the results.
Identification of Abnormal Rotor Dynamic Stiffness Using Measured Vibration Information and Analytical Modeling
Authors: Endres Ned M.
Published: September 2010

It is a relatively common practice to address the problem of unacceptable synchronous (1X) vibration levels (like unbalance) by applying corrective balance weights after a thorough review of vibration measurements, available engineering information, and prior balancing history of a unit if available. The balance history might include balance plane weight maps and/or balancing influence data. On occasion, other vibration malfunctions and symptoms within measured vibration data, such as misalignment, a rub, or proximity probe journal target area slow roll (sometimes called “runout” or “glitch”) can also appear to be “unbalance” but are not. A principal requirement when performing any corrective balancing of a rotor is that the fundamental synchronous rotor response of the unit should always be linear and time invariant. The fundamental synchronous rotor response is directly proportional to dynamic forces and inversely proportional to dynamic stiffness. If the principle requirements cannot be met while balancing, any further balancing of the rotor should be terminated and other root causes for the unacceptable synchronous vibration levels should be investigated. This paper will discuss a case history involving a steam turbine generator unit where excessive synchronous vibration levels were measured at the LP turbine bearings during transient and steady state operation. The initial concern was a steady increase in vibration levels at the LP turbine under steady state conditions. Prior balancing history and balancing information was reviewed and initial corrective balancing was performed. Initial correction of the unbalance proved to be inadequate, and the unit exhibited a significant change in balance influence. Since the response of the rotor to balance correction was not predictable and inconsistent with prior balancing data, alternative root causes for the unbalance symptoms were investigated. Integration of measured vibration data and numerical modeling were essential with proper identification of the root cause of the unbalance symptoms.
SNG Production Process Based on Hybrid Gasification
Authors: Deng Shimin , Hynes Rory
Published: September 2010

In this paper, SNG production technologies are investigated and summarized. A new SNG production process has been developed. It has advantages in performance, cost and operability. The performance of the new process is analyzed and compared with two existing processes — one process based on hydrogasification and one conventional SNG production process. Based on process modeling, exergy analysis is carried out to identify the specific loss of each sub-process. The thermodynamic features of the new process are investigated to show the trend of the parameters of the hybrid gasifier and the whole process. A concept of critical conversion rate is identified and defined. Key parameters of hybrid gasifier and thermal performance of the system are examined and presented. Besides thermal performance, other issues related to operation and cost are discussed.
Composite Materials for Repair of Pressure Boundary and Structural Components
Authors: Charest John A.
Published: September 2010

Deterioration of components and structures at power generating facilities has caused unscheduled plant outages, personnel safety concerns, and significant impact on operating budgets. However, new technology is now available that can increase the usable life of components and structures, while significantly reducing the economic burden normally associated with repair or replacement options. This technology, known as “Fiber Reinforced Polymers” or FRP, primarily utilizes carbon fibers and high strength epoxy resins to restore or enhance the structural and or pressure boundary capacity of plant components. The extent of the FRP reinforcement is determined by the targeted equipment operating parameters, and the inter-action of the composite materials with the host component. These repairs are typically accomplished in-place with small crews and completed during a relatively short duration. The material technology and engineering associated with FRP repair methods provides an effective mechanism to rehabilitate piping, pumps, heat exchangers, water boxes, structural shapes and numerous other items while minimizing the cost typically associated with direct replacement. This paper will focus on typical applications, design and installation of FRP technology as it relates to maintenance activities at power generating facilities.